linux_dsm_epyc7002/arch/mips/kernel/ptrace.c

1472 lines
35 KiB
C
Raw Normal View History

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1992 Ross Biro
* Copyright (C) Linus Torvalds
* Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
* Copyright (C) 1996 David S. Miller
* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 1999 MIPS Technologies, Inc.
* Copyright (C) 2000 Ulf Carlsson
*
* At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
* binaries.
*/
#include <linux/compiler.h>
#include <linux/context_tracking.h>
#include <linux/elf.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/regset.h>
#include <linux/smp.h>
#include <linux/security.h>
#include <linux/stddef.h>
#include <linux/tracehook.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/ftrace.h>
#include <asm/byteorder.h>
#include <asm/cpu.h>
#include <asm/cpu-info.h>
#include <asm/dsp.h>
#include <asm/fpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/pgtable.h>
#include <asm/page.h>
MIPS: Add DSP ASE regset support Define an NT_MIPS_DSP core file note type and implement a corresponding regset holding the DSP ASE register context, following the layout of the `mips_dsp_state' structure, except for the DSPControl register stored as a 64-bit rather than 32-bit quantity in a 64-bit note. The lack of DSP ASE register saving to core files can be considered a design flaw with commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE."), leading to an incomplete state being saved. Consequently no DSP ASE regset has been created with commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view."), when regset support was added to the MIPS port. Additionally there is no way for ptrace(2) to correctly access the DSP accumulator registers in n32 processes with the existing interfaces. This is due to 32-bit truncation of data passed with PTRACE_PEEKUSR and PTRACE_POKEUSR requests, which cannot be avoided owing to how the data types for ptrace(3) have been defined. This new NT_MIPS_DSP regset fills the missing interface gap. [paul.burton@mips.com: - Change NT_MIPS_DSP to 0x800 to avoid conflict with NT_VMCOREDD introduced by commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in second kernel"). - Drop stable tag. Whilst I agree the lack of this functionality can be considered a flaw in earlier DSP ASE support, it's still new functionality which doesn't meet up to the requirements set out in Documentation/process/stable-kernel-rules.rst.] Signed-off-by: Maciej W. Rozycki <macro@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> References: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Patchwork: https://patchwork.linux-mips.org/patch/19330/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
2018-05-16 05:34:28 +07:00
#include <asm/processor.h>
#include <asm/syscall.h>
#include <linux/uaccess.h>
#include <asm/bootinfo.h>
#include <asm/reg.h>
#define CREATE_TRACE_POINTS
#include <trace/events/syscalls.h>
/*
* Called by kernel/ptrace.c when detaching..
*
* Make sure single step bits etc are not set.
*/
void ptrace_disable(struct task_struct *child)
{
/* Don't load the watchpoint registers for the ex-child. */
clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
}
/*
* Read a general register set. We always use the 64-bit format, even
* for 32-bit kernels and for 32-bit processes on a 64-bit kernel.
* Registers are sign extended to fill the available space.
*/
int ptrace_getregs(struct task_struct *child, struct user_pt_regs __user *data)
{
struct pt_regs *regs;
int i;
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 09:57:57 +07:00
if (!access_ok(data, 38 * 8))
return -EIO;
regs = task_pt_regs(child);
for (i = 0; i < 32; i++)
__put_user((long)regs->regs[i], (__s64 __user *)&data->regs[i]);
__put_user((long)regs->lo, (__s64 __user *)&data->lo);
__put_user((long)regs->hi, (__s64 __user *)&data->hi);
__put_user((long)regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
__put_user((long)regs->cp0_badvaddr, (__s64 __user *)&data->cp0_badvaddr);
__put_user((long)regs->cp0_status, (__s64 __user *)&data->cp0_status);
__put_user((long)regs->cp0_cause, (__s64 __user *)&data->cp0_cause);
return 0;
}
/*
* Write a general register set. As for PTRACE_GETREGS, we always use
* the 64-bit format. On a 32-bit kernel only the lower order half
* (according to endianness) will be used.
*/
int ptrace_setregs(struct task_struct *child, struct user_pt_regs __user *data)
{
struct pt_regs *regs;
int i;
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 09:57:57 +07:00
if (!access_ok(data, 38 * 8))
return -EIO;
regs = task_pt_regs(child);
for (i = 0; i < 32; i++)
__get_user(regs->regs[i], (__s64 __user *)&data->regs[i]);
__get_user(regs->lo, (__s64 __user *)&data->lo);
__get_user(regs->hi, (__s64 __user *)&data->hi);
__get_user(regs->cp0_epc, (__s64 __user *)&data->cp0_epc);
/* badvaddr, status, and cause may not be written. */
MIPS/ptrace: Update syscall nr on register changes Update the thread_info::syscall field when registers are modified via ptrace to change or cancel the system call being entered. This is important to allow seccomp and the syscall entry and exit trace events to observe the new syscall number changed by the normal ptrace hook or seccomp. That includes allowing seccomp's recheck of the system call number after SECCOMP_RET_TRACE to notice if the syscall is changed to a denied one, which happens in seccomp since commit ce6526e8afa4 ("seccomp: recheck the syscall after RET_TRACE") in v4.8. In the process of doing this, the logic to determine whether an indirect system call is in progress (i.e. the O32 ABI's syscall()) is abstracted into mips_syscall_is_indirect(), and a new mips_syscall_update_nr() is used to update the thread_info::syscall based on the register state. The following ptrace operations are updated: - PTRACE_SETREGS (ptrace_setregs()). - PTRACE_SETREGSET with NT_PRSTATUS (gpr32_set() and gpr64_set()). - PTRACE_POKEUSR with 2/v0 or 4/a0 for indirect syscall ([compat_]arch_ptrace()). Fixes: c2d9f1775731 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.") Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Lars Persson <larper@axis.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16995/
2017-08-12 03:56:52 +07:00
/* System call number may have been changed */
mips_syscall_update_nr(child, regs);
return 0;
}
int ptrace_get_watch_regs(struct task_struct *child,
struct pt_watch_regs __user *addr)
{
enum pt_watch_style style;
int i;
if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
return -EIO;
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 09:57:57 +07:00
if (!access_ok(addr, sizeof(struct pt_watch_regs)))
return -EIO;
#ifdef CONFIG_32BIT
style = pt_watch_style_mips32;
#define WATCH_STYLE mips32
#else
style = pt_watch_style_mips64;
#define WATCH_STYLE mips64
#endif
__put_user(style, &addr->style);
__put_user(boot_cpu_data.watch_reg_use_cnt,
&addr->WATCH_STYLE.num_valid);
for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
__put_user(child->thread.watch.mips3264.watchlo[i],
&addr->WATCH_STYLE.watchlo[i]);
__put_user(child->thread.watch.mips3264.watchhi[i] &
(MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW),
&addr->WATCH_STYLE.watchhi[i]);
__put_user(boot_cpu_data.watch_reg_masks[i],
&addr->WATCH_STYLE.watch_masks[i]);
}
for (; i < 8; i++) {
__put_user(0, &addr->WATCH_STYLE.watchlo[i]);
__put_user(0, &addr->WATCH_STYLE.watchhi[i]);
__put_user(0, &addr->WATCH_STYLE.watch_masks[i]);
}
return 0;
}
int ptrace_set_watch_regs(struct task_struct *child,
struct pt_watch_regs __user *addr)
{
int i;
int watch_active = 0;
unsigned long lt[NUM_WATCH_REGS];
u16 ht[NUM_WATCH_REGS];
if (!cpu_has_watch || boot_cpu_data.watch_reg_use_cnt == 0)
return -EIO;
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 09:57:57 +07:00
if (!access_ok(addr, sizeof(struct pt_watch_regs)))
return -EIO;
/* Check the values. */
for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
__get_user(lt[i], &addr->WATCH_STYLE.watchlo[i]);
#ifdef CONFIG_32BIT
if (lt[i] & __UA_LIMIT)
return -EINVAL;
#else
if (test_tsk_thread_flag(child, TIF_32BIT_ADDR)) {
if (lt[i] & 0xffffffff80000000UL)
return -EINVAL;
} else {
if (lt[i] & __UA_LIMIT)
return -EINVAL;
}
#endif
__get_user(ht[i], &addr->WATCH_STYLE.watchhi[i]);
if (ht[i] & ~MIPS_WATCHHI_MASK)
return -EINVAL;
}
/* Install them. */
for (i = 0; i < boot_cpu_data.watch_reg_use_cnt; i++) {
if (lt[i] & MIPS_WATCHLO_IRW)
watch_active = 1;
child->thread.watch.mips3264.watchlo[i] = lt[i];
/* Set the G bit. */
child->thread.watch.mips3264.watchhi[i] = ht[i];
}
if (watch_active)
set_tsk_thread_flag(child, TIF_LOAD_WATCH);
else
clear_tsk_thread_flag(child, TIF_LOAD_WATCH);
return 0;
}
/* regset get/set implementations */
#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
static int gpr32_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct pt_regs *regs = task_pt_regs(target);
u32 uregs[ELF_NGREG] = {};
mips_dump_regs32(uregs, regs);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
sizeof(uregs));
}
static int gpr32_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct pt_regs *regs = task_pt_regs(target);
u32 uregs[ELF_NGREG];
unsigned start, num_regs, i;
int err;
start = pos / sizeof(u32);
num_regs = count / sizeof(u32);
if (start + num_regs > ELF_NGREG)
return -EIO;
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
sizeof(uregs));
if (err)
return err;
for (i = start; i < num_regs; i++) {
/*
* Cast all values to signed here so that if this is a 64-bit
* kernel, the supplied 32-bit values will be sign extended.
