![Ingo Molnar](/assets/img/avatar_default.png)
lockdep just caught this one:
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[ INFO: inconsistent lock state ]
2.6.24 #38
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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 8c914cb704
.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
#ifndef _X86_64_PGALLOC_H
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#define _X86_64_PGALLOC_H
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#include <asm/pda.h>
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#include <linux/threads.h>
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#include <linux/mm.h>
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#define pmd_populate_kernel(mm, pmd, pte) \
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set_pmd(pmd, __pmd(_PAGE_TABLE | __pa(pte)))
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#define pud_populate(mm, pud, pmd) \
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set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)))
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#define pgd_populate(mm, pgd, pud) \
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set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(pud)))
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static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *pte)
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{
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set_pmd(pmd, __pmd(_PAGE_TABLE | (page_to_pfn(pte) << PAGE_SHIFT)));
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}
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static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
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{
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BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
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free_page((unsigned long)pmd);
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}
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static inline pmd_t *pmd_alloc_one (struct mm_struct *mm, unsigned long addr)
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{
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return (pmd_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
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}
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static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
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{
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return (pud_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
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}
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static inline void pud_free(struct mm_struct *mm, pud_t *pud)
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{
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BUG_ON((unsigned long)pud & (PAGE_SIZE-1));
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free_page((unsigned long)pud);
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}
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static inline void pgd_list_add(pgd_t *pgd)
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{
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struct page *page = virt_to_page(pgd);
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unsigned long flags;
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spin_lock_irqsave(&pgd_lock, flags);
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list_add(&page->lru, &pgd_list);
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spin_unlock_irqrestore(&pgd_lock, flags);
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}
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static inline void pgd_list_del(pgd_t *pgd)
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{
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struct page *page = virt_to_page(pgd);
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unsigned long flags;
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spin_lock_irqsave(&pgd_lock, flags);
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list_del(&page->lru);
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spin_unlock_irqrestore(&pgd_lock, flags);
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}
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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unsigned boundary;
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pgd_t *pgd = (pgd_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT);
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if (!pgd)
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return NULL;
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pgd_list_add(pgd);
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/*
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* Copy kernel pointers in from init.
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* Could keep a freelist or slab cache of those because the kernel
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* part never changes.
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*/
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boundary = pgd_index(__PAGE_OFFSET);
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memset(pgd, 0, boundary * sizeof(pgd_t));
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memcpy(pgd + boundary,
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init_level4_pgt + boundary,
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(PTRS_PER_PGD - boundary) * sizeof(pgd_t));
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return pgd;
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}
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static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
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pgd_list_del(pgd);
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free_page((unsigned long)pgd);
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}
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static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
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{
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return (pte_t *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
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}
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static inline struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address)
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{
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void *p = (void *)get_zeroed_page(GFP_KERNEL|__GFP_REPEAT);
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if (!p)
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return NULL;
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return virt_to_page(p);
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}
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/* Should really implement gc for free page table pages. This could be
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done with a reference count in struct page. */
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static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
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{
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BUG_ON((unsigned long)pte & (PAGE_SIZE-1));
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free_page((unsigned long)pte);
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}
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static inline void pte_free(struct mm_struct *mm, struct page *pte)
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{
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__free_page(pte);
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}
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#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte))
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#define __pmd_free_tlb(tlb,x) tlb_remove_page((tlb),virt_to_page(x))
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#define __pud_free_tlb(tlb,x) tlb_remove_page((tlb),virt_to_page(x))
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#endif /* _X86_64_PGALLOC_H */
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