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 <[EMAIL PROTECTED]>
---
Ingo, I'll go back to the zero changes unifications now, just
wanted to send the last few for comment as they will eventually
need to be dealt with.
arch/x86/mm/fault_32.c | 16 +++++++---------
arch/x86/mm/fault_64.c | 7 ++-----
2 files changed, 9 insertions(+), 14 deletions(-)
diff --git a/arch/x86/mm/fault_32.c b/arch/x86/mm/fault_32.c
index f8fc240..363267a 100644
--- a/arch/x86/mm/fault_32.c
+++ b/arch/x86/mm/fault_32.c
@@ -306,13 +306,18 @@ void __kprobes do_page_fault(struct pt_regs *regs,
unsigned long error_code)
*/
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.
@@ -330,8 +335,6 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned
long error_code)
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.
@@ -339,16 +342,11 @@ void __kprobes do_page_fault(struct pt_regs *regs,
unsigned long error_code)
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 11e9398..128f812 100644
--- a/arch/x86/mm/fault_64.c
+++ b/arch/x86/mm/fault_64.c
@@ -366,6 +366,8 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs
*regs,
si_code = SEGV_MAPERR;
+ if (notify_page_fault(regs))
+ return;
/*
* We fault-in kernel-space virtual memory on-demand. The
@@ -391,8 +393,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs
*regs,
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.
@@ -400,9 +400,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs
*regs,
goto bad_area_nosemaphore;
}
- if (notify_page_fault(regs))
- return;
-
if (likely(regs->flags & X86_EFLAGS_IF))
local_irq_enable();
--
1.5.4.rc2.1164.g6451
--
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