*/
switch (i) {
case MIPS32_EF_R1 ... MIPS32_EF_R25:
/* k0/k1 are ignored. */
case MIPS32_EF_R28 ... MIPS32_EF_R31:
regs->regs[i - MIPS32_EF_R0] = (s32)uregs[i];
break;
case MIPS32_EF_LO:
regs->lo = (s32)uregs[i];
break;
case MIPS32_EF_HI:
regs->hi = (s32)uregs[i];
break;
case MIPS32_EF_CP0_EPC:
regs->cp0_epc = (s32)uregs[i];
break;
}
}
MIPS/ptrace: Update syscall nr on register changes Update the thread_info::syscall field when registers are modified via ptrace to change or cancel the system call being entered. This is important to allow seccomp and the syscall entry and exit trace events to observe the new syscall number changed by the normal ptrace hook or seccomp. That includes allowing seccomp's recheck of the system call number after SECCOMP_RET_TRACE to notice if the syscall is changed to a denied one, which happens in seccomp since commit ce6526e8afa4 ("seccomp: recheck the syscall after RET_TRACE") in v4.8. In the process of doing this, the logic to determine whether an indirect system call is in progress (i.e. the O32 ABI's syscall()) is abstracted into mips_syscall_is_indirect(), and a new mips_syscall_update_nr() is used to update the thread_info::syscall based on the register state. The following ptrace operations are updated: - PTRACE_SETREGS (ptrace_setregs()). - PTRACE_SETREGSET with NT_PRSTATUS (gpr32_set() and gpr64_set()). - PTRACE_POKEUSR with 2/v0 or 4/a0 for indirect syscall ([compat_]arch_ptrace()). Fixes: c2d9f1775731 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.") Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Lars Persson <larper@axis.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16995/
2017-08-12 03:56:52 +07:00
/* System call number may have been changed */
mips_syscall_update_nr(target, regs);
return 0;
}
#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
#ifdef CONFIG_64BIT
static int gpr64_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
struct pt_regs *regs = task_pt_regs(target);
u64 uregs[ELF_NGREG] = {};
mips_dump_regs64(uregs, regs);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, uregs, 0,
sizeof(uregs));
}
static int gpr64_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
struct pt_regs *regs = task_pt_regs(target);
u64 uregs[ELF_NGREG];
unsigned start, num_regs, i;
int err;
start = pos / sizeof(u64);
num_regs = count / sizeof(u64);
if (start + num_regs > ELF_NGREG)
return -EIO;
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, uregs, 0,
sizeof(uregs));
if (err)
return err;
for (i = start; i < num_regs; i++) {
switch (i) {
case MIPS64_EF_R1 ... MIPS64_EF_R25:
/* k0/k1 are ignored. */
case MIPS64_EF_R28 ... MIPS64_EF_R31:
regs->regs[i - MIPS64_EF_R0] = uregs[i];
break;
case MIPS64_EF_LO:
regs->lo = uregs[i];
break;
case MIPS64_EF_HI:
regs->hi = uregs[i];
break;
case MIPS64_EF_CP0_EPC:
regs->cp0_epc = uregs[i];
break;
}
}
MIPS/ptrace: Update syscall nr on register changes Update the thread_info::syscall field when registers are modified via ptrace to change or cancel the system call being entered. This is important to allow seccomp and the syscall entry and exit trace events to observe the new syscall number changed by the normal ptrace hook or seccomp. That includes allowing seccomp's recheck of the system call number after SECCOMP_RET_TRACE to notice if the syscall is changed to a denied one, which happens in seccomp since commit ce6526e8afa4 ("seccomp: recheck the syscall after RET_TRACE") in v4.8. In the process of doing this, the logic to determine whether an indirect system call is in progress (i.e. the O32 ABI's syscall()) is abstracted into mips_syscall_is_indirect(), and a new mips_syscall_update_nr() is used to update the thread_info::syscall based on the register state. The following ptrace operations are updated: - PTRACE_SETREGS (ptrace_setregs()). - PTRACE_SETREGSET with NT_PRSTATUS (gpr32_set() and gpr64_set()). - PTRACE_POKEUSR with 2/v0 or 4/a0 for indirect syscall ([compat_]arch_ptrace()). Fixes: c2d9f1775731 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.") Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Lars Persson <larper@axis.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16995/
2017-08-12 03:56:52 +07:00
/* System call number may have been changed */
mips_syscall_update_nr(target, regs);
return 0;
}
#endif /* CONFIG_64BIT */
#ifdef CONFIG_MIPS_FP_SUPPORT
/*
* Poke at FCSR according to its mask. Set the Cause bits even
* if a corresponding Enable bit is set. This will be noticed at
* the time the thread is switched to and SIGFPE thrown accordingly.
*/
static void ptrace_setfcr31(struct task_struct *child, u32 value)
{
u32 fcr31;
u32 mask;
fcr31 = child->thread.fpu.fcr31;
mask = boot_cpu_data.fpu_msk31;
child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask);
}
int ptrace_getfpregs(struct task_struct *child, __u32 __user *data)
{
int i;
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 09:57:57 +07:00
if (!access_ok(data, 33 * 8))
return -EIO;
if (tsk_used_math(child)) {
union fpureg *fregs = get_fpu_regs(child);
for (i = 0; i < 32; i++)
__put_user(get_fpr64(&fregs[i], 0),
i + (__u64 __user *)data);
} else {
for (i = 0; i < 32; i++)
__put_user((__u64) -1, i + (__u64 __user *) data);
}
__put_user(child->thread.fpu.fcr31, data + 64);
__put_user(boot_cpu_data.fpu_id, data + 65);
return 0;
}
int ptrace_setfpregs(struct task_struct *child, __u32 __user *data)
{
union fpureg *fregs;
u64 fpr_val;
u32 value;
int i;
Remove 'type' argument from access_ok() function Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument of the user address range verification function since we got rid of the old racy i386-only code to walk page tables by hand. It existed because the original 80386 would not honor the write protect bit when in kernel mode, so you had to do COW by hand before doing any user access. But we haven't supported that in a long time, and these days the 'type' argument is a purely historical artifact. A discussion about extending 'user_access_begin()' to do the range checking resulted this patch, because there is no way we're going to move the old VERIFY_xyz interface to that model. And it's best done at the end of the merge window when I've done most of my merges, so let's just get this done once and for all. This patch was mostly done with a sed-script, with manual fix-ups for the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form. There were a couple of notable cases: - csky still had the old "verify_area()" name as an alias. - the iter_iov code had magical hardcoded knowledge of the actual values of VERIFY_{READ,WRITE} (not that they mattered, since nothing really used it) - microblaze used the type argument for a debug printout but other than those oddities this should be a total no-op patch. I tried to fix up all architectures, did fairly extensive grepping for access_ok() uses, and the changes are trivial, but I may have missed something. Any missed conversion should be trivially fixable, though. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 09:57:57 +07:00
if (!access_ok(data, 33 * 8))
return -EIO;
init_fp_ctx(child);
fregs = get_fpu_regs(child);
for (i = 0; i < 32; i++) {
__get_user(fpr_val, i + (__u64 __user *)data);
set_fpr64(&fregs[i], 0, fpr_val);
}
__get_user(value, data + 64);
ptrace_setfcr31(child, value);
/* FIR may not be written. */
return 0;
}
/*
* Copy the floating-point context to the supplied NT_PRFPREG buffer,
* !CONFIG_CPU_HAS_MSA variant. FP context's general register slots
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
* correspond 1:1 to buffer slots. Only general registers are copied.
