[apparmor] [PATCH v2 06/42] Use the gcc cleanup extension attribute to handle freeing temp allocations
Tyler Hicks
tyhicks at canonical.com
Fri Mar 6 21:48:22 UTC 2015
From: John Johansen <john.johansen at canonical.com>
While some of these allocations will go away as we convert to C++,
some of these need to stay C as the are going to be moved into a
library to support loading cache from init daemons etc.
For the bits that will eventually be C++ this helps clean things up,
in the interim.
TODO: apply to libapparmor as well
Signed-off-by: John Johansen <john.johansen at canonical.com>
---
parser/lib.c | 11 ++++++++---
parser/lib.h | 3 +++
parser/parser_interface.c | 13 ++++---------
parser/parser_lex.l | 16 ++++------------
parser/parser_main.c | 39 ++++++++++++---------------------------
5 files changed, 31 insertions(+), 51 deletions(-)
diff --git a/parser/lib.c b/parser/lib.c
index 85e39e0..fb9df49 100644
--- a/parser/lib.c
+++ b/parser/lib.c
@@ -33,6 +33,13 @@
#include "lib.h"
#include "parser.h"
+/* automaticly free allocated variables tagged with autofree on fn exit */
+void __autofree(void *p)
+{
+ void **_p = (void**)p;
+ free(*_p);
+}
+
/**
* dirat_for_each: iterate over a directory calling cb for each entry
* @dir: already opened directory (MAY BE NULL)
@@ -62,7 +69,7 @@
int dirat_for_each(DIR *dir, const char *name, void *data,
int (* cb)(DIR *, const char *, struct stat *, void *))
{
- struct dirent *dirent = NULL;
+ autofree struct dirent *dirent = NULL;
DIR *d = NULL;
int error;
@@ -132,7 +139,6 @@ int dirat_for_each(DIR *dir, const char *name, void *data,
if (d != dir)
closedir(d);
- free(dirent);
return 0;
@@ -140,7 +146,6 @@ fail:
error = errno;
if (d && d != dir)
closedir(d);
- free(dirent);
errno = error;
return -1;
diff --git a/parser/lib.h b/parser/lib.h
index aac2223..73e1ffc 100644
--- a/parser/lib.h
+++ b/parser/lib.h
@@ -3,6 +3,9 @@
#include <dirent.h>
+#define autofree __attribute((cleanup(__autofree)))
+void __autofree(void *p);
+
int dirat_for_each(DIR *dir, const char *name, void *data,
int (* cb)(DIR *, const char *, struct stat *, void *));
diff --git a/parser/parser_interface.c b/parser/parser_interface.c
index 0d6626d..485c30b 100644
--- a/parser/parser_interface.c
+++ b/parser/parser_interface.c
@@ -28,6 +28,7 @@
#include <string>
#include <sstream>
+#include "lib.h"
#include "parser.h"
#include "profile.h"
#include "libapparmor_re/apparmor_re.h"
@@ -374,13 +375,11 @@ void sd_serialize_profile(std::ostringstream &buf, Profile *profile,
sd_write_struct(buf, "profile");
if (flattened) {
assert(profile->parent);
- char *name = (char *) malloc(3 + strlen(profile->name) +
- strlen(profile->parent->name));
+ autofree char *name = (char *) malloc(3 + strlen(profile->name) + strlen(profile->parent->name));
if (!name)
return;
sprintf(name, "%s//%s", profile->parent->name, profile->name);
sd_write_string(buf, name, NULL);
- free(name);
} else {
sd_write_string(buf, profile->name, NULL);
}
@@ -483,7 +482,7 @@ int __sd_serialize_profile(int option, Profile *prof)
int fd = -1;
int error = -ENOMEM, size, wsize;
std::ostringstream work_area;
- char *filename = NULL;
+ autofree char *filename = NULL;
switch (option) {
case OPTION_ADD:
@@ -523,8 +522,6 @@ int __sd_serialize_profile(int option, Profile *prof)
error = 0;
- free(filename);
-
if (option == OPTION_REMOVE) {
char *name, *ns = NULL;
int len = 0;
@@ -646,7 +643,7 @@ int sd_load_buffer(int option, char *buffer, int size)
{
int fd = -1;
int error, bsize;
- char *filename = NULL;
+ autofree char *filename = NULL;
/* TODO: push backup into caller */
if (!kernel_load)
@@ -694,7 +691,5 @@ int sd_load_buffer(int option, char *buffer, int size)
close(fd);
out:
- free(filename);
-
return error;
}
diff --git a/parser/parser_lex.l b/parser/parser_lex.l
index 2f6f914..0456843 100644
--- a/parser/parser_lex.l
+++ b/parser/parser_lex.l
@@ -125,15 +125,13 @@ static int include_dir_cb(DIR *dir unused, const char *name, struct stat *st,
{
struct cb_struct *d = (struct cb_struct *) data;
- char *path;
+ autofree char *path = NULL;
if (asprintf(&path, "%s/%s", d->fullpath, name) < 0)
yyerror("Out of memory");
- if (is_blacklisted(name, path)) {
- free(path);
+ if (is_blacklisted(name, path))
return 0;
- }
if (S_ISREG(st->st_mode)) {
if (!(yyin = fopen(path,"r")))
@@ -144,8 +142,6 @@ static int include_dir_cb(DIR *dir unused, const char *name, struct stat *st,
