diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 44d279698c0f..a12f64fa0a63 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -120,6 +120,7 @@ config X86 select GENERIC_IRQ_RESERVATION_MODE select GENERIC_IRQ_SHOW select GENERIC_PENDING_IRQ if SMP + select GENERIC_PTDUMP select GENERIC_SMP_IDLE_THREAD select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index c4eab8ed33a3..2e74690b028a 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -62,26 +62,10 @@ config EARLY_PRINTK_USB_XDBC config MCSAFE_TEST def_bool n -config X86_PTDUMP_CORE - def_bool n - -config X86_PTDUMP - tristate "Export kernel pagetable layout to userspace via debugfs" - depends on DEBUG_KERNEL - select DEBUG_FS - select X86_PTDUMP_CORE - ---help--- - Say Y here if you want to show the kernel pagetable layout in a - debugfs file. This information is only useful for kernel developers - who are working in architecture specific areas of the kernel. - It is probably not a good idea to enable this feature in a production - kernel. - If in doubt, say "N" - config EFI_PGT_DUMP bool "Dump the EFI pagetable" depends on EFI - select X86_PTDUMP_CORE + select PTDUMP_CORE ---help--- Enable this if you want to dump the EFI page table before enabling virtual mode. This can be used to debug miscellaneous @@ -90,7 +74,7 @@ config EFI_PGT_DUMP config DEBUG_WX bool "Warn on W+X mappings at boot" - select X86_PTDUMP_CORE + select PTDUMP_CORE ---help--- Generate a warning if any W+X mappings are found at boot. diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile index 98aecb14fbcc..98f7c6fa2eaa 100644 --- a/arch/x86/mm/Makefile +++ b/arch/x86/mm/Makefile @@ -28,8 +28,8 @@ CFLAGS_fault.o := -I $(srctree)/$(src)/../include/asm/trace obj-$(CONFIG_X86_32) += pgtable_32.o iomap_32.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o -obj-$(CONFIG_X86_PTDUMP_CORE) += dump_pagetables.o -obj-$(CONFIG_X86_PTDUMP) += debug_pagetables.o +obj-$(CONFIG_PTDUMP_CORE) += dump_pagetables.o +obj-$(CONFIG_PTDUMP_DEBUGFS) += debug_pagetables.o obj-$(CONFIG_HIGHMEM) += highmem_32.o diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c index 2f5f32f21f81..a0b8ffc927bb 100644 --- a/arch/x86/mm/dump_pagetables.c +++ b/arch/x86/mm/dump_pagetables.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -26,11 +27,12 @@ * when a "break" in the continuity is found. */ struct pg_state { + struct ptdump_state ptdump; int level; - pgprot_t current_prot; + pgprotval_t current_prot; pgprotval_t effective_prot; + pgprotval_t prot_levels[5]; unsigned long start_address; - unsigned long current_address; const struct addr_marker *marker; unsigned long lines; bool to_dmesg; @@ -175,9 +177,8 @@ static struct addr_marker address_markers[] = { /* * Print a readable form of a pgprot_t to the seq_file */ -static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg) +static void printk_prot(struct seq_file *m, pgprotval_t pr, int level, bool dmsg) { - pgprotval_t pr = pgprot_val(prot); static const char * const level_name[] = { "cr3", "pgd", "p4d", "pud", "pmd", "pte" }; @@ -224,24 +225,11 @@ static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg) pt_dump_cont_printf(m, dmsg, "%s\n", level_name[level]); } -/* - * On 64 bits, sign-extend the 48 bit address to 64 bit - */ -static