On at least one system I've used recently sizeof(size_t) == 4
and sizeof(unsigned long) == 8. Trying to pass a pointer to an 8
byte value into strbuf_detach() causes problems as the function is
expecting an address for a 4 byte result location. Writing only 4
bytes here will leave the other 4 bytes unitialized and may cause
problems when the caller evalutes the result.
I am introducing strbuf_detach_ul() as a variant that takes its
size as an unsigned long rather than as a size_t. This approach is
shorter than fixing all of the callers to use their own temporary
size_t value for the call.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
builtin-apply.c | 2 +-
builtin-archive.c | 2 +-
diff.c | 4 ++--
entry.c | 2 +-
strbuf.h | 8 +++++++-
test-delta.c | 3 ++-
6 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/builtin-apply.c b/builtin-apply.c
index 05c6bc3..022f916 100644
--- a/builtin-apply.c
+++ b/builtin-apply.c
@@ -1955,7 +1955,7 @@ static int apply_data(struct patch *patch, struct stat *st, struct cache_entry *
if (apply_fragments(&buf, patch) < 0)
return -1; /* note with --reject this succeeds. */
- patch->result = strbuf_detach(&buf, &patch->resultsize);
+ patch->result = strbuf_detach_ul(&buf, &patch->resultsize);
if (0 < patch->is_delete && patch->resultsize)
return error("removal patch leaves file contents");
diff --git a/builtin-archive.c b/builtin-archive.c
index 04385de..46d5de0 100644
--- a/builtin-archive.c
+++ b/builtin-archive.c
@@ -153,7 +153,7 @@ void *sha1_file_to_archive(const char *path, const unsigned char *sha1,
strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
convert_to_working_tree(path, buf.buf, buf.len, &buf);
convert_to_archive(path, buf.buf, buf.len, &buf, commit);
- buffer = strbuf_detach(&buf, sizep);
+ buffer = strbuf_detach_ul(&buf, sizep);
}
return buffer;
diff --git a/diff.c b/diff.c
index 6648e01..6fd0c0a 100644
--- a/diff.c
+++ b/diff.c
@@ -1519,7 +1519,7 @@ static int populate_from_stdin(struct diff_filespec *s)
strerror(errno));
s->should_munmap = 0;
- s->data = strbuf_detach(&buf, &s->size);
+ s->data = strbuf_detach_ul(&buf, &s->size);
s->should_free = 1;
return 0;
}
@@ -1611,7 +1611,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
if (convert_to_git(s->path, s->data, s->size, &buf)) {
munmap(s->data, s->size);
s->should_munmap = 0;
- s->data = strbuf_detach(&buf, &s->size);
+ s->data = strbuf_detach_ul(&buf, &s->size);
s->should_free = 1;
}
}
diff --git a/entry.c b/entry.c
index 98f5f6d..d36a0bb 100644
--- a/entry.c
+++ b/entry.c
@@ -120,7 +120,7 @@ static int write_entry(struct cache_entry *ce, char *path, const struct checkout
strbuf_init(&buf, 0);
if (convert_to_working_tree(ce->name, new, size, &buf)) {
free(new);
- new = strbuf_detach(&buf, &size);
+ new = strbuf_detach_ul(&buf, &size);
}
if (to_tempfile) {
diff --git a/strbuf.h b/strbuf.h
index 9b9e861..d6d6bd0 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -52,7 +52,13 @@ struct strbuf {
/*----- strbuf life cycle -----*/
extern void strbuf_init(struct strbuf *, size_t);
extern void strbuf_release(struct strbuf *);
-extern char *strbuf_detach(struct strbuf *, size_t *);
+extern char *strbuf_detach(struct strbuf *, unsigned long *);
+static inline char *strbuf_detach_ul(struct strbuf *a, unsigned long *n) {
+ size_t len;
+ char *res = strbuf_detach(a, &len);
+ *n = len;
+ return res;
+}
extern void strbuf_attach(struct strbuf *, void *, size_t, size_t);
static inline void strbuf_swap(struct strbuf *a, struct strbuf *b) {
struct strbuf tmp = *a;
diff --git a/test-delta.c b/test-delta.c
index 3d885ff..018e7dc 100644
--- a/test-delta.c
+++ b/test-delta.c
@@ -20,7 +20,8 @@ int main(int argc, char *argv[])
int fd;
struct stat st;
void *from_buf, *data_buf, *out_buf;
- unsigned long from_size, data_size, out_size;
+ unsigned long from_size, data_size;
+ size_t out_size;
if (argc != 5 || (strcmp(argv[1], "-d") && strcmp(argv[1], "-p"))) {
fprintf(stderr, "Usage: %s\n", usage_str);
--
1.5.3.4.1270.g2fe543
-
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