[POWERPC] Implement logging of unhandled signals

Implement show_unhandled_signals sysctl + support to print when a process
is killed due to unhandled signals just as i386 and x86_64 does.

Default to having it off, unlike x86 that defaults on.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 15 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index de895e6d8c62..faeb8f207ea4 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -64,6 +64,11 @@ struct rt_sigframe {
         char abigap[288];
 } __attribute__ ((aligned (16)));
 
+static const char fmt32[] = KERN_INFO \
+        "%s[%d]: bad frame in %s: %08lx nip %08lx lr %08lx\n";
+static const char fmt64[] = KERN_INFO \
+        "%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
+
 /*
  * Set up the sigcontext for the signal frame.
  */
@@ -315,6 +320,11 @@ badframe:
         printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
                regs, uc, &uc->uc_mcontext);
 #endif
+        if (show_unhandled_signals && printk_ratelimit())
+                printk(regs->msr & MSR_SF ? fmt64 : fmt32,
+                        current->comm, current->pid, "rt_sigreturn",
+                        (long)uc, regs->nip, regs->link);
+
         force_sig(SIGSEGV, current);
         return 0;
 }
@@ -398,6 +408,11 @@ badframe:
         printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
                regs, frame, newsp);
 #endif
+        if (show_unhandled_signals && printk_ratelimit())
+                printk(regs->msr & MSR_SF ? fmt64 : fmt32,
+                        current->comm, current->pid, "setup_rt_frame",
+                        (long)frame, regs->nip, regs->link);
+
         force_sigsegv(signr, current);
         return 0;
 }