diff options
| author | Abel Vesa <abelvesa@linux.com> | 2017-04-03 23:58:54 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-24 11:00:11 +0100 |
| commit | 84c9248a240ec9c5cd98ecbe6f241d7b2cb7eeca (patch) | |
| tree | eecd4e5d89d927ed749165a34169a15b376bb4cb /arch/arm/kernel | |
| parent | b7de32ed33d8ce036f7b33d902318523b73d1b74 (diff) | |
ARM: 8668/1: ftrace: Fix dynamic ftrace with DEBUG_RODATA and !FRAME_POINTER
[ Upstream commit 6f05d0761af612e04572ba4d65b4c0274a88444f ]
The support for dynamic ftrace with CONFIG_DEBUG_RODATA involves
overriding the weak arch_ftrace_update_code() with a variant which makes
the kernel text writable around the patching.
This override was however added under the CONFIG_OLD_MCOUNT ifdef, and
CONFIG_OLD_MCOUNT is only enabled if frame pointers are enabled.
This leads to non-functional dynamic ftrace (ftrace triggers a
WARN_ON()) when CONFIG_DEBUG_RODATA is enabled and CONFIG_FRAME_POINTER
is not.
Move the override out of that ifdef and into the CONFIG_DYNAMIC_FTRACE
ifdef where it belongs.
Fixes: 80d6b0c2eed2a ("ARM: mm: allow text and rodata sections to be read-only")
Suggested-by: Nicolai Stange <nicstange@gmail.com>
Suggested-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Abel Vesa <abelvesa@gmail.com>
Acked-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/ftrace.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index 3f1759411d51..414e60ed0257 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -29,11 +29,6 @@ #endif #ifdef CONFIG_DYNAMIC_FTRACE -#ifdef CONFIG_OLD_MCOUNT -#define OLD_MCOUNT_ADDR ((unsigned long) mcount) -#define OLD_FTRACE_ADDR ((unsigned long) ftrace_caller_old) - -#define OLD_NOP 0xe1a00000 /* mov r0, r0 */ static int __ftrace_modify_code(void *data) { @@ -51,6 +46,12 @@ void arch_ftrace_update_code(int command) stop_machine(__ftrace_modify_code, &command, NULL); } +#ifdef CONFIG_OLD_MCOUNT +#define OLD_MCOUNT_ADDR ((unsigned long) mcount) +#define OLD_FTRACE_ADDR ((unsigned long) ftrace_caller_old) + +#define OLD_NOP 0xe1a00000 /* mov r0, r0 */ + static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec) { return rec->arch.old_mcount ? OLD_NOP : NOP; |