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authorLinus Torvalds <torvalds@linux-foundation.org>2008-05-08 19:03:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-08 19:03:19 -0700
commit89f92d6425b099538932e9b881588f87ef9f3184 (patch)
treed60eef7715df2a34459fc118fd59f7f8701cf7fd
parent8d539108560ec121d59eee05160236488266221c (diff)
parentdc5dc7e6d71ca9fd1ea01a1418150af3b2937489 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc: Fix SA_ONSTACK signal handling.
-rw-r--r--arch/sparc/kernel/signal.c20
-rw-r--r--arch/sparc64/kernel/signal.c21
-rw-r--r--arch/sparc64/kernel/signal32.c18
3 files changed, 51 insertions, 8 deletions
diff --git a/arch/sparc/kernel/signal.c b/arch/sparc/kernel/signal.c
index 3c312290c3c..368157926d2 100644
--- a/arch/sparc/kernel/signal.c
+++ b/arch/sparc/kernel/signal.c
@@ -245,15 +245,29 @@ static inline int invalid_frame_pointer(void __user *fp, int fplen)
static inline void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, unsigned long framesize)
{
- unsigned long sp;
+ unsigned long sp = regs->u_regs[UREG_FP];
- sp = regs->u_regs[UREG_FP];
+ /*
+ * 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 - framesize)))
+ return (void __user *) -1L;
/* This is the X/Open sanctioned signal stack switching. */
if (sa->sa_flags & SA_ONSTACK) {
- if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))
+ if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
+
+ /* Always align the stack frame. This handles two cases. First,
+ * sigaltstack need not be mindful of platform specific stack
+ * alignment. Second, if we took this signal because the stack
+ * is not aligned properly, we'd like to take the signal cleanly
+ * and report that.
+ */
+ sp &= ~7UL;
+
return (void __user *)(sp - framesize);
}
diff --git a/arch/sparc64/kernel/signal.c b/arch/sparc64/kernel/signal.c
index 45d6bf632da..07c0443ea3f 100644
--- a/arch/sparc64/kernel/signal.c
+++ b/arch/sparc64/kernel/signal.c
@@ -376,16 +376,29 @@ save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
{
- unsigned long sp;
+ unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
- sp = regs->u_regs[UREG_FP] + STACK_BIAS;
+ /*
+ * 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 - framesize)))
+ return (void __user *) -1L;
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
- if (!on_sig_stack(sp) &&
- !((current->sas_ss_sp + current->sas_ss_size) & 7))
+ if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
+
+ /* Always align the stack frame. This handles two cases. First,
+ * sigaltstack need not be mindful of platform specific stack
+ * alignment. Second, if we took this signal because the stack
+ * is not aligned properly, we'd like to take the signal cleanly
+ * and report that.
+ */
+ sp &= ~7UL;
+
return (void __user *)(sp - framesize);
}
diff --git a/arch/sparc64/kernel/signal32.c b/arch/sparc64/kernel/signal32.c
index 9415d2c918c..0f6b7b156ef 100644
--- a/arch/sparc64/kernel/signal32.c
+++ b/arch/sparc64/kernel/signal32.c
@@ -406,11 +406,27 @@ static void __user *get_sigframe(struct sigaction *sa, struct pt_regs *regs, uns
regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
sp = regs->u_regs[UREG_FP];
+ /*
+ * 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 - framesize)))
+ return (void __user *) -1L;
+
/* This is the X/Open sanctioned signal stack switching. */
if (sa->sa_flags & SA_ONSTACK) {
- if (!on_sig_stack(sp) && !((current->sas_ss_sp + current->sas_ss_size) & 7))
+ if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
+
+ /* Always align the stack frame. This handles two cases. First,
+ * sigaltstack need not be mindful of platform specific stack
+ * alignment. Second, if we took this signal because the stack
+ * is not aligned properly, we'd like to take the signal cleanly
+ * and report that.
+ */
+ sp &= ~7UL;
+
return (void __user *)(sp - framesize);
}