linux_dsm_epyc7002/arch
Dave Hansen 639d6aafe4 x86/mm: Do not forbid _PAGE_RW before init for __ro_after_init
__ro_after_init data gets stuck in the .rodata section.  That's normally
fine because the kernel itself manages the R/W properties.

But, if we run __change_page_attr() on an area which is __ro_after_init,
the .rodata checks will trigger and force the area to be immediately
read-only, even if it is early-ish in boot.  This caused problems when
trying to clear the _PAGE_GLOBAL bit for these area in the PTI code:
it cleared _PAGE_GLOBAL like I asked, but also took it up on itself
to clear _PAGE_RW.  The kernel then oopses the next time it wrote to
a __ro_after_init data structure.

To fix this, add the kernel_set_to_readonly check, just like we have
for kernel text, just a few lines below in this function.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20180406205514.8D898241@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-04-12 09:05:59 +02:00
..
alpha Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 11:06:34 -07:00
arc ARC fixes for 4.16-rc4 2018-03-01 14:32:23 -08:00
arm Merge branch 'x86-dma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:18:45 -07:00
arm64 Merge branch 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:46:37 -07:00
blackfin unify {de,}mangle_poll(), get rid of kernel-side POLL... 2018-02-11 14:37:22 -08:00
c6x The core framework has a handful of patches this time around, mostly due 2018-02-01 16:56:07 -08:00
cris bug.h: work around GCC PR82365 in BUG() 2018-02-21 15:35:43 -08:00
frv unify {de,}mangle_poll(), get rid of kernel-side POLL... 2018-02-11 14:37:22 -08:00
h8300 h8300: remove extraneous __BIG_ENDIAN definition 2018-03-22 17:07:01 -07:00
hexagon The core framework has a handful of patches this time around, mostly due 2018-02-01 16:56:07 -08:00
ia64 ia64/err-inject: fix spelling mistake: "capapbilities" -> "capabilities" 2018-03-05 14:44:53 -08:00
m32r The core framework has a handful of patches this time around, mostly due 2018-02-01 16:56:07 -08:00
m68k bug.h: work around GCC PR82365 in BUG() 2018-02-21 15:35:43 -08:00
metag The core framework has a handful of patches this time around, mostly due 2018-02-01 16:56:07 -08:00
microblaze microblaze: switch to NO_BOOTMEM 2018-03-16 12:51:27 +01:00
mips Merge branch 'x86-dma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:18:45 -07:00
mn10300 The core framework has a handful of patches this time around, mostly due 2018-02-01 16:56:07 -08:00
nios2 nios2 update for v4.16-rc1 2018-02-11 13:52:32 -08:00
openrisc The core framework has a handful of patches this time around, mostly due 2018-02-01 16:56:07 -08:00
parisc parisc: Handle case where flush_cache_range is called with no context 2018-03-17 11:49:39 +01:00
powerpc Merge branch 'x86-dma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-04-02 17:18:45 -07:00
riscv riscv/barrier: Define __smp_{mb,rmb,wmb} 2018-02-26 08:44:50 -08:00
s390 KVM fixes for v4.16-rc5 2018-03-09 16:59:19 -08:00
score arch/score/kernel/setup.c: combine two seq_printf() calls into one call in show_cpuinfo() 2018-02-06 18:32:47 -08:00
sh sh: fix build error for empty CONFIG_BUILTIN_DTB_SOURCE 2018-03-02 09:20:55 +09:00
sparc Linux 4.16-rc6 2018-03-19 20:37:35 +01:00
tile The core framework has a handful of patches this time around, mostly due 2018-02-01 16:56:07 -08:00
um mconsole_proc(): don't mess with file->f_pos 2018-02-09 19:28:01 -08:00
unicore32 lib: optimize cpumask_next_and() 2018-02-06 18:32:44 -08:00
x86 x86/mm: Do not forbid _PAGE_RW before init for __ro_after_init 2018-04-12 09:05:59 +02:00
xtensa xtensa: support DMA buffers in high memory 2018-02-16 19:19:54 -08:00
.gitignore
Kconfig Makefile: introduce CONFIG_CC_STACKPROTECTOR_AUTO 2018-02-06 18:32:44 -08:00