diff options
| -rw-r--r-- | arch/powerpc/Kconfig | 2 | ||||
| -rw-r--r-- | arch/powerpc/Kconfig.debug | 30 | ||||
| -rw-r--r-- | arch/powerpc/mm/Makefile | 2 | ||||
| -rw-r--r-- | arch/powerpc/mm/mmu_decl.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/mm/ptdump/Makefile | 9 | ||||
| -rw-r--r-- | arch/powerpc/mm/ptdump/ptdump.c | 146 |
6 files changed, 47 insertions, 144 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index d01e3401581d..ec866085ff8b 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -123,6 +123,7 @@ config PPC select ARCH_HAS_COPY_MC if PPC64 select ARCH_HAS_DEBUG_VIRTUAL select ARCH_HAS_DEBUG_VM_PGTABLE + select ARCH_HAS_DEBUG_WX if STRICT_KERNEL_RWX select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_DMA_MAP_DIRECT if PPC_PSERIES select ARCH_HAS_ELF_RANDOMIZE @@ -182,6 +183,7 @@ config PPC select GENERIC_IRQ_SHOW select GENERIC_IRQ_SHOW_LEVEL select GENERIC_PCI_IOMAP if PCI + select GENERIC_PTDUMP select GENERIC_SMP_IDLE_THREAD select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNLEN_USER diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index 205cd77f321f..192f0ed0097f 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -365,36 +365,6 @@ config FAIL_IOMMU If you are unsure, say N. -config PPC_PTDUMP - bool "Export kernel pagetable layout to userspace via debugfs" - depends on DEBUG_KERNEL && DEBUG_FS - help - This option exports the state of the kernel pagetables to a - debugfs file. This is only useful for kernel developers who are - working in architecture specific areas of the kernel - probably - not a good idea to enable this feature in a production kernel. - - If you are unsure, say N. - -config PPC_DEBUG_WX - bool "Warn on W+X mappings at boot" - depends on PPC_PTDUMP && STRICT_KERNEL_RWX - help - Generate a warning if any W+X mappings are found at boot. - - This is useful for discovering cases where the kernel is leaving - W+X mappings after applying NX, as such mappings are a security risk. - - Note that even if the check fails, your kernel is possibly - still fine, as W+X mappings are not a security hole in - themselves, what they do is that they make the exploitation - of other unfixed kernel bugs easier. - - There is no runtime or memory usage effect of this option - once the kernel has booted up - it's a one time check. - - If in doubt, say "Y". - config PPC_FAST_ENDIAN_SWITCH bool "Deprecated fast endian-switch syscall" depends on DEBUG_KERNEL && PPC_BOOK3S_64 diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile index eae4ec2988fc..df8172da2301 100644 --- a/arch/powerpc/mm/Makefile +++ b/arch/powerpc/mm/Makefile @@ -18,5 +18,5 @@ obj-$(CONFIG_PPC_MM_SLICES) += slice.