x86/mm: Remove CONFIG_DEBUG_NX_TEST

Browse source

CONFIG_DEBUG_NX_TEST has been broken since CONFIG_DEBUG_SET_MODULE_RONX=y
was added in v2.6.37 via:

  84e1c6bb38 ("x86: Add RO/NX protection for loadable kernel modules")

since the exception table was then made read-only.

Additionally, the manually constructed extables were never fixed when
relative extables were introduced in v3.5 via:

  706276543b ("x86, extable: Switch to relative exception table entries")

However, relative extables won't work for test_nx.c, since test instruction
memory areas may be more than INT_MAX away from an executable fixup
(e.g. stack and heap too far away from executable memory with the fixup).

Since clearly no one has been using this code for a while now, and similar
tests exist in LKDTM, this should just be removed entirely.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jinbum Park <jinb.park7@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170131003711.GA74048@beast
Signed-off-by: Ingo Molnar <mingo@kernel.org>

...

This commit is contained in:

Kees Cook 2017-01-30 16:37:11 -08:00 • committed by Ingo Molnar

parent 459fbe0069

commit 3ad38ceb27

3 changed files with 0 additions and 182 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

8

arch/x86/Kconfig.debug

View file

1

arch/x86/kernel/Makefile

View file

173

arch/x86/kernel/test_nx.c

View file