summaryrefslogtreecommitdiffstats
path: root/mm/ptdump.c
diff options
context:
space:
mode:
authorSang-Heon Jeon <ekffu200098@gmail.com>2026-08-24 01:18:14 +0900
committerJulia Lawall <Julia.Lawall@inria.fr>2026-08-23 22:12:11 +0200
commit2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c (patch)
treedcc4da1d99f17541c5590ac63c77da4bf372a4ab /mm/ptdump.c
downloadlinux-stable-2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c.tar.gz
linux-stable-2bd30b8dc75b823dd7bbef9d7bc68e1fd7ecee5c.zip
coccinelle: alloc_cast: drop removed allocatorsgrafted
- pci_alloc_consistent() and pci_zalloc_consistent() were removed by commit 7968778914e5 ("PCI: Remove the deprecated "pci-dma-compat.h" API") - kmem_alloc() was removed by commit f078d4ea8276 ("xfs: convert kmem_alloc() to kmalloc()") - kmem_zalloc() was removed by commit 10634530f7ba ("xfs: convert kmem_zalloc() to kzalloc()") - kmem_zone_alloc() and kmem_zone_zalloc() were removed by commit bae633a4a283 ("xfs: remove xfs_zone_{alloc,zalloc} helpers") So drop them from the rules. No functional change. Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Diffstat (limited to 'mm/ptdump.c')
-rw-r--r--mm/ptdump.c219
1 files changed, 219 insertions, 0 deletions
diff --git a/mm/ptdump.c b/mm/ptdump.c
new file mode 100644
index 000000000..5851096e6
--- /dev/null
+++ b/mm/ptdump.c
@@ -0,0 +1,219 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/pagewalk.h>
+#include <linux/debugfs.h>
+#include <linux/ptdump.h>
+#include <linux/kasan.h>
+#include "internal.h"
+
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+/*
+ * This is an optimization for KASAN=y case. Since all kasan page tables
+ * eventually point to the kasan_early_shadow_page we could call note_page()
+ * right away without walking through lower level page tables. This saves
+ * us dozens of seconds (minutes for 5-level config) while checking for
+ * W+X mapping or reading kernel_page_tables debugfs file.
+ */
+static inline int note_kasan_page_table(struct mm_walk *walk,
+ unsigned long addr)
+{
+ struct ptdump_state *st = walk->private;
+
+ st->note_page_pte(st, addr, kasan_early_shadow_pte[0]);
+
+ walk->action = ACTION_CONTINUE;
+
+ return 0;
+}
+#endif
+
+static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ struct ptdump_state *st = walk->private;
+ pgd_t val = pgdp_get(pgd);
+
+#if CONFIG_PGTABLE_LEVELS > 4 && \
+ (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
+ if (pgd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_p4d)))
+ return note_kasan_page_table(walk, addr);
+#endif
+
+ if (st->effective_prot_pgd)
+ st->effective_prot_pgd(st, val);
+
+ if (pgd_leaf(val)) {
+ st->note_page_pgd(st, addr, val);
+ walk->action = ACTION_CONTINUE;
+ }
+
+ return 0;
+}
+
+static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ struct ptdump_state *st = walk->private;
+ p4d_t val = p4dp_get(p4d);
+
+#if CONFIG_PGTABLE_LEVELS > 3 && \
+ (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
+ if (p4d_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pud)))
+ return note_kasan_page_table(walk, addr);
+#endif
+
+ if (st->effective_prot_p4d)
+ st->effective_prot_p4d(st, val);
+
+ if (p4d_leaf(val)) {
+ st->note_page_p4d(st, addr, val);
+ walk->action = ACTION_CONTINUE;
+ }
+
+ return 0;
+}
+
+static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ struct ptdump_state *st = walk->private;
+ pud_t val = pudp_get(pud);
+
+#if CONFIG_PGTABLE_LEVELS > 2 && \
+ (defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS))
+ if (pud_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pmd)))
+ return note_kasan_page_table(walk, addr);
+#endif
+
+ if (st->effective_prot_pud)
+ st->effective_prot_pud(st, val);
+
+ if (pud_leaf(val)) {
+ st->note_page_pud(st, addr, val);
+ walk->action = ACTION_CONTINUE;
+ }
+
+ return 0;
+}
+
+static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ struct ptdump_state *st = walk->private;
+ pmd_t val = pmdp_get(pmd);
+
+#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
+ if (pmd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pte)))
+ return note_kasan_page_table(walk, addr);
+#endif
+
+ if (st->effective_prot_pmd)
+ st->effective_prot_pmd(st, val);
+ if (pmd_leaf(val)) {
+ st->note_page_pmd(st, addr, val);
+ walk->action = ACTION_CONTINUE;
+ }
+
+ return 0;
+}
+
+static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
+ unsigned long next, struct mm_walk *walk)
+{
+ struct ptdump_state *st = walk->private;
+ pte_t val = ptep_get(pte);
+
+ if (st->effective_prot_pte)
+ st->effective_prot_pte(st, val);
+
+ st->note_page_pte(st, addr, val);
+
+ return 0;
+}
+
+static int ptdump_hole(unsigned long addr, unsigned long next,
+ int depth, struct mm_walk *walk)
+{
+ struct ptdump_state *st = walk->private;
+ pte_t pte_zero = {0};
+ pmd_t pmd_zero = {0};
+ pud_t pud_zero = {0};
+ p4d_t p4d_zero = {0};
+ pgd_t pgd_zero = {0};
+
+ switch (depth) {
+ case 4:
+ st->note_page_pte(st, addr, pte_zero);
+ break;
+ case 3:
+ st->note_page_pmd(st, addr, pmd_zero);
+ break;
+ case 2:
+ st->note_page_pud(st, addr, pud_zero);
+ break;
+ case 1:
+ st->note_page_p4d(st, addr, p4d_zero);
+ break;
+ case 0:
+ st->note_page_pgd(st, addr, pgd_zero);
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static const struct mm_walk_ops ptdump_ops = {
+ .pgd_entry = ptdump_pgd_entry,
+ .p4d_entry = ptdump_p4d_entry,
+ .pud_entry = ptdump_pud_entry,
+ .pmd_entry = ptdump_pmd_entry,
+ .pte_entry = ptdump_pte_entry,
+ .pte_hole = ptdump_hole,
+};
+
+void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd)
+{
+ const struct ptdump_range *range = st->range;
+
+ get_online_mems();
+ mmap_write_lock(mm);
+ /* To stabilise kernel page tables we must hold the init_mm lock too. */
+ if (mm != &init_mm)
+ mmap_write_lock_nested(&init_mm, SINGLE_DEPTH_NESTING);
+
+ while (range->start != range->end) {
+ walk_page_range_debug(mm, range->start, range->end,
+ &ptdump_ops, pgd, st);
+ range++;
+ }
+
+ if (mm != &init_mm)
+ mmap_write_unlock(&init_mm);
+ mmap_write_unlock(mm);
+ put_online_mems();
+
+ /* Flush out the last page */
+ st->note_page_flush(st);
+}
+
+static int check_wx_show(struct seq_file *m, void *v)
+{
+ if (ptdump_check_wx())
+ seq_puts(m, "SUCCESS\n");
+ else
+ seq_puts(m, "FAILED\n");
+
+ return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(check_wx);
+
+static int ptdump_debugfs_init(void)
+{
+ debugfs_create_file("check_wx_pages", 0400, NULL, NULL, &check_wx_fops);
+
+ return 0;
+}
+
+device_initcall(ptdump_debugfs_init);