diff options
Diffstat (limited to 'arch/x86/mm/dump_pagetables.c')
| -rw-r--r-- | arch/x86/mm/dump_pagetables.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index ea9c49adaa1f..58b5bee7ea27 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -15,8 +15,10 @@ #include <linux/debugfs.h> #include <linux/mm.h> #include <linux/init.h> +#include <linux/sched.h> #include <linux/seq_file.h> +#include <asm/kasan.h> #include <asm/pgtable.h> /* @@ -50,6 +52,10 @@ enum address_markers_idx { LOW_KERNEL_NR, VMALLOC_START_NR, VMEMMAP_START_NR, +#ifdef CONFIG_KASAN + KASAN_SHADOW_START_NR, + KASAN_SHADOW_END_NR, +#endif # ifdef CONFIG_X86_ESPFIX64 ESPFIX_START_NR, # endif @@ -75,6 +81,10 @@ static struct addr_marker address_markers[] = { { 0/* PAGE_OFFSET */, "Low Kernel Mapping" }, { 0/* VMALLOC_START */, "vmalloc() Area" }, { 0/* VMEMMAP_START */, "Vmemmap" }, +#ifdef CONFIG_KASAN + { KASAN_SHADOW_START, "KASAN shadow" }, + { KASAN_SHADOW_END, "KASAN shadow end" }, +#endif # ifdef CONFIG_X86_ESPFIX64 { ESPFIX_BASE_ADDR, "ESPfix Area", 16 }, # endif @@ -326,18 +336,31 @@ static void walk_pmd_level(struct seq_file *m, struct pg_state *st, pud_t addr, #if PTRS_PER_PUD > 1 +/* + * This is an optimization for CONFIG_DEBUG_WX=y + CONFIG_KASAN=y + * KASAN fills page tables with the same values. Since there is no + * point in checking page table more than once we just skip repeated + * entries. This saves us dozens of seconds during boot. + */ +static bool pud_already_checked(pud_t *prev_pud, pud_t *pud, bool checkwx) +{ + return checkwx && prev_pud && (pud_val(*prev_pud) == pud_val(*pud)); +} + static void walk_pud_level(struct seq_file *m, struct pg_state *st, pgd_t addr, unsigned long P) { int i; pud_t *start; pgprotval_t prot; + pud_t *prev_pud = NULL; start = (pud_t *) pgd_page_vaddr(addr); for (i = 0; i < PTRS_PER_PUD; i++) { st->current_address = normalize_addr(P + i * PUD_LEVEL_MULT); - if (!pud_none(*start)) { + if (!pud_none(*start) && + !pud_already_checked(prev_pud, start, st->check_wx)) { if (pud_large(*start) || !pud_present(*start)) { prot = pud_flags(*start); note_page(m, st, __pgprot(prot), 2); @@ -348,6 +371,7 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st, pgd_t addr, } else note_page(m, st, __pgprot(0), 2); + prev_pud = start; start++; } } @@ -406,6 +430,7 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd, } else note_page(m, &st, __pgprot(0), 1); + cond_resched(); start++; } |