diff options
| author | Rafael J. Wysocki <rjw@sisk.pl> | 2008-03-03 01:17:37 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-03-03 14:18:27 +0100 |
| commit | 9b5cf48b06a52c04b85c88642c3b620db8e1d592 (patch) | |
| tree | 1cb87d4778bbac056a4abdde770555ea5f3221a2 /arch/x86/mm/pageattr.c | |
| parent | 038f2f725503b55ab76cfd2645915a85594710fe (diff) | |
x86: revert "x86: CPA: avoid split of alias mappings"
Revert:
commit 8be8f54bae3453588011cad06363813a5293af53
Author: Thomas Gleixner <tglx@linutronix.de>
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 <rjw@sisk.pl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/mm/pageattr.c')
| -rw-r--r-- | arch/x86/mm/pageattr.c | 21 |
1 files 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; } |