diff options
author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2009-12-07 06:51:44 -0500 |
---|---|---|
committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2009-12-07 06:51:33 -0500 |
commit | 7ecb344ae80bc03397ded3b004e06ecfe32becf9 (patch) | |
tree | 2337ff84522741e9101b9a0a4cf3045a424561d3 /arch/s390/mm/fault.c | |
parent | b11b53342773361f3353b285eb6a3fd6074e7997 (diff) |
[S390] Improve notify_page_fault implementation.
notify_page_fault does a preempt_disable/preempt_enable for each
fault generated by a kernel access to user space. If kprobes
is not active that is unnecessary since the interrupts are not
reenabled yet. To play safe repeat the kprobe_running check after
preempt_disable().
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/fault.c')
-rw-r--r-- | arch/s390/mm/fault.c | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 77108e34fc1a..fd72c269cdb4 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c | |||
@@ -52,11 +52,11 @@ | |||
52 | extern int sysctl_userprocess_debug; | 52 | extern int sysctl_userprocess_debug; |
53 | #endif | 53 | #endif |
54 | 54 | ||
55 | #ifdef CONFIG_KPROBES | 55 | static inline int notify_page_fault(struct pt_regs *regs) |
56 | static inline int notify_page_fault(struct pt_regs *regs, long err) | ||
57 | { | 56 | { |
58 | int ret = 0; | 57 | int ret = 0; |
59 | 58 | ||
59 | #ifdef CONFIG_KPROBES | ||
60 | /* kprobe_running() needs smp_processor_id() */ | 60 | /* kprobe_running() needs smp_processor_id() */ |
61 | if (!user_mode(regs)) { | 61 | if (!user_mode(regs)) { |
62 | preempt_disable(); | 62 | preempt_disable(); |
@@ -64,15 +64,9 @@ static inline int notify_page_fault(struct pt_regs *regs, long err) | |||
64 | ret = 1; | 64 | ret = 1; |
65 | preempt_enable(); | 65 | preempt_enable(); |
66 | } | 66 | } |
67 | 67 | #endif | |
68 | return ret; | 68 | return ret; |
69 | } | 69 | } |
70 | #else | ||
71 | static inline int notify_page_fault(struct pt_regs *regs, long err) | ||
72 | { | ||
73 | return 0; | ||
74 | } | ||
75 | #endif | ||
76 | 70 | ||
77 | 71 | ||
78 | /* | 72 | /* |
@@ -274,7 +268,7 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int write, | |||
274 | int si_code; | 268 | int si_code; |
275 | int fault; | 269 | int fault; |
276 | 270 | ||
277 | if (notify_page_fault(regs, error_code)) | 271 | if (notify_page_fault(regs)) |
278 | return; | 272 | return; |
279 | 273 | ||
280 | tsk = current; | 274 | tsk = current; |