[PATCH] system_path: use a static buffer
- From
Carlos Martín Nieto <cmn@elego.de>
- Date
- Mar 17, 2011, 11:01 UTC
- Message-ID
- <1300359664-6230-1-git-send-email-cmn@elego.de>
- In-Reply-To
- <7vipvi7q5g.fsf@alter.siamese.dyndns.org>
Make system_path behave like the other path functions by using a static buffer, fixing a memory leak.
Also make sure the prefix pointer is always initialized to either PREFIX or NULL.
git_etc_gitattributes and git_etc_gitconfig are the only users who are affected by this change. Make them use a static buffer, which fits their use better as well.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de> ---
On mié, 2011-03-16 at 13:43 -0700, Junio C Hamano wrote: Carlos Martín Nieto <cmn@elego.de> writes:
Show 16 quoted lines
> > > Make system_path behave like the other path functions by using a > > static buffer, fixing a memory leak. > > > > Also make sure the prefix pointer is always initialized to either > > PREFIX or NULL. > > > > Signed-off-by: Carlos Martín Nieto <cmn@elego.de> > > --- > > Have you made sure all the callers are Ok with this change? > > If somebody called system_path(GIT_EXEC_PATH), saved the result in a > variable without copying, and then called system_path(ETC_GITATTRIBUTES), > his variable may now have a value unrelated to GIT_EXEC_PATH, and you > would fix all such callers to save the value away with strdup().
I checked again, and except for the ones changed in this patch, the rest copy it to their own buffer or pass it to puts, setenv or strbuf_addstr.
The way these functions are used suggest the caller expects them to deal with their own memory, so that's what I've done.
TBH, valgrind only reports a win of ~6-7kB when doing git log on git.git, but it's a step in the right direction (and adds consistency to system_path, which is the main win).
attr.c | 6 +++--- config.c | 6 +++--- exec_cmd.c | 11 ++++++----- 3 files changed, 12 insertions(+), 11 deletions(-)
diff --git a/attr.c b/attr.c index 6aff695..64d803f 100644 --- a/attr.c +++ b/attr.c @@ -467,9 +467,9 @@ static void drop_attr_stack(void) const char *git_etc_gitattributes(void) { - static const char *system_wide; - if (!system_wide) - system_wide = system_path(ETC_GITATTRIBUTES); + static char system_wide[PATH_MAX]; + if (!system_wide[0]) + strlcpy(system_wide, system_path(ETC_GITATTRIBUTES), PATH_MAX); return system_wide; } diff --git a/config.c b/config.c index 822ef83..cd1c295 100644 --- a/config.c +++ b/config.c @@ -808,9 +808,9 @@ int git_config_from_file(config_fn_t fn, const char *filename, void *data) const char *git_etc_gitconfig(void) { - static const char *system_wide; - if (!system_wide) - system_wide = system_path(ETC_GITCONFIG); + static char system_wide[PATH_MAX]; + if (!system_wide[0]) + strlcpy(system_wide, system_path(ETC_GITCONFIG), PATH_MAX); return system_wide; } diff --git a/exec_cmd.c b/exec_cmd.c index 38545e8..5686952 100644 --- a/exec_cmd.c +++ b/exec_cmd.c @@ -9,11 +9,11 @@ static const char *argv0_path; const char *system_path(const char *path) { #ifdef RUNTIME_PREFIX - static const char *prefix; + static const char *prefix = NULL; #else static const char *prefix = PREFIX; #endif - struct strbuf d = STRBUF_INIT; + static char buf[PATH_MAX]; if (is_absolute_path(path)) return path; @@ -33,9 +33,10 @@ const char *system_path(const char *path) } #endif - strbuf_addf(&d, "%s/%s", prefix, path); - path = strbuf_detach(&d, NULL); - return path; + if (snprintf(buf, sizeof(buf), "%s/%s", prefix, path) >= sizeof(buf)) + die("system path too long for %s", path); + + return buf; } const char *git_extract_argv0_path(const char *argv0)
-- 1.7.4.1