linux/arch/mips/kernel/signal.c

922 lines
22 KiB
C

/*
* 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) 1991, 1992 Linus Torvalds
* Copyright (C) 1994 - 2000 Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 2014, Imagination Technologies Ltd.
*/
#include <linux/cache.h>
#include <linux/context_tracking.h>
#include <linux/irqflags.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/personality.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/unistd.h>
#include <linux/uprobes.h>
#include <linux/compiler.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/tracehook.h>
#include <asm/abi.h>
#include <asm/asm.h>
#include <linux/bitops.h>
#include <asm/cacheflush.h>
#include <asm/fpu.h>
#include <asm/sim.h>
#include <asm/ucontext.h>
#include <asm/cpu-features.h>
#include <asm/war.h>
#include <asm/dsp.h>
#include <asm/inst.h>
#include <asm/msa.h>
#include "signal-common.h"
static int (*save_fp_context)(void __user *sc);
static int (*restore_fp_context)(void __user *sc);
struct sigframe {
u32 sf_ass[4]; /* argument save space for o32 */
u32 sf_pad[2]; /* Was: signal trampoline */
/* Matches struct ucontext from its uc_mcontext field onwards */
struct sigcontext sf_sc;
sigset_t sf_mask;
unsigned long long sf_extcontext[0];
};
struct rt_sigframe {
u32 rs_ass[4]; /* argument save space for o32 */
u32 rs_pad[2]; /* Was: signal trampoline */
struct siginfo rs_info;
struct ucontext rs_uc;
};
/*
* Thread saved context copy to/from a signal context presumed to be on the
* user stack, and therefore accessed with appropriate macros from uaccess.h.
*/
static int copy_fp_to_sigcontext(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
int i;
int err = 0;
int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
for (i = 0; i < NUM_FPU_REGS; i += inc) {
err |=
__put_user(get_fpr64(&current->thread.fpu.fpr[i], 0),
&fpregs[i]);
}
err |= __put_user(current->thread.fpu.fcr31, csr);
return err;
}
static int copy_fp_from_sigcontext(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
int i;
int err = 0;
int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
u64 fpr_val;
for (i = 0; i < NUM_FPU_REGS; i += inc) {
err |= __get_user(fpr_val, &fpregs[i]);
set_fpr64(&current->thread.fpu.fpr[i], 0, fpr_val);
}
err |= __get_user(current->thread.fpu.fcr31, csr);
return err;
}
/*
* Wrappers for the assembly _{save,restore}_fp_context functions.
*/
static int save_hw_fp_context(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
return _save_fp_context(fpregs, csr);
}
static int restore_hw_fp_context(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
return _restore_fp_context(fpregs, csr);
}
/*
* Extended context handling.
*/
static inline void __user *sc_to_extcontext(void __user *sc)
{
struct ucontext __user *uc;
/*
* We can just pretend the sigcontext is always embedded in a struct
* ucontext here, because the offset from sigcontext to extended
* context is the same in the struct sigframe case.
*/
uc = container_of(sc, struct ucontext, uc_mcontext);
return &uc->uc_extcontext;
}
static int save_msa_extcontext(void __user *buf)
{
struct msa_extcontext __user *msa = buf;
uint64_t val;
int i, err;
if (!thread_msa_context_live())
return 0;
/*
* Ensure that we can't lose the live MSA context between checking
* for it & writing it to memory.
*/
preempt_disable();
if (is_msa_enabled()) {
/*
* There are no EVA versions of the vector register load/store
* instructions, so MSA context has to be saved to kernel memory
* and then copied to user memory. The save to kernel memory
* should already have been done when handling scalar FP
* context.
