From 9d719d39aab41d3b8b6f259574dc29a27f60e66c Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 4 Sep 2020 17:41:27 +0200 Subject: [PATCH] s390/mm,ptdump: convert to generic page table dumper Make use of generic ptdump infrastructure. Reviewed-by: Vasily Gorbik Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik --- arch/s390/Kconfig | 1 + arch/s390/Kconfig.debug | 12 -- arch/s390/configs/debug_defconfig | 2 +- arch/s390/configs/defconfig | 2 +- arch/s390/mm/Makefile | 2 +- arch/s390/mm/dump_pagetables.c | 233 ++++++------------------------ 6 files changed, 51 insertions(+), 201 deletions(-) diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 8a6121f93709..85bf121211d1 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -120,6 +120,7 @@ config S390 select GENERIC_CPU_VULNERABILITIES select GENERIC_FIND_FIRST_BIT select GENERIC_GETTIMEOFDAY + select GENERIC_PTDUMP select GENERIC_SMP_IDLE_THREAD select GENERIC_TIME_VSYSCALL select HAVE_ALIGNED_STRUCT_PAGE if SLUB diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug index 761fe2b0b2f6..ab48b694ade8 100644 --- a/arch/s390/Kconfig.debug +++ b/arch/s390/Kconfig.debug @@ -3,17 +3,5 @@ config TRACE_IRQFLAGS_SUPPORT def_bool y -config S390_PTDUMP - bool "Export kernel pagetable layout to userspace via debugfs" - depends on DEBUG_KERNEL - 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 EARLY_PRINTK def_bool y diff --git a/arch/s390/configs/debug_defconfig b/arch/s390/configs/debug_defconfig index 0cf9a82326a8..f79eafb597cb 100644 --- a/arch/s390/configs/debug_defconfig +++ b/arch/s390/configs/debug_defconfig @@ -774,6 +774,7 @@ CONFIG_MAGIC_SYSRQ=y CONFIG_DEBUG_PAGEALLOC=y CONFIG_PAGE_OWNER=y CONFIG_DEBUG_RODATA_TEST=y +CONFIG_PTDUMP_DEBUGFS=y CONFIG_DEBUG_OBJECTS=y CONFIG_DEBUG_OBJECTS_SELFTEST=y CONFIG_DEBUG_OBJECTS_FREE=y @@ -819,7 +820,6 @@ CONFIG_SCHED_TRACER=y CONFIG_FTRACE_SYSCALLS=y CONFIG_BLK_DEV_IO_TRACE=y CONFIG_HIST_TRIGGERS=y -CONFIG_S390_PTDUMP=y CONFIG_NOTIFIER_ERROR_INJECTION=m CONFIG_NETDEV_NOTIFIER_ERROR_INJECT=m CONFIG_FAULT_INJECTION=y diff --git a/arch/s390/configs/defconfig b/arch/s390/configs/defconfig index 5df9759e8ff6..9593cc8a9efd 100644 --- a/arch/s390/configs/defconfig +++ b/arch/s390/configs/defconfig @@ -758,6 +758,7 @@ CONFIG_GDB_SCRIPTS=y CONFIG_FRAME_WARN=1024 CONFIG_DEBUG_SECTION_MISMATCH=y CONFIG_MAGIC_SYSRQ=y +CONFIG_PTDUMP_DEBUGFS=y CONFIG_DEBUG_MEMORY_INIT=y CONFIG_PANIC_ON_OOPS=y CONFIG_TEST_LOCKUP=m @@ -772,7 +773,6 @@ CONFIG_SCHED_TRACER=y CONFIG_FTRACE_SYSCALLS=y CONFIG_BLK_DEV_IO_TRACE=y CONFIG_HIST_TRIGGERS=y -CONFIG_S390_PTDUMP=y CONFIG_LKDTM=m CONFIG_PERCPU_TEST=m CONFIG_ATOMIC64_SELFTEST=y diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile index 3175413186b9..8ab9daeeace3 100644 --- a/arch/s390/mm/Makefile +++ b/arch/s390/mm/Makefile @@ -8,7 +8,7 @@ obj-y += page-states.o pageattr.o pgtable.o pgalloc.o obj-$(CONFIG_CMM) += cmm.o obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o -obj-$(CONFIG_S390_PTDUMP) += dump_pagetables.o +obj-$(CONFIG_PTDUMP_DEBUGFS) += dump_pagetables.o obj-$(CONFIG_PGSTE) += gmap.o KASAN_SANITIZE_kasan_init.o := n diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c index c2ac9b8ae612..93a29e2f13d4 100644 --- a/arch/s390/mm/dump_pagetables.c +++ b/arch/s390/mm/dump_pagetables.