unsigned long normalize_addr(unsigned long u) -{ - int shift; - if (!IS_ENABLED(CONFIG_X86_64)) - return u; - - shift = 64 - (__VIRTUAL_MASK_SHIFT + 1); - return (signed long)(u << shift) >> shift; -} - -static void note_wx(struct pg_state *st) +static void note_wx(struct pg_state *st, unsigned long addr) { unsigned long npages; - npages = (st->current_address - st->start_address) / PAGE_SIZE; + npages = (addr - st->start_address) / PAGE_SIZE; #ifdef CONFIG_PCI_BIOS /* @@ -249,7 +237,7 @@ static void note_wx(struct pg_state *st) * Inform about it, but avoid the warning. */ if (pcibios_enabled && st->start_address >= PAGE_OFFSET + BIOS_BEGIN && - st->current_address <= PAGE_OFFSET + BIOS_END) { + addr <= PAGE_OFFSET + BIOS_END) { pr_warn_once("x86/mm: PCI BIOS W+X mapping %lu pages\n", npages); return; } @@ -261,25 +249,44 @@ static void note_wx(struct pg_state *st) (void *)st->start_address); } +static inline pgprotval_t effective_prot(pgprotval_t prot1, pgprotval_t prot2) +{ + return (prot1 & prot2 & (_PAGE_USER | _PAGE_RW)) | + ((prot1 | prot2) & _PAGE_NX); +} + /* * This function gets called on a break in a continuous series * of PTE entries; the next one is different so we need to * print what we collected so far. */ -static void note_page(struct pg_state *st, pgprot_t new_prot, - pgprotval_t new_eff, int level) +static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, + unsigned long val) { - pgprotval_t prot, cur, eff; + struct pg_state *st = container_of(pt_st, struct pg_state, ptdump); + pgprotval_t new_prot, new_eff; + pgprotval_t cur, eff; static const char units[] = "BKMGTPE"; struct seq_file *m = st->seq; + new_prot = val & PTE_FLAGS_MASK; + + if (level > 1) { + new_eff = effective_prot(st->prot_levels[level - 2], + new_prot); + } else { + new_eff = new_prot; + } + + if (level > 0) + st->prot_levels[level - 1] = new_eff; + /* * If we have a "break" in the series, we need to flush the state that * we have now. "break" is either changing perms, levels or * address space marker. */ - prot = pgprot_val(new_prot); - cur = pgprot_val(st->current_prot); + cur = st->current_prot; eff = st->effective_prot; if (!st->level) { @@ -291,14 +298,14 @@ static void note_page(struct pg_state *st, pgprot_t new_prot, st->lines = 0; pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n", st->marker->name); - } else if (prot != cur || new_eff != eff || level != st->level || - st->current_address >= st->marker[1].start_address) { + } else if (new_prot != cur || new_eff != eff || level != st->level || + addr >= st->marker[1].start_address) { const char *unit = units; unsigned long delta; int width = sizeof(unsigned long) * 2; if (st->check_wx && (eff & _PAGE_RW) && !(eff & _PAGE_NX)) - note_wx(st); + note_wx(st, addr); /* * Now print the actual finished series @@ -308,9 +315,9 @@ static void note_page(struct pg_state *st, pgprot_t new_prot, pt_dump_seq_printf(m, st->to_dmesg, "0x%0*lx-0x%0*lx ", width, st->start_address, - width, st->current_address); + width, addr); - delta = st->current_address - st->start_address; + delta = addr - st->start_address; while (!