From: Laurent MEYER Date: Mon, 27 Mar 2006 09:37:41 +0000 (+0200) Subject: [PATCH] powerpc: fix incorrect SA_ONSTACK behaviour for 64-bit processes X-Git-Tag: v2.6.17-rc1~165^2~19 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=11089f08d9dd8b89cd07d6f126ccb4849e3c61a3;p=linux-2.6 [PATCH] powerpc: fix incorrect SA_ONSTACK behaviour for 64-bit processes *) When setting a sighandler using sigaction() call, if the flag SA_ONSTACK is set and no alternate stack is provided via sigaltstack(), the kernel still try to install the alternate stack. This behavior is the opposite of the one which is documented in Single Unix Specifications V3. *) Also when setting an alternate stack using sigaltstack() with the flag SS_DISABLE, the kernel try to install the alternate stack on signal delivery. These two use cases makes the process crash at signal delivery. This fixes it. Signed-off-by: Laurent Meyer Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index 82ec2f3f67..27f65b9518 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -212,7 +212,7 @@ static inline void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs /* Default to using normal stack */ newsp = regs->gpr[1]; - if (ka->sa.sa_flags & SA_ONSTACK) { + if ((ka->sa.sa_flags & SA_ONSTACK) && current->sas_ss_size) { if (! on_sig_stack(regs->gpr[1])) newsp = (current->sas_ss_sp + current->sas_ss_size); }