Re: [PATCH v3] samples/kprobes: Fix typo in handler_{post,fault}()

[Masami Hiramatsu]

On Sat, 15 May 2021 10:39:06 +0800
Tiezhu Yang <yangtiezhu@xxxxxxxxxxx> wrote:

> It should use post_handler instead of pre_handler in handler_post().
> 
> As Joe Perches suggested, it would be better to use pr_fmt and remove
> all the embedded pre/post strings. This would change the style of the
> output through.
> 

NAK, this also shows which handler cought the event.
If you wanna change it. Please replace it with __func__ instead.

> Also fix a defective format in handler_fault() ending with an 'n' that
> should be '\n'.

This is another typo. Please split the fix from this patch.

Thank you,

> 
> Fixes: e16c5dd5157e ("samples/kprobes: Add s390 case in kprobe example module")
> Fixes: 804defea1c02 ("Kprobes: move kprobe examples to samples/")
> Acked-by: Marc Koderer <marc@xxxxxxxxxxx>
> Acked-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
> Suggested-by: Joe Perches <joe@xxxxxxxxxxx>
> Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
> ---
> 
> v3: use pr_fmt and fix typo in handler_fault() suggested by Joe Perches
> 
> v2: rebase on the latest mainline kernel
> 
>  samples/kprobes/kprobe_example.c | 33 +++++++++++++++++----------------
>  1 file changed, 17 insertions(+), 16 deletions(-)
> 
> diff --git a/samples/kprobes/kprobe_example.c b/samples/kprobes/kprobe_example.c
> index c495664..5f1eb8b 100644
> --- a/samples/kprobes/kprobe_example.c
> +++ b/samples/kprobes/kprobe_example.c
> @@ -10,6 +10,8 @@
>   * whenever kernel_clone() is invoked to create a new process.
>   */
>  
> +#define pr_fmt(fmt) "%s: " fmt, __func__
> +
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/kprobes.h>
> @@ -27,32 +29,31 @@ static struct kprobe kp = {
>  static int __kprobes handler_pre(struct kprobe *p, struct pt_regs *regs)
>  {
>  #ifdef CONFIG_X86
> -	pr_info("<%s> pre_handler: p->addr = 0x%p, ip = %lx, flags = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, ip = %lx, flags = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->ip, regs->flags);
>  #endif
>  #ifdef CONFIG_PPC
> -	pr_info("<%s> pre_handler: p->addr = 0x%p, nip = 0x%lx, msr = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, nip = 0x%lx, msr = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->nip, regs->msr);
>  #endif
>  #ifdef CONFIG_MIPS
> -	pr_info("<%s> pre_handler: p->addr = 0x%p, epc = 0x%lx, status = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, epc = 0x%lx, status = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->cp0_epc, regs->cp0_status);
>  #endif
>  #ifdef CONFIG_ARM64
> -	pr_info("<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx,"
> -			" pstate = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, pc = 0x%lx, pstate = 0x%lx\n",
>  		p->symbol_name, p->addr, (long)regs->pc, (long)regs->pstate);
>  #endif
>  #ifdef CONFIG_ARM
> -	pr_info("<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx, cpsr = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, pc = 0x%lx, cpsr = 0x%lx\n",
>  		p->symbol_name, p->addr, (long)regs->ARM_pc, (long)regs->ARM_cpsr);
>  #endif
>  #ifdef CONFIG_RISCV
> -	pr_info("<%s> pre_handler: p->addr = 0x%p, pc = 0x%lx, status = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, pc = 0x%lx, status = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->epc, regs->status);
>  #endif
>  #ifdef CONFIG_S390
> -	pr_info("<%s> pre_handler: p->addr, 0x%p, ip = 0x%lx, flags = 0x%lx\n",
> +	pr_info("<%s> p->addr, 0x%p, ip = 0x%lx, flags = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->psw.addr, regs->flags);
>  #endif
>  
> @@ -65,31 +66,31 @@ static void __kprobes handler_post(struct kprobe *p, struct pt_regs *regs,
>  				unsigned long flags)
>  {
>  #ifdef CONFIG_X86
> -	pr_info("<%s> post_handler: p->addr = 0x%p, flags = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, flags = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->flags);
>  #endif
>  #ifdef CONFIG_PPC
> -	pr_info("<%s> post_handler: p->addr = 0x%p, msr = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, msr = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->msr);
>  #endif
>  #ifdef CONFIG_MIPS
> -	pr_info("<%s> post_handler: p->addr = 0x%p, status = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, status = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->cp0_status);
>  #endif
>  #ifdef CONFIG_ARM64
> -	pr_info("<%s> post_handler: p->addr = 0x%p, pstate = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, pstate = 0x%lx\n",
>  		p->symbol_name, p->addr, (long)regs->pstate);
>  #endif
>  #ifdef CONFIG_ARM
> -	pr_info("<%s> post_handler: p->addr = 0x%p, cpsr = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, cpsr = 0x%lx\n",
>  		p->symbol_name, p->addr, (long)regs->ARM_cpsr);
>  #endif
>  #ifdef CONFIG_RISCV
> -	pr_info("<%s> post_handler: p->addr = 0x%p, status = 0x%lx\n",
> +	pr_info("<%s> p->addr = 0x%p, status = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->status);
>  #endif
>  #ifdef CONFIG_S390
> -	pr_info("<%s> pre_handler: p->addr, 0x%p, flags = 0x%lx\n",
> +	pr_info("<%s> p->addr, 0x%p, flags = 0x%lx\n",
>  		p->symbol_name, p->addr, regs->flags);
>  #endif
>  }
> @@ -101,7 +102,7 @@ static void __kprobes handler_post(struct kprobe *p, struct pt_regs *regs,
>   */
>  static int handler_fault(struct kprobe *p, struct pt_regs *regs, int trapnr)
>  {
> -	pr_info("fault_handler: p->addr = 0x%p, trap #%dn", p->addr, trapnr);
> +	pr_info("p->addr = 0x%p, trap #%d\n", p->addr, trapnr);
>  	/* Return 0 because we don't handle the fault. */
>  	return 0;
>  }
> -- 
> 2.1.0
> 


-- 
Masami Hiramatsu <mhiramat@xxxxxxxxxx>