Commit 342300cc authored by Martin Schwidefsky's avatar Martin Schwidefsky

s390/compat: correct restore of high gprs on signal return

git commit 80703617
"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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 81f70ba2
...@@ -271,7 +271,7 @@ static int restore_sigregs_ext32(struct pt_regs *regs, ...@@ -271,7 +271,7 @@ static int restore_sigregs_ext32(struct pt_regs *regs,
/* Restore high gprs from signal stack */ /* Restore high gprs from signal stack */
if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high, if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high,
sizeof(&sregs_ext->gprs_high))) sizeof(sregs_ext->gprs_high)))
return -EFAULT; return -EFAULT;
for (i = 0; i < NUM_GPRS; i++) for (i = 0; i < NUM_GPRS; i++)
*(__u32 *)&regs->gprs[i] = gprs_high[i]; *(__u32 *)&regs->gprs[i] = gprs_high[i];
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment