xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
91d1aa43d30505b0b825db8898ffc80a8eca96c7
android_kernel_xiaomi_sm8450/arch/x86/kernel/signal.c
Frederic Weisbecker 91d1aa43d3 context_tracking: New context tracking susbsystem 
Create a new subsystem that probes on kernel boundaries
to keep track of the transitions between level contexts
with two basic initial contexts: user or kernel.

This is an abstraction of some RCU code that use such tracking
to implement its userspace extended quiescent state.

We need to pull this up from RCU into this new level of indirection
because this tracking is also going to be used to implement an "on
demand" generic virtual cputime accounting. A necessary step to
shutdown the tick while still accounting the cputime.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
[ paulmck: fix whitespace error and email address. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-11-30 11:40:07 -08:00

895 lines
22 KiB
C
Raw Blame History

/*
* Copyright (C) 1991, 1992 Linus Torvalds
* Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
*
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
* 2000-2002 x86-64 support by Andi Kleen
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/tracehook.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/uaccess.h>
#include <linux/user-return-notifier.h>
#include <linux/uprobes.h>
#include <linux/context_tracking.h>
#include <asm/processor.h>
#include <asm/ucontext.h>
#include <asm/i387.h>
#include <asm/fpu-internal.h>
#include <asm/vdso.h>
#include <asm/mce.h>
#include <asm/sighandling.h>
#ifdef CONFIG_X86_64
#include <asm/proto.h>
#include <asm/ia32_unistd.h>
#include <asm/sys_ia32.h>
#endif /* CONFIG_X86_64 */
#include <asm/syscall.h>
#include <asm/syscalls.h>
#include <asm/sigframe.h>
#ifdef CONFIG_X86_32
# define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
#else
# define FIX_EFLAGS __FIX_EFLAGS
#endif
#define COPY(x) do { \
get_user_ex(regs->x, &sc->x); \
} while (0)
#define GET_SEG(seg) ({ \
unsigned short tmp; \
get_user_ex(tmp, &sc->seg); \
tmp; \
})
#define COPY_SEG(seg) do { \
regs->seg = GET_SEG(seg); \
} while (0)
#define COPY_SEG_CPL3(seg) do { \
regs->seg = GET_SEG(seg) | 3; \
} while (0)
int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
unsigned long *pax)
{
void __user *buf;
unsigned int tmpflags;
unsigned int err = 0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
get_user_try {
#ifdef CONFIG_X86_32
set_user_gs(regs, GET_SEG(gs));
COPY_SEG(fs);
COPY_SEG(es);
COPY_SEG(ds);
#endif /* CONFIG_X86_32 */
COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
COPY(dx); COPY(cx); COPY(ip);
#ifdef CONFIG_X86_64
COPY(r8);
COPY(r9);
COPY(r10);
COPY(r11);
COPY(r12);
COPY(r13);
COPY(r14);
COPY(r15);
#endif /* CONFIG_X86_64 */
#ifdef CONFIG_X86_32
COPY_SEG_CPL3(cs);
COPY_SEG_CPL3(ss);
#else /* !CONFIG_X86_32 */
/* Kernel saves and restores only the CS segment register on signals,
* which is the bare minimum needed to allow mixed 32/64-bit code.