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o obj-$(CONFIG_PPC_COPRO_BASE) += copro_fault.o -obj-$(CONFIG_PPC_PTDUMP) += ptdump/ +obj-$(CONFIG_PTDUMP_CORE) += ptdump/ obj-$(CONFIG_KASAN) += kasan/ diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 7dac910c0b21..dd1cabc2ea0f 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -180,7 +180,7 @@ static inline void mmu_mark_rodata_ro(void) { } void __init mmu_mapin_immr(void); #endif -#ifdef CONFIG_PPC_DEBUG_WX +#ifdef CONFIG_DEBUG_WX void ptdump_check_wx(void); #else static inline void ptdump_check_wx(void) { } diff --git a/arch/powerpc/mm/ptdump/Makefile b/arch/powerpc/mm/ptdump/Makefile index 712762be3cb1..4050cbb55acf 100644 --- a/arch/powerpc/mm/ptdump/Makefile +++ b/arch/powerpc/mm/ptdump/Makefile @@ -5,5 +5,10 @@ obj-y += ptdump.o obj-$(CONFIG_4xx) += shared.o obj-$(CONFIG_PPC_8xx) += 8xx.o obj-$(CONFIG_PPC_BOOK3E_MMU) += shared.o -obj-$(CONFIG_PPC_BOOK3S_32) += shared.o bats.o segment_regs.o -obj-$(CONFIG_PPC_BOOK3S_64) += book3s64.o hashpagetable.o +obj-$(CONFIG_PPC_BOOK3S_32) += shared.o +obj-$(CONFIG_PPC_BOOK3S_64) += book3s64.o + +ifdef CONFIG_PTDUMP_DEBUGFS +obj-$(CONFIG_PPC_BOOK3S_32) += bats.o segment_regs.o +obj-$(CONFIG_PPC_BOOK3S_64) += hashpagetable.o +endif diff --git a/arch/powerpc/mm/ptdump/ptdump.c b/arch/powerpc/mm/ptdump/ptdump.c index fb531bc64fc5..2d80d775d15e 100644 --- a/arch/powerpc/mm/ptdump/ptdump.c +++ b/arch/powerpc/mm/ptdump/ptdump.c @@ -16,6 +16,7 @@ #include <linux/io.h> #include <linux/mm.h> #include <linux/highmem.h> +#include <linux/ptdump.h> #include <linux/sched.h> #include <linux/seq_file.h> #include <asm/fixmap.h> @@ -54,6 +55,7 @@ * */ struct pg_state { + struct ptdump_state ptdump; struct seq_file *seq; const struct addr_marker *marker; unsigned long start_address; @@ -102,6 +104,11 @@ static struct addr_marker address_markers[] = { { -1, NULL }, }; +static struct ptdump_range ptdump_range[] __ro_after_init = { + {TASK_SIZE_MAX, ~0UL}, + {0, 0} +}; + #define pt_dump_seq_printf(m, fmt, args...) \ ({ \ if (m) \ @@ -204,10 +211,10 @@ static void note_page_update_state(struct pg_state *st, unsigned long addr, int } } -static void note_page(struct pg_state *st, unsigned long addr, - int level, u64 val, unsigned long page_size) +static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, u64 val) { u64 flag = level >= 0 ? val & pg_level[level].mask : 0; + struct pg_state *st = container_of(pt_st, struct pg_state, ptdump); /* At first no level is set */ if (st->level == -1) { @@ -245,94 +252,6 @@ static void note_page(struct pg_state *st, unsigned long addr, } } -static void walk_pte(struct pg_state *st, pmd_t *pmd, unsigned long start) -{ - pte_t *pte = pte_offset_kernel(pmd, 0); - unsigned long addr; - unsigned int i; - - for (i = 0; i < PTRS_PER_PTE; i++, pte++) { - addr = start + i * PAGE_SIZE; - note_page(st, addr, 4, pte_val(*pte), PAGE_SIZE); - - } -} - -static void walk_hugepd(struct pg_state *st, hugepd_t *phpd, unsigned long start, - int pdshift, int level) -{ -#ifdef CONFIG_ARCH_HAS_HUGEPD - unsigned int i; - int shift = hugepd_shift(*phpd); - int ptrs_per_hpd = pdshift - shift > 0 ? 