Commit 7ecb344a authored by Martin Schwidefsky's avatar Martin Schwidefsky Committed by Martin Schwidefsky
Browse files

[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: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent b11b5334
......@@ -52,11 +52,11 @@
extern int sysctl_userprocess_debug;
#endif
#ifdef CONFIG_KPROBES
static inline int notify_page_fault(struct pt_regs *regs, long err)
static inline int notify_page_fault(struct pt_regs *regs)
{
int ret = 0;
#ifdef CONFIG_KPROBES
/* kprobe_running() needs smp_processor_id() */
if (!user_mode(regs)) {
preempt_disable();
......@@ -64,15 +64,9 @@ static inline int notify_page_fault(struct pt_regs *regs, long err)
ret = 1;
preempt_enable();
}
#endif
return ret;
}
#else
static inline int notify_page_fault(struct pt_regs *regs, long err)
{
return 0;
}
#endif
/*
......@@ -274,7 +268,7 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int write,
int si_code;
int fault;
if (notify_page_fault(regs, error_code))
if (notify_page_fault(regs))
return;
tsk = current;
......
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