* App's signal handler can save/restore other segments if needed. */
COPY_SEG_CPL3(cs);
#endif /* CONFIG_X86_32 */
get_user_ex(tmpflags, &sc->flags);
regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
regs->orig_ax = -1; /* disable syscall checks */
get_user_ex(buf, &sc->fpstate);
get_user_ex(*pax, &sc->ax);
} get_user_catch(err);
err |= restore_xstate_sig(buf, config_enabled(CONFIG_X86_32));
return err;
}
int setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
struct pt_regs *regs, unsigned long mask)
{
int err = 0;
put_user_try {
#ifdef CONFIG_X86_32
put_user_ex(get_user_gs(regs), (unsigned int __user *)&sc->gs);
put_user_ex(regs->fs, (unsigned int __user *)&sc->fs);
put_user_ex(regs->es, (unsigned int __user *)&sc->es);
put_user_ex(regs->ds, (unsigned int __user *)&sc->ds);
#endif /* CONFIG_X86_32 */
put_user_ex(regs->di, &sc->di);
put_user_ex(regs->si, &sc->si);
put_user_ex(regs->bp, &sc->bp);
put_user_ex(regs->sp, &sc->sp);
put_user_ex(regs->bx, &sc->bx);
put_user_ex(regs->dx, &sc->dx);
put_user_ex(regs->cx, &sc->cx);
put_user_ex(regs->ax, &sc->ax);
#ifdef CONFIG_X86_64
put_user_ex(regs->r8, &sc->r8);
put_user_ex(regs->r9, &sc->r9);
put_user_ex(regs->r10, &sc->r10);
put_user_ex(regs->r11, &sc->r11);
put_user_ex(regs->r12, &sc->r12);
put_user_ex(regs->r13, &sc->r13);
put_user_ex(regs->r14, &sc->r14);
put_user_ex(regs->r15, &sc->r15);
#endif /* CONFIG_X86_64 */
put_user_ex(current->thread.trap_nr, &sc->trapno);
put_user_ex(current->thread.error_code, &sc->err);
put_user_ex(regs->ip, &sc->ip);
#ifdef CONFIG_X86_32
put_user_ex(regs->cs, (unsigned int __user *)&sc->cs);
put_user_ex(regs->flags, &sc->flags);
put_user_ex(regs->sp, &sc->sp_at_signal);
put_user_ex(regs->ss, (unsigned int __user *)&sc->ss);
#else /* !CONFIG_X86_32 */
put_user_ex(regs->flags, &sc->flags);
put_user_ex(regs->cs, &sc->cs);
put_user_ex(0, &sc->gs);
put_user_ex(0, &sc->fs);
#endif /* CONFIG_X86_32 */
put_user_ex(fpstate, &sc->fpstate);
/* non-iBCS2 extensions.. */
put_user_ex(mask, &sc->oldmask);
put_user_ex(current->thread.cr2, &sc->cr2);
} put_user_catch(err);
return err;
}
/*
* Set up a signal frame.
*/
/*
* Determine which stack to use..
*/
static unsigned long align_sigframe(unsigned long sp)
{
#ifdef CONFIG_X86_32
/*
* Align the stack pointer according to the i386 ABI,
* i.e. so that on function entry ((sp + 4) & 15) == 0.
*/
sp = ((sp + 4) & -16ul) - 4;
#else /* !CONFIG_X86_32 */
sp = round_down(sp, 16) - 8;
#endif
return sp;
}
static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
void __user **fpstate)
{
/* Default to using normal stack */
unsigned long math_size = 0;
unsigned long sp = regs->sp;
unsigned long buf_fx = 0;
int onsigstack = on_sig_stack(sp);
/* redzone */
if (config_enabled(CONFIG_X86_64))
sp -= 128;
if (!onsigstack) {
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (current->sas_ss_size)
sp = current->sas_ss_sp + current->sas_ss_size;
} else if (config_enabled(CONFIG_X86_32) &&
(regs->ss & 0xffff) != __USER_DS &&
!(ka->sa.sa_flags & SA_RESTORER) &&
ka->sa.sa_restorer) {
/* This is the legacy signal stack switching. */
sp = (unsigned long) ka->sa.sa_restorer;
}
}
if (used_math()) {
sp = alloc_mathframe(sp, config_enabled(CONFIG_X86_32),
&buf_fx, &math_size);
*fpstate = (void __user *)sp;
}
sp = align_sigframe(sp - frame_size);
/*
* If we are on the alternate signal stack and would overflow it, don't.
* Return an always-bogus address instead so we will die with SIGSEGV.
