diff options
author | Jeff King <peff@peff.net> | 2018-08-30 10:07:52 +0300 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2018-08-30 20:30:21 +0300 |
commit | d65930c5a9fe73ebc4d157ebe1fb9fd9907f2f70 (patch) | |
tree | 261cdb60ac2c931f5d2e0dc794e75e5092618a7d /t/helper | |
parent | 2f743933341f276111103550fbf383a34dfcfd38 (diff) |
test-delta: read input into a heap buffer
We currently read the input to test-delta by mmap()-ing it.
However, memory-checking tools like valgrind and ASan are
less able to detect reads/writes past the end of an mmap'd
buffer, because the OS is likely to give us extra bytes to
pad out the final page size. So instead, let's read into a
heap buffer.
As a bonus, this also makes it possible to write tests with
empty bases, as mmap() will complain about a zero-length
map.
This is based on a patch by Jann Horn <jannh@google.com>
which actually aligned the data at the end of a page, and
followed it with another page marked with mprotect(). That
would detect problems even without a tool like ASan, but it
was significantly more complex and may have introduced
portability problems. By comparison, this approach pushes
the complexity onto existing memory-checking tools.
Note that this could be done even more simply by using
strbuf_read_file(), but that would defeat the purpose:
strbufs generally overallocate (and at the very least
include a trailing NUL which we do not care about), which
would defeat most memory checkers.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 't/helper')
-rw-r--r-- | t/helper/test-delta.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/t/helper/test-delta.c b/t/helper/test-delta.c index 34c7259248..e749a49c88 100644 --- a/t/helper/test-delta.c +++ b/t/helper/test-delta.c @@ -34,8 +34,8 @@ int cmd__delta(int argc, const char **argv) return 1; } from_size = st.st_size; - from_buf = mmap(NULL, from_size, PROT_READ, MAP_PRIVATE, fd, 0); - if (from_buf == MAP_FAILED) { + from_buf = xmalloc(from_size); + if (read_in_full(fd, from_buf, from_size) < 0) { perror(argv[2]); close(fd); return 1; @@ -48,8 +48,8 @@ int cmd__delta(int argc, const char **argv) return 1; } data_size = st.st_size; - data_buf = mmap(NULL, data_size, PROT_READ, MAP_PRIVATE, fd, 0); - if (data_buf == MAP_FAILED) { + data_buf = xmalloc(data_size); + if (read_in_full(fd, data_buf, data_size) < 0) { perror(argv[3]); close(fd); return 1; |