[PATCH] ppc32: Kill init on unhandled synchronous signals

This is a patch that I have had in my tree for ages.  If init causes
an exception that raises a signal, such as a SIGSEGV, SIGILL or
SIGFPE, and it hasn't registered a handler for it, we don't deliver
the signal, since init doesn't get any signals that it doesn't have a
handler for.  But that means that we just return to userland and
generate the same exception again immediately.  With this patch we
print a message and kill init in this situation.

This is very useful when you have a bug in the kernel that means that
init doesn't get as far as executing its first instruction. :)
Without this patch the system hangs when it gets to starting the
userland init; with it you at least get a message giving you a clue
about what has gone wrong.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/asm-ppc/system.h b/include/asm-ppc/system.h
index 513a334..d754ab5 100644
--- a/include/asm-ppc/system.h
+++ b/include/asm-ppc/system.h
@@ -88,6 +88,7 @@ extern void *cacheable_memcpy(void *, const void *, unsigned int);
 extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
 extern void bad_page_fault(struct pt_regs *, unsigned long, int);
 extern void die(const char *, struct pt_regs *, long);
+extern void _exception(int, struct pt_regs *, int, unsigned long);
 #ifdef CONFIG_BOOKE_WDT
 extern u32 booke_wdt_enabled;
 extern u32 booke_wdt_period;