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linux_dsm_epyc7002/arch/parisc/kernel/signal.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

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// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/parisc/kernel/signal.c: Architecture-specific signal
* handling support.
*
* Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
* Copyright (C) 2000 Linuxcare, Inc.
*
* Based on the ia64, i386, and alpha versions.
*
* Like the IA-64, we are a recent enough port (we are *starting*
* with glibc2.2) that we do not need to support the old non-realtime
* Linux signals. Therefore we don't.
*/
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/compat.h>
#include <linux/elf.h>
#include <asm/ucontext.h>
#include <asm/rt_sigframe.h>
#include <linux/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
#include <asm/asm-offsets.h>
#ifdef CONFIG_COMPAT
#include "signal32.h"
#endif
#define DEBUG_SIG 0
#define DEBUG_SIG_LEVEL 2
#if DEBUG_SIG
#define DBG(LEVEL, ...) \
((DEBUG_SIG_LEVEL >= LEVEL) \
? printk(__VA_ARGS__) : (void) 0)
#else
#define DBG(LEVEL, ...)
#endif
/* gcc will complain if a pointer is cast to an integer of different
* size. If you really need to do this (and we do for an ELF32 user
* application in an ELF64 kernel) then you have to do a cast to an
* integer of the same size first. The A() macro accomplishes
* this. */
#define A(__x) ((unsigned long)(__x))
/*
* Do a signal return - restore sigcontext.
*/
/* Trampoline for calling rt_sigreturn() */
#define INSN_LDI_R25_0 0x34190000 /* ldi 0,%r25 (in_syscall=0) */
#define INSN_LDI_R25_1 0x34190002 /* ldi 1,%r25 (in_syscall=1) */
#define INSN_LDI_R20 0x3414015a /* ldi __NR_rt_sigreturn,%r20 */
#define INSN_BLE_SR2_R0 0xe4008200 /* be,l 0x100(%sr2,%r0),%sr0,%r31 */
#define INSN_NOP 0x08000240 /* nop */
/* For debugging */
#define INSN_DIE_HORRIBLY 0x68000ccc /* stw %r0,0x666(%sr0,%r0) */
static long
restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
{
long err = 0;
err |= __copy_from_user(regs->gr, sc->sc_gr, sizeof(regs->gr));
err |= __copy_from_user(regs->fr, sc->sc_fr, sizeof(regs->fr));
err |= __copy_from_user(regs->iaoq, sc->sc_iaoq, sizeof(regs->iaoq));
err |= __copy_from_user(regs->iasq, sc->sc_iasq, sizeof(regs->iasq));
err |= __get_user(regs->sar, &sc->sc_sar);
DBG(2,"restore_sigcontext: iaoq is %#lx / %#lx\n",
regs->iaoq[0],regs->iaoq[1]);
DBG(2,"restore_sigcontext: r28 is %ld\n", regs->gr[28]);
return err;
}
void
sys_rt_sigreturn(struct pt_regs *regs, int in_syscall)
{
struct rt_sigframe __user *frame;
sigset_t set;
unsigned long usp = (regs->gr[30] & ~(0x01UL));
unsigned long sigframe_size = PARISC_RT_SIGFRAME_SIZE;
#ifdef CONFIG_64BIT
compat_sigset_t compat_set;
struct compat_rt_sigframe __user * compat_frame;
if (is_compat_task())
sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
#endif
current->restart_block.fn = do_no_restart_syscall;
/* Unwind the user stack to get the rt_sigframe structure. */
frame = (struct rt_sigframe __user *)
(usp - sigframe_size);
DBG(2,"sys_rt_sigreturn: frame is %p\n", frame);
regs->orig_r28 = 1; /* no restarts for sigreturn */
#ifdef CONFIG_64BIT
compat_frame = (struct compat_rt_sigframe __user *)frame;
if (is_compat_task()) {
DBG(2,"sys_rt_sigreturn: ELF32 process.\n");
if (__copy_from_user(&compat_set, &compat_frame->uc.uc_sigmask, sizeof(compat_set)))
goto give_sigsegv;
sigset_32to64(&set,&compat_set);
} else
#endif
{
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto give_sigsegv;
}
set_current_blocked(&set);
/* Good thing we saved the old gr[30], eh? */
#ifdef CONFIG_64BIT
if (is_compat_task()) {
DBG(1,"sys_rt_sigreturn: compat_frame->uc.uc_mcontext 0x%p\n",
&compat_frame->uc.uc_mcontext);
// FIXME: Load upper half from register file
if (restore_sigcontext32(&compat_frame->uc.uc_mcontext,
&compat_frame->regs, regs))
goto give_sigsegv;
DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
usp, &compat_frame->uc.uc_stack);
if (compat_restore_altstack(&compat_frame->uc.uc_stack))
goto give_sigsegv;
} else
#endif
{
DBG(1,"sys_rt_sigreturn: frame->uc.uc_mcontext 0x%p\n",
&frame->uc.uc_mcontext);
if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
goto give_sigsegv;
DBG(1,"sys_rt_sigreturn: usp %#08lx stack 0x%p\n",
usp, &frame->uc.uc_stack);
if (restore_altstack(&frame->uc.uc_stack))
goto give_sigsegv;
}
/* If we are on the syscall path IAOQ will not be restored, and
* if we are on the interrupt path we must not corrupt gr31.