*/
static int fpr_get_fpa(struct task_struct *target,
unsigned int *pos, unsigned int *count,
void **kbuf, void __user **ubuf)
{
return user_regset_copyout(pos, count, kbuf, ubuf,
&target->thread.fpu,
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
}
/*
* Copy the floating-point context to the supplied NT_PRFPREG buffer,
* CONFIG_CPU_HAS_MSA variant. Only lower 64 bits of FP context's
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
* general register slots are copied to buffer slots. Only general
* registers are copied.
*/
static int fpr_get_msa(struct task_struct *target,
unsigned int *pos, unsigned int *count,
void **kbuf, void __user **ubuf)
{
unsigned int i;
u64 fpr_val;
int err;
BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
for (i = 0; i < NUM_FPU_REGS; i++) {
fpr_val = get_fpr64(&target->thread.fpu.fpr[i], 0);
err = user_regset_copyout(pos, count, kbuf, ubuf,
&fpr_val, i * sizeof(elf_fpreg_t),
(i + 1) * sizeof(elf_fpreg_t));
if (err)
return err;
}
return 0;
}
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
/*
* Copy the floating-point context to the supplied NT_PRFPREG buffer.
* Choose the appropriate helper for general registers, and then copy
* the FCSR and FIR registers separately.
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
*/
static int fpr_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
const int fir_pos = fcr31_pos + sizeof(u32);
int err;
if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
err = fpr_get_fpa(target, &pos, &count, &kbuf, &ubuf);
else
err = fpr_get_msa(target, &pos, &count, &kbuf, &ubuf);
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
if (err)
return err;
err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.fpu.fcr31,
fcr31_pos, fcr31_pos + sizeof(u32));
if (err)
return err;
err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&boot_cpu_data.fpu_id,
fir_pos, fir_pos + sizeof(u32));
return err;
}
/*
* Copy the supplied NT_PRFPREG buffer to the floating-point context,
* !CONFIG_CPU_HAS_MSA variant. Buffer slots correspond 1:1 to FP
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
* context's general register slots. Only general registers are copied.
*/
static int fpr_set_fpa(struct task_struct *target,
unsigned int *pos, unsigned int *count,
const void **kbuf, const void __user **ubuf)
{
return user_regset_copyin(pos, count, kbuf, ubuf,
&target->thread.fpu,
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
0, NUM_FPU_REGS * sizeof(elf_fpreg_t));
}
/*
* Copy the supplied NT_PRFPREG buffer to the floating-point context,
* CONFIG_CPU_HAS_MSA variant. Buffer slots are copied to lower 64
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
* bits only of FP context's general register slots. Only general
* registers are copied.
*/
static int fpr_set_msa(struct task_struct *target,
unsigned int *pos, unsigned int *count,
const void **kbuf, const void __user **ubuf)
{
unsigned int i;
u64 fpr_val;
int err;
BUILD_BUG_ON(sizeof(fpr_val) != sizeof(elf_fpreg_t));
for (i = 0; i < NUM_FPU_REGS && *count > 0; i++) {
err = user_regset_copyin(pos, count, kbuf, ubuf,
&fpr_val, i * sizeof(elf_fpreg_t),
(i + 1) * sizeof(elf_fpreg_t));
if (err)
return err;
set_fpr64(&target->thread.fpu.fpr[i], 0, fpr_val);
}
return 0;
}
/*
* Copy the supplied NT_PRFPREG buffer to the floating-point context.
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
* Choose the appropriate helper for general registers, and then copy
* the FCSR register separately. Ignore the incoming FIR register
* contents though, as the register is read-only.
*
* We optimize for the case where `count % sizeof(elf_fpreg_t) == 0',
* which is supposed to have been guaranteed by the kernel before
* calling us, e.g. in `ptrace_regset'. We enforce that requirement,
* so that we can safely avoid preinitializing temporaries for
* partial register writes.
*/
static int fpr_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
const int fcr31_pos = NUM_FPU_REGS * sizeof(elf_fpreg_t);
const int fir_pos = fcr31_pos + sizeof(u32);
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
u32 fcr31;
int err;
BUG_ON(count % sizeof(elf_fpreg_t));
if (pos + count > sizeof(elf_fpregset_t))
return -EIO;
init_fp_ctx(target);
if (sizeof(target->thread.fpu.fpr[0]) == sizeof(elf_fpreg_t))
err = fpr_set_fpa(target, &pos, &count, &kbuf, &ubuf);
else
err = fpr_set_msa(target, &pos, &count, &kbuf, &ubuf);
MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSA Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org # v3.15+ Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-12-12 05:54:33 +07:00
if (err)
return err;
if (count > 0) {
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&fcr31,
fcr31_pos, fcr31_pos + sizeof(u32));
if (err)
return err;
ptrace_setfcr31(target, fcr31);
}
if (count > 0)
err = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
fir_pos,
fir_pos + sizeof(u32));
return err;
}
/* Copy the FP mode setting to the supplied NT_MIPS_FP_MODE buffer. */
static int fp_mode_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
int fp_mode;
fp_mode = mips_get_process_fp_mode(target);
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &fp_mode, 0,
sizeof(fp_mode));
}
/*
* Copy the supplied NT_MIPS_FP_MODE buffer to the FP mode setting.
*
* We optimize for the case where `count % sizeof(int) == 0', which
* is supposed to have been guaranteed by the kernel before calling
* us, e.g. in `ptrace_regset'. We enforce that requirement, so
* that we can safely avoid preinitializing temporaries for partial
* mode writes.