*/
if (onsigstack && !likely(on_sig_stack(sp)))
return (void __user *)-1L;
/* save i387 and extended state */
if (used_math() &&
save_xstate_sig(*fpstate, (void __user *)buf_fx, math_size) < 0)
return (void __user *)-1L;
return (void __user *)sp;
}
#ifdef CONFIG_X86_32
static const struct {
u16 poplmovl;
u32 val;
u16 int80;
} __attribute__((packed)) retcode = {
0xb858, /* popl %eax; movl $..., %eax */
__NR_sigreturn,
0x80cd, /* int $0x80 */
};
static const struct {
u8 movl;
u32 val;
u16 int80;
u8 pad;
} __attribute__((packed)) rt_retcode = {
0xb8, /* movl $..., %eax */
__NR_rt_sigreturn,
0x80cd, /* int $0x80 */
0
};
static int
__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
struct pt_regs *regs)
{
struct sigframe __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (__put_user(sig, &frame->sig))
return -EFAULT;
if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
return -EFAULT;
if (_NSIG_WORDS > 1) {
if (__copy_to_user(&frame->extramask, &set->sig[1],
sizeof(frame->extramask)))
return -EFAULT;
}
if (current->mm->context.vdso)
restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
else
restorer = &frame->retcode;
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
/* Set up to return from userspace. */
err |= __put_user(restorer, &frame->pretcode);
/*
* This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
*
* WE DO NOT USE IT ANY MORE! It's only left here for historical
* reasons and because gdb uses it as a signature to notice
* signal handler stack frames.
*/
err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->sp = (unsigned long)frame;
regs->ip = (unsigned long)ka->sa.sa_handler;
regs->ax = (unsigned long)sig;
regs->dx = 0;
regs->cx = 0;
regs->ds = __USER_DS;
regs->es = __USER_DS;
regs->ss = __USER_DS;
regs->cs = __USER_CS;
return 0;
}
static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
put_user_try {
put_user_ex(sig, &frame->sig);
put_user_ex(&frame->info, &frame->pinfo);
put_user_ex(&frame->uc, &frame->puc);
/* Create the ucontext. */
if (cpu_has_xsave)
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
put_user_ex(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
/* Set up to return from userspace. */
restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
put_user_ex(restorer, &frame->pretcode);
/*
* This is movl $__NR_rt_sigreturn, %ax ; int $0x80
*
* WE DO NOT USE IT ANY MORE! It's only left here for historical
* reasons and because gdb uses it as a signature to notice
* signal handler stack frames.
*/
put_user_ex(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
} put_user_catch(err);
err |= copy_siginfo_to_user(&frame->info, info);
err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->sp = (unsigned long)frame;
regs->ip = (unsigned long)ka->sa.sa_handler;
regs->ax = (unsigned long)sig;
regs->dx = (unsigned long)&frame->info;
regs->cx = (unsigned long)&frame->uc;
regs->ds = __USER_DS;
regs->es = __USER_DS;
regs->ss = __USER_DS;
regs->cs = __USER_CS;
return 0;
}
#else /* !CONFIG_X86_32 */
static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
void __user *fp = NULL;
int err = 0;
struct task_struct *me = current;
frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (ka->sa.sa_flags & SA_SIGINFO) {
if (copy_siginfo_to_user(&frame->info, info))
return -EFAULT;
}
put_user_try {
/* Create the ucontext. */
if (cpu_has_xsave)
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
put_user_ex(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
put_user_ex(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
put_user_ex(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
/* x86-64 should always use SA_RESTORER. */
if (ka->sa.sa_flags & SA_RESTORER) {
put_user_ex(ka->sa.sa_restorer, &frame->pretcode);
} else {
/* could use a vstub here */
err |= -EFAULT;
}
} put_user_catch(err);
err |= setup_sigcontext(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->di = sig;
/* In case the signal handler was declared without prototypes */
regs->ax = 0;
/* This also works for non SA_SIGINFO handlers because they expect the
next argument after the signal number on the stack. */
regs->si = (unsigned long)&frame->info;
regs->dx = (unsigned long)&frame->uc;
regs->ip = (unsigned long) ka->sa.sa_handler;
regs->sp = (unsigned long)frame;
/* Set up the CS register to run signal handlers in 64-bit mode,
even if the handler happens to be interrupting 32-bit code. */
regs->cs = __USER_CS;
return 0;
}
#endif /* CONFIG_X86_32 */
static int x32_setup_rt_frame(int sig, struct k_sigaction *ka,
siginfo_t *info, compat_sigset_t *set,
struct pt_regs *regs)
{
#ifdef CONFIG_X86_X32_ABI
struct rt_sigframe_x32 __user *frame;
void __user *restorer;
int err = 0;
void __user *fpstate = NULL;
frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;
