From: David Mosberger-Tang Date: Thu, 3 Nov 2005 06:40:19 +0000 (-0800) Subject: [IA64] align signal-frame even when not using alternate signal-stack X-Git-Tag: v2.6.15-rc1~42^2~7^2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=cf20d1eafb648bf395b153cbcd0cde40f88c220a;p=linux-2.6-omap-h63xx.git [IA64] align signal-frame even when not using alternate signal-stack At the moment, attempting to invoke a signal-handler on the normal stack is guaranteed to fail if the stack-pointer happens not to be 16-byte aligned. This is because the signal-trampoline will attempt to store fp-regs with stf.spill instructions, which will trap for misaligned addresses. This isn't terribly useful behavior. It's better to just always align the signal frame to the next lower 16-byte boundary. Signed-off-by: David Mosberger-Tang Signed-off-by: Tony Luck --- diff --git a/arch/ia64/kernel/signal.c b/arch/ia64/kernel/signal.c index 774f34b675c..58ce07efc56 100644 --- a/arch/ia64/kernel/signal.c +++ b/arch/ia64/kernel/signal.c @@ -387,15 +387,14 @@ setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, struct sigscratch *scr) { extern char __kernel_sigtramp[]; - unsigned long tramp_addr, new_rbs = 0; + unsigned long tramp_addr, new_rbs = 0, new_sp; struct sigframe __user *frame; long err; - frame = (void __user *) scr->pt.r12; + new_sp = scr->pt.r12; tramp_addr = (unsigned long) __kernel_sigtramp; - if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags((unsigned long) frame) == 0) { - frame = (void __user *) ((current->sas_ss_sp + current->sas_ss_size) - & ~(STACK_ALIGN - 1)); + if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags(new_sp) == 0) { + new_sp = current->sas_ss_sp + current->sas_ss_size; /* * We need to check for the register stack being on the signal stack * separately, because it's switched separately (memory stack is switched @@ -404,7 +403,7 @@ setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set, if (!rbs_on_sig_stack(scr->pt.ar_bspstore)) new_rbs = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1); } - frame = (void __user *) frame - ((sizeof(*frame) + STACK_ALIGN - 1) & ~(STACK_ALIGN - 1)); + frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN); if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) return force_sigsegv_info(sig, frame);