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ARM: 7330/1: ftrace: use canonical Thumb-2 wide instruction format

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As commit 592201a9f1 (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>
This commit is contained in:
Rabin Vincent 2012-02-18 17:47:03 +01:00 committed by Russell King
parent dc283d7037
commit 4394e2824c
1 changed files with 11 additions and 2 deletions
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13
arch/arm/kernel/ftrace.c
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@ -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;