X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=blobdiff_plain;f=sha1_file.c;h=1efd9ae19a84dbc2765d4011ea06b2145e86ebb3;hb=34a3e695497ab2abbf2fc33a46380accaa8c7c15;hp=3093ac9f5f0d6cfc76f532a2f6690593410e9d6e;hpb=bc8e478a285ff549a3e5182461b064313d400de3;p=git.git

diff --git a/sha1_file.c b/sha1_file.c
index 3093ac9f5..1efd9ae19 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -33,7 +33,7 @@ const unsigned char null_sha1[20];
 
 static unsigned int sha1_file_open_flag = O_NOATIME;
 
-signed char hexval_table[256] = {
+const signed char hexval_table[256] = {
 	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 00-07 */
 	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 08-0f */
 	 -1, -1, -1, -1, -1, -1, -1, -1,		/* 10-17 */
@@ -193,7 +193,7 @@ char *sha1_pack_name(const unsigned char *sha1)
 		*buf++ = hex[val >> 4];
 		*buf++ = hex[val & 0xf];
 	}
-	
+
 	return base;
 }
 
@@ -218,7 +218,7 @@ char *sha1_pack_index_name(const unsigned char *sha1)
 		*buf++ = hex[val >> 4];
 		*buf++ = hex[val & 0xf];
 	}
-	
+
 	return base;
 }
 
@@ -352,10 +352,14 @@ static void read_info_alternates(const char * relative_base, int depth)
 	char *map;
 	size_t mapsz;
 	struct stat st;
-	char path[PATH_MAX];
+	const char alt_file_name[] = "info/alternates";
+	/* Given that relative_base is no longer than PATH_MAX,
+	   ensure that "path" has enough space to append "/", the
+	   file name, "info/alternates", and a trailing NUL.  */
+	char path[PATH_MAX + 1 + sizeof alt_file_name];
 	int fd;
 
-	sprintf(path, "%s/info/alternates", relative_base);
+	sprintf(path, "%s/%s", relative_base, alt_file_name);
 	fd = open(path, O_RDONLY);
 	if (fd < 0)
 		return;
@@ -413,7 +417,7 @@ static size_t peak_pack_mapped;
 static size_t pack_mapped;
 struct packed_git *packed_git;
 
-void pack_report()
+void pack_report(void)
 {
 	fprintf(stderr,
 		"pack_report: getpagesize()            = %10" SZ_FMT "\n"
@@ -510,7 +514,10 @@ static int check_packed_git_idx(const char *path,  struct packed_git *p)
 		 * for offsets larger than 2^31.
 		 */
 		unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
-		if (idx_size < min_size || idx_size > min_size + (nr - 1)*8) {
+		unsigned long max_size = min_size;
+		if (nr)
+			max_size += (nr - 1)*8;
+		if (idx_size < min_size || idx_size > max_size) {
 			munmap(idx_map, idx_size);
 			return error("wrong index file size in %s", path);
 		}
@@ -833,7 +840,10 @@ void install_packed_git(struct packed_git *pack)
 
 static void prepare_packed_git_one(char *objdir, int local)
 {
-	char path[PATH_MAX];
+	/* Ensure that this buffer is large enough so that we can
+	   append "/pack/" without clobbering the stack even if
+	   strlen(objdir) were PATH_MAX.  */
+	char path[PATH_MAX + 1 + 4 + 1 + 1];
 	int len;
 	DIR *dir;
 	struct dirent *de;
@@ -855,6 +865,9 @@ static void prepare_packed_git_one(char *objdir, int local)
 		if (!has_extension(de->d_name, ".idx"))
 			continue;
 
+		if (len + namelen + 1 > sizeof(path))
+			continue;
+
 		/* Don't reopen a pack we already have. */
 		strcpy(path + len, de->d_name);
 		for (p = packed_git; p; p = p->next) {
@@ -959,7 +972,7 @@ int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long siz
 	return hashcmp(sha1, real_sha1) ? -1 : 0;
 }
 
-void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
+static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
 {
 	struct stat st;
 	void *map;
@@ -1139,7 +1152,7 @@ static int parse_sha1_header(const char *hdr, unsigned long *sizep)
 	unsigned long size;
 
 	/*
-	 * The type can be at most ten bytes (including the 
+	 * The type can be at most ten bytes (including the
 	 * terminating '\0' that we add), and is followed by
 	 * a space.
 	 */
@@ -1687,20 +1700,25 @@ static int matches_pack_name(struct packed_git *p, const char *ig)
 
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
 {
+	static struct packed_git *last_found = (void *)1;
 	struct packed_git *p;
 	off_t offset;
 
 	prepare_packed_git();
+	if (!packed_git)
+		return 0;
+	p = (last_found == (void *)1) ? packed_git : last_found;
 
-	for (p = packed_git; p; p = p->next) {
+	do {
 		if (ignore_packed) {
 			const char **ig;
 			for (ig = ignore_packed; *ig; ig++)
 				if (!matches_pack_name(p, *ig))
 					break;
 			if (*ig)
-				continue;
+				goto next;
 		}
+
 		offset = find_pack_entry_one(sha1, p);
 		if (offset) {
 			/*
@@ -1713,18 +1731,27 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, cons
 			 */
 			if (p->pack_fd == -1 && open_packed_git(p)) {
 				error("packfile %s cannot be accessed", p->pack_name);
-				continue;
+				goto next;
 			}
 			e->offset = offset;
 			e->p = p;
 			hashcpy(e->sha1, sha1);
+			last_found = p;
 			return 1;
 		}
-	}
+
+		next:
+		if (p == last_found)
+			p = packed_git;
+		else
+			p = p->next;
+		if (p == last_found)
+			p = p->next;
+	} while (p);
 	return 0;
 }
 
-struct packed_git *find_sha1_pack(const unsigned char *sha1, 
+struct packed_git *find_sha1_pack(const unsigned char *sha1,
 				  struct packed_git *packs)
 {
 	struct packed_git *p;