*/
BUG_ON(IS_ENABLED(CONFIG_EVA));
err = __put_user(read_msa_csr(), &msa->csr);
err |= _save_msa_all_upper(&msa->wr);
preempt_enable();
} else {
preempt_enable();
err = __put_user(current->thread.fpu.msacsr, &msa->csr);
for (i = 0; i < NUM_FPU_REGS; i++) {
val = get_fpr64(&current->thread.fpu.fpr[i], 1);
err |= __put_user(val, &msa->wr[i]);
}
}
err |= __put_user(MSA_EXTCONTEXT_MAGIC, &msa->ext.magic);
err |= __put_user(sizeof(*msa), &msa->ext.size);
return err ? -EFAULT : sizeof(*msa);
}
static int restore_msa_extcontext(void __user *buf, unsigned int size)
{
struct msa_extcontext __user *msa = buf;
unsigned long long val;
unsigned int csr;
int i, err;
if (!IS_ENABLED(CONFIG_CPU_HAS_MSA))
return SIGSYS;
if (size != sizeof(*msa))
return -EINVAL;
err = get_user(csr, &msa->csr);
if (err)
return err;
preempt_disable();
if (is_msa_enabled()) {
/*
* There are no EVA versions of the vector register load/store
* instructions, so MSA context has to be copied to kernel
* memory and later loaded to registers. The same is true of
* scalar FP context, so FPU & MSA should have already been
* disabled whilst handling scalar FP context.
*/
BUG_ON(IS_ENABLED(CONFIG_EVA));
write_msa_csr(csr);
err |= _restore_msa_all_upper(&msa->wr);
preempt_enable();
} else {
preempt_enable();
current->thread.fpu.msacsr = csr;
for (i = 0; i < NUM_FPU_REGS; i++) {
err |= __get_user(val, &msa->wr[i]);
set_fpr64(&current->thread.fpu.fpr[i], 1, val);
}
}
return err;
}
static int save_extcontext(void __user *buf)
{
int sz;
sz = save_msa_extcontext(buf);
if (sz < 0)
return sz;
buf += sz;
/* If no context was saved then trivially return */
if (!sz)
return 0;
/* Write the end marker */
if (__put_user(END_EXTCONTEXT_MAGIC, (u32 *)buf))
return -EFAULT;
sz += sizeof(((struct extcontext *)NULL)->magic);
return sz;
}
static int restore_extcontext(void __user *buf)
{
struct extcontext ext;
int err;
while (1) {
err = __get_user(ext.magic, (unsigned int *)buf);
if (err)
return err;
if (ext.magic == END_EXTCONTEXT_MAGIC)
return 0;
err = __get_user(ext.size, (unsigned int *)(buf
+ offsetof(struct extcontext, size)));
if (err)
return err;
switch (ext.magic) {
case MSA_EXTCONTEXT_MAGIC:
err = restore_msa_extcontext(buf, ext.size);
break;
default:
err = -EINVAL;
break;
}
if (err)
return err;
buf += ext.size;
}
}
/*
* Helper routines
*/
int protected_save_fp_context(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
uint32_t __user *used_math = sc + abi->off_sc_used_math;
unsigned int used, ext_sz;
int err;
used = used_math() ? USED_FP : 0;
if (!used)
goto fp_done;
if (!test_thread_flag(TIF_32BIT_FPREGS))
used |= USED_FR1;
if (test_thread_flag(TIF_HYBRID_FPREGS))
used |= USED_HYBRID_FPRS;
/*
* EVA does not have userland equivalents of ldc1 or sdc1, so
* save to the kernel FP context & copy that to userland below.
*/
if (IS_ENABLED(CONFIG_EVA))
lose_fpu(1);
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
err = save_fp_context(sc);
unlock_fpu_owner();
} else {
unlock_fpu_owner();
err = copy_fp_to_sigcontext(sc);
}
if (likely(!err))
break;
/* touch the sigcontext and try again */
err = __put_user(0, &fpregs[0]) |
__put_user(0, &fpregs[31]) |
__put_user(0, csr);
if (err)
return err; /* really bad sigcontext */
}
fp_done:
ext_sz = err = save_extcontext(sc_to_extcontext(sc));
if (err < 0)
return err;
used |= ext_sz ? USED_EXTCONTEXT : 0;
return __put_user(used, used_math);
}
int protected_restore_fp_context(void __user *sc)
{
struct mips_abi *abi = current->thread.abi;
uint64_t __user *fpregs = sc + abi->off_sc_fpregs;
uint32_t __user *csr = sc + abi->off_sc_fpc_csr;
uint32_t __user *used_math = sc + abi->off_sc_used_math;
unsigned int used;
int err, sig = 0, tmp __maybe_unused;
err = __get_user(used, used_math);
conditional_used_math(used & USED_FP);
/*
* The signal handler may have used FPU; give it up if the program
* doesn't want it following sigreturn.
