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Systemd/src/shared/rlimit-util.c
Zbigniew Jędrzejewski-Szmek d284b82b3e Move various files that don't need to be in basic/ to shared/ 
This doesn't have much effect on the final build, because we link libbasic.a
into libsystemd-shared.so, so in the end, all the object built from basic/
end up in libsystemd-shared. And when the static library is linked into binaries,
any objects that are included in it but are not used are trimmed. Hence, the
size of output artifacts doesn't change:

$ du -sb /var/tmp/inst*
54181861	/var/tmp/inst1    (old)
54207441	/var/tmp/inst1s   (old split-usr)
54182477	/var/tmp/inst2    (new)
54208041	/var/tmp/inst2s   (new split-usr)

(The negligible change in size is because libsystemd-shared.so is bigger
by a few hundred bytes. I guess it's because symbols are named differently
or something like that.)

The effect is on the build process, in particular partial builds. This change
effectively moves the requirements on some build steps toward the leaves of the
dependency tree. Two effects:
- when building items that do not depend on libsystemd-shared, we
  build less stuff for libbasic.a (which wouldn't be used anyway,
  so it's a net win).
- when building items that do depend on libshared, we reduce libbasic.a as a
  synchronization point, possibly allowing better parallelism.

Method:
1. copy list of .h files from src/basic/meson.build to /tmp/basic
2. $ for i in $(grep '.h$' /tmp/basic); do echo $i; git --no-pager grep "include \"$i\"" src/basic/ 'src/lib*' 'src/nss-*' 'src/journal/sd-journal.c' |grep -v "${i%.h}.c";echo ;done | less
2018-11-20 07:27:37 +01:00

