powerpc: Add trap_nr to thread_struct

Add thread_struct.trap_nr and use it to store the last exception
the thread experienced. In this patch, we populate the field at
various places where we force_sig_info() to the process.

This is also used in uprobes to determine if the probed instruction
caused an exception.

Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 08ffcf52a856..995f924e007f 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -133,6 +133,7 @@ static int do_sigbus(struct pt_regs *regs, unsigned long address)
         up_read(&current->mm->mmap_sem);
 
         if (user_mode(regs)) {
+                current->thread.trap_nr = BUS_ADRERR;
                 info.si_signo = SIGBUS;
                 info.si_errno = 0;
                 info.si_code = BUS_ADRERR;