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x86/mm: unify init task OOM handling

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Linus noticed that the "again:" versus "survive:" OOM logic for
the init task was arbitrarily different.

The 64-bit codepath is the better one, because it correctly re-lookups
the vma after having dropped the ->mmap_sem.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ingo Molnar
2008-10-13 17:49:02 +02:00
parent 891cffbd6b
commit 3a1dfe6eef
1 changed files with 6 additions and 9 deletions
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15
arch/x86/mm/fault.c
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@@ -671,7 +671,8 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
goto bad_area_nosemaphore; goto bad_area_nosemaphore;
again: again:
/* When running in the kernel we expect faults to occur only to /*
* When running in the kernel we expect faults to occur only to
* addresses in user space. All other faults represent errors in the * addresses in user space. All other faults represent errors in the
* kernel and should generate an OOPS. Unfortunately, in the case of an * kernel and should generate an OOPS. Unfortunately, in the case of an
* erroneous fault occurring in a code path which already holds mmap_sem * erroneous fault occurring in a code path which already holds mmap_sem
@@ -734,9 +735,6 @@ good_area:
goto bad_area; goto bad_area;
} }
#ifdef CONFIG_X86_32
survive:
#endif
/* /*
* If for any reason at all we couldn't handle the fault, * If for any reason at all we couldn't handle the fault,
* make sure we exit gracefully rather than endlessly redo * make sure we exit gracefully rather than endlessly redo
@@ -871,12 +869,11 @@ out_of_memory:
up_read(&mm->mmap_sem); up_read(&mm->mmap_sem);
if (is_global_init(tsk)) { if (is_global_init(tsk)) {
yield(); yield();
#ifdef CONFIG_X86_32 /*
down_read(&mm->mmap_sem); * Re-lookup the vma - in theory the vma tree might
goto survive; * have changed:
#else */
goto again; goto again;
#endif
} }
printk("VM: killing process %s\n", tsk->comm); printk("VM: killing process %s\n", tsk->comm);