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include #include -#include #include #include #include @@ -42,10 +42,11 @@ static struct addr_marker address_markers[] = { }; struct pg_state { + struct ptdump_state ptdump; + struct seq_file *seq; int level; unsigned int current_prot; unsigned long start_address; - unsigned long current_address; const struct addr_marker *marker; }; @@ -63,215 +64,75 @@ static void print_prot(struct seq_file *m, unsigned int pr, int level) seq_puts(m, (pr & _PAGE_NOEXEC) ? "NX\n" : "X\n"); } -static void note_page(struct seq_file *m, struct pg_state *st, - unsigned int new_prot, int level) +static void note_page(struct ptdump_state *pt_st, unsigned long addr, int level, u64 val) { - static const char units[] = "KMGTPE"; int width = sizeof(unsigned long) * 2; + static const char units[] = "KMGTPE"; const char *unit = units; - unsigned int prot, cur; unsigned long delta; + struct pg_state *st; + struct seq_file *m; + unsigned int prot; - /* - * 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 = new_prot; - cur = st->current_prot; - - if (!st->level) { - /* First entry */ - st->current_prot = new_prot; - st->level = level; - st->marker = address_markers; + st = container_of(pt_st, struct pg_state, ptdump); + m = st->seq; + prot = val & (_PAGE_PROTECT | _PAGE_NOEXEC); + if (level == 4 && (val & _PAGE_INVALID)) + prot = _PAGE_INVALID; + /* For pmd_none() & friends val gets passed as zero. */ + if (level != 4 && !val) + prot = _PAGE_INVALID; + /* Final flush from generic code. */ + if (level == -1) + addr = max_addr; + if (st->level == -1) { seq_printf(m, "---[ %s ]---\n", st->marker->name); - } else if (prot != cur || level != st->level || - st->current_address >= st->marker[1].start_address) { - /* Print the actual finished series */ + st->start_address = addr; + st->current_prot = prot; + st->level = level; + } else if (prot != st->current_prot || level != st->level || + addr >= st->marker[1].start_address) { seq_printf(m, "0x%0*lx-0x%0*lx ", width, st->start_address, - width, st->current_address); - delta = (st->current_address - st->start_address) >> 10; + width, addr); + delta = (addr - st->start_address) >> 10; while (!(delta & 0x3ff) && unit[1]) { delta >>= 10; unit++; } seq_printf(m, "%9lu%c ", delta, *unit); print_prot(m, st->current_prot, st->level); - while (st->current_address >= st->marker[1].start_address) { + while (addr >= st->marker[1].start_address) { st->marker++; seq_printf(m, "---[ %s ]---\n", st->marker->name); } - st->start_address = st->current_address; - st->current_prot = new_prot; + st->start_address = addr; + st->current_prot = prot; st->level = level; } } -#ifdef CONFIG_KASAN -static void note_kasan_early_shadow_page(struct seq_file *m, - struct pg_state *st) -{ - unsigned int prot; - - prot = pte_val(*kasan_early_shadow_pte) & - (_PAGE_PROTECT | _PAGE_INVALID | _PAGE_NOEXEC); - note_page(m, st, prot, 4); -} -#endif - -/* - * The actual page table walker functions. In order to keep the - * implementation of print_prot() short, we only check and pass - * _PAGE_INVALID and _PAGE_PROTECT flags to note_page() if a region, - * segment or page table entry is invalid or read-only. - * After all it's just a hint that the current level being walked - * contains an invalid or read-only entry. - */ -static void walk_pte_level(struct seq_file *m, struct pg_state *st, - pmd_t *pmd, unsigned long addr) -{ - unsigned int prot; - pte_t *pte; - int i; - - for (i = 0; i < PTRS_PER_PTE && addr < max_addr; i++) { - st->current_address = addr; - pte = pte_offset_kernel(pmd, addr); - prot = pte_val(*pte) & - (_PAGE_PROTECT | _PAGE_INVALID | _PAGE_NOEXEC); - note_page(m, st, prot, 4); - addr += PAGE_SIZE; - } -} - -static void walk_pmd_level(struct seq_file *m, struct pg_state *st, - pud_t *pud, unsigned long addr) -{ - unsigned int prot; - pmd_t *pmd; - int i; - -#ifdef CONFIG_KASAN - if ((pud_val(*pud) & PAGE_MASK) == __pa(kasan_early_shadow_pmd)) { - note_kasan_early_shadow_page(m, st); - return; - } -#endif - - pmd = pmd_offset(pud, addr); - for (i = 0; i < PTRS_PER_PMD && addr < max_addr; i++, pmd++) { - st->current_address = addr; - if (!pmd_none(*pmd)) { - if (pmd_large(*pmd)) { - prot = pmd_val(*pmd) & - (_SEGMENT_ENTRY_PROTECT | - _SEGMENT_ENTRY_NOEXEC); - note_page(m, st, prot, 3); - } else - walk_pte_level(m, st, pmd, addr); - } else - note_page(m, st, _PAGE_INVALID, 3); - addr += PMD_SIZE; - } -} - -static void walk_pud_level(struct seq_file *m, struct pg_state *st, - p4d_t *p4d, unsigned long addr) -{ - unsigned int prot; - pud_t *pud; - int i; - -#ifdef CONFIG_KASAN - if ((p4d_val(*p4d) & PAGE_MASK) == __pa(kasan_early_shadow_pud)) { - note_kasan_early_shadow_page(m, st); - return; - } -#endif - - pud = pud_offset(p4d, addr); - for (i = 0; i < PTRS_PER_PUD && addr < max_addr; i++, pud++) { - st->current_address = addr; - if (!pud_none(*pud)) - if (pud_large(*pud)) { - prot = pud_val(*pud) & - (_REGION_ENTRY_PROTECT | - _REGION_ENTRY_NOEXEC); - note_page(m, st, prot, 2); - } else - walk_pmd_level(m, st, pud, addr); - else - note_page(m, st, _PAGE_INVALID, 2); - addr += PUD_SIZE; - } -} - -static void walk_p4d_level(struct seq_file *m, struct pg_state *st, - pgd_t *pgd, unsigned long addr) -{ - p4d_t *p4d; - int i; - -#ifdef CONFIG_KASAN - if ((pgd_val(*pgd) & PAGE_MASK) == __pa(kasan_early_shadow_p4d)) { - note_kasan_early_shadow_page(m, st); - return; - } -#endif - - p4d = p4d_offset(pgd, addr); - for (i = 0; i < PTRS_PER_P4D && addr < max_addr; i++, p4d++) { - st->current_address = addr; - if (!p4d_none(*p4d)) - walk_pud_level(m, st, p4d, addr); - else - note_page(m, st, _PAGE_INVALID, 2); - addr += P4D_SIZE; - } -} - -static void walk_pgd_level(struct seq_file *m) -{ - unsigned long addr = 0; - struct pg_state st; - pgd_t *pgd; - int i; - - memset(&st, 0, sizeof(st)); - for (i = 0; i < PTRS_PER_PGD && addr < max_addr; i++) { - st.current_address = addr; - pgd = pgd_offset_k(addr); - if (!pgd_none(*pgd)) - walk_p4d_level(m, &st, pgd, addr); - else - note_page(m, &st, _PAGE_INVALID, 1); - addr += PGDIR_SIZE; - cond_resched(); - } - /* Flush out the last page */ - st.current_address = max_addr; - note_page(m, &st, 0, 0); -} - static int ptdump_show(struct seq_file *m, void *v) { - walk_pgd_level(m); + struct pg_state st = { + .ptdump = { + .note_page = note_page, + .range = (struct ptdump_range[]) { + {.start = 0, .end = max_addr}, + {.start = 0, .end = 0}, + } + }, + .seq = m, + .level = -1, + .current_prot = 0, + .start_address = 0, + .marker = address_markers, + }; + + ptdump_walk_pgd(&st.ptdump, &init_mm, NULL); return 0; } - -static int ptdump_open(struct inode *inode, struct file *filp) -{ - return single_open(filp, ptdump_show, NULL); -} - -static const struct file_operations ptdump_fops = { - .open = ptdump_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; +DEFINE_SHOW_ATTRIBUTE(ptdump); static int pt_dump_init(void) {