*/
if (in_syscall)
regs->gr[31] = regs->iaoq[0];
#if DEBUG_SIG
DBG(1,"sys_rt_sigreturn: returning to %#lx, DUMPING REGS:\n", regs->iaoq[0]);
show_regs(regs);
#endif
return;
give_sigsegv:
DBG(1,"sys_rt_sigreturn: Sending SIGSEGV\n");
force_sig(SIGSEGV, current);
return;
}
/*
* Set up a signal frame.
*/
static inline void __user *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
/*FIXME: ELF32 vs. ELF64 has different frame_size, but since we
don't use the parameter it doesn't matter */
DBG(1,"get_sigframe: ka = %#lx, sp = %#lx, frame_size = %#lx\n",
(unsigned long)ka, sp, frame_size);
/* Align alternate stack and reserve 64 bytes for the signal
handler's frame marker. */
if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
sp = (current->sas_ss_sp + 0x7f) & ~0x3f; /* Stacks grow up! */
DBG(1,"get_sigframe: Returning sp = %#lx\n", (unsigned long)sp);
return (void __user *) sp; /* Stacks grow up. Fun. */
}
static long
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, int in_syscall)
{
unsigned long flags = 0;
long err = 0;
if (on_sig_stack((unsigned long) sc))
flags |= PARISC_SC_FLAG_ONSTACK;
if (in_syscall) {
flags |= PARISC_SC_FLAG_IN_SYSCALL;
/* regs->iaoq is undefined in the syscall return path */
err |= __put_user(regs->gr[31], &sc->sc_iaoq[0]);
err |= __put_user(regs->gr[31]+4, &sc->sc_iaoq[1]);
err |= __put_user(regs->sr[3], &sc->sc_iasq[0]);
err |= __put_user(regs->sr[3], &sc->sc_iasq[1]);
DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (in syscall)\n",
regs->gr[31], regs->gr[31]+4);
} else {
err |= __copy_to_user(sc->sc_iaoq, regs->iaoq, sizeof(regs->iaoq));
err |= __copy_to_user(sc->sc_iasq, regs->iasq, sizeof(regs->iasq));
DBG(1,"setup_sigcontext: iaoq %#lx / %#lx (not in syscall)\n",
regs->iaoq[0], regs->iaoq[1]);
}
err |= __put_user(flags, &sc->sc_flags);
err |= __copy_to_user(sc->sc_gr, regs->gr, sizeof(regs->gr));
err |= __copy_to_user(sc->sc_fr, regs->fr, sizeof(regs->fr));
err |= __put_user(regs->sar, &sc->sc_sar);
DBG(1,"setup_sigcontext: r28 is %ld\n", regs->gr[28]);
return err;
}
static long
setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs,
int in_syscall)
{
struct rt_sigframe __user *frame;
unsigned long rp, usp;
unsigned long haddr, sigframe_size;
unsigned long start, end;
int err = 0;
#ifdef CONFIG_64BIT
struct compat_rt_sigframe __user * compat_frame;
compat_sigset_t compat_set;
#endif
usp = (regs->gr[30] & ~(0x01UL));
/*FIXME: frame_size parameter is unused, remove it. */
frame = get_sigframe(&ksig->ka, usp, sizeof(*frame));
DBG(1,"SETUP_RT_FRAME: START\n");
DBG(1,"setup_rt_frame: frame %p info %p\n", frame, ksig->info);
#ifdef CONFIG_64BIT
compat_frame = (struct compat_rt_sigframe __user *)frame;
if (is_compat_task()) {
DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &compat_frame->info);
err |= copy_siginfo_to_user32(&compat_frame->info, &ksig->info);
err |= __compat_save_altstack( &compat_frame->uc.uc_stack, regs->gr[30]);
DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &compat_frame->uc);
DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &compat_frame->uc.uc_mcontext);
err |= setup_sigcontext32(&compat_frame->uc.uc_mcontext,
&compat_frame->regs, regs, in_syscall);
sigset_64to32(&compat_set,set);
err |= __copy_to_user(&compat_frame->uc.uc_sigmask, &compat_set, sizeof(compat_set));
} else
#endif
{
DBG(1,"setup_rt_frame: frame->info = 0x%p\n", &frame->info);
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
err |= __save_altstack(&frame->uc.uc_stack, regs->gr[30]);
DBG(1,"setup_rt_frame: frame->uc = 0x%p\n", &frame->uc);
DBG(1,"setup_rt_frame: frame->uc.uc_mcontext = 0x%p\n", &frame->uc.uc_mcontext);
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, in_syscall);
/* FIXME: Should probably be converted as well for the compat case */
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
}
if (err)
return -EFAULT;
/* Set up to return from userspace. If provided, use a stub
already in userspace. The first words of tramp are used to
save the previous sigrestartblock trampoline that might be
on the stack. We start the sigreturn trampoline at
SIGRESTARTBLOCK_TRAMP+X. */
err |= __put_user(in_syscall ? INSN_LDI_R25_1 : INSN_LDI_R25_0,
&frame->tramp[SIGRESTARTBLOCK_TRAMP+0]);
err |= __put_user(INSN_LDI_R20,
&frame->tramp[SIGRESTARTBLOCK_TRAMP+1]);
err |= __put_user(INSN_BLE_SR2_R0,
&frame->tramp[SIGRESTARTBLOCK_TRAMP+2]);
err |= __put_user(INSN_NOP, &frame->tramp[SIGRESTARTBLOCK_TRAMP+3]);
#if DEBUG_SIG
/* Assert that we're flushing in the correct space... */
{
unsigned long sid;
asm ("mfsp %%sr3,%0" : "=r" (sid));
DBG(1,"setup_rt_frame: Flushing 64 bytes at space %#x offset %p\n",
sid, frame->tramp);
}
#endif
start = (unsigned long) &frame->tramp[0];
end = (unsigned long) &frame->tramp[TRAMP_SIZE];
flush_user_dcache_range_asm(start, end);
flush_user_icache_range_asm(start, end);
/* TRAMP Words 0-4, Length 5 = SIGRESTARTBLOCK_TRAMP
* TRAMP Words 5-9, Length 4 = SIGRETURN_TRAMP
* So the SIGRETURN_TRAMP is at the end of SIGRESTARTBLOCK_TRAMP
*/
rp = (unsigned long) &frame->tramp[SIGRESTARTBLOCK_TRAMP];
if (err)
return -EFAULT;
haddr = A(ksig->ka.sa.sa_handler);
/* The sa_handler may be a pointer to a function descriptor */
#ifdef CONFIG_64BIT
if (is_compat_task()) {
#endif
if (haddr & PA_PLABEL_FDESC) {
Elf32_Fdesc fdesc;
Elf32_Fdesc __user *ufdesc = (Elf32_Fdesc __user *)A(haddr & ~3);
err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
if (err)
return -EFAULT;
haddr = fdesc.addr;
regs->gr[19] = fdesc.gp;
}
#ifdef CONFIG_64BIT
} else {
Elf64_Fdesc fdesc;
Elf64_Fdesc __user *ufdesc = (Elf64_Fdesc __user *)A(haddr & ~3);
err = __copy_from_user(&fdesc, ufdesc, sizeof(fdesc));
if (err)
return -EFAULT;
haddr = fdesc.addr;
regs->gr[19] = fdesc.gp;
DBG(1,"setup_rt_frame: 64 bit signal, exe=%#lx, r19=%#lx, in_syscall=%d\n",
haddr, regs->gr[19], in_syscall);
}
#endif
/* The syscall return path will create IAOQ values from r31.