*/
static int fp_mode_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
int fp_mode;
int err;
BUG_ON(count % sizeof(int));
if (pos + count > sizeof(fp_mode))
return -EIO;
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &fp_mode, 0,
sizeof(fp_mode));
if (err)
return err;
if (count > 0)
err = mips_set_process_fp_mode(target, fp_mode);
return err;
}
#endif /* CONFIG_MIPS_FP_SUPPORT */
#ifdef CONFIG_CPU_HAS_MSA
struct msa_control_regs {
unsigned int fir;
unsigned int fcsr;
unsigned int msair;
unsigned int msacsr;
};
static int copy_pad_fprs(struct task_struct *target,
const struct user_regset *regset,
unsigned int *ppos, unsigned int *pcount,
void **pkbuf, void __user **pubuf,
unsigned int live_sz)
{
int i, j, start, start_pad, err;
unsigned long long fill = ~0ull;
unsigned int cp_sz, pad_sz;
cp_sz = min(regset->size, live_sz);
pad_sz = regset->size - cp_sz;
WARN_ON(pad_sz % sizeof(fill));
i = start = err = 0;
for (; i < NUM_FPU_REGS; i++, start += regset->size) {
err |= user_regset_copyout(ppos, pcount, pkbuf, pubuf,
&target->thread.fpu.fpr[i],
start, start + cp_sz);
start_pad = start + cp_sz;
for (j = 0; j < (pad_sz / sizeof(fill)); j++) {
err |= user_regset_copyout(ppos, pcount, pkbuf, pubuf,
&fill, start_pad,
start_pad + sizeof(fill));
start_pad += sizeof(fill);
}
}
return err;
}
static int msa_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
const unsigned int wr_size = NUM_FPU_REGS * regset->size;
const struct msa_control_regs ctrl_regs = {
.fir = boot_cpu_data.fpu_id,
.fcsr = target->thread.fpu.fcr31,
.msair = boot_cpu_data.msa_id,
.msacsr = target->thread.fpu.msacsr,
};
int err;
if (!tsk_used_math(target)) {
/* The task hasn't used FP or MSA, fill with 0xff */
err = copy_pad_fprs(target, regset, &pos, &count,
&kbuf, &ubuf, 0);
} else if (!test_tsk_thread_flag(target, TIF_MSA_CTX_LIVE)) {
/* Copy scalar FP context, fill the rest with 0xff */
err = copy_pad_fprs(target, regset, &pos, &count,
&kbuf, &ubuf, 8);
} else if (sizeof(target->thread.fpu.fpr[0]) == regset->size) {
/* Trivially copy the vector registers */
err = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&target->thread.fpu.fpr,
0, wr_size);
} else {
/* Copy as much context as possible, fill the rest with 0xff */
err = copy_pad_fprs(target, regset, &pos, &count,
&kbuf, &ubuf,
sizeof(target->thread.fpu.fpr[0]));
}
err |= user_regset_copyout(&pos, &count, &kbuf, &ubuf,
&ctrl_regs, wr_size,
wr_size + sizeof(ctrl_regs));
return err;
}
static int msa_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
const unsigned int wr_size = NUM_FPU_REGS * regset->size;
struct msa_control_regs ctrl_regs;
unsigned int cp_sz;
int i, err, start;
init_fp_ctx(target);
if (sizeof(target->thread.fpu.fpr[0]) == regset->size) {
/* Trivially copy the vector registers */
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.fpu.fpr,
0, wr_size);
} else {
/* Copy as much context as possible */
cp_sz = min_t(unsigned int, regset->size,
sizeof(target->thread.fpu.fpr[0]));
i = start = err = 0;
for (; i < NUM_FPU_REGS; i++, start += regset->size) {
err |= user_regset_copyin(&pos, &count, &kbuf, &ubuf,
&target->thread.fpu.fpr[i],
start, start + cp_sz);
}
}
if (!err)
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl_regs,
wr_size, wr_size + sizeof(ctrl_regs));
if (!err) {
target->thread.fpu.fcr31 = ctrl_regs.fcsr & ~FPU_CSR_ALL_X;
target->thread.fpu.msacsr = ctrl_regs.msacsr & ~MSA_CSR_CAUSEF;
}
return err;
}
#endif /* CONFIG_CPU_HAS_MSA */
MIPS: Add DSP ASE regset support Define an NT_MIPS_DSP core file note type and implement a corresponding regset holding the DSP ASE register context, following the layout of the `mips_dsp_state' structure, except for the DSPControl register stored as a 64-bit rather than 32-bit quantity in a 64-bit note. The lack of DSP ASE register saving to core files can be considered a design flaw with commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE."), leading to an incomplete state being saved. Consequently no DSP ASE regset has been created with commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view."), when regset support was added to the MIPS port. Additionally there is no way for ptrace(2) to correctly access the DSP accumulator registers in n32 processes with the existing interfaces. This is due to 32-bit truncation of data passed with PTRACE_PEEKUSR and PTRACE_POKEUSR requests, which cannot be avoided owing to how the data types for ptrace(3) have been defined. This new NT_MIPS_DSP regset fills the missing interface gap. [paul.burton@mips.com: - Change NT_MIPS_DSP to 0x800 to avoid conflict with NT_VMCOREDD introduced by commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in second kernel"). - Drop stable tag. Whilst I agree the lack of this functionality can be considered a flaw in earlier DSP ASE support, it's still new functionality which doesn't meet up to the requirements set out in Documentation/process/stable-kernel-rules.rst.] Signed-off-by: Maciej W. Rozycki <macro@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> References: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Patchwork: https://patchwork.linux-mips.org/patch/19330/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
2018-05-16 05:34:28 +07:00
#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
/*
* Copy the DSP context to the supplied 32-bit NT_MIPS_DSP buffer.
*/
static int dsp32_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
unsigned int start, num_regs, i;
u32 dspregs[NUM_DSP_REGS + 1];
BUG_ON(count % sizeof(u32));
if (!cpu_has_dsp)
return -EIO;
start = pos / sizeof(u32);
num_regs = count / sizeof(u32);
if (start + num_regs > NUM_DSP_REGS + 1)
return -EIO;
for (i = start; i < num_regs; i++)
switch (i) {
case 0 ... NUM_DSP_REGS - 1:
dspregs[i] = target->thread.dsp.dspr[i];
break;
case NUM_DSP_REGS:
dspregs[i] = target->thread.dsp.dspcontrol;
break;
}
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, dspregs, 0,
sizeof(dspregs));
}
/*
* Copy the supplied 32-bit NT_MIPS_DSP buffer to the DSP context.
*/
static int dsp32_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
unsigned int start, num_regs, i;
u32 dspregs[NUM_DSP_REGS + 1];
int err;
BUG_ON(count % sizeof(u32));
if (!cpu_has_dsp)
return -EIO;
start = pos / sizeof(u32);
num_regs = count / sizeof(u32);
if (start + num_regs > NUM_DSP_REGS + 1)
return -EIO;
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, dspregs, 0,
sizeof(dspregs));
if (err)
return err;
for (i = start; i < num_regs; i++)
switch (i) {
case 0 ... NUM_DSP_REGS - 1:
target->thread.dsp.dspr[i] = (s32)dspregs[i];
break;
case NUM_DSP_REGS:
target->thread.dsp.dspcontrol = (s32)dspregs[i];
break;
}
return 0;
}
#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
#ifdef CONFIG_64BIT
/*
* Copy the DSP context to the supplied 64-bit NT_MIPS_DSP buffer.
*/
static int dsp64_get(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
void *kbuf, void __user *ubuf)
{
unsigned int start, num_regs, i;
u64 dspregs[NUM_DSP_REGS + 1];
BUG_ON(count % sizeof(u64));
if (!cpu_has_dsp)
return -EIO;
start = pos / sizeof(u64);
num_regs = count / sizeof(u64);
if (start + num_regs > NUM_DSP_REGS + 1)
return -EIO;
for (i = start; i < num_regs; i++)
switch (i) {
case 0 ... NUM_DSP_REGS - 1:
dspregs[i] = target->thread.dsp.dspr[i];
break;
case NUM_DSP_REGS:
dspregs[i] = target->thread.dsp.dspcontrol;
break;
}
return user_regset_copyout(&pos, &count, &kbuf, &ubuf, dspregs, 0,
sizeof(dspregs));
}
/*
* Copy the supplied 64-bit NT_MIPS_DSP buffer to the DSP context.
*/
static int dsp64_set(struct task_struct *target,
const struct user_regset *regset,
unsigned int pos, unsigned int count,
const void *kbuf, const void __user *ubuf)
{
unsigned int start, num_regs, i;
u64 dspregs[NUM_DSP_REGS + 1];
int err;
BUG_ON(count % sizeof(u64));
if (!cpu_has_dsp)
return -EIO;
start = pos / sizeof(u64);
num_regs = count / sizeof(u64);
if (start + num_regs > NUM_DSP_REGS + 1)
return -EIO;
err = user_regset_copyin(&pos, &count, &kbuf, &ubuf, dspregs, 0,
sizeof(dspregs));
if (err)
return err;
for (i = start; i < num_regs; i++)
switch (i) {
case 0 ... NUM_DSP_REGS - 1:
target->thread.dsp.dspr[i] = dspregs[i];
break;
case NUM_DSP_REGS:
target->thread.dsp.dspcontrol = dspregs[i];
break;
}
return 0;
}
#endif /* CONFIG_64BIT */
/*
* Determine whether the DSP context is present.
