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Diffstat (limited to 'arch/x86/kernel/signal_32.c')
-rw-r--r--arch/x86/kernel/signal_32.c303
1 files changed, 154 insertions, 149 deletions
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 0157a6f0f41f..f1b117930837 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -4,32 +4,44 @@
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
*/
+#include <linux/list.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <linux/suspend.h>
#include <linux/kernel.h>
+#include <linux/ptrace.h>
#include <linux/signal.h>
+#include <linux/stddef.h>
+#include <linux/unistd.h>
#include <linux/errno.h>
+#include <linux/sched.h>
#include <linux/wait.h>
-#include <linux/unistd.h>
-#include <linux/stddef.h>
-#include <linux/personality.h>
-#include <linux/suspend.h>
-#include <linux/ptrace.h>
#include <linux/elf.h>
-#include <linux/binfmts.h>
+#include <linux/smp.h>
+#include <linux/mm.h>
+
#include <asm/processor.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/i387.h>
#include <asm/vdso.h>
-#include "sigframe_32.h"
-#define DEBUG_SIG 0
+#include "sigframe.h"
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
+#define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
+ X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
+ X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
+ X86_EFLAGS_CF)
+
+#ifdef CONFIG_X86_32
+# define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
+#else
+# define FIX_EFLAGS __FIX_EFLAGS
+#endif
+
/*
* Atomically swap in the new signal mask, and wait for a signal.
*/
@@ -46,10 +58,11 @@ sys_sigsuspend(int history0, int history1, old_sigset_t mask)
current->state = TASK_INTERRUPTIBLE;
schedule();
set_thread_flag(TIF_RESTORE_SIGMASK);
+
return -ERESTARTNOHAND;
}
-asmlinkage int
+asmlinkage int
sys_sigaction(int sig, const struct old_sigaction __user *act,
struct old_sigaction __user *oact)
{
@@ -58,10 +71,12 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
if (act) {
old_sigset_t mask;
+
if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
__get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
return -EFAULT;
+
__get_user(new_ka.sa.sa_flags, &act->sa_flags);
__get_user(mask, &act->sa_mask);
siginitset(&new_ka.sa.sa_mask, mask);
@@ -74,6 +89,7 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
__put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
return -EFAULT;
+
__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
}
@@ -81,10 +97,12 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
return ret;
}
-asmlinkage int
-sys_sigaltstack(unsigned long bx)
+asmlinkage int sys_sigaltstack(unsigned long bx)
{
- /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */
+ /*
+ * This is needed to make gcc realize it doesn't own the
+ * "struct pt_regs"
+ */
struct pt_regs *regs = (struct pt_regs *)&bx;
const stack_t __user *uss = (const stack_t __user *)bx;
stack_t __user *uoss = (stack_t __user *)regs->cx;
@@ -96,9 +114,9 @@ sys_sigaltstack(unsigned long bx)
/*
* Do a signal return; undo the signal stack.
