+ mm-ptdump-add-check_wx_pages-debugfs-attribute.patch added to mm-unstable branch

+ mm-ptdump-add-check_wx_pages-debugfs-attribute.patch added to mm-unstable branch

[Andrew Morton]

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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days

------------------------------------------------------
From: Christophe Leroy <christophe.leroy@csgroup.eu>
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@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Phong Tran <tranmanphong@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Price <steven.price@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@csgroup.eu 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