x86: do_page_fault small unification
Copy the prefetch of map_sem from X86_64 and move the check
notify_page_fault (soon to be kprobe_handle_fault) out of
the unlikely if() statement.
This makes the X86_32|64 pagefault handlers closer to each
other.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/mm/fault_32.c b/arch/x86/mm/fault_32.c
index 36cb67e..52c13d2 100644
--- a/arch/x86/mm/fault_32.c
+++ b/arch/x86/mm/fault_32.c
@@ -295,13 +295,18 @@
*/
trace_hardirqs_fixup();
+ tsk = current;
+ mm = tsk->mm;
+ prefetchw(&mm->mmap_sem);
+
/* get the address */
address = read_cr2();
- tsk = current;
-
si_code = SEGV_MAPERR;
+ if (notify_page_fault(regs))
+ return;
+
/*
* We fault-in kernel-space virtual memory on-demand. The
* 'reference' page table is init_mm.pgd.
@@ -319,8 +324,6 @@
if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
vmalloc_fault(address) >= 0)
return;
- if (notify_page_fault(regs))
- return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
@@ -328,16 +331,11 @@
goto bad_area_nosemaphore;
}
- if (notify_page_fault(regs))
- return;
-
/* It's safe to allow irq's after cr2 has been saved and the vmalloc
fault has been handled. */
if (regs->flags & (X86_EFLAGS_IF|VM_MASK))
local_irq_enable();
- mm = tsk->mm;
-
/*
* If we're in an interrupt, have no user context or are running in an
* atomic region then we must not take the fault.
diff --git a/arch/x86/mm/fault_64.c b/arch/x86/mm/fault_64.c
index 80f8436..c6b3ad5 100644
--- a/arch/x86/mm/fault_64.c
+++ b/arch/x86/mm/fault_64.c
@@ -355,6 +355,8 @@
si_code = SEGV_MAPERR;
+ if (notify_page_fault(regs))
+ return;
/*
* We fault-in kernel-space virtual memory on-demand. The
@@ -380,8 +382,6 @@
if (vmalloc_fault(address) >= 0)
return;
}
- if (notify_page_fault(regs))
- return;
/*
* Don't take the mm semaphore here. If we fixup a prefetch
* fault we could otherwise deadlock.
@@ -389,9 +389,6 @@
goto bad_area_nosemaphore;
}
- if (notify_page_fault(regs))
- return;
-
if (likely(regs->flags & X86_EFLAGS_IF))
local_irq_enable();