*/
if (err || !(used & USED_FP))
lose_fpu(0);
if (err)
return err;
if (!(used & USED_FP))
goto fp_done;
err = sig = fpcsr_pending(csr);
if (err < 0)
return err;
/*
* EVA does not have userland equivalents of ldc1 or sdc1, so we
* disable the FPU here such that the code below simply copies to
* the kernel FP context.
*/
if (IS_ENABLED(CONFIG_EVA))
lose_fpu(0);
while (1) {
lock_fpu_owner();
if (is_fpu_owner()) {
err = restore_fp_context(sc);
unlock_fpu_owner();
} else {
unlock_fpu_owner();
err = copy_fp_from_sigcontext(sc);
}
if (likely(!err))
break;
/* touch the sigcontext and try again */
err = __get_user(tmp, &fpregs[0]) |
__get_user(tmp, &fpregs[31]) |
__get_user(tmp, csr);
if (err)
break; /* really bad sigcontext */
}
fp_done:
if (!err && (used & USED_EXTCONTEXT))
err = restore_extcontext(sc_to_extcontext(sc));
return err ?: sig;
}
int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
int err = 0;
int i;
err |= __put_user(regs->cp0_epc, &sc->sc_pc);
err |= __put_user(0, &sc->sc_regs[0]);
for (i = 1; i < 32; i++)
err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
#ifdef CONFIG_CPU_HAS_SMARTMIPS
err |= __put_user(regs->acx, &sc->sc_acx);
#endif
err |= __put_user(regs->hi, &sc->sc_mdhi);
err |= __put_user(regs->lo, &sc->sc_mdlo);
if (cpu_has_dsp) {
err |= __put_user(mfhi1(), &sc->sc_hi1);
err |= __put_user(mflo1(), &sc->sc_lo1);
err |= __put_user(mfhi2(), &sc->sc_hi2);
err |= __put_user(mflo2(), &sc->sc_lo2);
err |= __put_user(mfhi3(), &sc->sc_hi3);
err |= __put_user(mflo3(), &sc->sc_lo3);
err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
}
/*
* Save FPU state to signal context. Signal handler
* will "inherit" current FPU state.
*/
err |= protected_save_fp_context(sc);
return err;
}
static size_t extcontext_max_size(void)
{
size_t sz = 0;
/*
* The assumption here is that between this point & the point at which
* the extended context is saved the size of the context should only
* ever be able to shrink (if the task is preempted), but never grow.
* That is, what this function returns is an upper bound on the size of
* the extended context for the current task at the current time.
*/
if (thread_msa_context_live())
sz += sizeof(struct msa_extcontext);
/* If any context is saved then we'll append the end marker */
if (sz)
sz += sizeof(((struct extcontext *)NULL)->magic);
return sz;
}
int fpcsr_pending(unsigned int __user *fpcsr)
{
int err, sig = 0;
unsigned int csr, enabled;
err = __get_user(csr, fpcsr);
enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
/*
* If the signal handler set some FPU exceptions, clear it and
* send SIGFPE.
*/
if (csr & enabled) {
csr &= ~enabled;
err |= __put_user(csr, fpcsr);
sig = SIGFPE;
}
return err ?: sig;
}
int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
unsigned long treg;
int err = 0;
int i;
/* Always make any pending restarted system calls return -EINTR */
current->restart_block.fn = do_no_restart_syscall;
err |= __get_user(regs->cp0_epc, &sc->sc_pc);
#ifdef CONFIG_CPU_HAS_SMARTMIPS
err |= __get_user(regs->acx, &sc->sc_acx);
#endif
err |= __get_user(regs->hi, &sc->sc_mdhi);
err |= __get_user(regs->lo, &sc->sc_mdlo);
if (cpu_has_dsp) {
err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
}
for (i = 1; i < 32; i++)
err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
return err ?: protected_restore_fp_context(sc);
}
void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
size_t frame_size)
{
unsigned long sp;
/* Leave space for potential extended context */
frame_size += extcontext_max_size();
/* Default to using normal stack */
sp = regs->regs[29];
/*
* FPU emulator may have it's own trampoline active just
* above the user stack, 16-bytes before the next lowest
* 16 byte boundary. Try to avoid trashing it.
