6937487be7
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>
128 lines
2.8 KiB
C
128 lines
2.8 KiB
C
/*
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* Copyright (C) 2017 by <assafgordon@gmail.com>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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//kbuild:lib-$(CONFIG_FEATURE_SETPRIV_CAPABILITIES) += capability.o
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//kbuild:lib-$(CONFIG_RUN_INIT) += capability.o
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#include <linux/capability.h>
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// #include <sys/capability.h>
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// This header is in libcap, but the functions are in libc.
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// Comment in the header says this above capset/capget:
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/* system calls - look to libc for function to system call mapping */
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extern int capset(cap_user_header_t header, cap_user_data_t data);
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extern int capget(cap_user_header_t header, const cap_user_data_t data);
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// so for bbox, let's just repeat the declarations.
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// This way, libcap needs not be installed in build environment.
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#include "libbb.h"
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static const char *const capabilities[] = {
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"chown",
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"dac_override",
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"dac_read_search",
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"fowner",
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"fsetid",
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"kill",
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"setgid",
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"setuid",
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"setpcap",
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"linux_immutable",
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"net_bind_service",
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"net_broadcast",
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"net_admin",
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"net_raw",
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"ipc_lock",
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"ipc_owner",
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"sys_module",
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"sys_rawio",
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"sys_chroot",
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"sys_ptrace",
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"sys_pacct",
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"sys_admin",
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"sys_boot",
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"sys_nice",
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"sys_resource",
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"sys_time",
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"sys_tty_config",
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"mknod",
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"lease",
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"audit_write",
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"audit_control",
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"setfcap",
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"mac_override",
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"mac_admin",
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"syslog",
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"wake_alarm",
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"block_suspend",
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"audit_read",
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};
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unsigned FAST_FUNC cap_name_to_number(const char *cap)
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{
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unsigned i, n;
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if ((sscanf(cap, "cap_%u", &n)) == 1) {
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i = n;
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goto found;
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}
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for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
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if (strcasecmp(capabilities[i], cap) == 0)
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goto found;
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}
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bb_error_msg_and_die("unknown capability '%s'", cap);
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found:
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if (!cap_valid(i))
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bb_error_msg_and_die("unknown capability '%s'", cap);
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return i;
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}
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void FAST_FUNC printf_cap(const char *pfx, unsigned cap_no)
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{
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if (cap_no < ARRAY_SIZE(capabilities)) {
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printf("%s%s", pfx, capabilities[cap_no]);
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return;
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}
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printf("%scap_%u", pfx, cap_no);
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}
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DEFINE_STRUCT_CAPS;
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void FAST_FUNC getcaps(void *arg)
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{
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static const uint8_t versions[] = {
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_LINUX_CAPABILITY_U32S_3, /* = 2 (fits into byte) */
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_LINUX_CAPABILITY_U32S_2, /* = 2 */
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_LINUX_CAPABILITY_U32S_1, /* = 1 */
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};
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int i;
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struct caps *caps = arg;
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caps->header.pid = 0;
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for (i = 0; i < ARRAY_SIZE(versions); i++) {
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caps->header.version = versions[i];
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if (capget(&caps->header, NULL) == 0)
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goto got_it;
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}
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bb_simple_perror_msg_and_die("capget");
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got_it:
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switch (caps->header.version) {
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case _LINUX_CAPABILITY_VERSION_1:
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caps->u32s = _LINUX_CAPABILITY_U32S_1;
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break;
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case _LINUX_CAPABILITY_VERSION_2:
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caps->u32s = _LINUX_CAPABILITY_U32S_2;
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break;
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case _LINUX_CAPABILITY_VERSION_3:
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caps->u32s = _LINUX_CAPABILITY_U32S_3;
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break;
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default:
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bb_simple_error_msg_and_die("unsupported capability version");
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}
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if (capget(&caps->header, caps->data) != 0)
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bb_simple_perror_msg_and_die("capget");
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}
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