[tip:x86/security] x86: Resume trampoline must be executable

From: tip-bot for Lin Ming
Date: Mon Nov 22 2010 - 08:43:42 EST


Commit-ID: 691513f70d3957939a318da970987b876c720861
Gitweb: http://git.kernel.org/tip/691513f70d3957939a318da970987b876c720861
Author: Lin Ming <ming.m.lin@xxxxxxxxx>
AuthorDate: Mon, 22 Nov 2010 14:03:28 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 22 Nov 2010 14:38:52 +0100

x86: Resume trampoline must be executable

commit 5bd5a452(x86: Add NX protection for kernel data) marked the
trampoline area NX - which unsurprisingly breaks resume and cpu
hotplug.

Revert the portion of that commit, which touches the trampoline.

Originally-from: Lin Ming <ming.m.lin@xxxxxxxxx>
LKML-Reference: <1290410581.2405.24.camel@xxxxxxxxxxxxxxxxxxx>
Cc: Matthieu Castet <castet.matthieu@xxxxxxx>
Cc: Siarhei Liakh <sliakh.lkml@xxxxxxxxx>
Cc: Xuxian Jiang <jiang@xxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Tested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
arch/x86/mm/init_64.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index ce59c05..71a5929 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -788,7 +788,6 @@ void mark_rodata_ro(void)
unsigned long rodata_start =
((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
unsigned long end = (unsigned long) &__end_rodata_hpage_align;
- unsigned long kernel_end = (((unsigned long)&__init_end + HPAGE_SIZE) & HPAGE_MASK);
unsigned long text_end = PAGE_ALIGN((unsigned long) &__stop___ex_table);
unsigned long rodata_end = PAGE_ALIGN((unsigned long) &__end_rodata);
unsigned long data_start = (unsigned long) &_sdata;
@@ -803,7 +802,7 @@ void mark_rodata_ro(void)
* The rodata section (but not the kernel text!) should also be
* not-executable.
*/
- set_memory_nx(rodata_start, (kernel_end - rodata_start) >> PAGE_SHIFT);
+ set_memory_nx(rodata_start, (end - rodata_start) >> PAGE_SHIFT);

rodata_test();

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