Instead of providing our own callbacks for walking the page tables,
switch to using the generic version instead.

Signed-off-by: Steven Price <steven.pr...@arm.com>
---
 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            | 104 +++++++++-----------------------
 arch/arm64/mm/ptdump_debugfs.c  |   2 +-
 6 files changed, 37 insertions(+), 101 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 117b2541ef3d..4ff55b3ce8dc 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -97,6 +97,7 @@ 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
diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
index 69c9170bdd24..570dba4d4a0e 100644
--- a/arch/arm64/Kconfig.debug
+++ b/arch/arm64/Kconfig.debug
@@ -1,21 +1,4 @@
 
-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
@@ -41,7 +24,7 @@ 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.
 
diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h
index 9e948a93d26c..f8fecda7b61d 100644
--- a/arch/arm64/include/asm/ptdump.h
+++ b/arch/arm64/include/asm/ptdump.h
@@ -16,7 +16,7 @@
 #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>
@@ -32,15 +32,15 @@ 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()
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index 849c1df3d214..d91030f0ffee 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -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
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index ea20c1213498..e68df2ad8863 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -19,6 +19,7 @@
 #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>
 
@@ -69,6 +70,7 @@ static const 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;
@@ -172,6 +174,10 @@ 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,
@@ -234,9 +240,10 @@ 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, int 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 = 0;
 
@@ -289,83 +296,21 @@ static void note_page(struct pg_state *st, unsigned long 
addr, int level,
 
 }
 
-static int pud_entry(pud_t *pud, unsigned long addr,
-               unsigned long next, struct mm_walk *walk)
-{
-       struct pg_state *st = walk->private;
-       pud_t val = READ_ONCE(*pud);
-
-       if (pud_table(val))
-               return 0;
-
-       note_page(st, addr, 2, pud_val(val));
-
-       return 0;
-}
-
-static int pmd_entry(pmd_t *pmd, unsigned long addr,
-               unsigned long next, struct mm_walk *walk)
-{
-       struct pg_state *st = walk->private;
-       pmd_t val = READ_ONCE(*pmd);
-
-       if (pmd_table(val))
-               return 0;
-
-       note_page(st, addr, 3, pmd_val(val));
-
-       return 0;
-}
-
-static int pte_entry(pte_t *pte, unsigned long addr,
-               unsigned long next, struct mm_walk *walk)
-{
-       struct pg_state *st = walk->private;
-       pte_t val = READ_ONCE(*pte);
-
-       note_page(st, addr, 4, pte_val(val));
-
-       return 0;
-}
-
-static int pte_hole(unsigned long addr, unsigned long next,
-               struct mm_walk *walk)
-{
-       struct pg_state *st = walk->private;
-
-       note_page(st, addr, -1, 0);
-
-       return 0;
-}
-
-static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
-               unsigned long start)
-{
-       struct mm_walk walk = {
-               .mm = mm,
-               .private = st,
-               .pud_entry = pud_entry,
-               .pmd_entry = pmd_entry,
-               .pte_entry = pte_entry,
-               .pte_hole = pte_hole
-       };
-       down_read(&mm->mmap_sem);
-       walk_page_range(start, start | (((unsigned long)PTRS_PER_PGD <<
-                                        PGDIR_SHIFT) - 1),
-                       &walk);
-       up_read(&mm->mmap_sem);
-}
-
-void ptdump_walk_pgd(struct seq_file *m, struct ptdump_info *info)
+void ptdump_walk(struct seq_file *s, struct ptdump_info *info)
 {
        struct pg_state st = {
-               .seq = m,
+               .seq = s,
                .marker = info->markers,
+               .ptdump = {
+                       .note_page = note_page,
+                       .range = (struct ptdump_range[]){
+                               {info->base_addr, ~0UL},
+                               {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)
@@ -393,10 +338,17 @@ void ptdump_check_wx(void)
                        { -1, NULL},
                },
                .check_wx = true,
+               .ptdump = {
+                       .note_page = note_page,
+                       .range = (struct ptdump_range[]) {
+                               {VA_START, ~0UL},
+                               {0, 0}
+                       }
+               }
        };
 
-       walk_pgd(&st, &init_mm, VA_START);
-       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);
diff --git a/arch/arm64/mm/ptdump_debugfs.c b/arch/arm64/mm/ptdump_debugfs.c
index 064163f25592..1f2eae3e988b 100644
--- a/arch/arm64/mm/ptdump_debugfs.c
+++ b/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);
-- 
2.20.1

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