*/
sigframe_size = PARISC_RT_SIGFRAME_SIZE;
#ifdef CONFIG_64BIT
if (is_compat_task())
sigframe_size = PARISC_RT_SIGFRAME_SIZE32;
#endif
if (in_syscall) {
regs->gr[31] = haddr;
#ifdef CONFIG_64BIT
if (!test_thread_flag(TIF_32BIT))
sigframe_size |= 1;
#endif
} else {
unsigned long psw = USER_PSW;
#ifdef CONFIG_64BIT
if (!test_thread_flag(TIF_32BIT))
psw |= PSW_W;
#endif
/* If we are singlestepping, arrange a trap to be delivered
when we return to userspace. Note the semantics -- we
should trap before the first insn in the handler is
executed. Ref:
http://sources.redhat.com/ml/gdb/2004-11/msg00245.html
*/
if (pa_psw(current)->r) {
pa_psw(current)->r = 0;
psw |= PSW_R;
mtctl(-1, 0);
}
regs->gr[0] = psw;
regs->iaoq[0] = haddr | 3;
regs->iaoq[1] = regs->iaoq[0] + 4;
}
regs->gr[2] = rp; /* userland return pointer */
regs->gr[26] = ksig->sig; /* signal number */
#ifdef CONFIG_64BIT
if (is_compat_task()) {
regs->gr[25] = A(&compat_frame->info); /* siginfo pointer */
regs->gr[24] = A(&compat_frame->uc); /* ucontext pointer */
} else
#endif
{
regs->gr[25] = A(&frame->info); /* siginfo pointer */
regs->gr[24] = A(&frame->uc); /* ucontext pointer */
}
DBG(1,"setup_rt_frame: making sigreturn frame: %#lx + %#lx = %#lx\n",
regs->gr[30], sigframe_size,
regs->gr[30] + sigframe_size);
/* Raise the user stack pointer to make a proper call frame. */
regs->gr[30] = (A(frame) + sigframe_size);
DBG(1,"setup_rt_frame: sig deliver (%s,%d) frame=0x%p sp=%#lx iaoq=%#lx/%#lx rp=%#lx\n",
current->comm, current->pid, frame, regs->gr[30],
regs->iaoq[0], regs->iaoq[1], rp);
return 0;
}
/*
* OK, we're invoking a handler.
*/
static void
handle_signal(struct ksignal *ksig, struct pt_regs *regs, int in_syscall)
{
int ret;
sigset_t *oldset = sigmask_to_save();
DBG(1,"handle_signal: sig=%ld, ka=%p, info=%p, oldset=%p, regs=%p\n",
ksig->sig, ksig->ka, ksig->info, oldset, regs);
/* Set up the stack frame */
ret = setup_rt_frame(ksig, oldset, regs, in_syscall);
signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP) ||
test_thread_flag(TIF_BLOCKSTEP));
DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
regs->gr[28]);
}
/*
* Check how the syscall number gets loaded into %r20 within
* the delay branch in userspace and adjust as needed.
*/
static void check_syscallno_in_delay_branch(struct pt_regs *regs)
{
u32 opcode, source_reg;
u32 __user *uaddr;
int err;
/* Usually we don't have to restore %r20 (the system call number)
* because it gets loaded in the delay slot of the branch external
* instruction via the ldi instruction.
* In some cases a register-to-register copy instruction might have
* been used instead, in which case we need to copy the syscall
* number into the source register before returning to userspace.
*/
/* A syscall is just a branch, so all we have to do is fiddle the
* return pointer so that the ble instruction gets executed again.