1 << (pdshift - shift) : 1; - - if (start & ((1 << shift) - 1)) - return; - - for (i = 0; i < ptrs_per_hpd; i++) { - unsigned long addr = start + (i << shift); - pte_t *pte = hugepte_offset(*phpd, addr, pdshift); - - note_page(st, addr, level + 1, pte_val(*pte), 1 << shift); - } -#endif -} - -static void walk_pmd(struct pg_state *st, pud_t *pud, unsigned long start) -{ - pmd_t *pmd = pmd_offset(pud, 0); - unsigned long addr; - unsigned int i; - - for (i = 0; i < PTRS_PER_PMD; i++, pmd++) { - addr = start + i * PMD_SIZE; - if (!pmd_none(*pmd) && !pmd_is_leaf(*pmd)) - /* pmd exists */ - walk_pte(st, pmd, addr); - else - note_page(st, addr, 3, pmd_val(*pmd), PMD_SIZE); - } -} - -static void walk_pud(struct pg_state *st, p4d_t *p4d, unsigned long start) -{ - pud_t *pud = pud_offset(p4d, 0); - unsigned long addr; - unsigned int i; - - for (i = 0; i < PTRS_PER_PUD; i++, pud++) { - addr = start + i * PUD_SIZE; - if (!pud_none(*pud) && !pud_is_leaf(*pud)) - /* pud exists */ - walk_pmd(st, pud, addr); - else - note_page(st, addr, 2, pud_val(*pud), PUD_SIZE); - } -} - -static void walk_pagetables(struct pg_state *st) -{ - unsigned int i; - unsigned long addr = st->start_address & PGDIR_MASK; - pgd_t *pgd = pgd_offset_k(addr); - - /* - * Traverse the linux pagetable structure and dump pages that are in - * the hash pagetable. - */ - for (i = pgd_index(addr); i < PTRS_PER_PGD; i++, pgd++, addr += PGDIR_SIZE) { - p4d_t *p4d = p4d_offset(pgd, 0); - - if (p4d_none(*p4d) || p4d_is_leaf(*p4d)) - note_page(st, addr, 1, p4d_val(*p4d), PGDIR_SIZE); - else if (is_hugepd(__hugepd(p4d_val(*p4d)))) - walk_hugepd(st, (hugepd_t *)p4d, addr, PGDIR_SHIFT, 1); - else - /* p4d exists */ - walk_pud(st, p4d, addr); - } -} - static void populate_markers(void) { int i = 0; @@ -383,17 +302,14 @@ static int ptdump_show(struct seq_file *m, void *v) .seq = m, .marker = address_markers, .level = -1, - .start_address = IS_ENABLED(CONFIG_PPC64) ? PAGE_OFFSET : TASK_SIZE, + .ptdump = { + .note_page = note_page, + .range = ptdump_range, + } }; -#ifdef CONFIG_PPC64 - if (!radix_enabled()) - st.start_address = KERN_VIRT_START; -#endif - /* Traverse kernel page tables */ - walk_pagetables(&st); - note_page(&st, 0, -1, 0, 0); + ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); return 0; } @@ -409,23 +325,24 @@ static void build_pgtable_complete_mask(void) pg_level[i].mask |= pg_level[i].flag[j].mask; } -#ifdef CONFIG_PPC_DEBUG_WX +#ifdef CONFIG_DEBUG_WX void ptdump_check_wx(void) { struct pg_state st = { .seq = NULL, - .marker = address_markers, + .marker = (struct addr_marker[]) { + { 0, NULL}, + { -1, NULL}, + }, .level = -1, .check_wx = true, - .start_address = IS_ENABLED(CONFIG_PPC64) ? PAGE_OFFSET : TASK_SIZE, + .ptdump = { + .note_page = note_page, + .range = ptdump_range, + } }; -#ifdef CONFIG_PPC64 - if (!radix_enabled()) - st.start_address = KERN_VIRT_START; -#endif - - walk_pagetables(&st); + ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); if (st.wx_pages) pr_warn("Checked W+X mappings: FAILED, %lu W+X pages found\n", @@ -435,12 +352,21 @@ void ptdump_check_wx(void) } #endif -static int ptdump_init(void) +static int __init ptdump_init(void) { +#ifdef CONFIG_PPC64 + if (!radix_enabled()) + ptdump_range[0].start = KERN_VIRT_START; + else + ptdump_range[0].start = PAGE_OFFSET; +#endif + populate_markers(); build_pgtable_complete_mask(); - debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, - &ptdump_fops); + + if (IS_ENABLED(CONFIG_PTDUMP_DEBUGFS)) + debugfs_create_file("kernel_page_tables", 0400, NULL, NULL, &ptdump_fops); + return 0; } device_initcall(ptdump_init); |