The patch titled
Subject: mm: ptdump: add check_wx_pages debugfs attribute
has been added to the -mm mm-unstable branch. Its filename is
mm-ptdump-add-check_wx_pages-debugfs-attribute.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-ptdump-add-check_wx_pages-debugfs-attribute.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Subject: mm: ptdump: add check_wx_pages debugfs attribute
Date: Tue, 30 Jan 2024 11:34:36 +0100
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.
Link: https://lkml.kernel.org/r/e947fb1a9f3f5466344823e532d343ff194ae03d.1706610398.git.christophe.leroy@xxxxxxxxxx
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@xxxxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: "Naveen N. Rao" <naveen.n.rao@xxxxxxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxx>
Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Phong Tran <tranmanphong@xxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Steven Price <steven.price@xxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/ptdump.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
--- a/mm/ptdump.c~mm-ptdump-add-check_wx_pages-debugfs-attribute
+++ a/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
/* 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);
_
Patches currently in -mm which might be from christophe.leroy@xxxxxxxxxx are
arm-ptdump-rename-config_debug_wx-to-config_arm_debug_wx.patch
arm64-powerpc-riscv-s390-x86-ptdump-refactor-config_debug_wx.patch
powerpcs390-ptdump-define-ptdump_check_wx-regardless-of-config_debug_wx.patch
mm-ptdump-have-ptdump_check_wx-return-bool.patch
mm-ptdump-add-check_wx_pages-debugfs-attribute.patch
