This removes the CONFIG_DEBUG_RODATA option and makes it always enabled.

This simplifies the code and also makes it clearer that read-only mapped
memory is just as fundamental a security feature in kernel-space as it is
in user-space.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NKees 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: H. Peter Anvin <hpa@zytor.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/1455748879-21872-4-git-send-email-keescook@chromium.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Cc: Joerg Roedel <joerg.roedel@amd.com> (supporter:AMD IOMMU (AMD-VI))
Cc: iommu@lists.linux-foundation.org (open list:AMD IOMMU (AMD-VI))
Link: http://lkml.kernel.org/r/1305918786-7239-3-git-send-email-padovan@profusion.mobiSigned-off-by: NIngo Molnar <mingo@elte.hu>

After an experimental cleanup of <linux/percpu.h>, these files were
exposed as invoking kmalloc() without including <linux/slab.h>.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The .rodata section shouldn't just be read-only,
but also non-executable. This is free since we've broken
up the 2MB page already anyway.

also update test_nx to check for this.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use the _ASM_EXTABLE macro from <asm/asm.h>, instead of open-coding
__ex_table entires in arch/x86/kernel/test_nx.c.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

fix this modular build bug:

>   CC [M]  arch/x86/kernel/test_nx.o
> {standard input}: Assembler messages:
> {standard input}:58: Error: cannot represent relocation type BFD_RELOC_64
> {standard input}:59: Error: cannot represent relocation type BFD_RELOC_64
> make[2]: *** [arch/x86/kernel/test_nx.o] Error 1
> make[1]: *** [arch/x86/kernel] Error 2
Reported-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Latest update; I now have 4 NX tests, but 2 fail so they're #if 0'd.
I also cleaned up the NX test code quite a bit, and got rid of the ugly
exception table sorting stuff.

From: Arjan van de Ven <arjan@linux.intel.com>

This patch adds testcases for the CONFIG_DEBUG_RODATA configuration option
as well as the NX CPU feature/mappings. Both testcases can move to tests/
once that patch gets merged into mainline.
(I'm half considering moving the rodata test into mm/init.c but I'll
wait with that until init.c is unified)

As part of this I had to fix a not-quite-right alignment in the vmlinux.lds.h
for the RODATA sections, which lead to 1 page less being marked read only.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>