[PATCH] ftrace: remove redundant test on nsigned

[PATCH] ftrace: remove redundant test on nsigned

[Roel Kluin]

Unsigned `cnt' cannot be less than 0.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
Or should it be `if (!cnt || cnt > MAX)' and what should MAX be then?

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index aa08be6..b83f030 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -204,7 +204,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
 	char *buf;
 	char ch;
 
-	if (!cnt || cnt < 0)
+	if (!cnt)
 		return 0;
 
 	ret = tracing_update_buffers();

[PATCH] spufs: remove redundant test on unsigned

[Roel Kluin]

Unsigned `len' cannot be less than 0.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
Or should it be `if (!buf || len > MAX)' and what should MAX be then?

diff --git a/arch/powerpc/platforms/cell/spufs/sputrace.c b/arch/powerpc/platforms/cell/spufs/sputrace.c
index d0b1f3f..8f799ee 100644
--- a/arch/powerpc/platforms/cell/spufs/sputrace.c
+++ b/arch/powerpc/platforms/cell/spufs/sputrace.c
@@ -73,7 +73,7 @@ static ssize_t sputrace_read(struct file *file, char __user *buf,
 {
 	int error = 0, cnt = 0;
 
-	if (!buf || len < 0)
+	if (!buf)
 		return -EINVAL;
 
 	while (cnt < len) {

Re: [PATCH] spufs: remove redundant test on unsigned

[Jeremy Kerr]

Roel,

> Unsigned `len' cannot be less than 0.
>
> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>

Thanks for the patch. However, we have a patch from Christoph Hellwig 
pending that will rework the sputrace code:

 http://patchwork.ozlabs.org/patch/28641/

It's currently queued in benh's tree, should be up soon.

Cheers,


Jeremy

Re: [PATCH] ftrace: remove redundant test on nsigned

[Li Zefan]

Roel Kluin wrote:
> Unsigned `cnt' cannot be less than 0.
> 

The patch is fine, but there's a typo in the title s/nsigned/unsigned

> Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
> ---
> Or should it be `if (!cnt || cnt > MAX)' and what should MAX be then?
> 

No, note there is another check:

	if (cnt > EVENT_BUF_SIZE)
		cnt = EVENT_BUF_SIZE;

> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index aa08be6..b83f030 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -204,7 +204,7 @@ ftrace_event_write(struct file *file, const char __user *ubuf,
>  	char *buf;
>  	char ch;
>  
> -	if (!cnt || cnt < 0)
> +	if (!cnt)
>  		return 0;
>  
>  	ret = tracing_update_buffers();
> --