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authorRabin Vincent <rabin@rab.in>2012-02-18 17:47:03 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-03-24 09:38:54 +0000
commit4394e2824c8d97d81a336edb469b13c8806604e4 (patch)
tree68ec90a882dc2df804a4d6e4e5521ad8ebe7743b /arch/arm/kernel/ftrace.c
parentdc283d7037555aa6891188719be2f1b4af9535c9 (diff)
ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format
As commit 592201a9f15 (ARM: Thumb-2: Support Thumb-2 in undefined instruction handler) says: 32-bit Thumb instructions are specified in the form: ((first_half << 16 ) | second_half) which matches the layout used by the ARM ARM. Convert the ftrace code to use the same format to avoid the usage of different formats in kernel code. Acked-by: Dave Martin <dave.martin@linaro.org> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/ftrace.c')
-rw-r--r--arch/arm/kernel/ftrace.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
index 6fd7c4a1e532..5c9cecfaeb21 100644
--- a/arch/arm/kernel/ftrace.c
+++ b/arch/arm/kernel/ftrace.c
@@ -16,10 +16,11 @@
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
+#include <asm/opcodes.h>
#include <asm/ftrace.h>
#ifdef CONFIG_THUMB2_KERNEL
-#define NOP 0xeb04f85d /* pop.w {lr} */
+#define NOP 0xf85deb04 /* pop.w {lr} */
#else
#define NOP 0xe8bd4000 /* pop {lr} */
#endif
@@ -88,7 +89,7 @@ static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
if (link)
second |= 1 << 14;
- return (second << 16) | first;
+ return __opcode_thumb32_compose(first, second);
}
#else
static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr,
@@ -125,6 +126,14 @@ static int ftrace_modify_code(unsigned long pc, unsigned long old,
{
unsigned long replaced;
+ if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
+ old = __opcode_to_mem_thumb32(old);
+ new = __opcode_to_mem_thumb32(new);
+ } else {
+ old = __opcode_to_mem_arm(old);
+ new = __opcode_to_mem_arm(new);
+ }
+
if (validate) {
if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE))
return -EFAULT;