After we add code use buffer in BRK to pre-map page table, it should be safe to remove early_memmap for page table accessing. Instead we get panic with that.
It turns out we clear the initial page table wrongly for next range that is separated by holes. And it only happens when we are trying to map range one by one range separately. We need to check if the range is ram before clearing page table. Signed-off-by: Yinghai Lu <[email protected]> --- arch/x86/mm/init_64.c | 37 ++++++++++++++++--------------------- 1 files changed, 16 insertions(+), 21 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index f40f383..61b3c44 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -363,20 +363,19 @@ static unsigned long __meminit phys_pte_init(pte_t *pte_page, unsigned long addr, unsigned long end, pgprot_t prot) { - unsigned pages = 0; + unsigned long pages = 0, next; unsigned long last_map_addr = end; int i; pte_t *pte = pte_page + pte_index(addr); - for(i = pte_index(addr); i < PTRS_PER_PTE; i++, addr += PAGE_SIZE, pte++) { - + for (i = pte_index(addr); i < PTRS_PER_PTE; i++, addr = next, pte++) { + next = (addr & PAGE_MASK) + PAGE_SIZE; if (addr >= end) { - if (!after_bootmem) { - for(; i < PTRS_PER_PTE; i++, pte++) - set_pte(pte, __pte(0)); - } - break; + if (!after_bootmem && + !e820_any_mapped(addr & PAGE_MASK, next, 0)) + set_pte(pte, __pte(0)); + continue; } /* @@ -418,16 +417,14 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end, pte_t *pte; pgprot_t new_prot = prot; + next = (address & PMD_MASK) + PMD_SIZE; if (address >= end) { - if (!after_bootmem) { - for (; i < PTRS_PER_PMD; i++, pmd++) - set_pmd(pmd, __pmd(0)); - } - break; + if (!after_bootmem && + !e820_any_mapped(address & PMD_MASK, next, 0)) + set_pmd(pmd, __pmd(0)); + continue; } - next = (address & PMD_MASK) + PMD_SIZE; - if (pmd_val(*pmd)) { if (!pmd_large(*pmd)) { spin_lock(&init_mm.page_table_lock); @@ -494,13 +491,11 @@ phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end, pmd_t *pmd; pgprot_t prot = PAGE_KERNEL; - if (addr >= end) - break; - next = (addr & PUD_MASK) + PUD_SIZE; - - if (!after_bootmem && !e820_any_mapped(addr, next, 0)) { - set_pud(pud, __pud(0)); + if (addr >= end) { + if (!after_bootmem && + !e820_any_mapped(addr & PUD_MASK, next, 0)) + set_pud(pud, __pud(0)); continue; } -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