*/
sp -= 32;
sp = sigsp(sp, ksig);
return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
}
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
#ifdef CONFIG_TRAD_SIGNALS
SYSCALL_DEFINE1(sigsuspend, sigset_t __user *, uset)
{
return sys_rt_sigsuspend(uset, sizeof(sigset_t));
}
#endif
#ifdef CONFIG_TRAD_SIGNALS
SYSCALL_DEFINE3(sigaction, int, sig, const struct sigaction __user *, act,
struct sigaction __user *, oact)
{
struct k_sigaction new_ka, old_ka;
int ret;
int err = 0;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)))
return -EFAULT;
err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
err |= __get_user(mask, &act->sa_mask.sig[0]);
if (err)
return -EFAULT;
siginitset(&new_ka.sa.sa_mask, mask);
}
ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
if (!ret && oact) {
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
return -EFAULT;
err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
err |= __put_user(0, &oact->sa_mask.sig[1]);
err |= __put_user(0, &oact->sa_mask.sig[2]);
err |= __put_user(0, &oact->sa_mask.sig[3]);
if (err)
return -EFAULT;
}
return ret;
}
#endif
#ifdef CONFIG_TRAD_SIGNALS
asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
{
struct sigframe __user *frame;
sigset_t blocked;
int sig;
frame = (struct sigframe __user *) regs.regs[29];
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
goto badframe;
set_current_blocked(&blocked);
sig = restore_sigcontext(&regs, &frame->sf_sc);
if (sig < 0)
goto badframe;
else if (sig)
force_sig(sig, current);
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tsyscall_exit"
:/* no outputs */
:"r" (&regs));
/* Unreached */
badframe:
force_sig(SIGSEGV, current);
}
#endif /* CONFIG_TRAD_SIGNALS */
asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
{
struct rt_sigframe __user *frame;
sigset_t set;
int sig;
frame = (struct rt_sigframe __user *) regs.regs[29];
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
if (sig < 0)
goto badframe;
else if (sig)
force_sig(sig, current);
if (restore_altstack(&frame->rs_uc.uc_stack))
goto badframe;
/*
* Don't let your children do this ...
*/
__asm__ __volatile__(
"move\t$29, %0\n\t"
"j\tsyscall_exit"
:/* no outputs */
:"r" (&regs));
/* Unreached */
badframe:
force_sig(SIGSEGV, current);
}
#ifdef CONFIG_TRAD_SIGNALS
static int setup_frame(void *sig_return, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *set)
{
struct sigframe __user *frame;
int err = 0;
frame = get_sigframe(ksig, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
return -EFAULT;
err |= setup_sigcontext(regs, &frame->sf_sc);
err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
if (err)
return -EFAULT;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to struct sigcontext
*
* $25 and c0_epc point to the signal handler, $29 points to the
* struct sigframe.
*/
regs->regs[ 4] = ksig->sig;
regs->regs[ 5] = 0;
regs->regs[ 6] = (unsigned long) &frame->sf_sc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) sig_return;
regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
current->comm, current->pid,
frame, regs->cp0_epc, regs->regs[31]);
return 0;
}
#endif
static int setup_rt_frame(void *sig_return, struct ksignal *ksig,
struct pt_regs *regs, sigset_t *set)
{
struct rt_sigframe __user *frame;
int err = 0;
frame = get_sigframe(ksig, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
return -EFAULT;
/* Create siginfo. */
err |= copy_siginfo_to_user(&frame->rs_info, &ksig->info);
/* Create the ucontext. */
err |= __put_user(0, &frame->rs_uc.uc_flags);
err |= __put_user(NULL, &frame->rs_uc.uc_link);
err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/*
* Arguments to signal handler:
*
* a0 = signal number
* a1 = 0 (should be cause)
* a2 = pointer to ucontext
*
* $25 and c0_epc point to the signal handler, $29 points to
* the struct rt_sigframe.
