diff options
| author | Jan Beulich | 2009-05-06 13:06:47 +0100 |
|---|---|---|
| committer | H. Peter Anvin | 2009-05-07 21:51:34 -0700 |
| commit | 498343967613183611ac37dccb2846496d954c06 (patch) | |
| tree | f0a1f93acbe49e4fb72c5dd77a25dc7f3d970e42 | |
| parent | 61438766514a2d7f191ce1b3cf6812eabbef4ef7 (diff) | |
x86-64: finish cleanup_highmaps()'s job wrt. _brk_end
With the introduction of the .brk section, special care must be taken
that no unused page table entries remain if _brk_end and _end are
separated by a 2M page boundary. cleanup_highmap() runs very early and
hence cannot take care of that, hence potential entries needing to be
removed past _brk_end must be cleared once the brk allocator has done
its job.
[ Impact: avoids undesirable TLB aliases ]
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | arch/x86/mm/init.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index fd3da1dda1c9..ae4f7b5d7104 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -7,6 +7,7 @@ #include <asm/page.h> #include <asm/page_types.h> #include <asm/sections.h> +#include <asm/setup.h> #include <asm/system.h> #include <asm/tlbflush.h> @@ -304,8 +305,23 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, #endif #ifdef CONFIG_X86_64 - if (!after_bootmem) + 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(); |