[PATCH v2 5/5] mm: ptdump: add check_wx_pages debugfs attribute
From: Christophe Leroy <hidden>
Date: 2024-01-30 10:36:56
Also in:
linux-arm-kernel, linux-mm, linux-riscv, linux-s390, lkml
Subsystem:
memory management, memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
Add a readable attribute in debugfs to trigger a W^X pages check at any time. To trigger the test, just read /sys/kernel/debug/check_wx_pages It will report FAILED if the test failed, SUCCESS otherwise. Detailed result is provided into dmesg. Signed-off-by: Christophe Leroy <redacted> --- v2: Make it a read attribute which reports SUCCESS/FAILED instead of only relying on kernel message log. --- mm/ptdump.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/mm/ptdump.c b/mm/ptdump.c
index 03c1bdae4a43..106e1d66e9f9 100644
--- a/mm/ptdump.c
+++ b/mm/ptdump.c@@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include <linux/pagewalk.h> +#include <linux/debugfs.h> #include <linux/ptdump.h> #include <linux/kasan.h>
@@ -163,3 +164,24 @@ void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd) /* Flush out the last page */ st->note_page(st, 0, -1, 0); } + +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);
--
2.43.0