*/
static int dsp_active(struct task_struct *target,
const struct user_regset *regset)
{
return cpu_has_dsp ? NUM_DSP_REGS + 1 : -ENODEV;
}
enum mips_regset {
REGSET_GPR,
MIPS: Add DSP ASE regset support Define an NT_MIPS_DSP core file note type and implement a corresponding regset holding the DSP ASE register context, following the layout of the `mips_dsp_state' structure, except for the DSPControl register stored as a 64-bit rather than 32-bit quantity in a 64-bit note. The lack of DSP ASE register saving to core files can be considered a design flaw with commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE."), leading to an incomplete state being saved. Consequently no DSP ASE regset has been created with commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view."), when regset support was added to the MIPS port. Additionally there is no way for ptrace(2) to correctly access the DSP accumulator registers in n32 processes with the existing interfaces. This is due to 32-bit truncation of data passed with PTRACE_PEEKUSR and PTRACE_POKEUSR requests, which cannot be avoided owing to how the data types for ptrace(3) have been defined. This new NT_MIPS_DSP regset fills the missing interface gap. [paul.burton@mips.com: - Change NT_MIPS_DSP to 0x800 to avoid conflict with NT_VMCOREDD introduced by commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in second kernel"). - Drop stable tag. Whilst I agree the lack of this functionality can be considered a flaw in earlier DSP ASE support, it's still new functionality which doesn't meet up to the requirements set out in Documentation/process/stable-kernel-rules.rst.] Signed-off-by: Maciej W. Rozycki <macro@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> References: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Patchwork: https://patchwork.linux-mips.org/patch/19330/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
2018-05-16 05:34:28 +07:00
REGSET_DSP,
#ifdef CONFIG_MIPS_FP_SUPPORT
REGSET_FPR,
REGSET_FP_MODE,
#endif
#ifdef CONFIG_CPU_HAS_MSA
REGSET_MSA,
#endif
};
struct pt_regs_offset {
const char *name;
int offset;
};
#define REG_OFFSET_NAME(reg, r) { \
.name = #reg, \
.offset = offsetof(struct pt_regs, r) \
}
#define REG_OFFSET_END { \
.name = NULL, \
.offset = 0 \
}
static const struct pt_regs_offset regoffset_table[] = {
REG_OFFSET_NAME(r0, regs[0]),
REG_OFFSET_NAME(r1, regs[1]),
REG_OFFSET_NAME(r2, regs[2]),
REG_OFFSET_NAME(r3, regs[3]),
REG_OFFSET_NAME(r4, regs[4]),
REG_OFFSET_NAME(r5, regs[5]),
REG_OFFSET_NAME(r6, regs[6]),
REG_OFFSET_NAME(r7, regs[7]),
REG_OFFSET_NAME(r8, regs[8]),
REG_OFFSET_NAME(r9, regs[9]),
REG_OFFSET_NAME(r10, regs[10]),
REG_OFFSET_NAME(r11, regs[11]),
REG_OFFSET_NAME(r12, regs[12]),
REG_OFFSET_NAME(r13, regs[13]),
REG_OFFSET_NAME(r14, regs[14]),
REG_OFFSET_NAME(r15, regs[15]),
REG_OFFSET_NAME(r16, regs[16]),
REG_OFFSET_NAME(r17, regs[17]),
REG_OFFSET_NAME(r18, regs[18]),
REG_OFFSET_NAME(r19, regs[19]),
REG_OFFSET_NAME(r20, regs[20]),
REG_OFFSET_NAME(r21, regs[21]),
REG_OFFSET_NAME(r22, regs[22]),
REG_OFFSET_NAME(r23, regs[23]),
REG_OFFSET_NAME(r24, regs[24]),
REG_OFFSET_NAME(r25, regs[25]),
REG_OFFSET_NAME(r26, regs[26]),
REG_OFFSET_NAME(r27, regs[27]),
REG_OFFSET_NAME(r28, regs[28]),
REG_OFFSET_NAME(r29, regs[29]),
REG_OFFSET_NAME(r30, regs[30]),
REG_OFFSET_NAME(r31, regs[31]),
REG_OFFSET_NAME(c0_status, cp0_status),
REG_OFFSET_NAME(hi, hi),
REG_OFFSET_NAME(lo, lo),
#ifdef CONFIG_CPU_HAS_SMARTMIPS
REG_OFFSET_NAME(acx, acx),
#endif
REG_OFFSET_NAME(c0_badvaddr, cp0_badvaddr),
REG_OFFSET_NAME(c0_cause, cp0_cause),
REG_OFFSET_NAME(c0_epc, cp0_epc),
#ifdef CONFIG_CPU_CAVIUM_OCTEON
REG_OFFSET_NAME(mpl0, mpl[0]),
REG_OFFSET_NAME(mpl1, mpl[1]),
REG_OFFSET_NAME(mpl2, mpl[2]),
REG_OFFSET_NAME(mtp0, mtp[0]),
REG_OFFSET_NAME(mtp1, mtp[1]),
REG_OFFSET_NAME(mtp2, mtp[2]),
#endif
REG_OFFSET_END,
};
/**
* regs_query_register_offset() - query register offset from its name
* @name: the name of a register
*
* regs_query_register_offset() returns the offset of a register in struct
* pt_regs from its name. If the name is invalid, this returns -EINVAL;
*/
int regs_query_register_offset(const char *name)
{
const struct pt_regs_offset *roff;
for (roff = regoffset_table; roff->name != NULL; roff++)
if (!strcmp(roff->name, name))
return roff->offset;
return -EINVAL;
}
#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
static const struct user_regset mips_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(unsigned int),
.align = sizeof(unsigned int),
.get = gpr32_get,
.set = gpr32_set,
},
MIPS: Add DSP ASE regset support Define an NT_MIPS_DSP core file note type and implement a corresponding regset holding the DSP ASE register context, following the layout of the `mips_dsp_state' structure, except for the DSPControl register stored as a 64-bit rather than 32-bit quantity in a 64-bit note. The lack of DSP ASE register saving to core files can be considered a design flaw with commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE."), leading to an incomplete state being saved. Consequently no DSP ASE regset has been created with commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view."), when regset support was added to the MIPS port. Additionally there is no way for ptrace(2) to correctly access the DSP accumulator registers in n32 processes with the existing interfaces. This is due to 32-bit truncation of data passed with PTRACE_PEEKUSR and PTRACE_POKEUSR requests, which cannot be avoided owing to how the data types for ptrace(3) have been defined. This new NT_MIPS_DSP regset fills the missing interface gap. [paul.burton@mips.com: - Change NT_MIPS_DSP to 0x800 to avoid conflict with NT_VMCOREDD introduced by commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in second kernel"). - Drop stable tag. Whilst I agree the lack of this functionality can be considered a flaw in earlier DSP ASE support, it's still new functionality which doesn't meet up to the requirements set out in Documentation/process/stable-kernel-rules.rst.] Signed-off-by: Maciej W. Rozycki <macro@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> References: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Patchwork: https://patchwork.linux-mips.org/patch/19330/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
2018-05-16 05:34:28 +07:00
[REGSET_DSP] = {
.core_note_type = NT_MIPS_DSP,
.n = NUM_DSP_REGS + 1,
.size = sizeof(u32),
.align = sizeof(u32),
.get = dsp32_get,
.set = dsp32_set,
.active = dsp_active,
},
#ifdef CONFIG_MIPS_FP_SUPPORT
[REGSET_FPR] = {
.core_note_type = NT_PRFPREG,
.n = ELF_NFPREG,
.size = sizeof(elf_fpreg_t),
.align = sizeof(elf_fpreg_t),
.get = fpr_get,
.set = fpr_set,
},
[REGSET_FP_MODE] = {
.core_note_type = NT_MIPS_FP_MODE,
.n = 1,
.size = sizeof(int),
.align = sizeof(int),
.get = fp_mode_get,
.set = fp_mode_set,
},
#endif
#ifdef CONFIG_CPU_HAS_MSA
[REGSET_MSA] = {
.core_note_type = NT_MIPS_MSA,
.n = NUM_FPU_REGS + 1,
.size = 16,
.align = 16,
.get = msa_get,
.set = msa_set,
},
#endif
};
static const struct user_regset_view user_mips_view = {
.name = "mips",
.e_machine = ELF_ARCH,
.ei_osabi = ELF_OSABI,
.regsets = mips_regsets,
.n = ARRAY_SIZE(mips_regsets),
};
#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
#ifdef CONFIG_64BIT
static const struct user_regset mips64_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(unsigned long),
.align = sizeof(unsigned long),
.get = gpr64_get,
.set = gpr64_set,
},
