Re: [PATCH 1/2] perf tools: Ensure --symfs ends with '/'

[Namhyung Kim]

Hi Arnaldo,

On Wed, 30 Jul 2014 17:55:21 -0300, Arnaldo Carvalho de Melo wrote:
> Em Wed, Jul 30, 2014 at 12:19:32PM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Wed, Jul 30, 2014 at 08:52:36AM +0900, Namhyung Kim escreveu:
>> > I also thought about that way first but changed my mind to the current
>> > approach because I don't want to change current behavior.
>> 
>> > I worried about the common case which has empty symfs.  By your patch,
>> > it makes a pathname absolute even with an empty symfs - I can see most
>> > filenames are already absolute paths but I'm not 100% sure it's always
>> > the case.
>> 
>> Yeah, after doing some research on the tools/perf/ 'git log' I got your point,
>> we can't add the / after symfs usages when it is "", i.e. we need something
>> like:
>> 
>> 	("%s%s%s, symfs, symfs[0] ? "/" : "", dso_name)
>> 
>> I.e. the equivalent of this:
>> 
>> [acme@zoo linux]$ python
>> >>> import os
>> >>> symfs = ""
>> >>> os.path.join(symfs, "dso_path")
>> 'dso_path'
>> >>> symfs = "/home/acme/embedded_device_dsos"
>> >>> os.path.join(symfs, "dso_path")
>> '/home/acme/embedded_device_dsos/dso_path'
>> >>> 
>> 
>> I'll try and get that in place.
>
> Ok, the patch below should implement it just like above, if Minchan
> could please retest, I did just minimal testing, will do more later.

Are you still against my approach - adding '/' at the end of the symfs
string itself?  It seems that mine is simpler and shorter.

