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powerpc/mm: Move mmap_sem unlocking in do_page_fault() 

Since the fault retry is now handled earlier, we can release the
mmap_sem lock earlier too and remove later unlocking previously done in
mm_fault_error().

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Laurent Dufour 2017-02-14 17:45:12 +01:00 committed by Michael Ellerman
parent 14c02e419a
commit 819cdcdb7b
1 changed files with 4 additions and 15 deletions
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19
arch/powerpc/mm/fault.c
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@ -152,13 +152,6 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
* continue the pagefault.
*/
if (fatal_signal_pending(current)) {
/*
* If we have retry set, the mmap semaphore will have
* alrady been released in __lock_page_or_retry(). Else
* we release it now.
*/
if (!(fault & VM_FAULT_RETRY))
up_read(&current->mm->mmap_sem);
/* Coming from kernel, we need to deal with uaccess fixups */
if (user_mode(regs))
return MM_FAULT_RETURN;
@ -171,8 +164,6 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
/* Out of memory */
if (fault & VM_FAULT_OOM) {
up_read(&current->mm->mmap_sem);
/*
* We ran out of memory, or some other thing happened to us that
* made us unable to handle the page fault gracefully.
@ -183,10 +174,8 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr, int fault)
return MM_FAULT_RETURN;
}
if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE)) {
up_read(&current->mm->mmap_sem);
if (fault & (VM_FAULT_SIGBUS|VM_FAULT_HWPOISON|VM_FAULT_HWPOISON_LARGE))
return do_sigbus(regs, addr, fault);
}
/* We don't understand the fault code, this is fatal */
BUG();
@ -476,11 +465,12 @@ good_area:
goto retry;
}
/* We will enter mm_fault_error() below */
}
} else
up_read(&current->mm->mmap_sem);
if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) {
if (fault & VM_FAULT_SIGSEGV)
goto bad_area;
goto bad_area_nosemaphore;
rc = mm_fault_error(regs, address, fault);
if (rc >= MM_FAULT_RETURN)
goto bail;
@ -512,7 +502,6 @@ good_area:
regs, address);
}
up_read(&mm->mmap_sem);
goto bail;
bad_area: