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Fix missing audit_syscall_exit() on ppc64 sigsuspend exit path

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When we leave sigsuspend() directly into a signal handler, we don't want
to go via the normal syscall exit path -- it'll corrupt r4 and r5 which
are supposed to be giving information to the signal handler, and it'll
give us one more single-step SIGTRAP than we need if single-stepping is
in operation.

However, we _should_ be calling audit_syscall_exit(), which would
normally get invoked in that patch. It's not wonderfully pretty, but I
suspect the best answer is just to call it directly...

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
David Woodhouse 2005-08-27 10:23:46 +01:00
parent 3c789a1905
commit 17888225c2
2 changed files with 13 additions and 4 deletions
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1
arch/ppc64/kernel/asm-offsets.c
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@ -68,6 +68,7 @@ int main(void)
DEFINE(THREAD_USED_VR, offsetof(struct thread_struct, used_vr));
#endif /* CONFIG_ALTIVEC */
DEFINE(MM, offsetof(struct task_struct, mm));
DEFINE(AUDITCONTEXT, offsetof(struct task_struct, audit_context));
DEFINE(DCACHEL1LINESIZE, offsetof(struct ppc64_caches, dline_size));
DEFINE(DCACHEL1LOGLINESIZE, offsetof(struct ppc64_caches, log_dline_size));

16
arch/ppc64/kernel/entry.S
View file

@ -276,12 +276,20 @@ _GLOBAL(ppc64_rt_sigsuspend)
_GLOBAL(ppc32_rt_sigsuspend)
bl .save_nvgprs
bl .sys32_rt_sigsuspend
/* If sigsuspend() returns zero, we are going into a signal handler */
70: cmpdi 0,r3,0
beq .ret_from_except
/* If it returned -EINTR, we need to return via syscall_exit to set
/* If it returned an error, we need to return via syscall_exit to set
the SO bit in cr0 and potentially stop for ptrace. */
b syscall_exit
bne syscall_exit
/* If sigsuspend() returns zero, we are going into a signal handler. We
may need to call audit_syscall_exit() to mark the exit from sigsuspend() */
ld r3,PACACURRENT(r13)
ld r4,AUDITCONTEXT(r3)
cmpdi 0,r4,0
beq .ret_from_except /* No audit_context: Leave immediately. */
li r4, 2 /* AUDITSC_FAILURE */
li r5,-4 /* It's always -EINTR */
bl .audit_syscall_exit
b .ret_from_except
_GLOBAL(ppc_fork)
bl .save_nvgprs