[PATCH] arm: clone: restore stack pointer just after return from syscall
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@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 Signed-off-by: Giuseppe Di Giore --- 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) movsa1, a1 - blt __error ldmnefd sp!, {r4} + blt __error IT(t, ne) #if defined(__USE_BX__) bxnelr -- 1.7.7.6 ___ uClibc mailing list uClibc@uclibc.org http://lists.busybox.net/mailman/listinfo/uclibc
Re: [PATCH] arm: clone: restore stack pointer just after return from syscall
On 11/12/2012 16.32, Filippo ARCIDIACONO wrote: > 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@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 > Signed-off-by: Giuseppe Di Giore > --- > 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) > movsa1, a1 > - blt __error > ldmnefd sp!, {r4} > + blt __error > IT(t, ne) > #if defined(__USE_BX__) > bxnelr > sneaky bug. well spotted. Applied, thanks. Carmelo ___ uClibc mailing list uClibc@uclibc.org http://lists.busybox.net/mailman/listinfo/uclibc