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Date: Thu, 02 May 2013 15:40:50 +0900 From: Fernando Luis Vázquez Cao <fernando_b1@....ntt.co.jp> To: "H. Peter Anvin" <hpa@...ux.intel.com>, Yinghai Lu <yinghai@...nel.org> Cc: x86@...nel.org, linux-kernel@...r.kernel.org Subject: [PATCH] x86, 64bit: do not assume CPU is NX capable when setting early page tables The kernel sets the NX bit in the early page tables without checking whether the CPU actually supports this feature. If it doesn't the first attempt to use them will cause a kernel hang. Since these are temporary page tables marked as initdata this fix takes the approach of not bothering with the NX bit at all. Noticed when my AMD machine that happened to have the NX feature disabled by the BIOS failed to boot after the update to 3.9. Cc: stable@...r.kernel.org Signed-off-by: Fernando Luis Vazquez Cao <fernando@....ntt.co.jp> --- diff -urNp linux-3.9/arch/x86/kernel/head64.c linux-3.9-fix/arch/x86/kernel/head64.c --- linux-3.9/arch/x86/kernel/head64.c 2013-04-29 09:36:01.000000000 +0900 +++ linux-3.9-fix/arch/x86/kernel/head64.c 2013-05-02 14:38:52.589276092 +0900 @@ -99,7 +99,7 @@ again: pmd_p[i] = 0; *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE; } - pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL); + pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL); pmd_p[pmd_index(address)] = pmd; return 0; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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