From: Steven Price <steven.price@xxxxxxx> Subject: arm64: mm: convert mm/dump.c to use walk_page_range() Now walk_page_range() can walk kernel page tables, we can switch the arm64 ptdump code over to using it, simplifying the code. Link: http://lkml.kernel.org/r/20191028135910.33253-22-steven.price@xxxxxxx Signed-off-by: Steven Price <steven.price@xxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx> Cc: Alexander Potapenko <glider@xxxxxxxxxx> Cc: Alexandre Ghiti <alex@xxxxxxxx> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: David S. Miller <davem@xxxxxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: James Hogan <jhogan@xxxxxxxxxx> Cc: James Morse <james.morse@xxxxxxx> Cc: "Liang, Kan" <kan.liang@xxxxxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Palmer Dabbelt <palmer@xxxxxxxxxx> Cc: Paul Burton <paul.burton@xxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxx> Cc: Shiraz Hashim <shashim@xxxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx> Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Zong Li <zong.li@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/arm64/Kconfig | 1 arch/arm64/Kconfig.debug | 19 ---- arch/arm64/include/asm/ptdump.h | 8 - arch/arm64/mm/Makefile | 4 arch/arm64/mm/dump.c | 117 ++++++++------------------- arch/arm64/mm/mmu.c | 4 arch/arm64/mm/ptdump_debugfs.c | 2 drivers/firmware/efi/arm-runtime.c | 2 8 files changed, 50 insertions(+), 107 deletions(-) --- a/arch/arm64/include/asm/ptdump.h~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/arch/arm64/include/asm/ptdump.h @@ -5,7 +5,7 @@ #ifndef __ASM_PTDUMP_H #define __ASM_PTDUMP_H -#ifdef CONFIG_ARM64_PTDUMP_CORE +#ifdef CONFIG_PTDUMP_CORE #include <linux/mm_types.h> #include <linux/seq_file.h> @@ -21,15 +21,15 @@ struct ptdump_info { unsigned long base_addr; }; -void ptdump_walk_pgd(struct seq_file *s, struct ptdump_info *info); -#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS +void ptdump_walk(struct seq_file *s, struct ptdump_info *info); +#ifdef CONFIG_PTDUMP_DEBUGFS void ptdump_debugfs_register(struct ptdump_info *info, const char *name); #else static inline void ptdump_debugfs_register(struct ptdump_info *info, const char *name) { } #endif void ptdump_check_wx(void); -#endif /* CONFIG_ARM64_PTDUMP_CORE */ +#endif /* CONFIG_PTDUMP_CORE */ #ifdef CONFIG_DEBUG_WX #define debug_checkwx() ptdump_check_wx() --- a/arch/arm64/Kconfig~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/arch/arm64/Kconfig @@ -103,6 +103,7 @@ config ARM64 select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL select GENERIC_PCI_IOMAP + select GENERIC_PTDUMP select GENERIC_SCHED_CLOCK select GENERIC_SMP_IDLE_THREAD select GENERIC_STRNCPY_FROM_USER --- a/arch/arm64/Kconfig.debug~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/arch/arm64/Kconfig.debug @@ -1,22 +1,5 @@ # SPDX-License-Identifier: GPL-2.0-only -config ARM64_PTDUMP_CORE - def_bool n - -config ARM64_PTDUMP_DEBUGFS - bool "Export kernel pagetable layout to userspace via debugfs" - depends on DEBUG_KERNEL - select ARM64_PTDUMP_CORE - select DEBUG_FS - 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 PID_IN_CONTEXTIDR bool "Write the current PID to the CONTEXTIDR register" help @@ -42,7 +25,7 @@ config ARM64_RANDOMIZE_TEXT_OFFSET config DEBUG_WX bool "Warn on W+X mappings at boot" - select ARM64_PTDUMP_CORE + select PTDUMP_CORE ---help--- Generate a warning if any W+X mappings are found at boot. --- a/arch/arm64/mm/dump.c~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/arch/arm64/mm/dump.c @@ -15,6 +15,7 @@ #include <linux/io.h> #include <linux/init.h> #include <linux/mm.h> +#include <linux/ptdump.h> #include <linux/sched.h> #include <linux/seq_file.h> @@ -75,10 +76,11 @@ static struct addr_marker address_marker * dumps out a description of the range. */ struct pg_state { + struct ptdump_state ptdump; struct seq_file *seq; const struct addr_marker *marker; unsigned long start_address; - unsigned level; + int level; u64 current_prot; bool check_wx; unsigned long wx_pages; @@ -178,6 +180,10 @@ static struct pg_level pg_level[] = { .name = "PGD", .bits = pte_bits, .num = ARRAY_SIZE(pte_bits), + }, { /* p4d */ + .name = "P4D", + .bits = pte_bits, + .num = ARRAY_SIZE(pte_bits), }, { /* pud */ .name = (CONFIG_PGTABLE_LEVELS > 3) ? "PUD" : "PGD", .bits = pte_bits, @@ -240,11 +246,15 @@ static void note_prot_wx(struct pg_state st->wx_pages += (addr - st->start_address) / PAGE_SIZE; } -static void note_page(struct pg_state *st, unsigned long addr, unsigned level, - u64 val) +static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, + unsigned long val) { + struct pg_state *st = container_of(pt_st, struct pg_state, ptdump); static const char units[] = "KMGTPE"; - u64 prot = val & pg_level[level].mask; + u64 prot = 0; + + if (level >= 0) + prot = val & pg_level[level].mask; if (!st->level) { st->level = level; @@ -292,85 +302,27 @@ static void note_page(struct pg_state *s } -static void walk_pte(struct pg_state *st, pmd_t *pmdp, unsigned long start, - unsigned long end) -{ - unsigned long addr = start; - pte_t *ptep = pte_offset_kernel(pmdp, start); - - do { - note_page(st, addr, 4, READ_ONCE(pte_val(*ptep))); - } while (ptep++, addr += PAGE_SIZE, addr != end); -} - -static void walk_pmd(struct pg_state *st, pud_t *pudp, unsigned long start, - unsigned long end) +void ptdump_walk(struct seq_file *s, struct ptdump_info *info) { - unsigned long next, addr = start; - pmd_t *pmdp = pmd_offset(pudp, start); - - do { - pmd_t pmd = READ_ONCE(*pmdp); - next = pmd_addr_end(addr, end); - - if (pmd_none(pmd) || pmd_sect(pmd)) { - note_page(st, addr, 3, pmd_val(pmd)); - } else { - BUG_ON(pmd_bad(pmd)); - walk_pte(st, pmdp, addr, next); - } - } while (pmdp++, addr = next, addr != end); -} - -static void walk_pud(struct pg_state *st, pgd_t *pgdp, unsigned long start, - unsigned long end) -{ - unsigned long next, addr = start; - pud_t *pudp = pud_offset(pgdp, start); - - do { - pud_t pud = READ_ONCE(*pudp); - next = pud_addr_end(addr, end); - - if (pud_none(pud) || pud_sect(pud)) { - note_page(st, addr, 2, pud_val(pud)); - } else { - BUG_ON(pud_bad(pud)); - walk_pmd(st, pudp, addr, next); - } - } while (pudp++, addr = next, addr != end); -} + unsigned long end = ~0UL; + struct pg_state st; -static void walk_pgd(struct pg_state *st, struct mm_struct *mm, - unsigned long start) -{ - unsigned long end = (start < TASK_SIZE_64) ? TASK_SIZE_64 : 0; - unsigned long next, addr = start; - pgd_t *pgdp = pgd_offset(mm, start); - - do { - pgd_t pgd = READ_ONCE(*pgdp); - next = pgd_addr_end(addr, end); - - if (pgd_none(pgd)) { - note_page(st, addr, 1, pgd_val(pgd)); - } else { - BUG_ON(pgd_bad(pgd)); - walk_pud(st, pgdp, addr, next); - } - } while (pgdp++, addr = next, addr != end); -} + if (info->base_addr < TASK_SIZE_64) + end = TASK_SIZE_64; -void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info) -{ - struct pg_state st = { - .seq = m, + st = (struct pg_state){ + .seq = s, .marker = info->markers, + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]){ + {info->base_addr, end}, + {0, 0} + } + } }; - walk_pgd(&st, info->mm, info->base_addr); - - note_page(&st, 0, 0, 0); + ptdump_walk_pgd(&st.ptdump, info->mm); } static void ptdump_initialize(void) @@ -398,10 +350,17 @@ void ptdump_check_wx(void) { -1, NULL}, }, .check_wx = true, + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]) { + {PAGE_OFFSET, ~0UL}, + {0, 0} + } + } }; - walk_pgd(&st, &init_mm, PAGE_OFFSET); - note_page(&st, 0, 0, 0); + ptdump_walk_pgd(&st.ptdump, &init_mm); + if (st.wx_pages || st.uxn_pages) pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found, %lu non-UXN pages found\n", st.wx_pages, st.uxn_pages); --- a/arch/arm64/mm/Makefile~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/arch/arm64/mm/Makefile @@ -4,8 +4,8 @@ obj-y := dma-mapping.o extable.o faul ioremap.o mmap.o pgd.o mmu.o \ context.o proc.o pageattr.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o -obj-$(CONFIG_ARM64_PTDUMP_CORE) += dump.o -obj-$(CONFIG_ARM64_PTDUMP_DEBUGFS) += ptdump_debugfs.o +obj-$(CONFIG_PTDUMP_CORE) += dump.o +obj-$(CONFIG_PTDUMP_DEBUGFS) += ptdump_debugfs.o obj-$(CONFIG_NUMA) += numa.o obj-$(CONFIG_DEBUG_VIRTUAL) += physaddr.o KASAN_SANITIZE_physaddr.o += n --- a/arch/arm64/mm/mmu.c~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/arch/arm64/mm/mmu.c @@ -943,13 +943,13 @@ int __init arch_ioremap_pud_supported(vo * SW table walks can't handle removal of intermediate entries. */ return IS_ENABLED(CONFIG_ARM64_4K_PAGES) && - !IS_ENABLED(CONFIG_ARM64_PTDUMP_DEBUGFS); + !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS); } int __init arch_ioremap_pmd_supported(void) { /* See arch_ioremap_pud_supported() */ - return !IS_ENABLED(CONFIG_ARM64_PTDUMP_DEBUGFS); + return !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS); } int pud_set_huge(pud_t *pudp, phys_addr_t phys, pgprot_t prot) --- a/arch/arm64/mm/ptdump_debugfs.c~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/arch/arm64/mm/ptdump_debugfs.c @@ -7,7 +7,7 @@ static int ptdump_show(struct seq_file *m, void *v) { struct ptdump_info *info = m->private; - ptdump_walk_pgd(m, info); + ptdump_walk(m, info); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); --- a/drivers/firmware/efi/arm-runtime.c~arm64-mm-convert-mm-dumpc-to-use-walk_page_range +++ a/drivers/firmware/efi/arm-runtime.c @@ -27,7 +27,7 @@ extern u64 efi_system_table; -#ifdef CONFIG_ARM64_PTDUMP_DEBUGFS +#if defined(CONFIG_PTDUMP_DEBUGFS) && defined(CONFIG_ARM64) #include <asm/ptdump.h> static struct ptdump_info efi_ptdump_info = { _
