We had two very similar functions: device_read_db_aux and device_read_db,
and a number of wrappers for them:
device_read_db_aux
← device_read_db (in sd-device.c)
← all functions in sd-device.c, including sd_device_is_initialized
← device_read_db_force
← event_execute_rules_on_remove (in udev-event.c)
device_read_db (in device-private.c)
← functions in device_private.c (but not device_read_db_force):
device_get_devnode_{mode,uid,gid}
device_get_devlink_priority
device_get_watch_handle
device_clone_with_db
← called from udevadm, udev-{node,event,watch}.c
Before 7141e4f62c (sd-device: don't retry loading
uevent/db files more than once), the two implementations were the same. In that
commit, device_read_db_aux was changed. Those changes were reverted in the parent
commit, so the two implementations are now again the same except for superficial
differences. This commit removes device_read_db (in sd-device.c), and renames
device_read_db_aux to device_read_db_internal and makes everyone use this one
implementation. There should be no functional change.
This mostly reverts "sd-device: don't retry loading uevent/db files more than
once", 7141e4f62c. We will retry if we couldn't
access the file, but not if parsing failed.
Not re-reading the database at all just doesn't seem like a good idea. We have
two implementations of device_read_db, and one does that, and the other retries
to read the db. Re-reading seems more useful, since we can create the object
and then access properties as some later time when we know that the device has
been initialized and we can get useful results. Otherwise, we force the user to
destroy this object and create a new one.
This changes device_read_uevent_file() and device_read_db_aux(). See next
commit for description of where those functions are used.
Ideally, coccinelle would strip unnecessary braces too. But I do not see any
option in coccinelle for this, so instead, I edited the patch text using
search&replace to remove the braces. Unfortunately this is not fully automatic,
in particular it didn't deal well with if-else-if-else blocks and ifdefs, so
there is an increased likelikehood be some bugs in such spots.
I also removed part of the patch that coccinelle generated for udev, where we
returns -1 for failure. This should be fixed independently.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
The function is similar to path_kill_slashes() but also removes
initial './', trailing '/.', and '/./' in the path.
When the second argument of path_simplify() is false, then it
behaves as the same as path_kill_slashes(). Hence, this also
replaces path_kill_slashes() with path_simplify().
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
When /sys is a symlink to the sysfs mountpoint, e.g. /path/to/sysfs.
Then, device->syspath was set to like /path/to/sysfs/devices/foo/baz.
This converts the path to /sys/devices/foo/baz.
Fixes#7676.
This prevents udev from double-freeing and crashing.
See https://github.com/systemd/systemd/issues/6040#issuecomment-306589836
==351== Invalid free() / delete / delete[] / realloc()
==351== at 0x4C2C14B: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==351== by 0x13CBE8: hashmap_clear_free_free (hashmap.c:900)
==351== by 0x13CBE8: hashmap_free_free_free (hashmap.c:852)
==351== by 0x147F4F: sd_device_unref (sd-device.c:88)
==351== by 0x130CCC: udev_device_unref (libudev-device.c:552)
==351== by 0x130CD5: udev_device_unref (libudev-device.c:553)
==351== by 0x11FBBB: worker_spawn (udevd.c:488)
==351== by 0x1216E5: event_run (udevd.c:584)
==351== by 0x1216E5: event_queue_start (udevd.c:823)
==351== by 0x122213: on_uevent (udevd.c:927)
==351== by 0x141F2F: source_dispatch (sd-event.c:2272)
==351== by 0x142D52: sd_event_dispatch (sd-event.c:2631)
==351== by 0x142D52: sd_event_run (sd-event.c:2690)
==351== by 0x142D52: sd_event_loop (sd-event.c:2710)
==351== by 0x1159CB: run (udevd.c:1643)
==351== by 0x1159CB: main (udevd.c:1772)
==351== Address 0x81745b0 is 0 bytes inside a block of size 1 free'd
==351== at 0x4C2C14B: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==351== by 0x1447F0: freep (alloc-util.h:57)
==351== by 0x1447F0: sd_device_set_sysattr_value (sd-device.c:1859)
==351== by 0x132081: udev_device_set_sysattr_value (libudev-device.c:849)
==351== by 0x12E777: set_trackpoint_sensitivity (udev-builtin-keyboard.c:180)
==351== by 0x12E777: builtin_keyboard.lto_priv.170 (udev-builtin-keyboard.c:263)
==351== by 0x14D03F: udev_builtin_run.constprop.75 (udev-builtin.c:133)