yypush_buffer_state(yy_create_buffer(yyin, YY_BUF_SIZE));
}
- free(path);
-
return 0;
}
@@ -153,7 +149,7 @@ void include_filename(char *filename, int search)
{
FILE *include_file = NULL;
struct stat my_stat;
- char *fullpath = NULL;
+ autofree char *fullpath = NULL;
if (search) {
if (preprocess_only)
@@ -188,9 +184,6 @@ void include_filename(char *filename, int search)
" '%s' in '%s'"), fullpath, filename);;
}
}
-
- if (fullpath)
- free(fullpath);
}
%}
@@ -281,9 +274,8 @@ LT_EQUAL <=
<INCLUDE>{
(\<([^\> \t\n]+)\>|\"([^\" \t\n]+)\") { /* <filename> */
- char *filename = strndup(yytext, yyleng - 1);
+ autofree char *filename = strndup(yytext, yyleng - 1);
include_filename(filename + 1, *filename == '<');
- free(filename);
POP_NODUMP();
}
diff --git a/parser/parser_main.c b/parser/parser_main.c
index f075618..f18d5f4 100644
--- a/parser/parser_main.c
+++ b/parser/parser_main.c
@@ -555,16 +555,13 @@ static void set_features_by_match_file(void)
{
FILE *ms = fopen(MATCH_FILE, "r");
if (ms) {
- char *match_string = (char *) malloc(1000);
+ autofree char *match_string = (char *) malloc(1000);
if (!match_string)
goto no_match;
- if (!fgets(match_string, 1000, ms)) {
- free(match_string);
+ if (!fgets(match_string, 1000, ms))
goto no_match;
- }
if (strstr(match_string, " perms=c"))
perms_create = 1;
- free(match_string);
kernel_supports_network = 1;
goto out;
}
@@ -618,7 +615,7 @@ static void set_supported_features(void) {
int process_binary(int option, const char *profilename)
{
- char *buffer = NULL;
+ autofree char *buffer = NULL;
int retval = 0, size = 0, asize = 0, rsize;
int chunksize = 1 << 14;
int fd;
@@ -637,7 +634,7 @@ int process_binary(int option, const char *profilename)
do {
if (asize - size == 0) {
- buffer = (char *) realloc(buffer, chunksize);
+ buffer = (char *) realloc(buffer, chunksize);
asize = chunksize;
chunksize <<= 1;
if (!buffer) {
@@ -658,8 +655,6 @@ int process_binary(int option, const char *profilename)
else
retval = rsize;
- free(buffer);
-
if (conf_verbose) {
switch (option) {
case OPTION_ADD:
@@ -694,7 +689,7 @@ int test_for_dir_mode(const char *basename, const char *linkdir)
int rc = 0;
if (!skip_mode_force) {
- char *target = NULL;
+ autofree char *target = NULL;
if (asprintf(&target, "%s/%s/%s", basedir, linkdir, basename) < 0) {
perror("asprintf");
exit(1);
@@ -702,8 +697,6 @@ int test_for_dir_mode(const char *basename, const char *linkdir)
if (access(target, R_OK) == 0)
rc = 1;
-
- free(target);
}
return rc;
@@ -713,8 +706,8 @@ int process_profile(int option, const char *profilename)
{
struct stat stat_bin;
int retval = 0;
- char * cachename = NULL;
- char * cachetemp = NULL;
+ autofree char *cachename = NULL;
+ autofree char *cachetemp = NULL;
const char *basename = NULL;
/* per-profile states */
@@ -879,10 +872,8 @@ out:
unlink(cachetemp);
PERROR("Warning failed to create cache: %s\n", basename);
}
- free(cachetemp);
}
- if (cachename)
- free(cachename);
+
return retval;
}
@@ -894,11 +885,10 @@ static int profile_dir_cb(DIR *dir unused, const char *name, struct stat *st,
if (!S_ISDIR(st->st_mode) && !is_blacklisted(name, NULL)) {
const char *dirname = (const char *)data;
- char *path;
+ autofree char *path = NULL;
if (asprintf(&path, "%s/%s", dirname, name) < 0)
PERROR(_("Out of memory"));
rc = process_profile(option, path);
- free(path);
}
return rc;
}
@@ -911,19 +901,18 @@ static int binary_dir_cb(DIR *dir unused, const char *name, struct stat *st,
if (!S_ISDIR(st->st_mode) && !is_blacklisted(name, NULL)) {
const char *dirname = (const char *)data;
- char *path;
+ autofree char *path = NULL;
if (asprintf(&path, "%s/%s", dirname, name) < 0)
PERROR(_("Out of memory"));
rc = process_binary(option, path);
- free(path);
}
return rc;
}
static void setup_flags(void)
{
- char *cache_features_path = NULL;
- char *cache_flags = NULL;
+ autofree char *cache_features_path = NULL;
+ autofree char *cache_flags = NULL;
/* Get the match string to determine type of regex support needed */
set_supported_features();
@@ -964,13 +953,9 @@ static void setup_flags(void)
skip_read_cache = 1;
}
}
- free(cache_flags);
- cache_flags = NULL;
} else if (write_cache) {
create_cache(cacheloc, cache_features_path, features_string);
}
-
- free(cache_features_path);
}
int main(int argc, char *argv[])
--
2.1.4
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