*/
regs->gr[31] -= 8; /* delayed branching */
/* Get assembler opcode of code in delay branch */
uaddr = (unsigned int *) ((regs->gr[31] & ~3) + 4);
err = get_user(opcode, uaddr);
if (err)
return;
/* Check if delay branch uses "ldi int,%r20" */
if ((opcode & 0xffff0000) == 0x34140000)
return; /* everything ok, just return */
/* Check if delay branch uses "nop" */
if (opcode == INSN_NOP)
return;
/* Check if delay branch uses "copy %rX,%r20" */
if ((opcode & 0xffe0ffff) == 0x08000254) {
source_reg = (opcode >> 16) & 31;
regs->gr[source_reg] = regs->gr[20];
return;
}
pr_warn("syscall restart: %s (pid %d): unexpected opcode 0x%08x\n",
current->comm, task_pid_nr(current), opcode);
}
static inline void
syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
{
if (regs->orig_r28)
return;
regs->orig_r28 = 1; /* no more restarts */
/* Check the return code */
switch (regs->gr[28]) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
regs->gr[28] = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
DBG(1,"ERESTARTSYS: putting -EINTR\n");
regs->gr[28] = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
check_syscallno_in_delay_branch(regs);
break;
}
}
static inline void
insert_restart_trampoline(struct pt_regs *regs)
{
if (regs->orig_r28)
return;
regs->orig_r28 = 1; /* no more restarts */
switch(regs->gr[28]) {
case -ERESTART_RESTARTBLOCK: {
/* Restart the system call - no handlers present */
unsigned int *usp = (unsigned int *)regs->gr[30];
unsigned long start = (unsigned long) &usp[2];
unsigned long end = (unsigned long) &usp[5];
long err = 0;
/* Setup a trampoline to restart the syscall
* with __NR_restart_syscall
*
* 0: <return address (orig r31)>
* 4: <2nd half for 64-bit>
* 8: ldw 0(%sp), %r31
* 12: be 0x100(%sr2, %r0)
* 16: ldi __NR_restart_syscall, %r20
*/
#ifdef CONFIG_64BIT
err |= put_user(regs->gr[31] >> 32, &usp[0]);
err |= put_user(regs->gr[31] & 0xffffffff, &usp[1]);
err |= put_user(0x0fc010df, &usp[2]);
#else
err |= put_user(regs->gr[31], &usp[0]);
err |= put_user(0x0fc0109f, &usp[2]);
#endif
err |= put_user(0xe0008200, &usp[3]);
err |= put_user(0x34140000, &usp[4]);
WARN_ON(err);
/* flush data/instruction cache for new insns */
flush_user_dcache_range_asm(start, end);
flush_user_icache_range_asm(start, end);
regs->gr[31] = regs->gr[30] + 8;
return;
}
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
check_syscallno_in_delay_branch(regs);
return;
default:
break;
}
}
/*
* Note that 'init' is a special process: it doesn't get signals it doesn't
* want to handle. Thus you cannot kill init even with a SIGKILL even by
* mistake.
*
* We need to be able to restore the syscall arguments (r21-r26) to
* restart syscalls. Thus, the syscall path should save them in the
* pt_regs structure (it's okay to do so since they are caller-save
* registers). As noted below, the syscall number gets restored for
* us due to the magic of delayed branching.
*/
asmlinkage void
do_signal(struct pt_regs *regs, long in_syscall)
{
struct ksignal ksig;
DBG(1,"\ndo_signal: regs=0x%p, sr7 %#lx, in_syscall=%d\n",
regs, regs->sr[7], in_syscall);
if (get_signal(&ksig)) {
DBG(3,"do_signal: signr = %d, regs->gr[28] = %ld\n", signr, regs->gr[28]);
/* Restart a system call if necessary. */
if (in_syscall)
syscall_restart(regs, &ksig.ka);
handle_signal(&ksig, regs, in_syscall);
return;
}
/* Did we come from a system call? */
if (in_syscall)
insert_restart_trampoline(regs);
DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n",
regs->gr[28]);
restore_saved_sigmask();
}
void do_notify_resume(struct pt_regs *regs, long in_syscall)
{
if (test_thread_flag(TIF_SIGPENDING))
do_signal(regs, in_syscall);
if (test_thread_flag(TIF_NOTIFY_RESUME)) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
}
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