Commit 64a47c01426a36cdb7e598d17018d5791e54bb97

Shawn O. Pearce 2008-12-30T23:21:36

Wrap malloc and friends and report out of memory as GIT_ENOMEM We now forbid direct use of malloc, strdup or calloc within the library and instead use wrapper functions git__malloc, etc. to invoke the underlying library malloc and set git_errno to a no memory error code if the allocation fails. In the future once we have pack objects in memory we are likely to enhance these routines with garbage collection logic to purge cached pack data when allocations fail. Because the size of the function will grow somewhat large, we don't want to mark them for inline as gcc tends to aggressively inline, creating larger than expected executables. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/src/commit.c b/src/commit.c
index ce02d0e..710a14e 100644
--- a/src/commit.c
+++ b/src/commit.c
@@ -23,6 +23,7 @@
  * Boston, MA 02110-1301, USA.
  */
 
+#include "common.h"
 #include "commit.h"
 
 const git_oid *git_commit_id(git_commit *c)
diff --git a/src/common.h b/src/common.h
index 3d1f0e5..3ba86b2 100644
--- a/src/common.h
+++ b/src/common.h
@@ -2,7 +2,6 @@
 #define INCLUDE_common_h__
 
 #include "cc-compat.h"
-#include "util.h"
 #include "errors.h"
 
 #ifdef GIT_HAS_PTHREAD
@@ -19,6 +18,7 @@
 # define PRIuPTR "lu"
 #endif
 
+#include "util.h"
 #include "git/common.h"
 
 #define GIT_PATH_MAX 4096
diff --git a/src/errors.c b/src/errors.c
index 75636f4..deb106b 100644
--- a/src/errors.c
+++ b/src/errors.c
@@ -19,7 +19,9 @@ int *git__errno_storage(void)
 {
 	int *e = pthread_getspecific(errno_key);
 	if (!e) {
+#undef calloc
 		e = calloc(1, sizeof(*e));
+#define calloc(a,b) GIT__FORBID_MALLOC
 		pthread_setspecific(errno_key, e);
 	}
 	return e;
@@ -33,6 +35,7 @@ static struct {
 } error_codes[] = {
 	{ GIT_ENOTOID, "Not a git oid" },
 	{ GIT_ENOTFOUND, "Object does not exist in the scope searched" },
+	{ GIT_ENOMEM, "Not enough space" },
 };
 
 const char *git_strerror(int num)
diff --git a/src/fileops.c b/src/fileops.c
index 1e4ac7e..6522d02 100644
--- a/src/fileops.c
+++ b/src/fileops.c
@@ -58,17 +58,18 @@ int gitfo_read_file(gitfo_buf *obj, const char *path)
 	assert(obj && path && *path);
 
 	if ((fd = gitfo_open(path, O_RDONLY)) < 0)
-		return GIT_ERROR;  /* TODO: error handling */
+		return GIT_ERROR;
 
-	if (((len = gitfo_size(fd)) < 0) || ((buff = malloc(len+1)) == NULL)) {
+	if (((len = gitfo_size(fd)) < 0) 
+		|| ((buff = git__malloc(len + 1)) == NULL)) {
 		gitfo_close(fd);
-		return GIT_ERROR;  /* TODO: error handling */
+		return GIT_ERROR;
 	}
 
 	if (gitfo_read(fd, buff, len) < 0) {
 		gitfo_close(fd);
 		free(buff);
-		return GIT_ERROR;  /* TODO: error handling */
+		return GIT_ERROR;
 	}
 	buff[len] = '\0';
 
@@ -98,13 +99,13 @@ gitfo_cache *gitfo_enable_caching(git_file fd, size_t cache_size)
 {
 	gitfo_cache *ioc;
 
-	ioc = malloc(sizeof(*ioc));
+	ioc = git__malloc(sizeof(*ioc));
 	if (!ioc)
 		return NULL;
 
 	ioc->pos = 0;
 	ioc->cache_size = cache_size;
-	ioc->cache = malloc(cache_size);
+	ioc->cache = git__malloc(cache_size);
 	if (!ioc->cache) {
 		free(ioc);
 		return NULL;
diff --git a/src/git/common.h b/src/git/common.h
index 87f7f37..6397533 100644
--- a/src/git/common.h
+++ b/src/git/common.h
@@ -55,6 +55,9 @@
 /** Input does not exist in the scope searched. */
 #define GIT_ENOTFOUND (GIT_ERROR - 2)
 
+/** Not enough space available. */
+#define GIT_ENOMEM (GIT_ERROR - 3)
+
 GIT_BEGIN_DECL
 
