[PATCH 4/5] x86: signal: unify get_sigframe()

From: Hiroshi Shimamoto
Date: Fri Feb 27 2009 - 13:30:17 EST


From: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>

Impact: cleanup

Unify get_sigframe().

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@xxxxxxxxxxxxx>
---
arch/x86/kernel/signal.c | 97 +++++++++++++++++++--------------------------
1 files changed, 41 insertions(+), 56 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 951aa60..83212e3 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -187,28 +187,6 @@ setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
/*
* Set up a signal frame.
*/
-#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
-};

/*
* Determine which stack to use..
@@ -217,10 +195,13 @@ static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
void __user **fpstate)
{
- unsigned long sp;
-
/* Default to using normal stack */
- sp = regs->sp;
+ unsigned long sp = regs->sp;
+
+#ifdef CONFIG_X86_64
+ /* redzone */
+ sp -= 128;
+#endif /* CONFIG_X86_64 */

/*
* If we are on the alternate signal stack and would overflow it, don't.
@@ -234,30 +215,64 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
if (sas_ss_flags(sp) == 0)
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 = sp - sig_xstate_size;
+ sp -= sig_xstate_size;
+#ifdef CONFIG_X86_32
*fpstate = (void __user *) sp;
+#else /* !CONFIG_X86_32 */
+ *fpstate = (void __user *)round_down(sp, 64);
+#endif /* CONFIG_X86_32 */
+
if (save_i387_xstate(*fpstate) < 0)
return (void __user *)-1L;
}

sp -= frame_size;
+#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 (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)
@@ -388,36 +403,6 @@ 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_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
- void __user **fpstate)
-{
- unsigned long sp;
-
- /* Default to using normal stack - redzone */
- sp = regs->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;
- }
-
- if (used_math()) {
- sp -= sig_xstate_size;
- *fpstate = (void __user *)round_down(sp, 64);
-
- if (save_i387_xstate(*fpstate) < 0)
- return (void __user *) -1L;
- }
-
- sp -= frame_size;
- return (void __user *)round_down(sp, 16) - 8;
-}
-
static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
--
1.6.1.2

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