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>
Between Busybox 1.24.2 and 1.25.0 the bb_info_msg() function was
eliminated and calls to it changed to be bb_error_msg(). The downside of
this is that daemons now log all messages to syslog at the LOG_ERR level
which makes it hard to filter errors from informational messages.
This change optionally re-introduces bb_info_msg(), controlled by a new
option FEATURE_SYSLOG_INFO, restores all the calls to bb_info_msg() that
were removed (only in applets that set logmode to LOGMODE_SYSLOG or
LOGMODE_BOTH), and also changes informational messages in ifplugd and
ntpd.
The code size change of this is as follows (using 'defconfig' on x86_64
with gcc 7.3.0-27ubuntu1~18.04)
function old new delta
bb_info_msg - 182 +182
bb_vinfo_msg - 27 +27
static.log7 194 198 +4
log8 190 191 +1
log5 190 191 +1
crondlog 45 - -45
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 3/0 up/down: 215/-45) Total: 170 bytes
If you don't care about everything being logged at LOG_ERR level
then when FEATURE_SYSLOG_INFO is disabled Busybox actually gets smaller:
function old new delta
static.log7 194 200 +6
log8 190 193 +3
log5 190 193 +3
syslog_level 1 - -1
bb_verror_msg 583 581 -2
crondlog 45 - -45
------------------------------------------------------------------------------
(add/remove: 0/2 grow/shrink: 3/1 up/down: 12/-48) Total: -36 bytes
Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
I see random field values like sll_hatype=0x267 when I strace.
They seem to not matter, but just in case they sometimes do,
let's at least have deterministic values (via memset(0)).
function old new delta
change_listen_mode 308 322 +14
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Patch is based on work by tiggerswelt.net. They say:
"
We wanted udhcpc6 to release its IPv6-Addresses on
quit (-R-commandline-option) which turned out to generate once again
kind of garbage on the network-link.
We tracked this down to two issues:
- udhcpc6 uses a variable called "srv6_buf" to send packets to
the dhcp6-server, but this variable is never initialized correctly
and contained kind of a garbage-address
- The address of the dhcp6-server is usually a link-local-address,
that requires an interface-index when using connect() on an AF_INET6-
socket
We added an
additional parameter for ifindex to d6_send_kernel_packet() and made
d6_recv_raw_packet() to capture the address of the dhcp6-server and
forward it to its callee.
"
Three last patches together:
function old new delta
d6_read_interface - 454 +454
d6_recv_raw_packet - 283 +283
option_to_env 249 504 +255
.rodata 165226 165371 +145
send_d6_discover 195 237 +42
send_d6_select 118 159 +41
send_d6_renew 173 186 +13
send_d6_release 162 173 +11
opt_req - 10 +10
d6_send_kernel_packet 304 312 +8
opt_fqdn_req - 6 +6
d6_mcast_from_client_config_ifindex 48 51 +3
d6_find_option 63 61 -2
udhcpc6_main 2416 2411 -5
static.d6_recv_raw_packet 266 - -266
------------------------------------------------------------------------------
(add/remove: 5/1 grow/shrink: 8/2 up/down: 1271/-273) Total: 998 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
