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linux_dsm_epyc7002/arch/arm64/kernel/signal32.c
Linus Torvalds 96d4f267e4 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>
2019-01-03 18:57:57 -08:00

517 lines
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/*
* Based on arch/arm/kernel/signal.c
*
* Copyright (C) 1995-2009 Russell King
* Copyright (C) 2012 ARM Ltd.
* Modified by Will Deacon <will.deacon@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/compat.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/ratelimit.h>
#include <asm/esr.h>
#include <asm/fpsimd.h>
#include <asm/signal32.h>
#include <asm/traps.h>
#include <linux/uaccess.h>
#include <asm/unistd.h>
struct compat_sigcontext {
/* We always set these two fields to 0 */
compat_ulong_t trap_no;
compat_ulong_t error_code;
compat_ulong_t oldmask;
compat_ulong_t arm_r0;
compat_ulong_t arm_r1;
compat_ulong_t arm_r2;
compat_ulong_t arm_r3;
compat_ulong_t arm_r4;
compat_ulong_t arm_r5;
compat_ulong_t arm_r6;
compat_ulong_t arm_r7;
compat_ulong_t arm_r8;
compat_ulong_t arm_r9;
compat_ulong_t arm_r10;
compat_ulong_t arm_fp;
compat_ulong_t arm_ip;
compat_ulong_t arm_sp;
compat_ulong_t arm_lr;
compat_ulong_t arm_pc;
compat_ulong_t arm_cpsr;
compat_ulong_t fault_address;
};
struct compat_ucontext {
compat_ulong_t uc_flags;
compat_uptr_t uc_link;
compat_stack_t uc_stack;
struct compat_sigcontext uc_mcontext;
compat_sigset_t uc_sigmask;
int __unused[32 - (sizeof (compat_sigset_t) / sizeof (int))];
compat_ulong_t uc_regspace[128] __attribute__((__aligned__(8)));
};
struct compat_vfp_sigframe {
compat_ulong_t magic;
compat_ulong_t size;
struct compat_user_vfp {
compat_u64 fpregs[32];
compat_ulong_t fpscr;
} ufp;
struct compat_user_vfp_exc {
compat_ulong_t fpexc;
compat_ulong_t fpinst;
compat_ulong_t fpinst2;
} ufp_exc;
} __attribute__((__aligned__(8)));
#define VFP_MAGIC 0x56465001
#define VFP_STORAGE_SIZE sizeof(struct compat_vfp_sigframe)
#define FSR_WRITE_SHIFT (11)
struct compat_aux_sigframe {
struct compat_vfp_sigframe vfp;
/* Something that isn't a valid magic number for any coprocessor. */
unsigned long end_magic;
} __attribute__((__aligned__(8)));
struct compat_sigframe {
struct compat_ucontext uc;
compat_ulong_t retcode[2];
};
struct compat_rt_sigframe {
struct compat_siginfo info;
struct compat_sigframe sig;
};
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
{
compat_sigset_t cset;
cset.sig[0] = set->sig[0] & 0xffffffffull;
cset.sig[1] = set->sig[0] >> 32;
return copy_to_user(uset, &cset, sizeof(*uset));
}
static inline int get_sigset_t(sigset_t *set,
const compat_sigset_t __user *uset)
{
compat_sigset_t s32;
if (copy_from_user(&s32, uset, sizeof(*uset)))
return -EFAULT;
set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
return 0;
}
/*
* VFP save/restore code.
*
* We have to be careful with endianness, since the fpsimd context-switch
* code operates on 128-bit (Q) register values whereas the compat ABI
* uses an array of 64-bit (D) registers. Consequently, we need to swap
* the two halves of each Q register when running on a big-endian CPU.