MIPS: Add DSP ASE regset support Define an NT_MIPS_DSP core file note type and implement a corresponding regset holding the DSP ASE register context, following the layout of the `mips_dsp_state' structure, except for the DSPControl register stored as a 64-bit rather than 32-bit quantity in a 64-bit note. The lack of DSP ASE register saving to core files can be considered a design flaw with commit e50c0a8fa60d ("Support the MIPS32 / MIPS64 DSP ASE."), leading to an incomplete state being saved. Consequently no DSP ASE regset has been created with commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view."), when regset support was added to the MIPS port. Additionally there is no way for ptrace(2) to correctly access the DSP accumulator registers in n32 processes with the existing interfaces. This is due to 32-bit truncation of data passed with PTRACE_PEEKUSR and PTRACE_POKEUSR requests, which cannot be avoided owing to how the data types for ptrace(3) have been defined. This new NT_MIPS_DSP regset fills the missing interface gap. [paul.burton@mips.com: - Change NT_MIPS_DSP to 0x800 to avoid conflict with NT_VMCOREDD introduced by commit 2724273e8fd0 ("vmcore: add API to collect hardware dump in second kernel"). - Drop stable tag. Whilst I agree the lack of this functionality can be considered a flaw in earlier DSP ASE support, it's still new functionality which doesn't meet up to the requirements set out in Documentation/process/stable-kernel-rules.rst.] Signed-off-by: Maciej W. Rozycki <macro@mips.com> Signed-off-by: Paul Burton <paul.burton@mips.com> References: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Patchwork: https://patchwork.linux-mips.org/patch/19330/ Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org
2018-05-16 05:34:28 +07:00
[REGSET_DSP] = {
.core_note_type = NT_MIPS_DSP,
.n = NUM_DSP_REGS + 1,
.size = sizeof(u64),
.align = sizeof(u64),
.get = dsp64_get,
.set = dsp64_set,
.active = dsp_active,
},
#ifdef CONFIG_MIPS_FP_SUPPORT
[REGSET_FP_MODE] = {
.core_note_type = NT_MIPS_FP_MODE,
.n = 1,
.size = sizeof(int),
.align = sizeof(int),
.get = fp_mode_get,
.set = fp_mode_set,
},
[REGSET_FPR] = {
.core_note_type = NT_PRFPREG,
.n = ELF_NFPREG,
.size = sizeof(elf_fpreg_t),
.align = sizeof(elf_fpreg_t),
.get = fpr_get,
.set = fpr_set,
},
#endif
#ifdef CONFIG_CPU_HAS_MSA
[REGSET_MSA] = {
.core_note_type = NT_MIPS_MSA,
.n = NUM_FPU_REGS + 1,
.size = 16,
.align = 16,
.get = msa_get,
.set = msa_set,
},
#endif
};
static const struct user_regset_view user_mips64_view = {
.name = "mips64",
.e_machine = ELF_ARCH,
.ei_osabi = ELF_OSABI,
.regsets = mips64_regsets,
.n = ARRAY_SIZE(mips64_regsets),
};
MIPS: Fix an n32 core file generation regset support regression Fix a commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") regression, then activated by commit 6a9c001b7ec3 ("MIPS: Switch ELF core dumper to use regsets.)", that caused n32 processes to dump o32 core files by failing to set the EF_MIPS_ABI2 flag in the ELF core file header's `e_flags' member: $ file tls-core tls-core: ELF 32-bit MSB executable, MIPS, N32 MIPS64 rel2 version 1 (SYSV), [...] $ ./tls-core Aborted (core dumped) $ file core core: ELF 32-bit MSB core file MIPS, MIPS-I version 1 (SYSV), SVR4-style $ Previously the flag was set as the result of a: statement placed in arch/mips/kernel/binfmt_elfn32.c, however in the regset case, i.e. when CORE_DUMP_USE_REGSET is set, ELF_CORE_EFLAGS is no longer used by `fill_note_info' in fs/binfmt_elf.c, and instead the `->e_flags' member of the regset view chosen is. We have the views defined in arch/mips/kernel/ptrace.c, however only an o32 and an n64 one, and the latter is used for n32 as well. Consequently an o32 core file is incorrectly dumped from n32 processes (the ELF32 vs ELF64 class is chosen elsewhere, and the 32-bit one is correctly selected for n32). Correct the issue then by defining an n32 regset view and using it as appropriate. Issue discovered in GDB testing. Fixes: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Signed-off-by: Maciej W. Rozycki <macro@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Djordje Todorovic <djordje.todorovic@rt-rk.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 3.13+ Patchwork: https://patchwork.linux-mips.org/patch/17617/ Signed-off-by: James Hogan <jhogan@kernel.org>
2017-11-08 02:09:20 +07:00
#ifdef CONFIG_MIPS32_N32
static const struct user_regset_view user_mipsn32_view = {
.name = "mipsn32",
.e_flags = EF_MIPS_ABI2,
.e_machine = ELF_ARCH,
.ei_osabi = ELF_OSABI,
.regsets = mips64_regsets,
.n = ARRAY_SIZE(mips64_regsets),
};
#endif /* CONFIG_MIPS32_N32 */
#endif /* CONFIG_64BIT */
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
#ifdef CONFIG_32BIT
return &user_mips_view;
#else
#ifdef CONFIG_MIPS32_O32
if (test_tsk_thread_flag(task, TIF_32BIT_REGS))
return &user_mips_view;
MIPS: Fix an n32 core file generation regset support regression Fix a commit 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") regression, then activated by commit 6a9c001b7ec3 ("MIPS: Switch ELF core dumper to use regsets.)", that caused n32 processes to dump o32 core files by failing to set the EF_MIPS_ABI2 flag in the ELF core file header's `e_flags' member: $ file tls-core tls-core: ELF 32-bit MSB executable, MIPS, N32 MIPS64 rel2 version 1 (SYSV), [...] $ ./tls-core Aborted (core dumped) $ file core core: ELF 32-bit MSB core file MIPS, MIPS-I version 1 (SYSV), SVR4-style $ Previously the flag was set as the result of a: statement placed in arch/mips/kernel/binfmt_elfn32.c, however in the regset case, i.e. when CORE_DUMP_USE_REGSET is set, ELF_CORE_EFLAGS is no longer used by `fill_note_info' in fs/binfmt_elf.c, and instead the `->e_flags' member of the regset view chosen is. We have the views defined in arch/mips/kernel/ptrace.c, however only an o32 and an n64 one, and the latter is used for n32 as well. Consequently an o32 core file is incorrectly dumped from n32 processes (the ELF32 vs ELF64 class is chosen elsewhere, and the 32-bit one is correctly selected for n32). Correct the issue then by defining an n32 regset view and using it as appropriate. Issue discovered in GDB testing. Fixes: 7aeb753b5353 ("MIPS: Implement task_user_regset_view.") Signed-off-by: Maciej W. Rozycki <macro@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Djordje Todorovic <djordje.todorovic@rt-rk.com> Cc: linux-mips@linux-mips.org Cc: <stable@vger.kernel.org> # 3.13+ Patchwork: https://patchwork.linux-mips.org/patch/17617/ Signed-off-by: James Hogan <jhogan@kernel.org>
2017-11-08 02:09:20 +07:00
#endif
#ifdef CONFIG_MIPS32_N32
if (test_tsk_thread_flag(task, TIF_32BIT_ADDR))
return &user_mipsn32_view;
#endif
return &user_mips64_view;
#endif
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
int ret;
void __user *addrp = (void __user *) addr;
void __user *datavp = (void __user *) data;
unsigned long __user *datalp = (void __user *) data;
switch (request) {
/* when I and D space are separate, these will need to be fixed. */
case PTRACE_PEEKTEXT: /* read word at location addr. */
case PTRACE_PEEKDATA:
ret = generic_ptrace_peekdata(child, addr, data);
break;
/* Read the word at location addr in the USER area. */
case PTRACE_PEEKUSR: {
struct pt_regs *regs;
unsigned long tmp = 0;
regs = task_pt_regs(child);
ret = 0; /* Default return value. */
switch (addr) {
case 0 ... 31:
tmp = regs->regs[addr];
break;
#ifdef CONFIG_MIPS_FP_SUPPORT
case FPR_BASE ... FPR_BASE + 31: {
union fpureg *fregs;
if (!tsk_used_math(child)) {
/* FP not yet used */
tmp = -1;
break;
}
fregs = get_fpu_regs(child);
#ifdef CONFIG_32BIT
if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers.