==351== by 0x11FAEB: udev_event_execute_run (udev-event.c:957)
==351== by 0x11FAEB: worker_spawn (udevd.c:461)
==351== by 0x1216E5: event_run (udevd.c:584)
==351== by 0x1216E5: event_queue_start (udevd.c:823)
==351== by 0x122213: on_uevent (udevd.c:927)
==351== by 0x141F2F: source_dispatch (sd-event.c:2272)
==351== by 0x142D52: sd_event_dispatch (sd-event.c:2631)
==351== by 0x142D52: sd_event_run (sd-event.c:2690)
==351== by 0x142D52: sd_event_loop (sd-event.c:2710)
==351== by 0x1159CB: run (udevd.c:1643)
==351== by 0x1159CB: main (udevd.c:1772)
==351== Block was alloc'd at
==351== at 0x4C2CF35: calloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==351== by 0x144853: sd_device_set_sysattr_value (sd-device.c:1888)
==351== by 0x132081: udev_device_set_sysattr_value (libudev-device.c:849)
==351== by 0x12E777: set_trackpoint_sensitivity (udev-builtin-keyboard.c:180)
==351== by 0x12E777: builtin_keyboard.lto_priv.170 (udev-builtin-keyboard.c:263)
==351== by 0x14D03F: udev_builtin_run.constprop.75 (udev-builtin.c:133)
==351== by 0x11FAEB: udev_event_execute_run (udev-event.c:957)
==351== by 0x11FAEB: worker_spawn (udevd.c:461)
==351== by 0x1216E5: event_run (udevd.c:584)
==351== by 0x1216E5: event_queue_start (udevd.c:823)
==351== by 0x122213: on_uevent (udevd.c:927)
==351== by 0x141F2F: source_dispatch (sd-event.c:2272)
==351== by 0x142D52: sd_event_dispatch (sd-event.c:2631)
==351== by 0x142D52: sd_event_run (sd-event.c:2690)
==351== by 0x142D52: sd_event_loop (sd-event.c:2710)
==351== by 0x1159CB: run (udevd.c:1643)
==351== by 0x1159CB: main (udevd.c:1772)
This adds /sys/firmware lookup for sysname when creating a new device,
which allows device-tree properties lookup. This look-up can then be
used in udev rules, allowing device-tree-based model detection.
All those uses were correct, but I think it's better to be explicit.
Using implicit errno is too error prone, and with this change we can require
(in the sense of a style guideline) that the code is always specified.
Helpful query: git grep -n -P 'log_[^s][a-z]+\(.*%m'
Coverity was complaining about TOCTOU (CID #745806). Indeed, it seems better
to open the file and avoid the stat altogether:
- O_NOFOLLOW means we'll get ELOOP, which we can translate to EINVAL as before,
- similarly, open(O_WRONLY) on a directory will fail with EISDIR,
- and finally, it makes no sense to check access mode ourselves: just let
the kernel do it and propagate the error.
v2:
- fix memleak, don't clober input arg
gcc 7 adds -Wimplicit-fallthrough=3 to -Wextra. There are a few ways
we could deal with that. After we take into account the need to stay compatible
with older versions of the compiler (and other compilers), I don't think adding
__attribute__((fallthrough)), even as a macro, is worth the trouble. It sticks
out too much, a comment is just as good. But gcc has some very specific
requiremnts how the comment should look. Adjust it the specific form that it
likes. I don't think the extra stuff we had in those comments was adding much
value.
(Note: the documentation seems to be wrong, and seems to describe a different
pattern from the one that is actually used. I guess either the docs or the code
will have to change before gcc 7 is finalized.)
Let's use chase_symlinks() everywhere, and stop using GNU
canonicalize_file_name() everywhere. For most cases this should not change
behaviour, however increase exposure of our function to get better tested. Most
importantly in a few cases (most notably nspawn) it can take the correct root
directory into account when chasing symlinks.
As suggested here:
https://github.com/systemd/systemd/pull/4296#issuecomment-251911349
Let's try AF_INET first as socket, but let's fall back to AF_NETLINK, so that
we can use a protocol-independent socket here if possible. This has the benefit
that our code will still work even if AF_INET/AF_INET6 is made unavailable (for
exmple via seccomp), at least on current kernels.
The 'drivers' pseudo-subsystem needs special treatment. These pseudo-devices are
found under /sys/bus/drivers/, so needs the real subsystem encoded
in the device_id in order to be resolved.
The reader side already assumed this to be the case.
The statemachine was unable to parse properties with empty values,
reported in [0].
When reaching the start of the KEY, we would unconditionally read
one more character before starting to look for the end-of-line.
Simply look for the end-of-line from the first character.
[0]: <https://bugzilla.redhat.com/show_bug.cgi?id=1338823>