*/
union __fpsimd_vreg {
__uint128_t raw;
struct {
#ifdef __AARCH64EB__
u64 hi;
u64 lo;
#else
u64 lo;
u64 hi;
#endif
};
};
static int compat_preserve_vfp_context(struct compat_vfp_sigframe __user *frame)
{
struct user_fpsimd_state const *fpsimd =
&current->thread.uw.fpsimd_state;
compat_ulong_t magic = VFP_MAGIC;
compat_ulong_t size = VFP_STORAGE_SIZE;
compat_ulong_t fpscr, fpexc;
int i, err = 0;
/*
* Save the hardware registers to the fpsimd_state structure.
* Note that this also saves V16-31, which aren't visible
* in AArch32.
*/
fpsimd_signal_preserve_current_state();
/* Place structure header on the stack */
__put_user_error(magic, &frame->magic, err);
__put_user_error(size, &frame->size, err);
/*
* Now copy the FP registers. Since the registers are packed,
* we can copy the prefix we want (V0-V15) as it is.
*/
for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
union __fpsimd_vreg vreg = {
.raw = fpsimd->vregs[i >> 1],
};
__put_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
__put_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
}
/* Create an AArch32 fpscr from the fpsr and the fpcr. */
fpscr = (fpsimd->fpsr & VFP_FPSCR_STAT_MASK) |
(fpsimd->fpcr & VFP_FPSCR_CTRL_MASK);
__put_user_error(fpscr, &frame->ufp.fpscr, err);
/*
* The exception register aren't available so we fake up a
* basic FPEXC and zero everything else.
*/
fpexc = (1 << 30);
__put_user_error(fpexc, &frame->ufp_exc.fpexc, err);
__put_user_error(0, &frame->ufp_exc.fpinst, err);
__put_user_error(0, &frame->ufp_exc.fpinst2, err);
return err ? -EFAULT : 0;
}
static int compat_restore_vfp_context(struct compat_vfp_sigframe __user *frame)
{
struct user_fpsimd_state fpsimd;
compat_ulong_t magic = VFP_MAGIC;
compat_ulong_t size = VFP_STORAGE_SIZE;
compat_ulong_t fpscr;
int i, err = 0;
__get_user_error(magic, &frame->magic, err);
__get_user_error(size, &frame->size, err);
if (err)
return -EFAULT;
if (magic != VFP_MAGIC || size != VFP_STORAGE_SIZE)
return -EINVAL;
/* Copy the FP registers into the start of the fpsimd_state. */
for (i = 0; i < ARRAY_SIZE(frame->ufp.fpregs); i += 2) {
union __fpsimd_vreg vreg;
__get_user_error(vreg.lo, &frame->ufp.fpregs[i], err);
__get_user_error(vreg.hi, &frame->ufp.fpregs[i + 1], err);
fpsimd.vregs[i >> 1] = vreg.raw;
}
/* Extract the fpsr and the fpcr from the fpscr */
__get_user_error(fpscr, &frame->ufp.fpscr, err);
fpsimd.fpsr = fpscr & VFP_FPSCR_STAT_MASK;
fpsimd.fpcr = fpscr & VFP_FPSCR_CTRL_MASK;
/*
* We don't need to touch the exception register, so
* reload the hardware state.
*/
if (!err)
fpsimd_update_current_state(&fpsimd);
return err ? -EFAULT : 0;
}
static int compat_restore_sigframe(struct pt_regs *regs,
struct compat_sigframe __user *sf)
{
int err;
sigset_t set;
struct compat_aux_sigframe __user *aux;
unsigned long psr;
err = get_sigset_t(&set, &sf->uc.uc_sigmask);
if (err == 0) {
sigdelsetmask(&set, ~_BLOCKABLE);
set_current_blocked(&set);
}
__get_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
__get_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
__get_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
__get_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
__get_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
__get_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
__get_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
__get_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
__get_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
__get_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
__get_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
__get_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
__get_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
__get_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
__get_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
__get_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
__get_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
regs->pstate = compat_psr_to_pstate(psr);
/*
* Avoid compat_sys_sigreturn() restarting.