if (ka->sa.sa_flags & SA_SIGINFO) {
if (copy_siginfo_to_user32(&frame->info, info))
return -EFAULT;
}
put_user_try {
/* Create the ucontext. */
if (cpu_has_xsave)
put_user_ex(UC_FP_XSTATE, &frame->uc.uc_flags);
else
put_user_ex(0, &frame->uc.uc_flags);
put_user_ex(0, &frame->uc.uc_link);
put_user_ex(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
put_user_ex(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
put_user_ex(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
put_user_ex(0, &frame->uc.uc__pad0);
if (ka->sa.sa_flags & SA_RESTORER) {
restorer = ka->sa.sa_restorer;
} else {
/* could use a vstub here */
restorer = NULL;
err |= -EFAULT;
}
put_user_ex(restorer, &frame->pretcode);
} put_user_catch(err);
err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
return -EFAULT;
/* Set up registers for signal handler */
regs->sp = (unsigned long) frame;
regs->ip = (unsigned long) ka->sa.sa_handler;
/* We use the x32 calling convention here... */
regs->di = sig;
regs->si = (unsigned long) &frame->info;
regs->dx = (unsigned long) &frame->uc;
loadsegment(ds, __USER_DS);
loadsegment(es, __USER_DS);
regs->cs = __USER_CS;
regs->ss = __USER_DS;
#endif /* CONFIG_X86_X32_ABI */
return 0;
}
#ifdef CONFIG_X86_32
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
asmlinkage int
sys_sigsuspend(int history0, int history1, old_sigset_t mask)
{
sigset_t blocked;
siginitset(&blocked, mask);
return sigsuspend(&blocked);
}
asmlinkage int
sys_sigaction(int sig, const struct old_sigaction __user *act,
struct old_sigaction __user *oact)
{
struct k_sigaction new_ka, old_ka;
int ret = 0;
if (act) {
old_sigset_t mask;
if (!access_ok(VERIFY_READ, act, sizeof(*act)))
return -EFAULT;
get_user_try {
get_user_ex(new_ka.sa.sa_handler, &act->sa_handler);
get_user_ex(new_ka.sa.sa_flags, &act->sa_flags);
get_user_ex(mask, &act->sa_mask);
get_user_ex(new_ka.sa.sa_restorer, &act->sa_restorer);
} get_user_catch(ret);
if (ret)
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;
put_user_try {
put_user_ex(old_ka.sa.sa_handler, &oact->sa_handler);
put_user_ex(old_ka.sa.sa_flags, &oact->sa_flags);
put_user_ex(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
put_user_ex(old_ka.sa.sa_restorer, &oact->sa_restorer);
} put_user_catch(ret);
if (ret)
return -EFAULT;
}
return ret;
}
#endif /* CONFIG_X86_32 */
long
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
struct pt_regs *regs)
{
return do_sigaltstack(uss, uoss, regs->sp);
}
/*
* Do a signal return; undo the signal stack.
*/
#ifdef CONFIG_X86_32
unsigned long sys_sigreturn(struct pt_regs *regs)
{
struct sigframe __user *frame;
unsigned long ax;
sigset_t set;
frame = (struct sigframe __user *)(regs->sp - 8);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
&& __copy_from_user(&set.sig[1], &frame->extramask,
sizeof(frame->extramask))))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->sc, &ax))
goto badframe;
return ax;
badframe:
signal_fault(regs, frame, "sigreturn");
return 0;
}
#endif /* CONFIG_X86_32 */
long sys_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe __user *frame;
unsigned long ax;
sigset_t set;
frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
goto badframe;
return ax;
badframe:
signal_fault(regs, frame, "rt_sigreturn");
return 0;
}
/*
* OK, we're invoking a handler:
*/
static int signr_convert(int sig)
{
#ifdef CONFIG_X86_32
struct thread_info *info = current_thread_info();
if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
return info->exec_domain->signal_invmap[sig];
#endif /* CONFIG_X86_32 */
return sig;
}
static int
setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
struct pt_regs *regs)
{
int usig = signr_convert(sig);
sigset_t *set = sigmask_to_save();
compat_sigset_t *cset = (compat_sigset_t *) set;
/* Set up the stack frame */
if (is_ia32_frame()) {
if (ka->sa.sa_flags & SA_SIGINFO)
return ia32_setup_rt_frame(usig, ka, info, cset, regs);
else
return ia32_setup_frame(usig, ka, cset, regs);
} else if (is_x32_frame()) {
return x32_setup_rt_frame(usig, ka, info, cset, regs);
} else {
return __setup_rt_frame(sig, ka, info, set, regs);
}
}
static void
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
struct pt_regs *regs)
{
/* Are we from a system call? */
if (syscall_get_nr(current, regs) >= 0) {
/* If so, check system call restarting.. */
switch (syscall_get_error(current, regs)) {
case -ERESTART_RESTARTBLOCK:
case -ERESTARTNOHAND:
regs->ax = -EINTR;
break;
case -ERESTARTSYS:
if (!(ka->sa.sa_flags & SA_RESTART)) {
regs->ax = -EINTR;
break;
}
/* fallthrough */
case -ERESTARTNOINTR:
regs->ax = regs->orig_ax;
regs->ip -= 2;
break;
}
}
/*
* If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
* flag so that register information in the sigcontext is correct.
