Commit 25051702 authored Mar 02, 2009 by Hiroshi Shimamoto Committed by Ingo Molnar Mar 03, 2009

x86, signals: fix xine & firefox bustage



Impact: fix bad frame in rt_sigreturn on 64-bit

After commit 97286a2b some applications
fail to return from signal handler:

[  145.150133] firefox[3250] bad frame in rt_sigreturn frame:00007f902b44eb28 ip:352e80b307 sp:7f902b44ef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000]
[  665.519017] firefox[5420] bad frame in rt_sigreturn frame:00007faa8deaeb28 ip:352e80b307 sp:7faa8deaef70 orax:ffffffffffffffff in libpthread-2.9.so[352e800000+17000]

The root cause is forgetting to keep 64 byte aligned value of
fpstate for next stack pointer calculation.

Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
LKML-Reference: <49AC85C1.7060600@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

parent 1fae0279

arch/x86/kernel/signal.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -240,11 +240,10 @@ get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size,

		if (used_math()) {
		sp -= sig_xstate_size;
		#ifdef CONFIG_X86_32
		#ifdef CONFIG_X86_64
		sp = round_down(sp, 64);
		#endif /* CONFIG_X86_64 */
		fpstate = (void __user )sp;
		#else /* !CONFIG_X86_32 */
		fpstate = (void __user )round_down(sp, 64);
		#endif /* CONFIG_X86_32 */

		if (save_i387_xstate(*fpstate) < 0)
		return (void __user *)-1L;

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