From dc944b65f1d13e258edc88a7608e2fe957ec334e Mon Sep 17 00:00:00 2001 From: Jeff King Date: Fri, 19 May 2017 08:54:43 -0400 Subject: get_sha1_with_context: dynamically allocate oc->path When a sha1 lookup returns the tree path via "struct object_context", it just copies it into a fixed-size buffer. This means the result can be truncated, and it means our "struct object_context" consumes a lot of stack space. Instead, let's allocate a string on the heap. Because most callers don't care about this information, we'll avoid doing it by default (so they don't all have to start calling free() on the result). There are basically two options for the caller to signal to us that it's interested: 1. By setting a pointer to storage in the object_context. 2. By passing a flag in another parameter. Doing (1) would match the way that sha1_object_info_extended() works. But it would mean that every caller would have to initialize the object_context, which they don't currently have to do. This patch does (2), and adds a new bit to the function's flags field. All of the callers that look at the "path" field are updated to pass the new flag. Signed-off-by: Jeff King Signed-off-by: Junio C Hamano diff --git a/builtin/cat-file.c b/builtin/cat-file.c index 1890d7a..4217095 100644 --- a/builtin/cat-file.c +++ b/builtin/cat-file.c @@ -61,7 +61,8 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name, if (unknown_type) flags |= LOOKUP_UNKNOWN_OBJECT; - if (get_sha1_with_context(obj_name, 0, oid.hash, &obj_context)) + if (get_sha1_with_context(obj_name, GET_SHA1_RECORD_PATH, + oid.hash, &obj_context)) die("Not a valid object name %s", obj_name); if (!path) @@ -165,6 +166,7 @@ static int cat_one_file(int opt, const char *exp_type, const char *obj_name, die("git cat-file %s: bad file", obj_name); write_or_die(1, buf, size); + free(obj_context.path); return 0; } diff --git a/builtin/grep.c b/builtin/grep.c index 3ffb5b4..254c1c7 100644 --- a/builtin/grep.c +++ b/builtin/grep.c @@ -1190,7 +1190,8 @@ int cmd_grep(int argc, const char **argv, const char *prefix) break; } - if (get_sha1_with_context(arg, 0, oid.hash, &oc)) { + if (get_sha1_with_context(arg, GET_SHA1_RECORD_PATH, + oid.hash, &oc)) { if (seen_dashdash) die(_("unable to resolve revision: %s"), arg); break; @@ -1200,6 +1201,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix) if (!seen_dashdash) verify_non_filename(prefix, arg); add_object_array_with_path(object, arg, &list, oc.mode, oc.path); + free(oc.path); } /* diff --git a/builtin/log.c b/builtin/log.c index b3b10cc..1db016b 100644 --- a/builtin/log.c +++ b/builtin/log.c @@ -483,16 +483,20 @@ static int show_blob_object(const struct object_id *oid, struct rev_info *rev, c !DIFF_OPT_TST(&rev->diffopt, ALLOW_TEXTCONV)) return stream_blob_to_fd(1, oid, NULL, 0); - if (get_sha1_with_context(obj_name, 0, oidc.hash, &obj_context)) + if (get_sha1_with_context(obj_name, GET_SHA1_RECORD_PATH, + oidc.hash, &obj_context)) die(_("Not a valid object name %s"), obj_name); - if (!obj_context.path[0] || - !textconv_object(obj_context.path, obj_context.mode, &oidc, 1, &buf, &size)) + if (!obj_context.path || + !textconv_object(obj_context.path, obj_context.mode, &oidc, 1, &buf, &size)) { + free(obj_context.path); return stream_blob_to_fd(1, oid, NULL, 0); + } if (!buf) die(_("git show %s: bad file"), obj_name); write_or_die(1, buf, size); + free(obj_context.path); return 0; } diff --git a/cache.h b/cache.h index 6cae30f..52b91f5 100644 --- a/cache.h +++ b/cache.h @@ -1333,13 +1333,18 @@ static inline int hex2chr(const char *s) struct object_context { unsigned char tree[20]; - char path[PATH_MAX]; unsigned mode; /* * symlink_path is only used by get_tree_entry_follow_symlinks, * and only for symlinks that point outside the repository. */ struct strbuf symlink_path; + /* + * If GET_SHA1_RECORD_PATH is set, this will record path (if any) + * found when resolving the name. The caller is responsible for + * releasing the memory. + */ + char *path; }; #define GET_SHA1_QUIETLY 01 @@ -1349,6 +1354,7 @@ struct object_context { #define GET_SHA1_TREEISH 020 #define GET_SHA1_BLOB 040 #define GET_SHA1_FOLLOW_SYMLINKS 0100 +#define GET_SHA1_RECORD_PATH 0200 #define GET_SHA1_ONLY_TO_DIE 04000 #define GET_SHA1_DISAMBIGUATORS \ diff --git a/sha1_name.c b/sha1_name.c index e7b0393..5e2ec37 100644 --- a/sha1_name.c +++ b/sha1_name.c @@ -1550,7 +1550,8 @@ static int get_sha1_with_context_1(const char *name, namelen = strlen(cp); } - strlcpy(oc->path, cp, sizeof(oc->path)); + if (flags & GET_SHA1_RECORD_PATH) + oc->path = xstrdup(cp); if (!active_cache) read_cache(); @@ -1613,7 +1614,8 @@ static int get_sha1_with_context_1(const char *name, } } hashcpy(oc->tree, tree_sha1); - strlcpy(oc->path, filename, sizeof(oc->path)); + if (flags & GET_SHA1_RECORD_PATH) + oc->path = xstrdup(filename); free(new_filename); return ret; -- cgit v0.10.2-6-g49f6