 /** A revision traversal pool. */
diff --git a/src/hash.c b/src/hash.c
index 4ff1dd0..65912de 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -33,7 +33,7 @@ struct git_hash_ctx {
 
 git_hash_ctx *git_hash_new_ctx(void)
 {
-	git_hash_ctx *ctx = malloc(sizeof(*ctx));
+	git_hash_ctx *ctx = git__malloc(sizeof(*ctx));
 
 	if (!ctx)
 		return NULL;
diff --git a/src/odb.c b/src/odb.c
index e96aa1e..e074873 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -279,7 +279,7 @@ static void *inflate_tail(z_stream *s, void *hb, size_t used, obj_hdr *hdr)
 	 * initial sequence of inflated data from the tail of the
 	 * head buffer, if any.
 	 */
-	if ((buf = malloc(hdr->size + 1)) == NULL)
+	if ((buf = git__malloc(hdr->size + 1)) == NULL)
 		return NULL;
 	tail = s->total_out - used;
 	if (used > 0 && tail > 0) {
@@ -352,7 +352,10 @@ static int inflate_packlike_loose_disk_obj(git_obj *out, gitfo_buf *obj)
 	/*
 	 * allocate a buffer and inflate the data into it
 	 */
-	buf = malloc(hdr.size+1);
+	buf = git__malloc(hdr.size + 1);
+	if (!buf)
+		return GIT_ERROR;
+
 	in  = ((unsigned char *)obj->data) + used;
 	len = obj->len - used;
 	if (inflate_buffer(in, len, buf, hdr.size)) {
@@ -414,7 +417,7 @@ static int open_alternates(git_odb *db)
 {
 	unsigned n = 0;
 
-	db->alternates = malloc(sizeof(*db->alternates) * (n + 1));
+	db->alternates = git__malloc(sizeof(*db->alternates) * (n + 1));
 	if (!db->alternates)
 		return GIT_ERROR;
 
@@ -424,11 +427,11 @@ static int open_alternates(git_odb *db)
 
 int git_odb_open(git_odb **out, const char *objects_dir)
 {
-	git_odb *db = malloc(sizeof(*db));
+	git_odb *db = git__malloc(sizeof(*db));
 	if (!db)
 		return GIT_ERROR;
 
-	db->objects_dir = strdup(objects_dir);
+	db->objects_dir = git__strdup(objects_dir);
 	if (!db->objects_dir) {
 		free(db);
 		return GIT_ERROR;
diff --git a/src/oid.c b/src/oid.c
index 8601554..b8fce12 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -87,7 +87,7 @@ void git_oid_pathfmt(char *str, const git_oid *oid)
 
 char *git_oid_allocfmt(const git_oid *oid)
 {
-	char *str = malloc(GIT_OID_HEXSZ + 1);
+	char *str = git__malloc(GIT_OID_HEXSZ + 1);
 	if (!str)
 		return NULL;
 	git_oid_fmt(str, oid);
diff --git a/src/revwalk.c b/src/revwalk.c
index 81d3ab6..11261fb 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -23,11 +23,12 @@
  * Boston, MA 02110-1301, USA.
  */
 
+#include "common.h"
 #include "revwalk.h"
 
 git_revpool *gitrp_alloc(git_odb *db)
 {
-	git_revpool *walk = malloc(sizeof(*walk));
+	git_revpool *walk = git__malloc(sizeof(*walk));
 	if (!walk)
 		return NULL;
 
diff --git a/src/thread-utils.c b/src/thread-utils.c
index c945829..5e8220f 100644
--- a/src/thread-utils.c
+++ b/src/thread-utils.c
@@ -1,3 +1,4 @@
+#include "common.h"
 #include "thread-utils.h"
 
 #ifdef _WIN32
diff --git a/src/util.c b/src/util.c
new file mode 100644
index 0000000..64b5d4f
--- /dev/null
+++ b/src/util.c
@@ -0,0 +1,26 @@
+#define GIT__NO_HIDE_MALLOC
+#include "common.h"
+
+void *git__malloc(size_t n)
+{
+	void *r = malloc(n);
+	if (!r)
+		return git_ptr_error(GIT_ENOMEM);
+	return r;
+}
+
+void *git__calloc(size_t a, size_t b)
+{
+	void *r = calloc(a, b);
+	if (!r)
+		return git_ptr_error(GIT_ENOMEM);
+	return r;
+}
+
+char *git__strdup(const char *s)
+{
+	char *r = strdup(s);
+	if (!s)
+		return git_ptr_error(GIT_ENOMEM);
+	return r;
+}
diff --git a/src/util.h b/src/util.h
index 45504b7..f09aecf 100644
--- a/src/util.h
+++ b/src/util.h
@@ -3,6 +3,17 @@
 
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(x[0]))
 
+extern void *git__malloc(size_t);
+extern void *git__calloc(size_t, size_t);
+extern char *git__strdup(const char *);
+
+#ifndef GIT__NO_HIDE_MALLOC
+# define GIT__FORBID_MALLOC do_not_use_malloc_directly
+# define malloc(a)          GIT__FORBID_MALLOC
+# define calloc(a,b)        GIT__FORBID_MALLOC
+# define strdup(a)          GIT__FORBID_MALLOC
+#endif
+
 /*
  * Realloc the buffer pointed at by variable 'x' so that it can hold
  * at least 'nr' entries; the number of entries currently allocated