From: Yinghai Lu Date: Fri, 18 Feb 2011 11:30:30 +0000 (+0000) Subject: x86: Cleanup highmap after brk is concluded X-Git-Tag: v2.6.37.6~12 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=72f2999e41d09468b29de855ffc02f94e87a675e;p=thirdparty%2Fkernel%2Fstable.git x86: Cleanup highmap after brk is concluded commit e5f15b45ddf3afa2bbbb10c7ea34fb32b6de0a0e upstream. Now cleanup_highmap actually is in two steps: one is early in head64.c and only clears above _end; a second one is in init_memory_mapping() and tries to clean from _brk_end to _end. It should check if those boundaries are PMD_SIZE aligned but currently does not. Also init_memory_mapping() is called several times for numa or memory hotplug, so we really should not handle initial kernel mappings there. This patch moves cleanup_highmap() down after _brk_end is settled so we can do everything in one step. Also we honor max_pfn_mapped in the implementation of cleanup_highmap. Signed-off-by: Yinghai Lu Signed-off-by: Stefano Stabellini LKML-Reference: Signed-off-by: H. Peter Anvin Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 2d2673c28aff2..5655c2272adb8 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -77,9 +77,6 @@ void __init x86_64_start_kernel(char * real_mode_data) /* Make NULL pointers segfault */ zap_identity_mappings(); - /* Cleanup the over mapped high alias */ - cleanup_highmap(); - max_pfn_mapped = KERNEL_IMAGE_SIZE >> PAGE_SHIFT; for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) { diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index a0f52af256a03..1d9b98e60dfc0 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -297,6 +297,9 @@ static void __init init_gbpages(void) static inline void init_gbpages(void) { } +static void __init cleanup_highmap(void) +{ +} #endif static void __init reserve_brk(void) @@ -922,6 +925,8 @@ void __init setup_arch(char **cmdline_p) */ reserve_brk(); + cleanup_highmap(); + memblock.current_limit = get_max_mapped(); memblock_x86_fill(); diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index c0e28a13de7df..0398a733c3879 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -279,25 +279,6 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, load_cr3(swapper_pg_dir); #endif -#ifdef CONFIG_X86_64 - if (!after_bootmem && !start) { - pud_t *pud; - pmd_t *pmd; - - mmu_cr4_features = read_cr4(); - - /* - * _brk_end cannot change anymore, but it and _end may be - * located on different 2M pages. cleanup_highmap(), however, - * can only consider _end when it runs, so destroy any - * mappings beyond _brk_end here. - */ - pud = pud_offset(pgd_offset_k(_brk_end), _brk_end); - pmd = pmd_offset(pud, _brk_end - 1); - while (++pmd <= pmd_offset(pud, (unsigned long)_end - 1)) - pmd_clear(pmd); - } -#endif __flush_tlb_all(); if (!after_bootmem && e820_table_end > e820_table_start) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index c14a5422e1522..68f9921ae9c16 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -51,6 +51,7 @@ #include #include #include +#include static int __init parse_direct_gbpages_off(char *arg) { @@ -293,18 +294,18 @@ void __init init_extra_mapping_uc(unsigned long phys, unsigned long size) * to the compile time generated pmds. This results in invalid pmds up * to the point where we hit the physaddr 0 mapping. * - * We limit the mappings to the region from _text to _end. _end is - * rounded up to the 2MB boundary. This catches the invalid pmds as + * We limit the mappings to the region from _text to _brk_end. _brk_end + * is rounded up to the 2MB boundary. This catches the invalid pmds as * well, as they are located before _text: */ void __init cleanup_highmap(void) { unsigned long vaddr = __START_KERNEL_map; - unsigned long end = roundup((unsigned long)_end, PMD_SIZE) - 1; + unsigned long vaddr_end = __START_KERNEL_map + (max_pfn_mapped << PAGE_SHIFT); + unsigned long end = roundup((unsigned long)_brk_end, PMD_SIZE) - 1; pmd_t *pmd = level2_kernel_pgt; - pmd_t *last_pmd = pmd + PTRS_PER_PMD; - for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) { + for (; vaddr + PMD_SIZE - 1 < vaddr_end; pmd++, vaddr += PMD_SIZE) { if (pmd_none(*pmd)) continue; if (vaddr < (unsigned long) _text || vaddr > end)