*/
forget_syscall(regs);
err |= !valid_user_regs(&regs->user_regs, current);
aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
if (err == 0)
err |= compat_restore_vfp_context(&aux->vfp);
return err;
}
COMPAT_SYSCALL_DEFINE0(sigreturn)
{
struct pt_regs *regs = current_pt_regs();
struct compat_sigframe __user *frame;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
/*
* Since we stacked the signal on a 64-bit boundary,
* then 'sp' should be word aligned here. If it's
* not, then the user is trying to mess with us.
*/
if (regs->compat_sp & 7)
goto badframe;
frame = (struct compat_sigframe __user *)regs->compat_sp;
if (!access_ok(frame, sizeof (*frame)))
goto badframe;
if (compat_restore_sigframe(regs, frame))
goto badframe;
return regs->regs[0];
badframe:
arm64_notify_segfault(regs->compat_sp);
return 0;
}
COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
{
struct pt_regs *regs = current_pt_regs();
struct compat_rt_sigframe __user *frame;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
/*
* Since we stacked the signal on a 64-bit boundary,
* then 'sp' should be word aligned here. If it's
* not, then the user is trying to mess with us.
*/
if (regs->compat_sp & 7)
goto badframe;
frame = (struct compat_rt_sigframe __user *)regs->compat_sp;
if (!access_ok(frame, sizeof (*frame)))
goto badframe;
if (compat_restore_sigframe(regs, &frame->sig))
goto badframe;
if (compat_restore_altstack(&frame->sig.uc.uc_stack))
goto badframe;
return regs->regs[0];
badframe:
arm64_notify_segfault(regs->compat_sp);
return 0;
}
static void __user *compat_get_sigframe(struct ksignal *ksig,
struct pt_regs *regs,
int framesize)
{
compat_ulong_t sp = sigsp(regs->compat_sp, ksig);
void __user *frame;
/*
* ATPCS B01 mandates 8-byte alignment
*/
frame = compat_ptr((compat_uptr_t)((sp - framesize) & ~7));
/*
* Check that we can actually write to the signal frame.
*/
if (!access_ok(frame, framesize))
frame = NULL;
return frame;
}
static void compat_setup_return(struct pt_regs *regs, struct k_sigaction *ka,
compat_ulong_t __user *rc, void __user *frame,
int usig)
{
compat_ulong_t handler = ptr_to_compat(ka->sa.sa_handler);
compat_ulong_t retcode;
compat_ulong_t spsr = regs->pstate & ~(PSR_f | PSR_AA32_E_BIT);
int thumb;
/* Check if the handler is written for ARM or Thumb */
thumb = handler & 1;
if (thumb)
spsr |= PSR_AA32_T_BIT;
else
spsr &= ~PSR_AA32_T_BIT;
/* The IT state must be cleared for both ARM and Thumb-2 */
spsr &= ~PSR_AA32_IT_MASK;
/* Restore the original endianness */
spsr |= PSR_AA32_ENDSTATE;
if (ka->sa.sa_flags & SA_RESTORER) {
retcode = ptr_to_compat(ka->sa.sa_restorer);
} else {
/* Set up sigreturn pointer */
unsigned int idx = thumb << 1;
if (ka->sa.sa_flags & SA_SIGINFO)
idx += 3;
retcode = AARCH32_VECTORS_BASE +
AARCH32_KERN_SIGRET_CODE_OFFSET +
(idx << 2) + thumb;
}
regs->regs[0] = usig;
regs->compat_sp = ptr_to_compat(frame);
regs->compat_lr = retcode;
regs->pc = handler;
regs->pstate = spsr;
}
static int compat_setup_sigframe(struct compat_sigframe __user *sf,
struct pt_regs *regs, sigset_t *set)
{
struct compat_aux_sigframe __user *aux;
unsigned long psr = pstate_to_compat_psr(regs->pstate);
