mm/init: Add 'rodata=off' boot cmdline parameter to disable read-only kernel mappings
authorKees Cook <keescook@chromium.org>
Wed, 17 Feb 2016 22:41:13 +0000 (14:41 -0800)
committerIngo Molnar <mingo@kernel.org>
Mon, 22 Feb 2016 07:51:37 +0000 (08:51 +0100)
commitd2aa1acad22f1bdd0cfa67b3861800e392254454
tree1f3b88086e364e87714dfcaeb66add3bbca81800
parente267d97b83d9cecc16c54825f9f3ac7f72dc1e1e
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>
Documentation/kernel-parameters.txt
init/main.c
kernel/debug/kdb/kdb_bp.c