From 86dffa4cd1a1d61fed68ab64c674d4094f2bdfe4 Mon Sep 17 00:00:00 2001 From: Shi Weihua Date: Tue, 19 Feb 2008 10:26:19 +0800 Subject: [IA64] signal(ia64_ia32): add a signal stack overflow check The similar check has been added to x86_32(i386) in commit id 83bd01024b1fdfc41d9b758e5669e80fca72df66. So we add this check to ia64_ia32 and improve it a liitle bit in that we need to check for stack overflow only when the signal is on stack. Signed-off-by: Shi Weihua Signed-off-by: Tony Luck --- arch/ia64/ia32/ia32_signal.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'arch/ia64/ia32') diff --git a/arch/ia64/ia32/ia32_signal.c b/arch/ia64/ia32/ia32_signal.c index 85e82f32e48..256a7faeda0 100644 --- a/arch/ia64/ia32/ia32_signal.c +++ b/arch/ia64/ia32/ia32_signal.c @@ -766,8 +766,19 @@ get_sigframe (struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) /* This is the X/Open sanctioned signal stack switching. */ if (ka->sa.sa_flags & SA_ONSTACK) { - if (!on_sig_stack(esp)) + int onstack = sas_ss_flags(esp); + + if (onstack == 0) esp = current->sas_ss_sp + current->sas_ss_size; + else if (onstack == SS_ONSTACK) { + /* + * 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 (!likely(on_sig_stack(esp - frame_size))) + return (void __user *) -1L; + } } /* Legacy stack switching not supported */ -- cgit v1.2.3