*/
tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
addr & 1);
break;
}
#endif
tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
break;
}
case FPC_CSR:
tmp = child->thread.fpu.fcr31;
break;
case FPC_EIR:
/* implementation / version register */
tmp = boot_cpu_data.fpu_id;
break;
#endif
case PC:
tmp = regs->cp0_epc;
break;
case CAUSE:
tmp = regs->cp0_cause;
break;
case BADVADDR:
tmp = regs->cp0_badvaddr;
break;
case MMHI:
tmp = regs->hi;
break;
case MMLO:
tmp = regs->lo;
break;
#ifdef CONFIG_CPU_HAS_SMARTMIPS
case ACX:
tmp = regs->acx;
break;
#endif
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;
if (!cpu_has_dsp) {
tmp = 0;
ret = -EIO;
goto out;
}
dregs = __get_dsp_regs(child);
tmp = dregs[addr - DSP_BASE];
break;
}
case DSP_CONTROL:
if (!cpu_has_dsp) {
tmp = 0;
ret = -EIO;
goto out;
}
tmp = child->thread.dsp.dspcontrol;
break;
default:
tmp = 0;
ret = -EIO;
goto out;
}
ret = put_user(tmp, datalp);
break;
}
/* when I and D space are separate, this will have to be fixed. */
case PTRACE_POKETEXT: /* write the word at location addr. */
case PTRACE_POKEDATA:
ret = generic_ptrace_pokedata(child, addr, data);
break;
case PTRACE_POKEUSR: {
struct pt_regs *regs;
ret = 0;
regs = task_pt_regs(child);
switch (addr) {
case 0 ... 31:
regs->regs[addr] = data;
MIPS/ptrace: Update syscall nr on register changes Update the thread_info::syscall field when registers are modified via ptrace to change or cancel the system call being entered. This is important to allow seccomp and the syscall entry and exit trace events to observe the new syscall number changed by the normal ptrace hook or seccomp. That includes allowing seccomp's recheck of the system call number after SECCOMP_RET_TRACE to notice if the syscall is changed to a denied one, which happens in seccomp since commit ce6526e8afa4 ("seccomp: recheck the syscall after RET_TRACE") in v4.8. In the process of doing this, the logic to determine whether an indirect system call is in progress (i.e. the O32 ABI's syscall()) is abstracted into mips_syscall_is_indirect(), and a new mips_syscall_update_nr() is used to update the thread_info::syscall based on the register state. The following ptrace operations are updated: - PTRACE_SETREGS (ptrace_setregs()). - PTRACE_SETREGSET with NT_PRSTATUS (gpr32_set() and gpr64_set()). - PTRACE_POKEUSR with 2/v0 or 4/a0 for indirect syscall ([compat_]arch_ptrace()). Fixes: c2d9f1775731 ("MIPS: Fix syscall_get_nr for the syscall exit tracing.") Signed-off-by: James Hogan <jhogan@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Lars Persson <larper@axis.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16995/
2017-08-12 03:56:52 +07:00
/* System call number may have been changed */
if (addr == 2)
mips_syscall_update_nr(child, regs);
else if (addr == 4 &&
mips_syscall_is_indirect(child, regs))
mips_syscall_update_nr(child, regs);
break;
#ifdef CONFIG_MIPS_FP_SUPPORT
case FPR_BASE ... FPR_BASE + 31: {
union fpureg *fregs = get_fpu_regs(child);
init_fp_ctx(child);
#ifdef CONFIG_32BIT
if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
/*
* The odd registers are actually the high
* order bits of the values stored in the even
* registers.
*/
set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
addr & 1, data);
break;
}
#endif
set_fpr64(&fregs[addr - FPR_BASE], 0, data);
break;
}
case FPC_CSR:
init_fp_ctx(child);
ptrace_setfcr31(child, data);
break;
#endif
case PC:
regs->cp0_epc = data;
break;
case MMHI:
regs->hi = data;
break;
case MMLO:
regs->lo = data;
break;
#ifdef CONFIG_CPU_HAS_SMARTMIPS
case ACX:
regs->acx = data;
break;
#endif
case DSP_BASE ... DSP_BASE + 5: {
dspreg_t *dregs;
if (!cpu_has_dsp) {
ret = -EIO;
break;
}
dregs = __get_dsp_regs(child);
dregs[addr - DSP_BASE] = data;
break;
}
case DSP_CONTROL:
if (!cpu_has_dsp) {
ret = -EIO;
break;
}
child->thread.dsp.dspcontrol = data;
break;
default:
/* The rest are not allowed. */
ret = -EIO;
break;
}
break;
}
case PTRACE_GETREGS:
ret = ptrace_getregs(child, datavp);
break;
case PTRACE_SETREGS:
ret = ptrace_setregs(child, datavp);
break;
#ifdef CONFIG_MIPS_FP_SUPPORT
case PTRACE_GETFPREGS:
ret = ptrace_getfpregs(child, datavp);
break;
case PTRACE_SETFPREGS:
ret = ptrace_setfpregs(child, datavp);
break;
#endif
case PTRACE_GET_THREAD_AREA:
ret = put_user(task_thread_info(child)->tp_value, datalp);
break;
case PTRACE_GET_WATCH_REGS:
ret = ptrace_get_watch_regs(child, addrp);
break;
case PTRACE_SET_WATCH_REGS:
ret = ptrace_set_watch_regs(child, addrp);
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
out:
return ret;
}
/*
* Notification of system call entry/exit
* - triggered by current->work.syscall_trace
*/
asmlinkage long syscall_trace_enter(struct pt_regs *regs, long syscall)
{
user_exit();
current_thread_info()->syscall = syscall;
if (test_thread_flag(TIF_SYSCALL_TRACE)) {
if (tracehook_report_syscall_entry(regs))
return -1;
syscall = current_thread_info()->syscall;
}
#ifdef CONFIG_SECCOMP
if (unlikely(test_thread_flag(TIF_SECCOMP))) {
int ret, i;
struct seccomp_data sd;
MIPS: seccomp: Fix indirect syscall args Since commit 669c4092225f ("MIPS: Give __secure_computing() access to syscall arguments."), upon syscall entry when seccomp is enabled, syscall_trace_enter() passes a carefully prepared struct seccomp_data containing syscall arguments to __secure_computing(). Unfortunately it directly uses mips_get_syscall_arg() and fails to take into account the indirect O32 system calls (i.e. syscall(2)) which put the system call number in a0 and have the arguments shifted up by one entry. We can't just revert that commit as samples/bpf/tracex5 would break again, so use syscall_get_arguments() which already takes indirect syscalls into account instead of directly using mips_get_syscall_arg(), similar to what populate_seccomp_data() does. This also removes the redundant error checking of the mips_get_syscall_arg() return value (get_user() already zeroes the result if an argument from the stack can't be loaded). Reported-by: James Cowgill <James.Cowgill@imgtec.com> Fixes: 669c4092225f ("MIPS: Give __secure_computing() access to syscall arguments.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: David Daney <david.daney@cavium.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16994/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-12 03:56:50 +07:00
unsigned long args[6];
sd.nr = syscall;
syscall_get_arch: add "struct task_struct *" argument This argument is required to extend the generic ptrace API with PTRACE_GET_SYSCALL_INFO request: syscall_get_arch() is going to be called from ptrace_request() along with syscall_get_nr(), syscall_get_arguments(), syscall_get_error(), and syscall_get_return_value() functions with a tracee as their argument. The primary intent is that the triple (audit_arch, syscall_nr, arg1..arg6) should describe what system call is being called and what its arguments are. Reverts: 5e937a9ae913 ("syscall_get_arch: remove useless function arguments") Reverts: 1002d94d3076 ("syscall.h: fix doc text for syscall_get_arch()") Reviewed-by: Andy Lutomirski <luto@kernel.org> # for x86 Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Acked-by: Paul Moore <paul@paul-moore.com> Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Kees Cook <keescook@chromium.org> # seccomp parts Acked-by: Mark Salter <msalter@redhat.com> # for the c6x bit Cc: Elvira Khabirova <lineprinter@altlinux.org> Cc: Eugene Syromyatnikov <esyr@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: x86@kernel.org Cc: linux-alpha@vger.kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-hexagon@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-m68k@lists.linux-m68k.org Cc: linux-mips@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Cc: openrisc@lists.librecores.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Cc: linux-audit@redhat.com Signed-off-by: Dmitry V. Levin <ldv@altlinux.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-18 06:30:18 +07:00
