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[IA64] signal(ia64): add a signal stack overflow check

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The similar check has been added to x86_32(i386) in commit
id 83bd01024b.
So we add this check to ia64 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 <shiwh@cn.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Shi Weihua 2008-02-19 10:25:09 +08:00 committed by Tony Luck
parent bd3be240cb
commit d7a6c68a2f
1 changed files with 27 additions and 9 deletions
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36
arch/ia64/kernel/signal.c
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@ -342,15 +342,33 @@ setup_frame (int sig, struct k_sigaction *ka, siginfo_t *info, sigset_t *set,
new_sp = scr->pt.r12;
tramp_addr = (unsigned long) __kernel_sigtramp;
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
* in the kernel, register stack is switched in the signal trampoline).
*/
if (!rbs_on_sig_stack(scr->pt.ar_bspstore))
new_rbs = (current->sas_ss_sp + sizeof(long) - 1) & ~(sizeof(long) - 1);
if (ka->sa.sa_flags & SA_ONSTACK) {
int onstack = sas_ss_flags(new_sp);
if (onstack == 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 in the kernel,
* register stack is switched in the signal trampoline).
*/
if (!rbs_on_sig_stack(scr->pt.ar_bspstore))
new_rbs = ALIGN(current->sas_ss_sp,
sizeof(long));
} else if (onstack == SS_ONSTACK) {
unsigned long check_sp;
/*
* 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.
*/
check_sp = (new_sp - sizeof(*frame)) & -STACK_ALIGN;
if (!likely(on_sig_stack(check_sp)))
return force_sigsegv_info(sig, (void __user *)
check_sp);
}
}
frame = (void __user *) ((new_sp - sizeof(*frame)) & -STACK_ALIGN);