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Diffstat (limited to 'arch/x86/kernel/signal.c')
-rw-r--r--arch/x86/kernel/signal.c147
1 files changed, 72 insertions, 75 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 4d344101806..611615a92c9 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -187,6 +187,77 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
/*
* 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 sp = regs->sp;
+ int onsigstack = on_sig_stack(sp);
+
+#ifdef CONFIG_X86_64
+ /* redzone */
+ sp -= 128;
+#endif /* CONFIG_X86_64 */
+
+ 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 {
+#ifdef CONFIG_X86_32
+ /* 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;
+#endif /* CONFIG_X86_32 */
+ }
+ }
+
+ if (used_math()) {
+ sp -= sig_xstate_size;
+#ifdef CONFIG_X86_64
+ sp = round_down(sp, 64);
+#endif /* CONFIG_X86_64 */
+ *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 state */
+ if (used_math() && save_i387_xstate(*fpstate) < 0)
+ return (void __user *)-1L;
+
+ return (void __user *)sp;
+}
+
#ifdef CONFIG_X86_32
static const struct {
u16 poplmovl;
@@ -210,54 +281,6 @@ static const struct {
0
};
-/*
- * Determine which stack to use..
- */
-static inline void __user *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
- void **fpstate)
-{
- unsigned long sp;
-
- /* Default to using normal stack */
- sp = regs->sp;
-
- /*
- * 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 (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
- return (void __user *) -1L;
-
- /* This is the X/Open sanctioned signal stack switching. */
- if (ka->sa.sa_flags & SA_ONSTACK) {
- if (sas_ss_flags(sp) == 0)
- sp = current->sas_ss_sp + current->sas_ss_size;
- } 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;
- }
-
- if (used_math()) {
- sp = sp - sig_xstate_size;
- *fpstate = (struct _fpstate *) sp;
- if (save_i387_xstate(*fpstate) < 0)
- return (void __user *)-1L;
- }
-
- sp -= frame_size;
- /*
- * 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;
-}
-
static int
__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
struct pt_regs *regs)
@@ -388,24 +411,6 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
return 0;
}
#else /* !CONFIG_X86_32 */
-/*
- * Determine which stack to use..
- */
-static void __user *
-get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
-{
- /* Default to using normal stack - redzone*/
- sp -= 128;
-
- /* This is the X/Open sanctioned signal stack switching. */
- if (ka->sa.sa_flags & SA_ONSTACK) {
- if (sas_ss_flags(sp) == 0)
- sp = current->sas_ss_sp + current->sas_ss_size;
- }
-
- return (void __user *)round_down(sp - size, 64);
-}
-
static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
@@ -414,15 +419,7 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
int err = 0;
struct task_struct *me = current;
- if (used_math()) {
- fp = get_stack(ka, regs->sp, sig_xstate_size);
- frame = (void __user *)round_down(
- (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
-
- if (save_i387_xstate(fp) < 0)
- return -EFAULT;
- } else
- frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8;
+ frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
return -EFAULT;