Re: [PATCH] tools lib api fs: Store tracing mountpoint for better error message

[David Ahern <dsahern@gmail.com>]

On 9/19/15 8:47 AM, Jiri Olsa wrote:

> diff --git a/tools/lib/api/fs/tracing_path.c b/tools/lib/api/fs/tracing_path.c
> index 38aca2dd1946..0406a7d5c891 100644
> --- a/tools/lib/api/fs/tracing_path.c
> +++ b/tools/lib/api/fs/tracing_path.c
> @@ -12,12 +12,14 @@
>   #include "tracing_path.h"
>
>
> +char tracing_mnt[PATH_MAX + 1]         = "/sys/kernel/debug";
>   char tracing_path[PATH_MAX + 1]        = "/sys/kernel/debug/tracing";
>   char tracing_events_path[PATH_MAX + 1] = "/sys/kernel/debug/tracing/events";

why all the +1s? null terminator has to fit within PATH_MAX as well.

>
>
>   static void __tracing_path_set(const char *tracing, const char *mountpoint)
>   {
> +	snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
>   	snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
>   		 mountpoint, tracing);
>   	snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
> @@ -109,19 +111,10 @@ static int strerror_open(int err, char *buf, size_t size, const char *filename)
>   			 "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
>   		break;
>   	case EACCES: {
> -		const char *mountpoint = debugfs__mountpoint();
> -
> -		if (!access(mountpoint, R_OK) && strncmp(filename, "tracing/", 8) == 0) {
> -			const char *tracefs_mntpoint = tracefs__mountpoint();
> -
> -			if (tracefs_mntpoint)
> -				mountpoint = tracefs__mountpoint();
> -		}
> -
>   		snprintf(buf, size,
>   			 "Error:\tNo permissions to read %s/%s\n"
>   			 "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
> -			 tracing_events_path, filename, mountpoint);
> +			 tracing_events_path, filename, tracing_mnt);
>   	}
>   		break;
>   	default:
>

LGTM.

David