s390: fix system call restart after inferior call

commit dbbfe487e5f3fc00c9fe5207d63309859704d12f upstream.

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.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 2 insertions, 0 deletions

diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 4d5e6f8a7978..32bb7bf29397 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -265,6 +265,7 @@ 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 4c17eece707e..2e3befddecee 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -293,6 +293,7 @@ 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