Thanks,
Namhyung


>
> - Arnaldo
>
> ---
>
> From d0240769e7d844ee21c1e8fc5cc57627c666f155 Mon Sep 17 00:00:00 2001
> From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Date: Tue, 29 Jul 2014 10:21:58 -0300
> Subject: [PATCH 1/1] perf symbols: Make sure --symfs usage includes the path
>  separator
>
> Minchan reported that perf failed to load vmlinux if --symfs argument
> doesn't end with '/' character.
>
> Fix it by making sure that the '/' path separator is used when composing
> pathnames with a --symfs provided directory name.
>
> Reported-by: Minchan Kim <minchan@xxxxxxxxxx>
> Tested-by: Minchan Kim <minchan@xxxxxxxxxx>
> Cc: David Ahern <dsahern@xxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Minchan Kim <minchan@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Paul Mackerras <paulus@xxxxxxxxx>
> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> Link: http://lkml.kernel.org/n/tip-8n4s6b6zvsez5ktanw006125@xxxxxxxxxxxxxx
> Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> ---
>  tools/perf/util/annotate.c |  9 +++------
>  tools/perf/util/dso.c      | 28 +++++++++++++---------------
>  tools/perf/util/symbol.c   |  3 +--
>  tools/perf/util/symbol.h   |  9 +++++++++
>  tools/perf/util/util.h     | 16 ++++++++++++++++
>  5 files changed, 42 insertions(+), 23 deletions(-)
>
> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> index 809b4c50beae..7745fec01a6b 100644
> --- a/tools/perf/util/annotate.c
> +++ b/tools/perf/util/annotate.c
> @@ -899,10 +899,8 @@ int symbol__annotate(struct symbol *sym, struct map *map, size_t privsize)
>  	struct kcore_extract kce;
>  	bool delete_extract = false;
>  
> -	if (filename) {
> -		snprintf(symfs_filename, sizeof(symfs_filename), "%s%s",
> -			 symbol_conf.symfs, filename);
> -	}
> +	if (filename)
> +		symbol__join_symfs(symfs_filename, filename);
>  
>  	if (filename == NULL) {
>  		if (dso->has_build_id) {
> @@ -922,8 +920,7 @@ fallback:
>  		 * DSO is the same as when 'perf record' ran.
>  		 */
>  		filename = (char *)dso->long_name;
> -		snprintf(symfs_filename, sizeof(symfs_filename), "%s%s",
> -			 symbol_conf.symfs, filename);
> +		symbol__join_symfs(symfs_filename, filename);
>  		free_filename = false;
>  	}
>  
> diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
> index 90d02c661dd4..bdafd306fb52 100644
> --- a/tools/perf/util/dso.c
> +++ b/tools/perf/util/dso.c
> @@ -37,6 +37,7 @@ int dso__read_binary_type_filename(const struct dso *dso,
>  {
>  	char build_id_hex[BUILD_ID_SIZE * 2 + 1];
>  	int ret = 0;
> +	size_t len;
>  
>  	switch (type) {
>  	case DSO_BINARY_TYPE__DEBUGLINK: {
> @@ -60,26 +61,25 @@ int dso__read_binary_type_filename(const struct dso *dso,
>  		break;
>  
>  	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
> -		snprintf(filename, size, "%s/usr/lib/debug%s.debug",
> -			 symbol_conf.symfs, dso->long_name);
> +		len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
> +		snprintf(filename + len, size - len, "%s.debug", dso->long_name);
>  		break;
>  
>  	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
> -		snprintf(filename, size, "%s/usr/lib/debug%s",
> -			 symbol_conf.symfs, dso->long_name);
> +		len = __symbol__join_symfs(filename, size, "/usr/lib/debug");
> +		snprintf(filename + len, size - len, "%s", dso->long_name);
>  		break;
>  
>  	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
>  	{
>  		const char *last_slash;
> -		size_t len;
>  		size_t dir_size;
>  
>  		last_slash = dso->long_name + dso->long_name_len;
>  		while (last_slash != dso->long_name && *last_slash != '/')
>  			last_slash--;
>  
> -		len = scnprintf(filename, size, "%s", symbol_conf.symfs);
> +		len = __symbol__join_symfs(filename, size, "");
>  		dir_size = last_slash - dso->long_name + 2;
>  		if (dir_size > (size - len)) {
>  			ret = -1;
> @@ -100,26 +100,24 @@ int dso__read_binary_type_filename(const struct dso *dso,
>  		build_id__sprintf(dso->build_id,
>  				  sizeof(dso->build_id),
>  				  build_id_hex);
> -		snprintf(filename, size,
> -			 "%s/usr/lib/debug/.build-id/%.2s/%s.debug",
> -			 symbol_conf.symfs, build_id_hex, build_id_hex + 2);
> +		len = __symbol__join_symfs(filename, size, "/usr/lib/debug/.build-id/");
> +		snprintf(filename + len, size - len, "%.2s/%s.debug",
> +			 build_id_hex, build_id_hex + 2);
>  		break;
>  
>  	case DSO_BINARY_TYPE__VMLINUX:
>  	case DSO_BINARY_TYPE__GUEST_VMLINUX:
>  	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
> -		snprintf(filename, size, "%s%s",
> -			 symbol_conf.symfs, dso->long_name);
> +		__symbol__join_symfs(filename, size, dso->long_name);
>  		break;
>  
>  	case DSO_BINARY_TYPE__GUEST_KMODULE:
> -		snprintf(filename, size, "%s%s%s", symbol_conf.symfs,
> -			 root_dir, dso->long_name);
> +		path__join3(filename, size, symbol_conf.symfs,
> +			    root_dir, dso->long_name);
>  		break;
>  
>  	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
> -		snprintf(filename, size, "%s%s", symbol_conf.symfs,
> -			 dso->long_name);
> +		__symbol__join_symfs(filename, size, dso->long_name);
>  		break;
>  
>  	case DSO_BINARY_TYPE__KCORE:
> diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
> index eb06746b06b2..f134ec138934 100644
> --- a/tools/perf/util/symbol.c
> +++ b/tools/perf/util/symbol.c
> @@ -1468,8 +1468,7 @@ int dso__load_vmlinux(struct dso *dso, struct map *map,
>  	if (vmlinux[0] == '/')
>  		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s", vmlinux);
>  	else
> -		snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s%s",
> -			 symbol_conf.symfs, vmlinux);
> +		symbol__join_symfs(symfs_vmlinux, vmlinux);
>  
>  	if (dso->kernel == DSO_TYPE_GUEST_KERNEL)
>  		symtab_type = DSO_BINARY_TYPE__GUEST_VMLINUX;
> diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
> index e7295e93cff9..196b29104276 100644
> --- a/tools/perf/util/symbol.h
> +++ b/tools/perf/util/symbol.h
> @@ -13,6 +13,7 @@
>  #include <libgen.h>
>  #include "build-id.h"
>  #include "event.h"
> +#include "util.h"
>  
>  #ifdef HAVE_LIBELF_SUPPORT
>  #include <libelf.h>
> @@ -143,6 +144,14 @@ struct symbol_conf {
>  };
>  
>  extern struct symbol_conf symbol_conf;
> +
> +static inline int __symbol__join_symfs(char *bf, size_t size, const char *path)
> +{
> +	return path__join(bf, size, symbol_conf.symfs, path);
> +}
> +
> +#define symbol__join_symfs(bf, path) __symbol__join_symfs(bf, sizeof(bf), path)
> +
>  extern int vmlinux_path__nr_entries;
>  extern char **vmlinux_path;
>  
> diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h
> index 66864364ccb4..38af77550c75 100644
> --- a/tools/perf/util/util.h
> +++ b/tools/perf/util/util.h
> @@ -68,6 +68,7 @@
>  #include <sys/socket.h>
>  #include <sys/ioctl.h>
>  #include <inttypes.h>
> +#include <linux/kernel.h>
>  #include <linux/magic.h>
>  #include <linux/types.h>
>  #include <sys/ttydefaults.h>
> @@ -317,6 +318,21 @@ unsigned long parse_tag_value(const char *str, struct parse_tag *tags);
>  
>  #define SRCLINE_UNKNOWN  ((char *) "??:0")
>  
> +static inline int path__join(char *bf, size_t size,
> +			     const char *path1, const char *path2)
> +{
> +	return scnprintf(bf, size, "%s%s%s", path1, path1[0] ? "/" : "", path2);
> +}
> +
> +static inline int path__join3(char *bf, size_t size,
> +			      const char *path1, const char *path2,
> +			      const char *path3)
> +{
> +	return scnprintf(bf, size, "%s%s%s%s%s",
> +			 path1, path1[0] ? "/" : "",
> +			 path2, path2[0] ? "/" : "", path3);
> +}
> +
>  struct dso;
>  
>  char *get_srcline(struct dso *dso, unsigned long addr);
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