These were categorized as the following:
* Dead assignment 23
* Dead increment 4
* Dead initialization 6
* Dead nested assignment 18
Most of these are harmless, but since actual issues can hide among them,
we correct them.
That said, there were a few return values that were being ignored that
appeared to merit some correction:
* `destroy_callback()` in `cmd/zfs/zfs_main.c` ignored the error from
`destroy_batched()`. We handle it by returning -1 if there is an
error.
* `zfs_do_upgrade()` in `cmd/zfs/zfs_main.c` ignored the error from
`zfs_for_each()`. We handle it by doing a binary OR of the error
value from the subsequent `zfs_for_each()` call to the existing
value. This is how errors are mostly handled inside `zfs_for_each()`.
The error value here is passed to exit from the zfs command, so doing
a binary or on it is better than what we did previously.
* `get_zap_prop()` in `module/zfs/zcp_get.c` ignored the error from
`dsl_prop_get_ds()` when the property is not of type string. We
return an error when it does. There is a small concern that the
`zfs_get_temporary_prop()` call would handle things, but in the case
that it does not, we would be pushing an uninitialized numval onto
the lua stack. It is expected that `dsl_prop_get_ds()` will succeed
anytime that `zfs_get_temporary_prop()` does, so that not giving it a
chance to fix things is not a problem.
* `draid_merge_impl()` in `tests/zfs-tests/cmd/draid.c` used
`nvlist_add_nvlist()` twice in ways in which errors are expected to
be impossible, so we switch to `fnvlist_add_nvlist()`.
A few notable ones did not merit use of the return value, so we
suppressed it with `(void)`:
* `write_free_diffs()` in `lib/libzfs/libzfs_diff.c` ignored the error
value from `describe_free()`. A look through the commit history
revealed that this was intentional.
* `arc_evict_hdr()` in `module/zfs/arc.c` did not need to use the
returned handle from `arc_hdr_realloc()` because it is already
referenced in lists.
* `spa_vdev_detach()` in `module/zfs/spa.c` has a comment explicitly
saying not to use the error from `vdev_label_init()` because whatever
causes the error could be the reason why a detach is being done.
Unfortunately, I am not presently able to analyze the kernel modules
with Clang's static analyzer, so I could have missed some cases of this.
In cases where reports were present in code that is duplicated between
Linux and FreeBSD, I made a conscious effort to fix the FreeBSD version
too.
After this commit is merged, regressions like dee8934 should become
extremely obvious with Clang's static analyzer since a regression would
appear in the results as the only instance of unused code. That assumes
that Coverity does not catch the issue first.
My local branch with fixes from all of my outstanding non-draft pull
requests shows 118 reports from Clang's static anlayzer after this
patch. That is down by 51 from 169.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Cedric Berger <cedric@precidata.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13986
Coverity had various complaints about minor issues. They are all fairly
straightforward to understand without reading additional files, with the
exception of the draid.c issue. vdev_draid_rand() takes a 128-bit
starting seed, but we were passing a pointer to a 64-bit value, which
understandably made Coverity complain. This is perhaps the only
significant issue fixed in this patch, since it causes stack corruption.
These are not all of the issues in the ZTS that Coverity caught, but a
number of them are already fixed in other PRs. There is also a class of
TOUTOC complaints that involve very minor things in the ZTS (e.g.
access() before unlink()). I have yet to decide whether they are false
positives (since this is not security sensitive code) or something to
cleanup.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Neal Gompa <ngompa@datto.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13943
Coverity found a bug in `zfs_secpolicy_create_clone()` where it is
possible for us to pass an unterminated string when `zfs_get_parent()`
returns an error. Upon inspection, it is clear that using `strlcpy()`
would have avoided this issue.
Looking at the codebase, there are a number of other uses of `strncpy()`
that are unsafe and even when it is used safely, switching to
`strlcpy()` would make the code more readable. Therefore, we switch all
instances where we use `strncpy()` to use `strlcpy()`.
