From: Martin Schwidefsky Date: Fri, 19 Feb 2016 13:44:14 +0000 (+0100) Subject: s390/compat: correct restore of high gprs on signal return X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=342300cc9cd3428bc6bfe5809bfcc1b9a0f06702;p=linux-beck.git s390/compat: correct restore of high gprs on signal return git commit 8070361799ae1e3f4ef347bd10f0a508ac10acfb "s390: add support for vector extension" broke 31-bit compat processes in regard to signal handling. The restore_sigregs_ext32() function is used to restore the additional elements from the user space signal frame. Among the additional elements are the upper registers halves for 64-bit register support for 31-bit processes. The copy_from_user that is used to retrieve the high-gprs array from the user stack uses an incorrect length, 8 bytes instead of 64 bytes. This causes incorrect upper register halves to get loaded. Cc: stable@vger.kernel.org # 3.8+ Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/kernel/compat_signal.c b/arch/s390/kernel/compat_signal.c index 66c94417c0ba..4af60374eba0 100644 --- a/arch/s390/kernel/compat_signal.c +++ b/arch/s390/kernel/compat_signal.c @@ -271,7 +271,7 @@ static int restore_sigregs_ext32(struct pt_regs *regs, /* Restore high gprs from signal stack */ if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high, - sizeof(&sregs_ext->gprs_high))) + sizeof(sregs_ext->gprs_high))) return -EFAULT; for (i = 0; i < NUM_GPRS; i++) *(__u32 *)®s->gprs[i] = gprs_high[i];