Re: [PATCH perf/core v2 4/8] perf: Make alias handler to check return value of strbuf

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Sat, Apr 30, 2016 at 12:10:23AM +0900, Masami Hiramatsu escreveu:
> Make alias handler and sq_quote_argv to check the return
> value of strbuf APIs.
> In sq_quote_argv() calls die(), but this fix handles strbuf
> failure as a special case and returns to caller, since
> the caller - handle_alias() also has to check the return
> value of other strbuf APIs and those checks can be merged
> to one if() statement.

Fair enough, looks ok.
 
> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
> ---
>  tools/perf/perf.c       |    8 +++++---
>  tools/perf/util/quote.c |   36 ++++++++++++++++++++----------------
>  tools/perf/util/quote.h |    2 +-
>  3 files changed, 26 insertions(+), 20 deletions(-)
> 
> diff --git a/tools/perf/perf.c b/tools/perf/perf.c
> index 83ffe7c..7970008 100644
> --- a/tools/perf/perf.c
> +++ b/tools/perf/perf.c
> @@ -309,9 +309,11 @@ static int handle_alias(int *argcp, const char ***argv)
>  			if (*argcp > 1) {
>  				struct strbuf buf;
>  
> -				strbuf_init(&buf, PATH_MAX);
> -				strbuf_addstr(&buf, alias_string);
> -				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
> +				if (strbuf_init(&buf, PATH_MAX) < 0 ||
> +				    strbuf_addstr(&buf, alias_string) < 0 ||
> +				    sq_quote_argv(&buf, (*argv) + 1,
> +						  PATH_MAX) < 0)
> +					die("Failed to allocate memory.");
>  				free(alias_string);
>  				alias_string = buf.buf;
>  			}
> diff --git a/tools/perf/util/quote.c b/tools/perf/util/quote.c
> index 01f0324..c6d4ee2 100644
> --- a/tools/perf/util/quote.c
> +++ b/tools/perf/util/quote.c
> @@ -17,38 +17,42 @@ static inline int need_bs_quote(char c)
>  	return (c == '\'' || c == '!');
>  }
>  
> -static void sq_quote_buf(struct strbuf *dst, const char *src)
> +static int sq_quote_buf(struct strbuf *dst, const char *src)
>  {
>  	char *to_free = NULL;
> +	int ret;
>  
>  	if (dst->buf == src)
>  		to_free = strbuf_detach(dst, NULL);
>  
> -	strbuf_addch(dst, '\'');
> -	while (*src) {
> +	ret = strbuf_addch(dst, '\'');
> +	while (!ret && *src) {
>  		size_t len = strcspn(src, "'!");
> -		strbuf_add(dst, src, len);
> +		ret = strbuf_add(dst, src, len);
>  		src += len;
> -		while (need_bs_quote(*src)) {
> -			strbuf_addstr(dst, "'\\");
> -			strbuf_addch(dst, *src++);
> -			strbuf_addch(dst, '\'');
> -		}
> +		while (!ret && need_bs_quote(*src))
> +			ret = strbuf_addf(dst, "'\\%c\'", *src++);
>  	}
> -	strbuf_addch(dst, '\'');
> +	if (!ret)
> +		ret = strbuf_addch(dst, '\'');
>  	free(to_free);
> +
> +	return ret;
>  }
>  
> -void sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
> +int sq_quote_argv(struct strbuf *dst, const char** argv, size_t maxlen)
>  {
> -	int i;
> +	int i, ret;
>  
>  	/* Copy into destination buffer. */
> -	strbuf_grow(dst, 255);
> -	for (i = 0; argv[i]; ++i) {
> -		strbuf_addch(dst, ' ');
> -		sq_quote_buf(dst, argv[i]);
> +	ret = strbuf_grow(dst, 255);
> +	for (i = 0; !ret && argv[i]; ++i) {
> +		ret = strbuf_addch(dst, ' ');
> +		if (ret)
> +			break;
> +		ret = sq_quote_buf(dst, argv[i]);
>  		if (maxlen && dst->len > maxlen)
>  			die("Too many or long arguments");
>  	}
> +	return ret;
>  }
> diff --git a/tools/perf/util/quote.h b/tools/perf/util/quote.h
> index 3340c9c..e1ec191 100644
> --- a/tools/perf/util/quote.h
> +++ b/tools/perf/util/quote.h
> @@ -24,6 +24,6 @@
>   * sq_quote() in a real application.
>   */
>  
> -void sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
> +int sq_quote_argv(struct strbuf *, const char **argv, size_t maxlen);
>  
>  #endif /* __PERF_QUOTE_H */