diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-02-07 00:39:45 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-07 00:39:45 +0300 |
| commit | 58d5d0d8dd52cbca988af24b5692a20b00285543 (patch) | |
| tree | 285539cf1ad60d9ebcda310b97f818c17ef634c8 /include/asm-x86 | |
| parent | a09771bef9a375091f8ae706d992e20970e5d1e7 (diff) | |
| download | linux-58d5d0d8dd52cbca988af24b5692a20b00285543.tar.xz | |
x86: fix deadlock, make pgd_lock irq-safe
lockdep just caught this one:
=================================
[ INFO: inconsistent lock state ]
2.6.24 #38
---------------------------------
inconsistent {in-softirq-W} -> {softirq-on-W} usage.
swapper/1 [HC0[0]:SC0[0]:HE1:SE1] takes:
(pgd_lock){-+..}, at: [<ffffffff8022a9ea>] mm_init+0x1da/0x250
{in-softirq-W} state was registered at:
[<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 394559
hardirqs last enabled at (394559): [<ffffffff80267f0a>] get_page_from_freelist+0x30a/0x4c0
hardirqs last disabled at (394558): [<ffffffff80267d25>] get_page_from_freelist+0x125/0x4c0
softirqs last enabled at (393952): [<ffffffff80232f8e>] __do_softirq+0xce/0xe0
softirqs last disabled at (393945): [<ffffffff8020c57c>] call_softirq+0x1c/0x30
other info that might help us debug this:
no locks held by swapper/1.
stack backtrace:
Pid: 1, comm: swapper Not tainted 2.6.24 #38
Call Trace:
[<ffffffff8024e1fb>] print_usage_bug+0x18b/0x190
[<ffffffff8024f55d>] mark_lock+0x53d/0x560
[<ffffffff8024fffa>] __lock_acquire+0x3ca/0xed0
[<ffffffff80250ba8>] lock_acquire+0xa8/0xe0
[<ffffffff8022a9ea>] ? mm_init+0x1da/0x250
[<ffffffff809bcd10>] _spin_lock+0x30/0x70
[<ffffffff8022a9ea>] mm_init+0x1da/0x250
[<ffffffff8022aa99>] mm_alloc+0x39/0x50
[<ffffffff8028b95a>] bprm_mm_init+0x2a/0x1a0
[<ffffffff8028d12b>] do_execve+0x7b/0x220
[<ffffffff80209776>] sys_execve+0x46/0x70
[<ffffffff8020c214>] kernel_execve+0x64/0xd0
[<ffffffff8020901e>] ? _stext+0x1e/0x20
[<ffffffff802090ba>] init_post+0x9a/0xf0
[<ffffffff809bc5f6>] ? trace_hardirqs_on_thunk+0x35/0x3a
[<ffffffff8024f75a>] ? trace_hardirqs_on+0xba/0xd0
[<ffffffff8020c1a8>] ? child_rip+0xa/0x12
[<ffffffff8020bcbc>] ? restore_args+0x0/0x44
[<ffffffff8020c19e>] ? child_rip+0x0/0x12
turns out that pgd_lock has been used on 64-bit x86 in an irq-unsafe
way for almost two years, since commit 8c914cb704a11460e.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include/asm-x86')
| -rw-r--r-- | include/asm-x86/pgalloc_64.h | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/include/asm-x86/pgalloc_64.h b/include/asm-x86/pgalloc_64.h index 315314ce4bfb..4f6220db22b1 100644 --- a/include/asm-x86/pgalloc_64.h +++ b/include/asm-x86/pgalloc_64.h @@ -42,19 +42,21 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud) static inline void pgd_list_add(pgd_t *pgd) { struct page *page = virt_to_page(pgd); + unsigned long flags; - spin_lock(&pgd_lock); + spin_lock_irqsave(&pgd_lock, flags); list_add(&page->lru, &pgd_list); - spin_unlock(&pgd_lock); + spin_unlock_irqrestore(&pgd_lock, flags); } static inline void pgd_list_del(pgd_t *pgd) { struct page *page = virt_to_page(pgd); + unsigned long flags; - spin_lock(&pgd_lock); + spin_lock_irqsave(&pgd_lock, flags); list_del(&page->lru); - spin_unlock(&pgd_lock); + spin_unlock_irqrestore(&pgd_lock, flags); } static inline pgd_t *pgd_alloc(struct mm_struct *mm) |