15263807472

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <unistd.h>

#include "alloc-util.h"
#include "extract-word.h"
#include "fd-util.h"
#include "fileio.h"
#include "parse-util.h"
#include "process-util.h"
#include "procfs-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "time-util.h"

int procfs_get_pid_max(uint64_t *ret) {
        _cleanup_free_ char *value = NULL;
        int r;

        assert(ret);

        r = read_one_line_file("/proc/sys/kernel/pid_max", &value);
        if (r < 0)
                return r;

        return safe_atou64(value, ret);
}

int procfs_get_threads_max(uint64_t *ret) {
        _cleanup_free_ char *value = NULL;
        int r;

        assert(ret);

        r = read_one_line_file("/proc/sys/kernel/threads-max", &value);
        if (r < 0)
                return r;

        return safe_atou64(value, ret);
}

int procfs_tasks_set_limit(uint64_t limit) {
        char buffer[DECIMAL_STR_MAX(uint64_t)+1];
        uint64_t pid_max;
        int r;

        if (limit == 0) /* This makes no sense, we are userspace and hence count as tasks too, and we want to live,
                         * hence the limit conceptually has to be above 0. Also, most likely if anyone asks for a zero
                         * limit they probably mean "no limit", hence let's better refuse this to avoid
                         * confusion. */
                return -EINVAL;

        /* The Linux kernel doesn't allow this value to go below 20, hence don't allow this either, higher values than
         * TASKS_MAX are not accepted by the pid_max sysctl. We'll treat anything this high as "unbounded" and hence
         * set it to the maximum. */
        limit = CLAMP(limit, 20U, TASKS_MAX);

        r = procfs_get_pid_max(&pid_max);
        if (r < 0)
                return r;

        /* As pid_max is about the numeric pid_t range we'll bump it if necessary, but only ever increase it, never
         * decrease it, as threads-max is the much more relevant sysctl. */
        if (limit > pid_max-1) {
                xsprintf(buffer, "%" PRIu64, limit+1); /* Add one, since PID 0 is not a valid PID */
                r = write_string_file("/proc/sys/kernel/pid_max", buffer, WRITE_STRING_FILE_DISABLE_BUFFER);
                if (r < 0)
                        return r;
        }

        xsprintf(buffer, "%" PRIu64, limit);
        r = write_string_file("/proc/sys/kernel/threads-max", buffer, WRITE_STRING_FILE_DISABLE_BUFFER);
        if (r < 0) {
                uint64_t threads_max;

                /* Hmm, we couldn't write this? If so, maybe it was already set properly? In that case let's not
                 * generate an error */

                if (procfs_get_threads_max(&threads_max) < 0)
                        return r; /* return original error */

                if (MIN(pid_max - 1, threads_max) != limit)
                        return r; /* return original error */

                /* Yay! Value set already matches what we were trying to set, hence consider this a success. */
        }

        return 0;
}

int procfs_tasks_get_current(uint64_t *ret) {
        _cleanup_free_ char *value = NULL;
        const char *p, *nr;
        size_t n;
        int r;

        assert(ret);

        r = read_one_line_file("/proc/loadavg", &value);
        if (r < 0)
                return r;

        /* Look for the second part of the fourth field, which is separated by a slash from the first part. None of the
         * earlier fields use a slash, hence let's use this to find the right spot. */
        p = strchr(value, '/');
        if (!p)
                return -EINVAL;

        p++;
        n = strspn(p, DIGITS);
        nr = strndupa_safe(p, n);

        return safe_atou64(nr, ret);
}

static uint64_t calc_gcd64(uint64_t a, uint64_t b) {

        while (b > 0) {
                uint64_t t;

                t = a % b;

                a = b;
                b = t;
        }

        return a;
}

int procfs_cpu_get_usage(nsec_t *ret) {
        _cleanup_free_ char *first_line = NULL;
        unsigned long user_ticks, nice_ticks, system_ticks, irq_ticks, softirq_ticks,
                guest_ticks = 0, guest_nice_ticks = 0;
        long ticks_per_second;
        uint64_t sum, gcd, a, b;
        const char *p;
        int r;

