s390: fix system call restart after inferior call

Git commit 616498813b11ffef "s390: system call path micro optimization"
introduced a regression in regard to system call restarting and inferior
function calls via the ptrace interface. The pointer to the system call
table needs to be loaded in sysc_sigpending if do_signal returns with
TIF_SYSCALl set after it restored a system call context.

Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 2 insertions, 0 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index cc30d1fb000c..0dc2b6d0a1ec 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -266,6 +266,7 @@ sysc_sigpending:
         tm      __TI_flags+3(%r12),_TIF_SYSCALL
         jno     sysc_return
         lm      %r2,%r7,__PT_R2(%r11)   # load svc arguments
+        l       %r10,__TI_sysc_table(%r12)      # 31 bit system call table
         xr      %r8,%r8                 # svc 0 returns -ENOSYS
         clc     __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2)
         jnl     sysc_nr_ok              # invalid svc number -> do svc 0
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 2b2188b97c6a..e5b43c97a834 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -297,6 +297,7 @@ sysc_sigpending:
         tm      __TI_flags+7(%r12),_TIF_SYSCALL
         jno     sysc_return
         lmg     %r2,%r7,__PT_R2(%r11)   # load svc arguments
+        lg      %r10,__TI_sysc_table(%r12)      # address of system call table
         lghi    %r8,0                   # svc 0 returns -ENOSYS
         llgh    %r1,__PT_INT_CODE+2(%r11)       # load new svc number
         cghi    %r1,NR_syscalls