From aa770aa790f3a5f3ff568388d02aea2ef78773ec Mon Sep 17 00:00:00 2001 From: Robin Getz Date: Mon, 29 Oct 2007 18:14:15 +0800 Subject: [PATCH] Blackfin arch: Fix random crash issue found by Michael. This is fixes a problem where we could jump to the wrong address. By doing a "p0 = reti; jump (p0)". If a different, higher level interrupt came in, just before, rather than returning to the calling function, we would return to a random place in the kernel. This very elegant fix from Bernd grabs the return location off the stack, and places it into P0, so when we do a return, it goes to the correct place. Signed-off-by: Robin Getz Signed-off-by: Bryan Wu --- arch/blackfin/kernel/entry.S | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/blackfin/kernel/entry.S b/arch/blackfin/kernel/entry.S index 65c5ba4260b0..65f4e67a65c4 100644 --- a/arch/blackfin/kernel/entry.S +++ b/arch/blackfin/kernel/entry.S @@ -54,9 +54,11 @@ ENTRY(_ret_from_fork) [sp + PT_IPEND] = r0; /* do a 'fake' RTI by jumping to [RETI] * to avoid clearing supervisor mode in child - */ + */ + r0 = [sp + PT_PC]; + [sp + PT_P0] = r0; + RESTORE_ALL_SYS - p0 = reti; jump (p0); ENDPROC(_ret_from_fork) -- GitLab