*/
if (unlikely(regs->flags & X86_EFLAGS_TF) &&
likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
regs->flags &= ~X86_EFLAGS_TF;
if (setup_rt_frame(sig, ka, info, regs) < 0) {
force_sigsegv(sig, current);
return;
}
/*
* Clear the direction flag as per the ABI for function entry.
*/
regs->flags &= ~X86_EFLAGS_DF;
/*
* Clear TF when entering the signal handler, but
* notify any tracer that was single-stepping it.
* The tracer may want to single-step inside the
* handler too.
*/
regs->flags &= ~X86_EFLAGS_TF;
signal_delivered(sig, info, ka, regs,
test_thread_flag(TIF_SINGLESTEP));
}
#ifdef CONFIG_X86_32
#define NR_restart_syscall __NR_restart_syscall
#else /* !CONFIG_X86_32 */
#define NR_restart_syscall \
test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
#endif /* CONFIG_X86_32 */
/*
* 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.
*/
static void do_signal(struct pt_regs *regs)
{
struct k_sigaction ka;
siginfo_t info;
int signr;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
/* Whee! Actually deliver the signal. */
handle_signal(signr, &info, &ka, regs);
return;
}
/* Did we come from a system call? */
if (syscall_get_nr(current, regs) >= 0) {
/* Restart the system call - no handlers present */
switch (syscall_get_error(current, regs)) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->ax = regs->orig_ax;
regs->ip -= 2;
break;
case -ERESTART_RESTARTBLOCK:
regs->ax = NR_restart_syscall;
regs->ip -= 2;
break;
}
}
/*
* 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
*/
void
do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
{
user_exit();
#ifdef CONFIG_X86_MCE
/* notify userspace of pending MCEs */
if (thread_info_flags & _TIF_MCE_NOTIFY)
mce_notify_process();
#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
if (thread_info_flags & _TIF_UPROBE) {
clear_thread_flag(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);
}
if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
fire_user_return_notifiers();
user_enter();
}
void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
{
struct task_struct *me = current;
if (show_unhandled_signals && printk_ratelimit()) {
printk("%s"
"%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
me->comm, me->pid, where, frame,
regs->ip, regs->sp, regs->orig_ax);
print_vma_addr(" in ", regs->ip);
pr_cont("\n");
}
force_sig(SIGSEGV, me);
}
#ifdef CONFIG_X86_X32_ABI
asmlinkage long sys32_x32_rt_sigreturn(struct pt_regs *regs)
{
struct rt_sigframe_x32 __user *frame;
sigset_t set;
unsigned long ax;
struct pt_regs tregs;
frame = (struct rt_sigframe_x32 __user *)(regs->sp - 8);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
tregs = *regs;
if (sys32_sigaltstack(&frame->uc.uc_stack, NULL, &tregs) == -EFAULT)
goto badframe;
return ax;
badframe:
signal_fault(regs, frame, "x32 rt_sigreturn");
return 0;
}
#endif
Reference in New Issue View Git Blame Copy Permalink