*/
-
static int
-restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax)
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
+ unsigned long *pax)
{
unsigned int err = 0;
@@ -120,37 +138,29 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax
#define GET_SEG(seg) \
{ unsigned short tmp; \
err |= __get_user(tmp, &sc->seg); \
- loadsegment(seg,tmp); }
-
-#define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \
- X86_EFLAGS_OF | X86_EFLAGS_DF | \
- X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \
- X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF)
+ loadsegment(seg, tmp); }
GET_SEG(gs);
COPY_SEG(fs);
COPY_SEG(es);
COPY_SEG(ds);
- COPY(di);
- COPY(si);
- COPY(bp);
- COPY(sp);
- COPY(bx);
- COPY(dx);
- COPY(cx);
- COPY(ip);
+ COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
+ COPY(dx); COPY(cx); COPY(ip);
COPY_SEG_STRICT(cs);
COPY_SEG_STRICT(ss);
-
+
{
unsigned int tmpflags;
+
err |= __get_user(tmpflags, &sc->flags);
- regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
+ regs->flags = (regs->flags & ~FIX_EFLAGS) |
+ (tmpflags & FIX_EFLAGS);
regs->orig_ax = -1; /* disable syscall checks */
}
{
- struct _fpstate __user * buf;
+ struct _fpstate __user *buf;
+
err |= __get_user(buf, &sc->fpstate);
if (buf) {
if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
@@ -158,6 +168,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax
err |= restore_i387(buf);
} else {
struct task_struct *me = current;
+
if (used_math()) {
clear_fpu(me);
clear_used_math();
@@ -165,24 +176,26 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax
}
}
- err |= __get_user(*peax, &sc->ax);
+ err |= __get_user(*pax, &sc->ax);
return err;
badframe:
return 1;
}
-asmlinkage int sys_sigreturn(unsigned long __unused)
+asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
{
- struct pt_regs *regs = (struct pt_regs *) &__unused;
- struct sigframe __user *frame = (struct sigframe __user *)(regs->sp - 8);
+ struct sigframe __user *frame;
+ struct pt_regs *regs;
+ unsigned long ax;
sigset_t set;
- int ax;
+
+ regs = (struct pt_regs *) &__unused;
+ 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
+ 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;
@@ -192,33 +205,35 @@ asmlinkage int sys_sigreturn(unsigned long __unused)
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
-
+
if (restore_sigcontext(regs, &frame->sc, &ax))
goto badframe;
return ax;
badframe:
if (show_unhandled_signals && printk_ratelimit()) {
- printk("%s%s[%d] bad frame in sigreturn frame:%p ip:%lx"
- " sp:%lx oeax:%lx",
+ printk(KERN_INFO "%s%s[%d] bad frame in sigreturn frame:"
+ "%p ip:%lx sp:%lx oeax:%lx",
task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
current->comm, task_pid_nr(current), frame, regs->ip,
regs->sp, regs->orig_ax);
print_vma_addr(" in ", regs->ip);
- printk("\n");
+ printk(KERN_CONT "\n");
}
force_sig(SIGSEGV, current);
+
return 0;
-}
+}
asmlinkage int sys_rt_sigreturn(unsigned long __unused)
{
- struct pt_regs *regs = (struct pt_regs *) &__unused;
- struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->sp - 4);
+ struct pt_regs *regs = (struct pt_regs *)&__unused;
+ struct rt_sigframe __user *frame;
+ unsigned long ax;
sigset_t set;
- int ax;
+ 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)))
@@ -229,7 +244,7 @@ asmlinkage int sys_rt_sigreturn(unsigned long __unused)
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
-
+
if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
goto badframe;
@@ -241,12 +256,11 @@ asmlinkage int sys_rt_sigreturn(unsigned long __unused)
badframe:
force_sig(SIGSEGV, current);
return 0;
-}
+}
/*
* Set up a signal frame.
*/
-
static int
setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
struct pt_regs *regs, unsigned long mask)
@@ -277,9 +291,9 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
tmp = save_i387(fpstate);
if (tmp < 0)
- err = 1;
+ err = 1;
else
- err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
+ err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate);
/* non-iBCS2 extensions.. */
err |= __put_user(mask, &sc->oldmask);
@@ -292,7 +306,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,
* Determine which stack to use..
*/
static inline void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
{
unsigned long sp;
@@ -310,32 +324,30 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
if (ka->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
- }
-
- /* This is the legacy signal stack switching. */
- else if ((regs->ss & 0xffff) != __USER_DS &&
- !(ka->sa.sa_flags & SA_RESTORER) &&
- ka->sa.sa_restorer) {
- sp = (unsigned long) ka->sa.sa_restorer;
+ } else {
+ /* This is the legacy signal stack switching. */
+ if ((regs->ss & 0xffff) != __USER_DS &&
+ !(ka->sa.sa_flags & SA_RESTORER) &&
+ ka->sa.sa_restorer)
+ sp = (unsigned long) ka->sa.sa_restorer;
}
sp -= frame_size;
- /* Align the stack pointer according to the i386 ABI,
- * i.e. so that on function entry ((sp + 4) & 15) == 0. */
+ /*
+ * 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;
+
return (void __user *) sp;
}
-/* These symbols are defined with the addresses in the vsyscall page.
