From 2d892c7a1b4aa0dd42004a217c13cc90a37ae4dd Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 15 Dec 2014 14:46:06 -0800 Subject: [PATCH] x86: mm: move mmap_sem unlock from mm_fault_error() to caller commit 7fb08eca45270d0ae86e1ad9d39c40b7a55d0190 upstream. This replaces four copies in various stages of mm_fault_error() handling with just a single one. It will also allow for more natural placement of the unlocking after some further cleanup. Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/fault.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 18bce18b2a7e..e4780b052531 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -812,11 +812,8 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address, unsigned int fault) { struct task_struct *tsk = current; - struct mm_struct *mm = tsk->mm; int code = BUS_ADRERR; - up_read(&mm->mmap_sem); - /* Kernel mode? Handle exceptions or die: */ if (!(error_code & PF_USER)) { no_context(regs, error_code, address, SIGBUS, BUS_ADRERR); @@ -847,7 +844,6 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code, unsigned long address, unsigned int fault) { if (fatal_signal_pending(current) && !(error_code & PF_USER)) { - up_read(¤t->mm->mmap_sem); no_context(regs, error_code, address, 0, 0); return; } @@ -855,14 +851,11 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code, if (fault & VM_FAULT_OOM) { /* Kernel mode? Handle exceptions or die: */ if (!(error_code & PF_USER)) { - up_read(¤t->mm->mmap_sem); no_context(regs, error_code, address, SIGSEGV, SEGV_MAPERR); return; } - up_read(¤t->mm->mmap_sem); - /* * We ran out of memory, call the OOM killer, and return the * userspace (which will retry the fault, or kill us if we got @@ -1195,6 +1188,7 @@ good_area: return; if (unlikely(fault & VM_FAULT_ERROR)) { + up_read(&mm->mmap_sem); mm_fault_error(regs, error_code, address, fault); return; } -- 2.20.1