[PATCH] arm: clone: restore stack pointer just after return from syscall
Filippo ARCIDIACONO
filippo.arcidiacono at st.com
Tue Dec 11 15:32:13 UTC 2012
If the syscall returns with an error the stack pointer and r4 register
are not restored because the instruction 'ldmnefd sp!, {r4}' is executed
after branching to '__error' label.
This bug has been spotted out by running './utstest clone 5' from LTP
built with -fstack-protector-all compiler flag as log below:
root at cortex-a9:/usr/tests/ltp/testcases/bin# ./utstest clone 5
stack smashing detected: ./utstest terminated()
Regression introduced by commit e58798e107d652644629a1daaa95d76430808d53
Signed-off-by: Filippo Arcidiacono <filippo.arcidiacono at st.com>
Signed-off-by: Giuseppe Di Giore <giuseppe.di-giore at st.com>
---
libc/sysdeps/linux/arm/clone.S | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/libc/sysdeps/linux/arm/clone.S b/libc/sysdeps/linux/arm/clone.S
index fdc05b8..e4101ba 100644
--- a/libc/sysdeps/linux/arm/clone.S
+++ b/libc/sysdeps/linux/arm/clone.S
@@ -111,8 +111,8 @@ __clone:
ldr r4, [sp, #12]
DO_CALL (clone)
movs a1, a1
- blt __error
ldmnefd sp!, {r4}
+ blt __error
IT(t, ne)
#if defined(__USE_BX__)
bxne lr
--
1.7.7.6
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