[PATCH 4/4] kprobes: remove __dummy_buf

[PATCH 4/4] kprobes: remove __dummy_buf

[Namhyung Kim]

remove __dummy_buf which is needed for kallsyms_lookup only.
use kallsysm_lookup_size_offset instead.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>

diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
index 4986160..a4ff35d 100644
--- a/arch/x86/kernel/kprobes.c
+++ b/arch/x86/kernel/kprobes.c
@@ -224,9 +224,6 @@ static int recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
 	return 0;
 }
 
-/* Dummy buffers for kallsyms_lookup */
-static char __dummy_buf[KSYM_NAME_LEN];
-
 /* Check if paddr is at an instruction boundary */
 static int __kprobes can_probe(unsigned long paddr)
 {
@@ -235,7 +232,7 @@ static int __kprobes can_probe(unsigned long paddr)
 	struct insn insn;
 	kprobe_opcode_t buf[MAX_INSN_SIZE];
 
-	if (!kallsyms_lookup(paddr, NULL, &offset, NULL, __dummy_buf))
+	if (!kallsyms_lookup_size_offset(paddr, NULL, &offset))
 		return 0;
 
 	/* Decode instructions */
@@ -1249,11 +1246,9 @@ static int __kprobes can_optimize(unsigned long paddr)
 	unsigned long addr, size = 0, offset = 0;
 	struct insn insn;
 	kprobe_opcode_t buf[MAX_INSN_SIZE];
-	/* Dummy buffers for lookup_symbol_attrs */
-	static char __dummy_buf[KSYM_NAME_LEN];
 
 	/* Lookup symbol including addr */
-	if (!kallsyms_lookup(paddr, &size, &offset, NULL, __dummy_buf))
+	if (!kallsyms_lookup_size_offset(paddr, &size, &offset))
 		return 0;
 
 	/* Check there is enough space for a relative jump. */
-- 
1.7.0.4

Re: [PATCH 4/4] kprobes: remove __dummy_buf

[Masami Hiramatsu]

Namhyung Kim wrote:
> remove __dummy_buf which is needed for kallsyms_lookup only.
> use kallsysm_lookup_size_offset instead.
> 
> Signed-off-by: Namhyung Kim <namhyung@gmail.com>

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

Thanks!

> 
> diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
> index 4986160..a4ff35d 100644
> --- a/arch/x86/kernel/kprobes.c
> +++ b/arch/x86/kernel/kprobes.c
> @@ -224,9 +224,6 @@ static int recover_probed_instruction(kprobe_opcode_t *buf, unsigned long addr)
>  	return 0;
>  }
>  
> -/* Dummy buffers for kallsyms_lookup */
> -static char __dummy_buf[KSYM_NAME_LEN];
> -
>  /* Check if paddr is at an instruction boundary */
>  static int __kprobes can_probe(unsigned long paddr)
>  {
> @@ -235,7 +232,7 @@ static int __kprobes can_probe(unsigned long paddr)
>  	struct insn insn;
>  	kprobe_opcode_t buf[MAX_INSN_SIZE];
>  
> -	if (!kallsyms_lookup(paddr, NULL, &offset, NULL, __dummy_buf))
> +	if (!kallsyms_lookup_size_offset(paddr, NULL, &offset))
>  		return 0;
>  
>  	/* Decode instructions */
> @@ -1249,11 +1246,9 @@ static int __kprobes can_optimize(unsigned long paddr)
>  	unsigned long addr, size = 0, offset = 0;
>  	struct insn insn;
>  	kprobe_opcode_t buf[MAX_INSN_SIZE];
> -	/* Dummy buffers for lookup_symbol_attrs */
> -	static char __dummy_buf[KSYM_NAME_LEN];
>  
>  	/* Lookup symbol including addr */
> -	if (!kallsyms_lookup(paddr, &size, &offset, NULL, __dummy_buf))
> +	if (!kallsyms_lookup_size_offset(paddr, &size, &offset))
>  		return 0;
>  
>  	/* Check there is enough space for a relative jump. */