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/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <sys/resource.h>
#include "alloc-util.h"
#include "extract-word.h"
#include "fd-util.h"
#include "format-util.h"
#include "macro.h"
#include "missing.h"
#include "rlimit-util.h"
#include "string-table.h"
#include "time-util.h"
int setrlimit_closest(int resource, const struct rlimit *rlim) {
struct rlimit highest, fixed;
assert(rlim);
if (setrlimit(resource, rlim) >= 0)
return 0;
if (errno != EPERM)
return -errno;
/* So we failed to set the desired setrlimit, then let's try
* to get as close as we can */
if (getrlimit(resource, &highest) < 0)
return -errno;
/* If the hard limit is unbounded anyway, then the EPERM had other reasons, let's propagate the original EPERM
* then */
if (highest.rlim_max == RLIM_INFINITY)
return -EPERM;
fixed = (struct rlimit) {
.rlim_cur = MIN(rlim->rlim_cur, highest.rlim_max),
.rlim_max = MIN(rlim->rlim_max, highest.rlim_max),
};
/* Shortcut things if we wouldn't change anything. */
if (fixed.rlim_cur == highest.rlim_cur &&
fixed.rlim_max == highest.rlim_max)
return 0;
if (setrlimit(resource, &fixed) < 0)
return -errno;
return 0;
}
int setrlimit_closest_all(const struct rlimit *const *rlim, int *which_failed) {
int i, r;
assert(rlim);
/* On failure returns the limit's index that failed in *which_failed, but only if non-NULL */
for (i = 0; i < _RLIMIT_MAX; i++) {
if (!rlim[i])
continue;
r = setrlimit_closest(i, rlim[i]);
if (r < 0) {
if (which_failed)
*which_failed = i;
return r;
}
}
if (which_failed)
*which_failed = -1;
return 0;
}
static int rlimit_parse_u64(const char *val, rlim_t *ret) {
uint64_t u;
int r;
assert(val);
assert(ret);
if (streq(val, "infinity")) {
*ret = RLIM_INFINITY;
return 0;
}
/* setrlimit(2) suggests rlim_t is always 64bit on Linux. */
assert_cc(sizeof(rlim_t) == sizeof(uint64_t));
r = safe_atou64(val, &u);
if (r < 0)
return r;
if (u >= (uint64_t) RLIM_INFINITY)
return -ERANGE;
*ret = (rlim_t) u;
return 0;
}
static int rlimit_parse_size(const char *val, rlim_t *ret) {
uint64_t u;
int r;
assert(val);
assert(ret);
if (streq(val, "infinity")) {
*ret = RLIM_INFINITY;
return 0;
}
r = parse_size(val, 1024, &u);
if (r < 0)
return r;
if (u >= (uint64_t) RLIM_INFINITY)
return -ERANGE;
*ret = (rlim_t) u;
return 0;
}
static int rlimit_parse_sec(const char *val, rlim_t *ret) {
uint64_t u;
usec_t t;
int r;
assert(val);
assert(ret);
if (streq(val, "infinity")) {
*ret = RLIM_INFINITY;
return 0;
}
r = parse_sec(val, &t);
if (r < 0)
return r;
if (t == USEC_INFINITY) {
*ret = RLIM_INFINITY;
return 0;
}
u = (uint64_t) DIV_ROUND_UP(t, USEC_PER_SEC);
if (u >= (uint64_t) RLIM_INFINITY)
return -ERANGE;
*ret = (rlim_t) u;
return 0;
}
static int rlimit_parse_usec(const char *val, rlim_t *ret) {
usec_t t;
int r;
assert(val);
assert(ret);
if (streq(val, "infinity")) {
*ret = RLIM_INFINITY;
return 0;
}
r = parse_time(val, &t, 1);
if (r < 0)
return r;
if (t == USEC_INFINITY) {
*ret = RLIM_INFINITY;
return 0;
}
*ret = (rlim_t) t;
return 0;
}
static int rlimit_parse_nice(const char *val, rlim_t *ret) {
uint64_t rl;
int r;
/* So, Linux is weird. The range for RLIMIT_NICE is 40..1, mapping to the nice levels -20..19. However, the
* RLIMIT_NICE limit defaults to 0 by the kernel, i.e. a value that maps to nice level 20, which of course is
* bogus and does not exist. In order to permit parsing the RLIMIT_NICE of 0 here we hence implement a slight
* asymmetry: when parsing as positive nice level we permit 0..19. When parsing as negative nice level, we
* permit -20..0. But when parsing as raw resource limit value then we also allow the special value 0.
*
* Yeah, Linux is quality engineering sometimes... */
if (val[0] == '+') {
/* Prefixed with "+": Parse as positive user-friendly nice value */
r = safe_atou64(val + 1, &rl);
if (r < 0)
return r;
if (rl >= PRIO_MAX)
return -ERANGE;
rl = 20 - rl;
} else if (val[0] == '-') {
/* Prefixed with "-": Parse as negative user-friendly nice value */
r = safe_atou64(val + 1, &rl);
if (r < 0)
return r;
if (rl > (uint64_t) (-PRIO_MIN))