- See vsyscall-sigreturn.S. */
-extern void __user __kernel_sigreturn;
-extern void __user __kernel_rt_sigreturn;
-
-static int setup_frame(int sig, struct k_sigaction *ka,
- sigset_t *set, struct pt_regs * regs)
+static int
+setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
+ struct pt_regs *regs)
{
- void __user *restorer;
struct sigframe __user *frame;
+ void __user *restorer;
int err = 0;
int usig;
@@ -365,7 +377,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
goto give_sigsegv;
}
- if (current->binfmt->hasvdso)
+ if (current->mm->context.vdso)
restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
else
restorer = &frame->retcode;
@@ -374,9 +386,9 @@ static int setup_frame(int sig, struct k_sigaction *ka,
/* Set up to return from userspace. */
err |= __put_user(restorer, &frame->pretcode);
-
+
/*
- * This is popl %eax ; movl $,%eax ; int $0x80
+ * 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
@@ -390,11 +402,11 @@ static int setup_frame(int sig, struct k_sigaction *ka,
goto give_sigsegv;
/* 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) 0;
- regs->cx = (unsigned long) 0;
+ 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;
@@ -407,15 +419,10 @@ static int setup_frame(int sig, struct k_sigaction *ka,
* The tracer may want to single-step inside the
* handler too.
*/
- regs->flags &= ~(TF_MASK | X86_EFLAGS_DF);
+ regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
-#if DEBUG_SIG
- printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
- current->comm, current->pid, frame, regs->ip, frame->pretcode);
-#endif
-
return 0;
give_sigsegv:
@@ -424,10 +431,10 @@ give_sigsegv:
}
static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
- sigset_t *set, struct pt_regs * regs)
+ sigset_t *set, struct pt_regs *regs)
{
- void __user *restorer;
struct rt_sigframe __user *frame;
+ void __user *restorer;
int err = 0;
int usig;
@@ -457,7 +464,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->fpstate,
- regs, set->sig[0]);
+ regs, set->sig[0]);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
@@ -467,9 +474,9 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ka->sa.sa_restorer;
err |= __put_user(restorer, &frame->pretcode);
-
+
/*
- * This is movl $,%ax ; int $0x80
+ * 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
@@ -483,11 +490,11 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
goto give_sigsegv;
/* Set up registers for signal handler */
- regs->sp = (unsigned long) frame;
- regs->ip = (unsigned long) ka->sa.sa_handler;
- regs->ax = (unsigned long) usig;
- regs->dx = (unsigned long) &frame->info;
- regs->cx = (unsigned long) &frame->uc;
+ regs->sp = (unsigned long)frame;
+ regs->ip = (unsigned long)ka->sa.sa_handler;
+ regs->ax = (unsigned long)usig;
+ regs->dx = (unsigned long)&frame->info;
+ regs->cx = (unsigned long)&frame->uc;
regs->ds = __USER_DS;
regs->es = __USER_DS;
@@ -500,15 +507,10 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
* The tracer may want to single-step inside the
* handler too.
