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.
Newer kernels will emit uevents with "bind" and "unbind" actions. These
uevents will be issued when driver is bound to or unbound from a device.
"Bind" events are helpful when device requires a firmware to operate
properly, and driver is unable to create a child device before firmware
is properly loaded.
For some reason systemd validates actions and drops the ones it does not
know, instead of passing them on through as old udev did, so we need to
explicitly teach it about them.
This prevents udev from reading the data after freeing it.
See https://github.com/systemd/systemd/issues/6040#issuecomment-306589836
==264== Invalid read of size 1
==264== at 0x4C2E112: strlen (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==264== by 0x5943EBD: strdup (in /usr/lib/libc-2.25.so)
==264== by 0x13E263: device_add_property_aux (sd-device.c:122)
==264== by 0x14788C: device_add_property_internal (sd-device.c:150)
==264== by 0x14788C: device_rename (device-private.c:786)
==264== by 0x120DB6: udev_device_rename (libudev-device-private.c:213)
==264== by 0x120DB6: udev_event_execute_rules (udev-event.c:895)
==264== by 0x120DB6: worker_spawn (udevd.c:456)
==264== by 0x1216E5: event_run (udevd.c:584)
==264== by 0x1216E5: event_queue_start (udevd.c:823)
==264== by 0x122213: on_uevent (udevd.c:927)
==264== by 0x141F2F: source_dispatch (sd-event.c:2272)
==264== by 0x142D52: sd_event_dispatch (sd-event.c:2631)
==264== by 0x142D52: sd_event_run (sd-event.c:2690)
==264== by 0x142D52: sd_event_loop (sd-event.c:2710)
==264== by 0x1159CB: run (udevd.c:1643)
==264== by 0x1159CB: main (udevd.c:1772)
==264== Address 0x7b251a0 is 0 bytes inside a block of size 5 free'd
==264== at 0x4C2C14B: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==264== by 0x13E2A2: freep (alloc-util.h:57)
==264== by 0x13E2A2: device_add_property_aux (sd-device.c:111)
==264== by 0x147873: device_add_property_internal (sd-device.c:150)
==264== by 0x147873: device_rename (device-private.c:781)
==264== by 0x120DB6: udev_device_rename (libudev-device-private.c:213)
==264== by 0x120DB6: udev_event_execute_rules (udev-event.c:895)
==264== by 0x120DB6: worker_spawn (udevd.c:456)
==264== by 0x1216E5: event_run (udevd.c:584)
==264== by 0x1216E5: event_queue_start (udevd.c:823)
==264== by 0x122213: on_uevent (udevd.c:927)
==264== by 0x141F2F: source_dispatch (sd-event.c:2272)
==264== by 0x142D52: sd_event_dispatch (sd-event.c:2631)
==264== by 0x142D52: sd_event_run (sd-event.c:2690)
==264== by 0x142D52: sd_event_loop (sd-event.c:2710)
==264== by 0x1159CB: run (udevd.c:1643)
==264== by 0x1159CB: main (udevd.c:1772)
==264== Block was alloc'd at
==264== at 0x4C2AF1F: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==264== by 0x5943EC9: strdup (in /usr/lib/libc-2.25.so)
==264== by 0x13E263: device_add_property_aux (sd-device.c:122)
==264== by 0x143B45: device_add_property_internal (sd-device.c:150)
==264== by 0x143B45: device_amend.lto_priv.235 (device-private.c:454)
==264== by 0x1387B7: device_append (device-private.c:516)
==264== by 0x1387B7: device_new_from_nulstr (device-private.c:620)
==264== by 0x1387B7: udev_device_new_from_nulstr (libudev-device-private.c:268)
==264== by 0x1387B7: udev_monitor_receive_device (libudev-monitor.c:682)
==264== by 0x11FC69: worker_spawn (udevd.c:509)
==264== by 0x1216E5: event_run (udevd.c:584)
==264== by 0x1216E5: event_queue_start (udevd.c:823)
==264== by 0x122213: on_uevent (udevd.c:927)
==264== by 0x141F2F: source_dispatch (sd-event.c:2272)
==264== by 0x142D52: sd_event_dispatch (sd-event.c:2631)
==264== by 0x142D52: sd_event_run (sd-event.c:2690)
==264== by 0x142D52: sd_event_loop (sd-event.c:2710)
==264== by 0x1159CB: run (udevd.c:1643)
==264== by 0x1159CB: main (udevd.c:1772)
==264==
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.
