From 0f8f308925ebe0480bd9831d32963ee0b885e24b Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto Date: Thu, 26 Mar 2009 10:03:08 -0700 Subject: [PATCH] x86: signal: check sas_ss_size instead of sas_ss_flags() Impact: fix redundant and incorrect check Oleg Nesterov noticed wrt commit: 14fc9fb: x86: signal: check signal stack overflow properly >> No need to check SA_ONSTACK if we're already using alternate signal stack. > > Yes, but this also mean that we don't need sas_ss_flags() under > "if (!onsigstack)", Checking on_sig_stack() in sas_ss_flags() at get_sigframe() is redundant and not correct on 64 bit. To check sas_ss_size is enough. Reported-by: Oleg Nesterov Signed-off-by: Hiroshi Shimamoto Cc: roland@redhat.com LKML-Reference: <49CBB54C.5080201@ct.jp.nec.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index dfcc74ab0ab6..14425166b8e3 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -221,7 +221,7 @@ get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, if (!onsigstack) { /* This is the X/Open sanctioned signal stack switching. */ if (ka->sa.sa_flags & SA_ONSTACK) { - if (sas_ss_flags(sp) == 0) + if (current->sas_ss_size) sp = current->sas_ss_sp + current->sas_ss_size; } else { #ifdef CONFIG_X86_32