diff options
| author |   Andi Kleen <ak@suse.de> | 2005-05-20 14:27:57 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-20 15:48:20 -0700 |
| commit | 7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9 (patch) | |
| tree | 0e9f799c3882dce14b49356c6db10bb6f4ba1713 /arch | |
| parent | [PATCH] x86_64: Don't allow accesses below register frame in ptrace (diff) | |
| download | linux-dev-7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9.tar.xz linux-dev-7856dfeb23c16ef3d8dac8871b4d5b93c70b59b9.zip | |
[PATCH] x86_64: Fixed guard page handling again in iounmap
Caused oopses again. Also fix potential mismatch in checking if
change_page_attr was needed.
To do it without races I needed to change mm/vmalloc.c to export a
__remove_vm_area that does not take vmlist lock.
Noticed by Terence Ripperda and based on a patch of his.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86_64/mm/ioremap.c | 29 |
1 files changed, 8 insertions, 21 deletions
diff --git a/arch/x86_64/mm/ioremap.c b/arch/x86_64/mm/ioremap.c index c6fb0cb69992..58aac23760ef 100644 --- a/arch/x86_64/mm/ioremap.c +++ b/arch/x86_64/mm/ioremap.c @@ -133,7 +133,7 @@ ioremap_change_attr(unsigned long phys_addr, unsigned long size, unsigned long flags) { int err = 0; - if (flags && phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT)) { + if (phys_addr + size - 1 < (end_pfn_map << PAGE_SHIFT)) { unsigned long npages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; unsigned long vaddr = (unsigned long) __va(phys_addr); @@ -214,7 +214,7 @@ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned l remove_vm_area((void *)(PAGE_MASK & (unsigned long) addr)); return NULL; } - if (ioremap_change_attr(phys_addr, size, flags) < 0) { + if (flags && ioremap_change_attr(phys_addr, size, flags) < 0) { area->flags &= 0xffffff; vunmap(addr); return NULL; @@ -251,7 +251,7 @@ void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size) void iounmap(volatile void __iomem *addr) { - struct vm_struct *p, **pprev; + struct vm_struct *p; if (addr <= high_memory) return; @@ -260,24 +260,11 @@ void iounmap(volatile void __iomem *addr) return; write_lock(&vmlist_lock); - for (p = vmlist, pprev = &vmlist; p != NULL; pprev = &p->next, p = *pprev) - if (p->addr == (void *)(PAGE_MASK & (unsigned long)addr)) - break; - if (!p) { - printk("__iounmap: bad address %p\n", addr); - goto out_unlock; - } - *pprev = p->next; - unmap_vm_area(p); - if ((p->flags >> 20) && - p->phys_addr + p->size - 1 < virt_to_phys(high_memory)) { - /* p->size includes the guard page, but cpa doesn't like that */ - change_page_attr_addr((unsigned long)__va(p->phys_addr), - p->size >> PAGE_SHIFT, - PAGE_KERNEL); - global_flush_tlb(); - } -out_unlock: + p = __remove_vm_area((void *)((unsigned long)addr & PAGE_MASK)); + if (!p) + printk("iounmap: bad address %p\n", addr); + else if (p->flags >> 20) + ioremap_change_attr(p->phys_addr, p->size, 0); write_unlock(&vmlist_lock); kfree(p); } |