From 41c2e949cb7b80c5a6247c7df97759953b0f71b5 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Tue, 7 Oct 2008 06:10:03 +0000 Subject: [PATCH] powerpc: Fix error path in kernel_thread function The powerpc 32-bit and 64-bit kernel_thread functions don't properly propagate errors being returned by the clone syscall. (In the case of error, the syscall exit code returns a positive errno in r3 and sets the CR0[SO] bit.) This patch fixes that by negating r3 if CR0[SO] is set after the syscall. Signed-off-by: Josh Poimboeuf Signed-off-by: Josh Boyer Acked-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/misc_32.S | 8 +++++--- arch/powerpc/kernel/misc_64.S | 8 +++++--- 2 files changed, 10 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index e9c8ab6eabfe..6a9b4bf0d173 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -900,8 +900,10 @@ _GLOBAL(kernel_thread) li r4,0 /* new sp (unused) */ li r0,__NR_clone sc - cmpwi 0,r3,0 /* parent or child? */ - bne 1f /* return if parent */ + bns+ 1f /* did system call indicate error? */ + neg r3,r3 /* if so, make return code negative */ +1: cmpwi 0,r3,0 /* parent or child? */ + bne 2f /* return if parent */ li r0,0 /* make top-level stack frame */ stwu r0,-16(r1) mtlr r30 /* fn addr in lr */ @@ -911,7 +913,7 @@ _GLOBAL(kernel_thread) li r0,__NR_exit /* exit if function returns */ li r3,0 sc -1: lwz r30,8(r1) +2: lwz r30,8(r1) lwz r31,12(r1) addi r1,r1,16 blr diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 4dd70cf7bb4e..3053fe5c62f2 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -426,8 +426,10 @@ _GLOBAL(kernel_thread) li r4,0 /* new sp (unused) */ li r0,__NR_clone sc - cmpdi 0,r3,0 /* parent or child? */ - bne 1f /* return if parent */ + bns+ 1f /* did system call indicate error? */ + neg r3,r3 /* if so, make return code negative */ +1: cmpdi 0,r3,0 /* parent or child? */ + bne 2f /* return if parent */ li r0,0 stdu r0,-STACK_FRAME_OVERHEAD(r1) ld r2,8(r29) @@ -438,7 +440,7 @@ _GLOBAL(kernel_thread) li r0,__NR_exit /* exit after child exits */ li r3,0 sc -1: addi r1,r1,STACK_FRAME_OVERHEAD +2: addi r1,r1,STACK_FRAME_OVERHEAD ld r29,-24(r1) ld r30,-16(r1) blr -- GitLab