(delta & 1023) && unit[1]) { delta >>= 10; unit++; @@ -327,7 +334,7 @@ static void note_page(struct pg_state *st, pgprot_t new_prot, * such as the start of vmalloc space etc. * This helps in the interpretation. */ - if (st->current_address >= st->marker[1].start_address) { + if (addr >= st->marker[1].start_address) { if (st->marker->max_lines && st->lines > st->marker->max_lines) { unsigned long nskip = @@ -343,217 +350,48 @@ static void note_page(struct pg_state *st, pgprot_t new_prot, st->marker->name); } - st->start_address = st->current_address; + st->start_address = addr; st->current_prot = new_prot; st->effective_prot = new_eff; st->level = level; } } -static inline pgprotval_t effective_prot(pgprotval_t prot1, pgprotval_t prot2) -{ - return (prot1 & prot2 & (_PAGE_USER | _PAGE_RW)) | - ((prot1 | prot2) & _PAGE_NX); -} - -static void walk_pte_level(struct pg_state *st, pmd_t addr, pgprotval_t eff_in, - unsigned long P) -{ - int i; - pte_t *pte; - pgprotval_t prot, eff; - - for (i = 0; i < PTRS_PER_PTE; i++) { - st->current_address = normalize_addr(P + i * PTE_LEVEL_MULT); - pte = pte_offset_map(&addr, st->current_address); - prot = pte_flags(*pte); - eff = effective_prot(eff_in, prot); - note_page(st, __pgprot(prot), eff, 5); - pte_unmap(pte); - } -} -#ifdef CONFIG_KASAN - -/* - * This is an optimization for KASAN=y case. Since all kasan page tables - * eventually point to the kasan_early_shadow_page we could call note_page() - * right away without walking through lower level page tables. This saves - * us dozens of seconds (minutes for 5-level config) while checking for - * W+X mapping or reading kernel_page_tables debugfs file. - */ -static inline bool kasan_page_table(struct pg_state *st, void *pt) -{ - if (__pa(pt) == __pa(kasan_early_shadow_pmd) || - (pgtable_l5_enabled() && - __pa(pt) == __pa(kasan_early_shadow_p4d)) || - __pa(pt) == __pa(kasan_early_shadow_pud)) { - pgprotval_t prot = pte_flags(kasan_early_shadow_pte[0]); - note_page(st, __pgprot(prot), 0, 5); - return true; - } - return false; -} -#else -static inline bool kasan_page_table(struct pg_state *st, void *pt) -{ - return false; -} -#endif - -#if PTRS_PER_PMD > 1 - -static void walk_pmd_level(struct pg_state *st, pud_t addr, - pgprotval_t eff_in, unsigned long P) -{ - int i; - pmd_t *start, *pmd_start; - pgprotval_t prot, eff; - - pmd_start = start = (pmd_t *)pud_page_vaddr(addr); - for (i = 0; i < PTRS_PER_PMD; i++) { - st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT); - if (!pmd_none(*start)) { - prot = pmd_flags(*start); - eff = effective_prot(eff_in, prot); - if (pmd_large(*start) || !pmd_present(*start)) { - note_page(st, __pgprot(prot), eff, 4); - } else if (!kasan_page_table(st, pmd_start)) { - walk_pte_level(st, *start, eff, - P + i * PMD_LEVEL_MULT); - } - } else - note_page(st, __pgprot(0), 0, 4); - start++; - } -} - -#else -#define walk_pmd_level(s,a,e,p) walk_pte_level(s,__pmd(pud_val(a)),e,p) -#define pud_large(a) pmd_large(__pmd(pud_val(a))) -#define pud_none(a) pmd_none(__pmd(pud_val(a))) -#endif - -#if PTRS_PER_PUD > 1 - -static void walk_pud_level(struct pg_state *st, p4d_t addr, pgprotval_t eff_in, - unsigned long P) -{ - int i; - pud_t *start, *pud_start; - pgprotval_t prot, eff; - - pud_start = start = (pud_t *)p4d_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)) { - prot = pud_flags(*start); - eff = effective_prot(eff_in, prot); - if (pud_large(*start) || !pud_present(*start)) { - note_page(st, __pgprot(prot), eff, 3); - } else if (!kasan_page_table(st, pud_start)) { - walk_pmd_level(st, *start, eff, - P + i * PUD_LEVEL_MULT); - } - } else - note_page(st, __pgprot(0), 0, 3); - - start++; - } -} - -#else -#define walk_pud_level(s,a,e,p) walk_pmd_level(s,__pud(p4d_val(a)),e,p) -#define p4d_large(a) pud_large(__pud(p4d_val(a))) -#define p4d_none(a) pud_none(__pud(p4d_val(a))) -#endif - -static void walk_p4d_level(struct pg_state *st, pgd_t addr, pgprotval_t eff_in, - unsigned long P) -{ - int i; - p4d_t *start, *p4d_start; - pgprotval_t prot, eff; - - if (PTRS_PER_P4D == 1) - return walk_pud_level(st, __p4d(pgd_val(addr)), eff_in, P); - - p4d_start = start = (p4d_t *)pgd_page_vaddr(addr); - - for (i = 0; i < PTRS_PER_P4D; i++) { - st->current_address = normalize_addr(P + i * P4D_LEVEL_MULT); - if (!p4d_none(*start)) { - prot = p4d_flags(*start); - eff = effective_prot(eff_in, prot); - if (p4d_large(*start) || !p4d_present(*start)) { - note_page(st, __pgprot(prot), eff, 2); - } else if (!kasan_page_table(st, p4d_start)) { - walk_pud_level(st, *start, eff, - P + i * P4D_LEVEL_MULT); - } - } else - note_page(st, __pgprot(0), 0, 2); - - start++; - } -} - -#define pgd_large(a) (pgtable_l5_enabled() ? pgd_large(a) : p4d_large(__p4d(pgd_val(a)))) -#define pgd_none(a) (pgtable_l5_enabled() ? pgd_none(a) : p4d_none(__p4d(pgd_val(a)))) - -static inline bool is_hypervisor_range(int idx) -{ -#ifdef CONFIG_X86_64 - /* - * A hole in the beginning of kernel address space reserved - * for a hypervisor. - */ - return (idx >= pgd_index(GUARD_HOLE_BASE_ADDR)) && - (idx < pgd_index(GUARD_HOLE_END_ADDR)); -#else - return false; -#endif -} - static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd, bool checkwx, bool dmesg) { - pgd_t *start = pgd; - pgprotval_t prot, eff; - int i; - struct pg_state st = {}; + const struct ptdump_range ptdump_ranges[] = { +#ifdef CONFIG_X86_64 - st.to_dmesg = dmesg; - st.check_wx = checkwx; - st.seq = m; - if (checkwx) - st.wx_pages = 0; +#define normalize_addr_shift (64 - (__VIRTUAL_MASK_SHIFT + 1)) +#define normalize_addr(u) ((signed long)((u) << normalize_addr_shift) >> \ + normalize_addr_shift) - for (i = 0; i < PTRS_PER_PGD; i++) { - st.current_address = normalize_addr(i * PGD_LEVEL_MULT); - if (!pgd_none(*start) && !is_hypervisor_range(i)) { - prot = pgd_flags(*start); -#ifdef CONFIG_X86_PAE - eff = _PAGE_USER | _PAGE_RW; + {0, PTRS_PER_PGD * PGD_LEVEL_MULT / 2}, + {normalize_addr(PTRS_PER_PGD * PGD_LEVEL_MULT / 2), ~0UL}, #else - eff = prot; + {0, ~0UL}, #endif - if (pgd_large(*start) || !pgd_present(*start)) { - note_page(&st, __pgprot(prot), eff, 1); - } else { - walk_p4d_level(&st, *start, eff, - i * PGD_LEVEL_MULT); - } - } else - note_page(&st, __pgprot(0), 0, 1); + {0, 0} +}; - cond_resched(); - start++; - } + struct pg_state st = { + .ptdump = { + .note_page = note_page, + .range = ptdump_ranges + }, + .to_dmesg = dmesg, + .check_wx = checkwx, + .seq = m + }; + + struct mm_struct fake_mm = { + .pgd = pgd + }; + init_rwsem(&fake_mm.mmap_sem); + + ptdump_walk_pgd(&st.ptdump, &fake_mm); - /* Flush out the last page */ - st.current_address = normalize_addr(PTRS_PER_PGD*PGD_LEVEL_MULT); - note_page(&st, __pgprot(0), 0, 0); if (!checkwx) return; if (st.wx_pages)