| From e5f15b45ddf3afa2bbbb10c7ea34fb32b6de0a0e Mon Sep 17 00:00:00 2001 |
| From: Yinghai Lu <yinghai@kernel.org> |
| Date: Fri, 18 Feb 2011 11:30:30 +0000 |
| Subject: x86: Cleanup highmap after brk is concluded |
| |
| From: Yinghai Lu <yinghai@kernel.org> |
| |
| 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 <yinghai@kernel.org> |
| Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> |
| LKML-Reference: <alpine.DEB.2.00.1103171739050.3382@kaball-desktop> |
| Signed-off-by: H. Peter Anvin <hpa@zytor.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| arch/x86/kernel/head64.c | 3 --- |
| arch/x86/kernel/setup.c | 5 +++++ |
| arch/x86/mm/init.c | 19 ------------------- |
| arch/x86/mm/init_64.c | 11 ++++++----- |
| 4 files changed, 11 insertions(+), 27 deletions(-) |
| |
| --- a/arch/x86/kernel/head64.c |
| +++ b/arch/x86/kernel/head64.c |
| @@ -76,9 +76,6 @@ void __init x86_64_start_kernel(char * r |
| /* Make NULL pointers segfault */ |
| zap_identity_mappings(); |
| |
| - /* Cleanup the over mapped high alias */ |
| - cleanup_highmap(); |
| - |
| for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) { |
| #ifdef CONFIG_EARLY_PRINTK |
| set_intr_gate(i, &early_idt_handlers[i]); |
| --- a/arch/x86/kernel/setup.c |
| +++ b/arch/x86/kernel/setup.c |
| @@ -295,6 +295,9 @@ 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) |
| @@ -895,6 +898,8 @@ void __init setup_arch(char **cmdline_p) |
| |
| reserve_brk(); |
| |
| + cleanup_highmap(); |
| + |
| /* |
| * Find and reserve possible boot-time SMP configuration: |
| */ |
| --- a/arch/x86/mm/init.c |
| +++ b/arch/x86/mm/init.c |
| @@ -283,25 +283,6 @@ unsigned long __init_refok init_memory_m |
| 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) |
| --- a/arch/x86/mm/init_64.c |
| +++ b/arch/x86/mm/init_64.c |
| @@ -49,6 +49,7 @@ |
| #include <asm/numa.h> |
| #include <asm/cacheflush.h> |
| #include <asm/init.h> |
| +#include <asm/setup.h> |
| #include <linux/bootmem.h> |
| |
| static unsigned long dma_reserve __initdata; |
| @@ -257,18 +258,18 @@ void __init init_extra_mapping_uc(unsign |
| * 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) |