From: dave.martin@linaro.org (Dave Martin)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 2/6] ARM: ftrace: use canonical Thumb-2 wide instruction format
Date: Mon, 30 Jan 2012 16:54:22 +0000 [thread overview]
Message-ID: <20120130165421.GC2248@linaro.org> (raw)
In-Reply-To: <1327757725-10114-3-git-send-email-rabin@rab.in>
On Sat, Jan 28, 2012 at 07:05:21PM +0530, Rabin Vincent wrote:
> 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.
>
> Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Dave Martin <dave.martin@linaro.org>
I haven't tried it out, but the use of the opcode helpers looks correct.
Cheers
---Dave
> ---
> arch/arm/kernel/ftrace.c | 13 +++++++++++--
> 1 files changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c
> index e9488ad..72a381a 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 (old) {
> if (probe_kernel_read(&replaced, (void *)pc, MCOUNT_INSN_SIZE))
> return -EFAULT;
> --
> 1.7.8.3
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2012-01-30 16:54 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-28 13:35 [PATCHv2 0/6] ARM: jump label support Rabin Vincent
2012-01-28 13:35 ` [PATCHv2 1/6] ARM: ftrace: remove useless memory checks Rabin Vincent
2012-02-20 16:16 ` Russell King - ARM Linux
2012-02-22 14:13 ` Rabin Vincent
2012-02-22 21:28 ` Russell King - ARM Linux
2012-02-24 16:48 ` Rabin Vincent
2012-02-27 11:21 ` Russell King - ARM Linux
2012-01-28 13:35 ` [PATCHv2 2/6] ARM: ftrace: use canonical Thumb-2 wide instruction format Rabin Vincent
2012-01-30 16:54 ` Dave Martin [this message]
2012-01-28 13:35 ` [PATCHv2 3/6] ARM: extract out insn generation code from ftrace Rabin Vincent
2012-01-28 13:35 ` [PATCHv2 4/6] ARM: extract out code patch function from kprobes Rabin Vincent
2012-01-30 17:00 ` Dave Martin
2012-02-07 16:07 ` [PATCHv3] " Rabin Vincent
2012-01-31 18:32 ` [PATCHv2 4/6] " Tixy
2012-01-28 13:35 ` [PATCHv2 5/6] jump label: detect %c support for ARM Rabin Vincent
2012-02-07 16:18 ` Rabin Vincent
2012-02-07 18:04 ` Jason Baron
2012-02-20 17:21 ` Russell King - ARM Linux
2012-02-22 13:32 ` Rabin Vincent
2012-01-28 13:35 ` [PATCHv2 6/6] ARM: add jump label support Rabin Vincent
2012-02-15 17:00 ` [PATCHv3] " Rabin Vincent
2012-02-29 15:24 ` Rabin Vincent
2012-02-29 15:47 ` Jason Baron
2012-01-31 8:23 ` [PATCHv2 0/6] ARM: " Jon Medhurst (Tixy)
2012-01-31 11:11 ` Dave Martin
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