[PATCH 3.12 139/175] x86: mm: move mmap_sem unlock from mm_fault_error() to caller
From: Jiri Slaby <hidden>
Date: 2015-03-17 08:51:01
Also in:
lkml
Subsystem:
the rest, x86 architecture (32-bit and 64-bit), x86 mm · Maintainers:
Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, Andy Lutomirski, Peter Zijlstra
From: Linus Torvalds <torvalds@linux-foundation.org> 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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 <torvalds@linux-foundation.org> Signed-off-by: Jiri Slaby <redacted> --- 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 5b90bbcad9f6..31dceb131c46 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
@@ -1193,6 +1186,7 @@ good_area: return; if (unlikely(fault & VM_FAULT_ERROR)) { + up_read(&mm->mmap_sem); mm_fault_error(regs, error_code, address, fault); return; }
--
2.3.0