From 9b5cf48b06a52c04b85c88642c3b620db8e1d592 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 3 Mar 2008 01:17:37 +0100 Subject: x86: revert "x86: CPA: avoid split of alias mappings" Revert: commit 8be8f54bae3453588011cad06363813a5293af53 Author: Thomas Gleixner Date: Sat Feb 23 20:43:21 2008 +0100 x86: CPA: avoid split of alias mappings because it clearly mishandles the case when __change_page_attr(), called from __change_page_attr_set_clr(), changes cpa->processed to 1 and cpa_process_alias(cpa) is executed right after that. This crashes my x86-64 test box early in the boot process (ref. http://bugzilla.kernel.org/show_bug.cgi?id=10140#c4). Signed-off-by: Rafael J. Wysocki Acked-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/mm/pageattr.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 7049294fb46..14e48b5a94b 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -26,7 +26,6 @@ struct cpa_data { pgprot_t mask_set; pgprot_t mask_clr; int numpages; - int processed; int flushtlb; unsigned long pfn; }; @@ -291,8 +290,8 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, */ nextpage_addr = (address + psize) & pmask; numpages = (nextpage_addr - address) >> PAGE_SHIFT; - if (numpages < cpa->processed) - cpa->processed = numpages; + if (numpages < cpa->numpages) + cpa->numpages = numpages; /* * We are safe now. Check whether the new pgprot is the same: @@ -319,7 +318,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, */ addr = address + PAGE_SIZE; pfn++; - for (i = 1; i < cpa->processed; i++, addr += PAGE_SIZE, pfn++) { + for (i = 1; i < cpa->numpages; i++, addr += PAGE_SIZE, pfn++) { pgprot_t chk_prot = static_protections(new_prot, addr, pfn); if (pgprot_val(chk_prot) != pgprot_val(new_prot)) @@ -343,7 +342,7 @@ try_preserve_large_page(pte_t *kpte, unsigned long address, * that we limited the number of possible pages already to * the number of pages in the large page. */ - if (address == (nextpage_addr - psize) && cpa->processed == numpages) { + if (address == (nextpage_addr - psize) && cpa->numpages == numpages) { /* * The address is aligned and the number of pages * covers the full page. @@ -573,7 +572,7 @@ repeat: set_pte_atomic(kpte, new_pte); cpa->flushtlb = 1; } - cpa->processed = 1; + cpa->numpages = 1; return 0; } @@ -584,7 +583,7 @@ repeat: do_split = try_preserve_large_page(kpte, address, cpa); /* * When the range fits into the existing large page, - * return. cp->processed and cpa->tlbflush have been updated in + * return. cp->numpages and cpa->tlbflush have been updated in * try_large_page: */ if (do_split <= 0) @@ -663,7 +662,7 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias) * Store the remaining nr of pages for the large page * preservation check. */ - cpa->numpages = cpa->processed = numpages; + cpa->numpages = numpages; ret = __change_page_attr(cpa, checkalias); if (ret) @@ -680,9 +679,9 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias) * CPA operation. Either a large page has been * preserved or a single page update happened. */ - BUG_ON(cpa->processed > numpages); - numpages -= cpa->processed; - cpa->vaddr += cpa->processed * PAGE_SIZE; + BUG_ON(cpa->numpages > numpages); + numpages -= cpa->numpages; + cpa->vaddr += cpa->numpages * PAGE_SIZE; } return 0; } -- cgit v1.2.3 From 902955fc13259dcec1321d45251a477977fcba39 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Mar 2008 13:53:58 +0100 Subject: x86: revert "x86: fix pmd_bad and pud_bad to support huge pages" revert commit cded932b75ab0a5f9181ee3da34a0a488d1a14fd, "x86: fix pmd_bad and pud_bad to support huge pages", it causes a bootup hang, as reported and bisected by Arjan van de Ven. Bisected-by: Arjan van de Ven Signed-off-by: Ingo Molnar --- include/asm-x86/pgtable_32.h | 4 +--- include/asm-x86/pgtable_64.h | 6 ++---- 2 files changed, 3 insertions(+), 7 deletions(-) diff --git a/include/asm-x86/pgtable_32.h b/include/asm-x86/pgtable_32.h index b478efa971e..a842c7222b1 100644 --- a/include/asm-x86/pgtable_32.h +++ b/include/asm-x86/pgtable_32.h @@ -91,9 +91,7 @@ extern unsigned long pg0[]; /* To avoid harmful races, pmd_none(x) should check only the lower when PAE */ #define pmd_none(x) (!(unsigned long)pmd_val(x)) #define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) -#define pmd_bad(x) ((pmd_val(x) \ - & ~(PAGE_MASK | _PAGE_USER | _PAGE_PSE | _PAGE_NX)) \ - != _KERNPG_TABLE) +#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE) #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT)) diff --git a/include/asm-x86/pgtable_64.h b/include/asm-x86/pgtable_64.h index 0a9258333cb..0a0b77bc736 100644 --- a/include/asm-x86/pgtable_64.h +++ b/include/asm-x86/pgtable_64.h @@ -153,14 +153,12 @@ static inline unsigned long pgd_bad(pgd_t pgd) static inline unsigned long pud_bad(pud_t pud) { - return pud_val(pud) & - ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER | _PAGE_PSE | _PAGE_NX); + return pud_val(pud) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER); } static inline unsigned long pmd_bad(pmd_t pmd) { - return pmd_val(pmd) & - ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER | _PAGE_PSE | _PAGE_NX); + return pmd_val(pmd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER); } #define pte_none(x) (!pte_val(x)) -- cgit v1.2.3