[PATCH] missing audit_syscall_exit() on sigsuspend exit to signal handler

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(a)infradead.org&gt; --- linux-2.6.12/arch/ppc64/kernel/asm-offsets.c.audit 2005-08-24 23:21:51.000000000 +0100 +++ linux-2.6.12/arch/ppc64/kernel/asm-offsets.c 2005-08-24 23:34:26.000000000 +0100 @@ -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)); --- linux-2.6.12/arch/ppc64/kernel/entry.S.audit 2005-08-24 23:20:57.000000000 +0100 +++ linux-2.6.12/arch/ppc64/kernel/entry.S 2005-08-24 23:33:18.000000000 +0100 @@ -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 -- dwmw2