Re: [PATCH 10/10] tools, perf: Add asprintf replacement

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

Em Wed, Nov 12, 2014 at 06:05:28PM -0800, Andi Kleen escreveu:
> From: Andi Kleen <ak@linux.intel.com>
> 
> asprintf corrupts memory on some older glibc versions.
> Provide a replacement. This fixes various segfaults
> with --branch-history on older Fedoras.
> 
> v2: Remove bogus hunk.
>     Support arbitrary size (Geert Uytterhoeven)
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
>  tools/perf/Makefile.perf    |  1 +
>  tools/perf/builtin-report.c |  1 +
>  tools/perf/util/asprintf.c  | 34 ++++++++++++++++++++++++++++++++++
>  3 files changed, 36 insertions(+)
>  create mode 100644 tools/perf/util/asprintf.c
> 
> diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
> index aecf61dc..9db4ff1 100644
> --- a/tools/perf/Makefile.perf
> +++ b/tools/perf/Makefile.perf
> @@ -395,6 +395,7 @@ LIB_OBJS += $(OUTPUT)util/vdso.o
>  LIB_OBJS += $(OUTPUT)util/stat.o
>  LIB_OBJS += $(OUTPUT)util/record.o
>  LIB_OBJS += $(OUTPUT)util/srcline.o
> +LIB_OBJS += $(OUTPUT)util/asprintf.o
>  LIB_OBJS += $(OUTPUT)util/data.o
>  LIB_OBJS += $(OUTPUT)util/tsc.o
>  LIB_OBJS += $(OUTPUT)util/cloexec.o
> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> index fb272ff..493f011 100644
> --- a/tools/perf/builtin-report.c
> +++ b/tools/perf/builtin-report.c
> @@ -762,6 +762,7 @@ repeat:
>  	}
>  	if (branch_call_mode) {
>  		callchain_param.branch_callstack = 1;
> +		callchain_param.key = CCKEY_ADDRESS;

unrelated hunk?

- Arnaldo

>  		symbol_conf.use_callchain = true;
>  		callchain_register_param(&callchain_param);
>  		if (sort_order == NULL)
> diff --git a/tools/perf/util/asprintf.c b/tools/perf/util/asprintf.c
> new file mode 100644
> index 0000000..6177ee8
> --- /dev/null
> +++ b/tools/perf/util/asprintf.c
> @@ -0,0 +1,34 @@
> +/* Replacement for asprintf as it's buggy in older glibc versions */
> +#include <stdio.h>
> +#include <stdarg.h>
> +#include <stdlib.h>
> +#include <string.h>
> +
> +int vasprintf(char **str, const char *fmt, va_list ap)
> +{
> +	va_list ao;
> +	char buf[1024];
> +	int len;
> +
> +	va_copy(ao, ap);
> +	len = vsnprintf(buf, sizeof(buf), fmt, ap);
> +	*str = malloc(len + 1);
> +	if (!*str)
> +		return -1;
> +	if ((size_t)len < sizeof(buf)) {
> +		strcpy(*str, buf);
> +		return len;
> +	}
> +	return vsnprintf(*str, len + 1, fmt, ao);
> +}
> +
> +int asprintf(char **str, const char *fmt, ...)
> +{
> +	va_list ap;
> +	int ret;
> +
> +	va_start(ap, fmt);
> +	ret = vasprintf(str, fmt, ap);
> +	va_end(ap);
> +	return ret;
> +}
> -- 
> 1.9.3