Current dev_urandom() assumes that reading /dev/urandom
will never block regardless if the random pool is fully
initialized or not.
This assumption is no longer applicable since linux kerrnel
enforces the /dev/urandom entropy initialization from
v5.18-rc2 with the commit:
48bff1053c17 ("random: opportunistically initialize on /dev/urandom reads").
With this, when we use the linux v5.18-rc2 or later,
dev_urandom() will block if enough random pool is not supplied.
It causes the boot delay, typically 1024msec(4msec * 256 = 1024msec)
delay to fill the 256 bits entropy for the case CONFIG_HZ=250.
To prevent this boot delay, this commit syncs dev_urandom()
implementation to the systemd-udev.
The systemd-udev implementation of reading /dev/urandom is as follows.
- Try to get random with calling getrandom(GRND_INSECURE)
- If kernel does not support GRND_INSECURE, fallback to GRND_NONBLOCK
- If enough entropy is not supplied, fallback to reading /dev/urandom,
this will block when the kernel version is v5.18-rc2 or later
With this modification, dev_urandom() tries not to block
as much as possible.
This modification still keeps the backword compatibility,
dev_random() will never block if the commit(48bff1053c17) is not
applied to the linux kernel, the behavior is same as before
in this case.
Signed-off-by: Masahisa Kojima <kojima.masahisa@socionext.com>
This appends the nvme name and namespace identifier attribute the the
PCI path for by-path links. Symlinks like the following are now present:
lrwxrwxrwx. 1 root root 13 Sep 16 12:12 pci-0000:01:00.0-nvme-1 -> ../../nvme0n1
lrwxrwxrwx. 1 root root 15 Sep 16 12:12 pci-0000:01:00.0-nvme-1-part1 -> ../../nvme0n1p1
Cc: Michal Sekletar <sekletar.m@gmail.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Pipewire requires ID_PATH to use the same device names as with systemd's
udev. Some rules, such as the ones in asahi-audio [1] use those names, and
fail if they don't match [2].
On systemd's udev this is instead imported in 71-seat.rules, which we don't
have.
[1]: https://github.com/AsahiLinux/asahi-audio
[2]: https://github.com/AsahiLinux/asahi-audio/issues/16
Signed-off-by: Johannes Nixdorf <mixi@shadowice.org>
Add persistent symlinks for MTD devices like SPI-NOR flash, based on the
partition names specified on the cmdline, in a Device Tree, or by other
MTD partitioning parser drivers. Using the persistent name can be
preferable to using the numbered /dev/mtdX device, as the latter can
change depending on probe order or when partitioning has changed.
This directory never seemed to exist. The wording is very similar to
that of the Rules Files section, so it is possible that the same text
was copied and pasted by mistake. The HWDB never looked for files in
/run.
Having a non-volatile index of volatile files would probably not be
useful.
Introduce UDEV_HWDB_PATH, containing a colon-separated path with hwdb
files in it. The whole path is searched, in addition to the system
locations, when searching for hwdb files.
Due to how conf_files_list_strv is implemented, as a thin wrapper
around the internal function, it is easy to also implement a variant
accepting a search path in the same way. Since the internal function
expects an allocated array of allocated strings, the path scanning is
done in 2 steps, to first get the array length, and then duplicate the
items. It is not possible to use strtok(_r) here because it would work
for only 1 pass.
* src/shared/conf-files.c (conf_files_list_follow_path): New function.
(conf_files_list_strv_path): Use it here.
* src/shared/conf-files.h: Export the signature for the _path variant.
* src/udev/udevadm-hwdb.c (list_conf_file_path): New function
replacing conf_file_dirs.
(help): Document the search path for hwdb files.
(adm_hwdb): Use list_conf_file_path and conf_files_list_strv_path.
* man/udevadm.xml: Mention UDEV_HWDB_PATH.
* man/udev.xml: Same.
* man/udevadm.8: Regenerate.
* man/udev.7: Same.
Instead of always writing /etc/udev/hwdb.bin or UDEV_LIBEXEC_DIR
/hwdb.bin, let the user specify a full file name.
* src/udev/udevadm-hwdb.c (adm_hwdb): New option "output". Construct
hwdb_bin when processing options, and prepend root after processing
options.
* man/udev.xml: Mention --output.
* man/udevadm.xml: Document --output.
* man/udev.7: Regenerate.
* man/udevadm.8: Same.
* src/libudev/libudev-hwdb.c (get_hwdb_bin_paths): New function,
replacing hwdb_bin_paths.
(struct udev_hwdb): New bin_paths field.
(udev_hwdb_new): Initialize it with get_hwdb_bin_paths.
(udev_hwdb_validate): Use the bin_paths field to find hwdb.bin.
(udev_hwdb_unref): Free the bin_paths field.
* src/libudev/libudev.h: Warn about UDEV_HWDB_BIN.
* man/udev.xml: Mention run-time UDEV_HWDB_BIN.
* man/udev.7: Re-generate.
- udev_device_has_current_tag
- udev_device_get_current_tags_list_entry
since the current eudev device database does not support the concept of
current tags