*/
- regs->flags &= ~(TF_MASK | X86_EFLAGS_DF);
+ regs->flags &= ~(X86_EFLAGS_TF | X86_EFLAGS_DF);
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
-#if DEBUG_SIG
- printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
- current->comm, current->pid, frame, regs->ip, frame->pretcode);
-#endif
-
return 0;
give_sigsegv:
@@ -517,33 +519,33 @@ give_sigsegv:
}
/*
- * OK, we're invoking a handler
- */
-
+ * OK, we're invoking a handler:
+ */
static int
handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
- sigset_t *oldset, struct pt_regs * regs)
+ sigset_t *oldset, struct pt_regs *regs)
{
int ret;
/* Are we from a system call? */
- if (regs->orig_ax >= 0) {
+ if ((long)regs->orig_ax >= 0) {
/* If so, check system call restarting.. */
switch (regs->ax) {
- case -ERESTART_RESTARTBLOCK:
- case -ERESTARTNOHAND:
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ regs->ax = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (!(ka->sa.sa_flags & SA_RESTART)) {
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;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ regs->ax = regs->orig_ax;
+ regs->ip -= 2;
+ break;
}
}
@@ -561,16 +563,17 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
else
ret = setup_frame(sig, ka, oldset, regs);
- if (ret == 0) {
- spin_lock_irq(&current->sighand->siglock);
- sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
- if (!(ka->sa.sa_flags & SA_NODEFER))
- sigaddset(&current->blocked,sig);
- recalc_sigpending();
- spin_unlock_irq(&current->sighand->siglock);
- }
+ if (ret)
+ return ret;
- return ret;
+ spin_lock_irq(&current->sighand->siglock);
+ sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
+ if (!(ka->sa.sa_flags & SA_NODEFER))
+ sigaddset(&current->blocked, sig);
+ recalc_sigpending();
+ spin_unlock_irq(&current->sighand->siglock);
+
+ return 0;
}
/*
@@ -580,18 +583,17 @@ handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
*/
static void do_signal(struct pt_regs *regs)
{
+ struct k_sigaction ka;
siginfo_t info;
int signr;
- struct k_sigaction ka;
sigset_t *oldset;
/*
- * We want the common case to go fast, which
- * is why we may in certain cases get here from
- * kernel mode. Just return without doing anything
- * if so. vm86 regs switched out by assembly code
- * before reaching here, so testing against kernel
- * CS suffices.
+ * We want the common case to go fast, which is why we may in certain
+ * cases get here from kernel mode. Just return without doing anything
+ * if so.
+ * X86_32: vm86 regs switched out by assembly code before reaching
+ * here, so testing against kernel CS suffices.
*/
if (!user_mode(regs))
return;
@@ -603,29 +605,31 @@ static void do_signal(struct pt_regs *regs)
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
if (signr > 0) {
- /* Re-enable any watchpoints before delivering the
+ /*
+ * Re-enable any watchpoints before delivering the
* signal to user space. The processor register will
* have been cleared if the watchpoint triggered
* inside the kernel.
*/
- if (unlikely(current->thread.debugreg7))
+ if (current->thread.debugreg7)
set_debugreg(current->thread.debugreg7, 7);
- /* Whee! Actually deliver the signal. */
+ /* Whee! Actually deliver the signal. */
if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
- /* a signal was successfully delivered; the saved
+ /*
+ * a signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
* and will be restored by sigreturn, so we can simply
- * clear the TIF_RESTORE_SIGMASK flag */
+ * clear the TIF_RESTORE_SIGMASK flag
+ */
if (test_thread_flag(TIF_RESTORE_SIGMASK))
clear_thread_flag(TIF_RESTORE_SIGMASK);
}
-
return;
}
/* Did we come from a system call? */
- if (regs->orig_ax >= 0) {
+ if ((long)regs->orig_ax >= 0) {
/* Restart the system call - no handlers present */
switch (regs->ax) {
case -ERESTARTNOHAND:
@@ -642,8 +646,10 @@ static void do_signal(struct pt_regs *regs)
}
}
- /* if there's no signal to deliver, we just put the saved sigmask
- * back */
+ /*
+ * If there's no signal to deliver, we just put the saved sigmask
+ * back.
+ */
if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
clear_thread_flag(TIF_RESTORE_SIGMASK);
sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
@@ -654,13 +660,12 @@ static void do_signal(struct pt_regs *regs)
* notification of userspace execution resumption
* - triggered by the TIF_WORK_MASK flags
*/
-__attribute__((regparm(3)))
-void do_notify_resume(struct pt_regs *regs, void *_unused,
- __u32 thread_info_flags)
+void
+do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
{
/* Pending single-step? */
if (thread_info_flags & _TIF_SINGLESTEP) {
- regs->flags |= TF_MASK;
+ regs->flags |= X86_EFLAGS_TF;
clear_thread_flag(TIF_SINGLESTEP);
}
@@ -670,6 +675,6 @@ void do_notify_resume(struct pt_regs *regs, void *_unused,
if (thread_info_flags & _TIF_HRTICK_RESCHED)
hrtick_resched();
-
+
clear_thread_flag(TIF_IRET);
}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.