*/
regs->regs[ 4] = ksig->sig;
regs->regs[ 5] = (unsigned long) &frame->rs_info;
regs->regs[ 6] = (unsigned long) &frame->rs_uc;
regs->regs[29] = (unsigned long) frame;
regs->regs[31] = (unsigned long) sig_return;
regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
current->comm, current->pid,
frame, regs->cp0_epc, regs->regs[31]);
return 0;
}
struct mips_abi mips_abi = {
#ifdef CONFIG_TRAD_SIGNALS
.setup_frame = setup_frame,
#endif
.setup_rt_frame = setup_rt_frame,
.restart = __NR_restart_syscall,
.off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
.off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
.off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
.vdso = &vdso_image,
};
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
sigset_t *oldset = sigmask_to_save();
int ret;
struct mips_abi *abi = current->thread.abi;
void *vdso = current->mm->context.vdso;
/*
* If we were emulating a delay slot instruction, exit that frame such
* that addresses in the sigframe are as expected for userland and we
* don't have a problem if we reuse the thread's frame for an
* instruction within the signal handler.
*/
dsemul_thread_rollback(regs);
if (regs->regs[0]) {
switch(regs->regs[2]) {
case ERESTART_RESTARTBLOCK:
case ERESTARTNOHAND:
regs->regs[2] = EINTR;
break;
case ERESTARTSYS:
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
regs->regs[2] = EINTR;
break;
}
/* fallthrough */
case ERESTARTNOINTR:
regs->regs[7] = regs->regs[26];
regs->regs[2] = regs->regs[0];
regs->cp0_epc -= 4;
}
regs->regs[0] = 0; /* Don't deal with this again. */
}
if (sig_uses_siginfo(&ksig->ka, abi))
ret = abi->setup_rt_frame(vdso + abi->vdso->off_rt_sigreturn,
ksig, regs, oldset);
else
ret = abi->setup_frame(vdso + abi->vdso->off_sigreturn,
ksig, regs, oldset);
signal_setup_done(ret, ksig, 0);
}
static void do_signal(struct pt_regs *regs)
{
struct ksignal ksig;
if (get_signal(&ksig)) {
/* Whee! Actually deliver the signal. */
handle_signal(&ksig, regs);
return;
}
if (regs->regs[0]) {
switch (regs->regs[2]) {
case ERESTARTNOHAND:
case ERESTARTSYS:
case ERESTARTNOINTR:
regs->regs[2] = regs->regs[0];
regs->regs[7] = regs->regs[26];
regs->cp0_epc -= 4;
break;
case ERESTART_RESTARTBLOCK:
regs->regs[2] = current->thread.abi->restart;
regs->regs[7] = regs->regs[26];
regs->cp0_epc -= 4;
break;
}
regs->regs[0] = 0; /* Don't deal with this again. */
}
/*
* If there's no signal to deliver, we just put the saved sigmask
* back
*/
restore_saved_sigmask();
}
/*
* notification of userspace execution resumption
* - triggered by the TIF_WORK_MASK flags
*/
asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
__u32 thread_info_flags)
{
local_irq_enable();
user_exit();
if (thread_info_flags & _TIF_UPROBE)
uprobe_notify_resume(regs);
/* deal with pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
user_enter();
}
#ifdef CONFIG_SMP
static int smp_save_fp_context(void __user *sc)
{
return raw_cpu_has_fpu
? save_hw_fp_context(sc)
: copy_fp_to_sigcontext(sc);
}
static int smp_restore_fp_context(void __user *sc)
{
return raw_cpu_has_fpu
? restore_hw_fp_context(sc)
: copy_fp_from_sigcontext(sc);
}
#endif
static int signal_setup(void)
{
/*
* The offset from sigcontext to extended context should be the same
* regardless of the type of signal, such that userland can always know
* where to look if it wishes to find the extended context structures.
*/
BUILD_BUG_ON((offsetof(struct sigframe, sf_extcontext) -
offsetof(struct sigframe, sf_sc)) !=
(offsetof(struct rt_sigframe, rs_uc.uc_extcontext) -
offsetof(struct rt_sigframe, rs_uc.uc_mcontext)));
#ifdef CONFIG_SMP
/* For now just do the cpu_has_fpu check when the functions are invoked */
save_fp_context = smp_save_fp_context;
restore_fp_context = smp_restore_fp_context;
#else
if (cpu_has_fpu) {
save_fp_context = save_hw_fp_context;
restore_fp_context = restore_hw_fp_context;
} else {
save_fp_context = copy_fp_to_sigcontext;
restore_fp_context = copy_fp_from_sigcontext;
}
#endif /* CONFIG_SMP */
return 0;
}
arch_initcall(signal_setup);