int err = 0;
__put_user_error(regs->regs[0], &sf->uc.uc_mcontext.arm_r0, err);
__put_user_error(regs->regs[1], &sf->uc.uc_mcontext.arm_r1, err);
__put_user_error(regs->regs[2], &sf->uc.uc_mcontext.arm_r2, err);
__put_user_error(regs->regs[3], &sf->uc.uc_mcontext.arm_r3, err);
__put_user_error(regs->regs[4], &sf->uc.uc_mcontext.arm_r4, err);
__put_user_error(regs->regs[5], &sf->uc.uc_mcontext.arm_r5, err);
__put_user_error(regs->regs[6], &sf->uc.uc_mcontext.arm_r6, err);
__put_user_error(regs->regs[7], &sf->uc.uc_mcontext.arm_r7, err);
__put_user_error(regs->regs[8], &sf->uc.uc_mcontext.arm_r8, err);
__put_user_error(regs->regs[9], &sf->uc.uc_mcontext.arm_r9, err);
__put_user_error(regs->regs[10], &sf->uc.uc_mcontext.arm_r10, err);
__put_user_error(regs->regs[11], &sf->uc.uc_mcontext.arm_fp, err);
__put_user_error(regs->regs[12], &sf->uc.uc_mcontext.arm_ip, err);
__put_user_error(regs->compat_sp, &sf->uc.uc_mcontext.arm_sp, err);
__put_user_error(regs->compat_lr, &sf->uc.uc_mcontext.arm_lr, err);
__put_user_error(regs->pc, &sf->uc.uc_mcontext.arm_pc, err);
__put_user_error(psr, &sf->uc.uc_mcontext.arm_cpsr, err);
__put_user_error((compat_ulong_t)0, &sf->uc.uc_mcontext.trap_no, err);
/* set the compat FSR WnR */
__put_user_error(!!(current->thread.fault_code & ESR_ELx_WNR) <<
FSR_WRITE_SHIFT, &sf->uc.uc_mcontext.error_code, err);
__put_user_error(current->thread.fault_address, &sf->uc.uc_mcontext.fault_address, err);
__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
err |= put_sigset_t(&sf->uc.uc_sigmask, set);
aux = (struct compat_aux_sigframe __user *) sf->uc.uc_regspace;
if (err == 0)
err |= compat_preserve_vfp_context(&aux->vfp);
__put_user_error(0, &aux->end_magic, err);
return err;
}
/*
* 32-bit signal handling routines called from signal.c
*/
int compat_setup_rt_frame(int usig, struct ksignal *ksig,
sigset_t *set, struct pt_regs *regs)
{
struct compat_rt_sigframe __user *frame;
int err = 0;
frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
if (!frame)
return 1;
err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
__put_user_error(0, &frame->sig.uc.uc_flags, err);
__put_user_error(0, &frame->sig.uc.uc_link, err);
err |= __compat_save_altstack(&frame->sig.uc.uc_stack, regs->compat_sp);
err |= compat_setup_sigframe(&frame->sig, regs, set);
if (err == 0) {
compat_setup_return(regs, &ksig->ka, frame->sig.retcode, frame, usig);
regs->regs[1] = (compat_ulong_t)(unsigned long)&frame->info;
regs->regs[2] = (compat_ulong_t)(unsigned long)&frame->sig.uc;
}
return err;
}
int compat_setup_frame(int usig, struct ksignal *ksig, sigset_t *set,
struct pt_regs *regs)
{
struct compat_sigframe __user *frame;
int err = 0;
frame = compat_get_sigframe(ksig, regs, sizeof(*frame));
if (!frame)
return 1;
__put_user_error(0x5ac3c35a, &frame->uc.uc_flags, err);
err |= compat_setup_sigframe(frame, regs, set);
if (err == 0)
compat_setup_return(regs, &ksig->ka, frame->retcode, frame, usig);
return err;
}
void compat_setup_restart_syscall(struct pt_regs *regs)
{
regs->regs[7] = __NR_compat_restart_syscall;
}
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