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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2012-10-09 13:33:53 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-10-09 14:17:02 +0200
commit450e47da67499aeb6f1700e8f84747460c11ab56 (patch)
tree1b08137d04483cf5b352d4b848a368a409d06209
parentfc7e48aad35bf98c84cf21aed5c2f100c5ce009b (diff)
s390/entry: fix svc number for TIF_SYSCALL system call restart
The load of the svc number in the TIF_SYSCALL restart path needs to be done with an instruction that loads all 64 bits of %r1, 'lh' only loads 32 bits. If the upper half of %r1 is not zero and has the msb set, entry64.S will try to execute an svc with a really large number. What will be in the upper half of %r1 depends on the code generated by gcc for the functions on the do_signal() callchain. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/kernel/entry64.S2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 7549985402f7..8f211ad1c695 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -295,7 +295,7 @@ sysc_sigpending:
jno sysc_return
lmg %r2,%r7,__PT_R2(%r11) # load svc arguments
lghi %r8,0 # svc 0 returns -ENOSYS
- lh %r1,__PT_INT_CODE+2(%r11) # load new svc number
+ llgh %r1,__PT_INT_CODE+2(%r11) # load new svc number
cghi %r1,NR_syscalls
jnl sysc_nr_ok # invalid svc number -> do svc 0
slag %r8,%r1,2