return -ERANGE;
rl = 20 + rl;
} else {
/* Not prefixed: parse as raw resource limit value */
r = safe_atou64(val, &rl);
if (r < 0)
return r;
if (rl > (uint64_t) (20 - PRIO_MIN))
return -ERANGE;
}
*ret = (rlim_t) rl;
return 0;
}
static int (*const rlimit_parse_table[_RLIMIT_MAX])(const char *val, rlim_t *ret) = {
[RLIMIT_CPU] = rlimit_parse_sec,
[RLIMIT_FSIZE] = rlimit_parse_size,
[RLIMIT_DATA] = rlimit_parse_size,
[RLIMIT_STACK] = rlimit_parse_size,
[RLIMIT_CORE] = rlimit_parse_size,
[RLIMIT_RSS] = rlimit_parse_size,
[RLIMIT_NOFILE] = rlimit_parse_u64,
[RLIMIT_AS] = rlimit_parse_size,
[RLIMIT_NPROC] = rlimit_parse_u64,
[RLIMIT_MEMLOCK] = rlimit_parse_size,
[RLIMIT_LOCKS] = rlimit_parse_u64,
[RLIMIT_SIGPENDING] = rlimit_parse_u64,
[RLIMIT_MSGQUEUE] = rlimit_parse_size,
[RLIMIT_NICE] = rlimit_parse_nice,
[RLIMIT_RTPRIO] = rlimit_parse_u64,
[RLIMIT_RTTIME] = rlimit_parse_usec,
};
int rlimit_parse_one(int resource, const char *val, rlim_t *ret) {
assert(val);
assert(ret);
if (resource < 0)
return -EINVAL;
if (resource >= _RLIMIT_MAX)
return -EINVAL;
return rlimit_parse_table[resource](val, ret);
}
int rlimit_parse(int resource, const char *val, struct rlimit *ret) {
_cleanup_free_ char *hard = NULL, *soft = NULL;
rlim_t hl, sl;
int r;
assert(val);
assert(ret);
r = extract_first_word(&val, &soft, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
if (r < 0)
return r;
if (r == 0)
return -EINVAL;
r = rlimit_parse_one(resource, soft, &sl);
if (r < 0)
return r;
r = extract_first_word(&val, &hard, ":", EXTRACT_DONT_COALESCE_SEPARATORS);
if (r < 0)
return r;
if (!isempty(val))
return -EINVAL;
if (r == 0)
hl = sl;
else {
r = rlimit_parse_one(resource, hard, &hl);
if (r < 0)
return r;
if (sl > hl)
return -EILSEQ;
}
*ret = (struct rlimit) {
.rlim_cur = sl,
.rlim_max = hl,
};
return 0;
}
int rlimit_format(const struct rlimit *rl, char **ret) {
char *s = NULL;
assert(rl);
assert(ret);
if (rl->rlim_cur >= RLIM_INFINITY && rl->rlim_max >= RLIM_INFINITY)
s = strdup("infinity");
else if (rl->rlim_cur >= RLIM_INFINITY)
(void) asprintf(&s, "infinity:" RLIM_FMT, rl->rlim_max);
else if (rl->rlim_max >= RLIM_INFINITY)
(void) asprintf(&s, RLIM_FMT ":infinity", rl->rlim_cur);
else if (rl->rlim_cur == rl->rlim_max)
(void) asprintf(&s, RLIM_FMT, rl->rlim_cur);
else
(void) asprintf(&s, RLIM_FMT ":" RLIM_FMT, rl->rlim_cur, rl->rlim_max);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
static const char* const rlimit_table[_RLIMIT_MAX] = {
[RLIMIT_AS] = "AS",
[RLIMIT_CORE] = "CORE",
[RLIMIT_CPU] = "CPU",
[RLIMIT_DATA] = "DATA",
[RLIMIT_FSIZE] = "FSIZE",
[RLIMIT_LOCKS] = "LOCKS",
[RLIMIT_MEMLOCK] = "MEMLOCK",
[RLIMIT_MSGQUEUE] = "MSGQUEUE",
[RLIMIT_NICE] = "NICE",
[RLIMIT_NOFILE] = "NOFILE",
[RLIMIT_NPROC] = "NPROC",
[RLIMIT_RSS] = "RSS",
[RLIMIT_RTPRIO] = "RTPRIO",
[RLIMIT_RTTIME] = "RTTIME",
[RLIMIT_SIGPENDING] = "SIGPENDING",
[RLIMIT_STACK] = "STACK",
};
DEFINE_STRING_TABLE_LOOKUP(rlimit, int);
int rlimit_from_string_harder(const char *s) {
const char *suffix;
/* The official prefix */
suffix = startswith(s, "RLIMIT_");
if (suffix)
return rlimit_from_string(suffix);
/* Our own unit file setting prefix */
suffix = startswith(s, "Limit");
if (suffix)
return rlimit_from_string(suffix);
return rlimit_from_string(s);
}
void rlimit_free_all(struct rlimit **rl) {
int i;
if (!rl)
return;
for (i = 0; i < _RLIMIT_MAX; i++)
rl[i] = mfree(rl[i]);
}
int rlimit_nofile_bump(int limit) {
int r;
/* Bumps the (soft) RLIMIT_NOFILE resource limit as close as possible to the specified limit. If a negative
* limit is specified, bumps it to the maximum the kernel and the hard resource limit allows. This call should
* be used by all our programs that might need a lot of fds, and that know how to deal with high fd numbers
* (i.e. do not use select() — which chokes on fds >= 1024) */
if (limit < 0)
limit = read_nr_open();
if (limit < 3)
limit = 3;
r = setrlimit_closest(RLIMIT_NOFILE, &RLIMIT_MAKE_CONST(limit));
if (r < 0)
return log_debug_errno(r, "Failed to set RLIMIT_NOFILE: %m");
return 0;
}
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