sd.arch = syscall_get_arch(current);
syscalls: Remove start and number from syscall_get_arguments() args At Linux Plumbers, Andy Lutomirski approached me and pointed out that the function call syscall_get_arguments() implemented in x86 was horribly written and not optimized for the standard case of passing in 0 and 6 for the starting index and the number of system calls to get. When looking at all the users of this function, I discovered that all instances pass in only 0 and 6 for these arguments. Instead of having this function handle different cases that are never used, simply rewrite it to return the first 6 arguments of a system call. This should help out the performance of tracing system calls by ptrace, ftrace and perf. Link: http://lkml.kernel.org/r/20161107213233.754809394@goodmis.org Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Dave Martin <dave.martin@arm.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: x86@kernel.org Cc: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-c6x-dev@linux-c6x.org Cc: uclinux-h8-devel@lists.sourceforge.jp Cc: linux-hexagon@vger.kernel.org Cc: linux-ia64@vger.kernel.org Cc: linux-mips@vger.kernel.org Cc: nios2-dev@lists.rocketboards.org Cc: openrisc@lists.librecores.org Cc: linux-parisc@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org Cc: linux-riscv@lists.infradead.org Cc: linux-s390@vger.kernel.org Cc: linux-sh@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-um@lists.infradead.org Cc: linux-xtensa@linux-xtensa.org Cc: linux-arch@vger.kernel.org Acked-by: Paul Burton <paul.burton@mips.com> # MIPS parts Acked-by: Max Filippov <jcmvbkbc@gmail.com> # For xtensa changes Acked-by: Will Deacon <will.deacon@arm.com> # For the arm64 bits Reviewed-by: Thomas Gleixner <tglx@linutronix.de> # for x86 Reviewed-by: Dmitry V. Levin <ldv@altlinux.org> Reported-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2016-11-08 04:26:37 +07:00
syscall_get_arguments(current, regs, args);
MIPS: seccomp: Fix indirect syscall args Since commit 669c4092225f ("MIPS: Give __secure_computing() access to syscall arguments."), upon syscall entry when seccomp is enabled, syscall_trace_enter() passes a carefully prepared struct seccomp_data containing syscall arguments to __secure_computing(). Unfortunately it directly uses mips_get_syscall_arg() and fails to take into account the indirect O32 system calls (i.e. syscall(2)) which put the system call number in a0 and have the arguments shifted up by one entry. We can't just revert that commit as samples/bpf/tracex5 would break again, so use syscall_get_arguments() which already takes indirect syscalls into account instead of directly using mips_get_syscall_arg(), similar to what populate_seccomp_data() does. This also removes the redundant error checking of the mips_get_syscall_arg() return value (get_user() already zeroes the result if an argument from the stack can't be loaded). Reported-by: James Cowgill <James.Cowgill@imgtec.com> Fixes: 669c4092225f ("MIPS: Give __secure_computing() access to syscall arguments.") Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: David Daney <david.daney@cavium.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16994/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-12 03:56:50 +07:00
for (i = 0; i < 6; i++)
sd.args[i] = args[i];
sd.instruction_pointer = KSTK_EIP(current);
ret = __secure_computing(&sd);
if (ret == -1)
return ret;
syscall = current_thread_info()->syscall;
}
#endif
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_enter(regs, regs->regs[2]);
audit_syscall_entry(syscall, regs->regs[4], regs->regs[5],
regs->regs[6], regs->regs[7]);
/*
* Negative syscall numbers are mistaken for rejected syscalls, but
* won't have had the return value set appropriately, so we do so now.
*/
if (syscall < 0)
syscall_set_return_value(current, regs, -ENOSYS, 0);
return syscall;
}
/*
* Notification of system call entry/exit
* - triggered by current->work.syscall_trace
*/
asmlinkage void syscall_trace_leave(struct pt_regs *regs)
{
/*
* We may come here right after calling schedule_user()
* or do_notify_resume(), in which case we can be in RCU
* user mode.
*/
user_exit();
Audit: push audit success and retcode into arch ptrace.h The audit system previously expected arches calling to audit_syscall_exit to supply as arguments if the syscall was a success and what the return code was. Audit also provides a helper AUDITSC_RESULT which was supposed to simplify things by converting from negative retcodes to an audit internal magic value stating success or failure. This helper was wrong and could indicate that a valid pointer returned to userspace was a failed syscall. The fix is to fix the layering foolishness. We now pass audit_syscall_exit a struct pt_reg and it in turns calls back into arch code to collect the return value and to determine if the syscall was a success or failure. We also define a generic is_syscall_success() macro which determines success/failure based on if the value is < -MAX_ERRNO. This works for arches like x86 which do not use a separate mechanism to indicate syscall failure. We make both the is_syscall_success() and regs_return_value() static inlines instead of macros. The reason is because the audit function must take a void* for the regs. (uml calls theirs struct uml_pt_regs instead of just struct pt_regs so audit_syscall_exit can't take a struct pt_regs). Since the audit function takes a void* we need to use static inlines to cast it back to the arch correct structure to dereference it. The other major change is that on some arches, like ia64, MIPS and ppc, we change regs_return_value() to give us the negative value on syscall failure. THE only other user of this macro, kretprobe_example.c, won't notice and it makes the value signed consistently for the audit functions across all archs. In arch/sh/kernel/ptrace_64.c I see that we were using regs[9] in the old audit code as the return value. But the ptrace_64.h code defined the macro regs_return_value() as regs[3]. I have no idea which one is correct, but this patch now uses the regs_return_value() function, so it now uses regs[3]. For powerpc we previously used regs->result but now use the regs_return_value() function which uses regs->gprs[3]. regs->gprs[3] is always positive so the regs_return_value(), much like ia64 makes it negative before calling the audit code when appropriate. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: H. Peter Anvin <hpa@zytor.com> [for x86 portion] Acked-by: Tony Luck <tony.luck@intel.com> [for ia64] Acked-by: Richard Weinberger <richard@nod.at> [for uml] Acked-by: David S. Miller <davem@davemloft.net> [for sparc] Acked-by: Ralf Baechle <ralf@linux-mips.org> [for mips] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [for ppc]
2012-01-04 02:23:06 +07:00
audit_syscall_exit(regs);
if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
trace_sys_exit(regs, regs_return_value(regs));
if (test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, 0);
user_enter();
}