Back in 2007, commit 0c97c9d437 ("'simple' error message functions by
Loic Grenie") introduced bb_simple_perror_msg() to allow for a lower
overhead call to bb_perror_msg() when only a string was being printed
with no parameters. This saves space for some CPU architectures because
it avoids the overhead of a call to a variadic function. However there
has never been a simple version of bb_error_msg(), and since 2007 many
new calls to bb_perror_msg() have been added that only take a single
parameter and so could have been using bb_simple_perror_message().
This changeset introduces 'simple' versions of bb_info_msg(),
bb_error_msg(), bb_error_msg_and_die(), bb_herror_msg() and
bb_herror_msg_and_die(), and replaces all calls that only take a
single parameter, or use something like ("%s", arg), with calls to the
corresponding 'simple' version.
Since it is likely that single parameter calls to the variadic functions
may be accidentally reintroduced in the future a new debugging config
option WARN_SIMPLE_MSG has been introduced. This uses some macro magic
which will cause any such calls to generate a warning, but this is
turned off by default to avoid use of the unpleasant macros in normal
circumstances.
This is a large changeset due to the number of calls that have been
replaced. The only files that contain changes other than simple
substitution of function calls are libbb.h, libbb/herror_msg.c,
libbb/verror_msg.c and libbb/xfuncs_printf.c. In miscutils/devfsd.c,
networking/udhcp/common.h and util-linux/mdev.c additonal macros have
been added for logging so that single parameter and multiple parameter
logging variants exist.
The amount of space saved varies considerably by architecture, and was
found to be as follows (for 'defconfig' using GCC 7.4):
Arm: -92 bytes
MIPS: -52 bytes
PPC: -1836 bytes
x86_64: -938 bytes
Note that for the MIPS architecture only an exception had to be made
disabling the 'simple' calls for 'udhcp' (in networking/udhcp/common.h)
because it made these files larger on MIPS.
Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Adds the -d option to run mdev in daemon mode handling hotplug events
from the kernel like udev. If the system generates many hotplug events
this mode of operation will consume less resources than registering
mdev as hotplug helper or using the uevent applet.
function old new delta
daemon_loop - 152 +152
initial_scan - 127 +127
open_mdev_log - 85 +85
mdev_main 255 314 +59
packed_usage 33284 33316 +32
process_action 1051 992 -59
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 2/1 up/down: 455/-59) Total: 396 bytes
Signed-off-by: Jan Klötzke <jan@kloetzke.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This purely moves code from main() to separate functions for better
extensibility.
Signed-off-by: Jan Klötzke <jan@kloetzke.net>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Currently some new devices that have a bus but no class will
be missed by mdev coldplug device creation after boot. This
happens because mdev recursively searches /sys/class which will
by definition only find class devices.
Some important devices such as iio and gpiochip does not have
a class. But users will need them.
This switches from using /sys/class as the place to look for
devices to create to using /sys/dev where all char and block
devices are listed.
The subsystem lookup code that provide the G.subsystem
environment variable is changed from using the directory
name of the class device to instead dereference the
"subsystem" symlink for the device, and look at the last
element of the path of the symlink for the subsystem, which
will work with class devices and bus devices alike. (The new
bus-only devices only symlink to the /sys/bus/* hierarchy.)
We delete the legacy kernel v2.6.2x /sys/block device path
code as part of this change. It's too old to be kept alive.
Tested on kernel v4.6-rc2 with a bunch of devices, including
some IIO and gpiochip devices.
With a print inserted before make_device() the log looks
like so:
Create device from "/sys/dev/char/1:1", subsystem "mem"
Create device from "/sys/dev/char/1:2", subsystem "mem"
Create device from "/sys/dev/char/1:3", subsystem "mem"
Create device from "/sys/dev/char/1:5", subsystem "mem"
(...)
Create device from "/sys/dev/block/179:56", subsystem "block"
Create device from "/sys/dev/block/179:64", subsystem "block"
function old new delta
mdev_main 1388 1346 -42
dirAction 134 14 -120
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-162) Total: -162 bytes
Cc: Isaac Dunham <ibid.ag@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Introduce a library routine to package the idiom:
p = xmalloc(b, n);
memcpy(p, b, n);
and use it where possible. The example in traceroute used xzalloc
but it didn't need to.
function old new delta
xmemdup - 32 +32
last_main 834 826 -8
make_device 2321 2311 -10
common_traceroute_main 3698 3685 -13
readtoken1 3182 3168 -14
procps_scan 1222 1206 -16
forkchild 655 638 -17
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/6 up/down: 32/-78) Total: -46 bytes
Signed-off-by: Ron Yorston <rmy@frippery.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This was seen to happen if two mdevs are run in parallel,
mdev.seq is empty, and the "newer" one manages to write it first.
function old new delta
mdev_main 1366 1388 +22
atoll - 20 +20
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
516530c932 uses $DEVNAME variable
for device node name. This is fine, but only works for hotplugging,
"mdev -s" will behave differently when DEVNAME and basename(path)
differ.
This patch extracts the DEVNAME from the uevent sysfs file in
make_device(), thus works for hot- and coldplugging; so using
the environment DEVNAME on hotplug events is no longer necessary.
Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Sequential run of concurrent mdev's was too simplistic:
they waited for /dev/mdev.seq to match. This could sometimes
cause cumulative loss of time on the order of a second.
Added SIGCHLD signaling from exiting mdev to all other mdev's.
Added debugging required to see that code actually works as intended.
Example of /dev/mdev.log (with "woken up" elevated from dbg lvl 3 to 2):
mdev[1023]: first seq written
^^^^ seq, not pid
mdev[1023]: 35.022395 ACTION:add SUBSYSTEM:module DEVNAME:(null) DEVPATH:/module/lib80211
mdev[1023]: rule matched, line -1
^^^^^^^ means "default rule"
mdev[1023]: 35.022676 exiting
^^^^^^^^^ second,usec timestamp
mdev[1024]: 35.069691 ACTION:add SUBSYSTEM:vc DEVNAME:vcs9 DEVPATH:/devices/virtual/vc/vcs9
mdev[1024]: dev 7,9
mdev[1025]: 35.069889 waiting for '1024'
mdev[1026]: 35.069946 waiting for '1024'
mdev[1027]: 35.070151 waiting for '1024'
mdev[1024]: rule matched, line -1
mdev[1024]: mknod vcs9 (7,9) 20660 0:0
mdev[1024]: 35.070346 exiting
mdev[1025]: woken up
mdev[1026]: woken up
mdev[1025]: 35.071213 ACTION:add SUBSYSTEM:vc DEVNAME:vcsa9 DEVPATH:/devices/virtual/vc/vcsa9
^^^^^^^^^ took only a millisecond to start running after prev mdev exited
mdev[1025]: dev 7,137
mdev[1027]: woken up
mdev[1025]: rule matched, line -1
mdev[1025]: mknod vcsa9 (7,137) 20660 0:0
mdev[1025]: 35.072109 exiting
function old new delta
mdev_main 849 1372 +523
curtime - 59 +59
dirAction 87 134 +47
static.ts - 8 +8
keywords 19 12 -7
make_device 2189 2119 -70
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
It was colliding with matching of devnames with slashes.
We need a more generic way to examine env.vars in rules anyway.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This change retains "or later" state! No licensing _changes_ here,
only form is adjusted (article, space between "GPL" and "v2" and so on).
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Based on the patch by Steve Bennett <steveb@workware.net.au>
function old new delta
make_device 1640 1673 +33
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
