diff options
| author | David Mosberger-Tang <davidm@mostang.com> | 2005-11-02 22:40:19 -0800 |
|---|---|---|
| committer | Tony Luck <tony.luck@intel.com> | 2005-11-08 09:58:06 -0800 |
| commit | cf20d1eafb648bf395b153cbcd0cde40f88c220a (patch) | |
| tree | b8ffb8bd95fb62738f891ace618b3727bd8dbeca | |
| parent | f093182d313edde9b1f86dbdaf40ba4da2dbd0e7 (diff) | |
[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 <David.Mosberger@acm.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
| -rw-r--r-- | arch/ia64/kernel/signal.c | 11 |
1 files changed, 5 insertions, 6 deletions
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); |