From e5f15b45ddf3afa2bbbb10c7ea34fb32b6de0a0e Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 18 Feb 2011 11:30:30 +0000 Subject: [PATCH] x86: Cleanup highmap after brk is concluded 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 --- arch/x86/kernel/head64.c | 3 --- arch/x86/kernel/setup.c | 25 +++---------------------- arch/x86/mm/init_64.c | 11 ++++++----- 3 files changed, 9 insertions(+), 30 deletions(-) diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 2d2673c28af..5655c2272ad 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 b176f2b1f45..4a52a5f9afc 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -294,30 +294,11 @@ static void __init init_gbpages(void) else direct_gbpages = 0; } - -static void __init cleanup_highmap_brk_end(void) -{ - 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); -} #else static inline void init_gbpages(void) { } -static inline void cleanup_highmap_brk_end(void) +static void __init cleanup_highmap(void) { } #endif @@ -330,8 +311,6 @@ static void __init reserve_brk(void) /* Mark brk area as locked down and no longer taking any new allocations */ _brk_start = 0; - - cleanup_highmap_brk_end(); } #ifdef CONFIG_BLK_DEV_INITRD @@ -950,6 +929,8 @@ 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_64.c b/arch/x86/mm/init_64.c index a08a62cb136..7026505a33b 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) -- 2.20.1