arm64: mm: convert mm/dump.c to use walk_page_range()
authorSteven Price <steven.price@arm.com>
Tue, 4 Feb 2020 01:36:29 +0000 (17:36 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 4 Feb 2020 03:05:25 +0000 (03:05 +0000)
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/20191218162402.45610-22-steven.price@arm.com
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Liang, Kan" <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zong Li <zong.li@sifive.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/arm64/Kconfig
arch/arm64/Kconfig.debug
arch/arm64/include/asm/ptdump.h
arch/arm64/mm/Makefile
arch/arm64/mm/dump.c
arch/arm64/mm/mmu.c
arch/arm64/mm/ptdump_debugfs.c
drivers/firmware/efi/arm-runtime.c

index de238b5..21de6ff 100644 (file)
@@ -104,6 +104,7 @@ 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
index cf09010..1c906d9 100644 (file)
@@ -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.
 
index 0b8e726..38187f7 100644 (file)
@@ -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()
index 849c1df..d91030f 100644 (file)
@@ -4,8 +4,8 @@ obj-y                           := dma-mapping.o extable.o fault.o init.o \
                                   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
index 0a920b5..f8c3ef7 100644 (file)
@@ -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_markers[] = {
  * 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;
@@ -179,6 +181,10 @@ 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,
@@ -241,11 +247,15 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
        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;
@@ -293,85 +303,27 @@ static void note_page(struct pg_state *st, unsigned long addr, unsigned level,
 
 }
 
-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)
-{
-       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)
+void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
 {
-       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)
@@ -399,10 +351,17 @@ 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);
index 40797cb..128f708 100644 (file)
@@ -943,13 +943,13 @@ int __init arch_ioremap_pud_supported(void)
         * 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)
index 064163f..1f2eae3 100644 (file)
@@ -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);
index 899b803..9dda260 100644 (file)
@@ -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 = {