Unfortunately, we do not portably have access to `strlcpy()` in
tests/zfs-tests/cmd/zfs_diff-socket.c because it does not link to
libspl. Modifying the appropriate Makefile.am to try to link to it
resulted in an error from the naming choice used in the file. Trying to
disable the check on the file did not work on FreeBSD because Clang
ignores `#undef` when a definition is provided by `-Dstrncpy(...)=...`.
We workaround that by explictly including the C file from libspl into
the test. This makes things build correctly everywhere.
We add a deprecation warning to `config/Rules.am` and suppress it on the
remaining `strncpy()` usage. `strlcpy()` is not portably avaliable in
tests/zfs-tests/cmd/zfs_diff-socket.c, so we use `snprintf()` there as a
substitute.
This patch does not tackle the related problem of `strcpy()`, which is
even less safe. Thankfully, a quick inspection found that it is used far
more correctly than strncpy() was used. A quick inspection did not find
any problems with `strcpy()` usage outside of zhack, but it should be
said that I only checked around 90% of them.
Lastly, some of the fields in kstat_t varied in size by 1 depending on
whether they were in userspace or in the kernel. The origin of this
discrepancy appears to be 04a479f706 where
it was made for no apparent reason. It conflicts with the comment on
KSTAT_STRLEN, so we shrink the kernel field sizes to match the userspace
field sizes.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13876
Recently, I have been making a push to fix things that coverity found.
However, I was curious what Clang's static analyzer reported, so I ran
it and found things that coverity had missed.
* contrib/pam_zfs_key/pam_zfs_key.c: If prop_mountpoint is passed more
than once, we leak memory.
* module/zfs/zcp_get.c: We leak memory on temporary properties in
userspace.
* tests/zfs-tests/cmd/draid.c: On error from vdev_draid_rand(), we leak
memory if best_map had been allocated by a prior iteration.
* tests/zfs-tests/cmd/mkfile.c: Memory used by the loop is not freed
before program termination.
Arguably, these are all minor issues, but if we ignore them, then they
could obscure serious bugs, so we fix them.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13955
Coverity caught these. With the exception of the file descriptor leak in
tests/zfs-tests/cmd/draid.c, they are all memory leaks.
Also, there is a piece of dead code in zfs_get_enclosure_sysfs_path().
We delete it as cleanup.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13921
Coverity complained about unchecked return values and unused values that
turned out to be unused return values.
Different approaches were used to handle the different cases of
unchecked return values:
* cmd/zdb/zdb.c: VERIFY0 was used in one place since the existing code
had no error handling. An error message was printed in another to
match the rest of the code.
* cmd/zed/agents/zfs_retire.c: We dismiss the return value with `(void)`
because the value is expected to be potentially unset.
* cmd/zpool_influxdb/zpool_influxdb.c: We dismiss the return value with
`(void)` because the values are expected to be potentially unset.
* cmd/ztest.c: VERIFY0 was used since we want failures if something goes
wrong in ztest.
* module/zfs/dsl_dir.c: We dismiss the return value with `(void)`
because there is no guarantee that the zap entry will always be there.
For example, old pools imported readonly would not have it and we do
not want to fail here because of that.
* module/zfs/zfs_fm.c: `fnvlist_add_*()` was used since the
allocations sleep and thus can never fail.
* module/zfs/zvol.c: We dismiss the return value with `(void)` because
we do not need it. This matches what is already done in the analogous
`zfs_replay_write2()`.
* tests/zfs-tests/cmd/draid.c: We suppress one return value with
`(void)` since the code handles errors already. The other return value
is handled by switching to `fnvlist_lookup_uint8_array()`.
* tests/zfs-tests/cmd/file/file_fadvise.c: We add error handling.
* tests/zfs-tests/cmd/mmap_sync.c: We add error handling for munmap, but
ignore failures on remove() with (void) since it is expected to be
able to fail.
* tests/zfs-tests/cmd/mmapwrite.c: We add error handling.
As for unused return values, they were all in places where there was
error handling, so logic was added to handle the return values.
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13920
Found with -Wunused-but-set-variable on Clang trunk
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#13304
This confers an >10x speedup on t/z-t/cmd builds (12s -> 1.1s),
gets rid of 23 redundant identical automake specs and gitignores,
and groups the binaries with their common headers
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes#13259
