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authorKees Cook <keescook@chromium.org>2016-02-17 14:41:13 -0800
committerIngo Molnar <mingo@kernel.org>2016-02-22 08:51:37 +0100
commitd2aa1acad22f1bdd0cfa67b3861800e392254454 (patch)
tree1f3b88086e364e87714dfcaeb66add3bbca81800 /Documentation
parentasm-generic: Consolidate mark_rodata_ro() (diff)
downloadlinux-dev-d2aa1acad22f1bdd0cfa67b3861800e392254454.tar.xz
linux-dev-d2aa1acad22f1bdd0cfa67b3861800e392254454.zip
mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
It may be useful to debug writes to the readonly sections of memory, so provide a cmdline "rodata=off" to allow for this. This can be expanded in the future to support "log" and "write" modes, but that will need to be architecture-specific. This also makes KDB software breakpoints more usable, as read-only mappings can now be disabled on any kernel. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: David Brown <david.brown@linaro.org> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathias Krause <minipli@googlemail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: PaX Team <pageexec@freemail.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kernel-hardening@lists.openwall.com Cc: linux-arch <linux-arch@vger.kernel.org> Link: http://lkml.kernel.org/r/1455748879-21872-3-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kernel-parameters.txt4
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9a53c929f017..000336733a6a 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3491,6 +3491,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ro [KNL] Mount root device read-only on boot
+ rodata= [KNL]
+ on Mark read-only kernel memory as read-only (default).
+ off Leave read-only kernel memory writable for debugging.
+
root= [KNL] Root filesystem
See name_to_dev_t comment in init/do_mounts.c.