        assert(ret);

        r = read_one_line_file("/proc/stat", &first_line);
        if (r < 0)
                return r;

        p = first_word(first_line, "cpu");
        if (!p)
                return -EINVAL;

        if (sscanf(p, "%lu %lu %lu %*u %*u %lu %lu %*u %lu %lu",
                   &user_ticks,
                   &nice_ticks,
                   &system_ticks,
                   &irq_ticks,
                   &softirq_ticks,
                   &guest_ticks,
                   &guest_nice_ticks) < 5) /* we only insist on the first five fields */
                return -EINVAL;

        ticks_per_second = sysconf(_SC_CLK_TCK);
        if (ticks_per_second  < 0)
                return -errno;
        assert(ticks_per_second > 0);

        sum = (uint64_t) user_ticks + (uint64_t) nice_ticks + (uint64_t) system_ticks +
                (uint64_t) irq_ticks + (uint64_t) softirq_ticks +
                (uint64_t) guest_ticks + (uint64_t) guest_nice_ticks;

        /* Let's reduce this fraction before we apply it to avoid overflows when converting this to μsec */
        gcd = calc_gcd64(NSEC_PER_SEC, ticks_per_second);

        a = (uint64_t) NSEC_PER_SEC / gcd;
        b = (uint64_t) ticks_per_second / gcd;

        *ret = DIV_ROUND_UP((nsec_t) sum * (nsec_t) a, (nsec_t) b);
        return 0;
}

int convert_meminfo_value_to_uint64_bytes(const char *s, uint64_t *ret) {
        _cleanup_free_ char *w = NULL;
        uint64_t v;
        int r;

        assert(s);
        assert(ret);

        r = extract_first_word(&s, &w, /* separators = */ NULL, /* flags = */ 0);
        if (r < 0)
                return r;
        if (r == 0)
                return -EINVAL;

        /* Ensure the line ends in "kB" */
        if (!streq(s, "kB"))
                return -EINVAL;

        r = safe_atou64(w, &v);
        if (r < 0)
                return r;
        if (v == UINT64_MAX)
                return -EINVAL;

        if (!MUL_ASSIGN_SAFE(&v, U64_KB))
                return -EOVERFLOW;

        *ret = v;
        return 0;
}

int procfs_memory_get(uint64_t *ret_total, uint64_t *ret_used) {
        uint64_t mem_total = UINT64_MAX, mem_available = UINT64_MAX;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        f = fopen("/proc/meminfo", "re");
        if (!f)
                return -errno;

        for (;;) {
                _cleanup_free_ char *line = NULL;
                uint64_t *v;
                char *p;

                r = read_line(f, LONG_LINE_MAX, &line);
                if (r < 0)
                        return r;
                if (r == 0)
                        return -EINVAL; /* EOF: Couldn't find one or both fields? */

                p = first_word(line, "MemTotal:");
                if (p)
                        v = &mem_total;
                else {
                        p = first_word(line, "MemAvailable:");
                        if (p)
                                v = &mem_available;
                        else
                                continue;
                }

                r = convert_meminfo_value_to_uint64_bytes(p, v);
                if (r < 0)
                        return r;

                if (mem_total != UINT64_MAX && mem_available != UINT64_MAX)
                        break;
        }

        if (mem_available > mem_total)
                return -EINVAL;

        if (ret_total)
                *ret_total = mem_total;
        if (ret_used)
                *ret_used = mem_total - mem_available;
        return 0;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <unistd.h>
4
5	#include "alloc-util.h"
6	#include "extract-word.h"
7	#include "fd-util.h"
8	#include "fileio.h"
9	#include "parse-util.h"
10	#include "process-util.h"
11	#include "procfs-util.h"
12	#include "stdio-util.h"
13	#include "string-util.h"
14	#include "time-util.h"
15
16	int procfs_get_pid_max(uint64_t *ret) {	6,914✔
17	_cleanup_free_ char *value = NULL;	6,914✔
18	int r;	6,914✔
19
20	assert(ret);	6,914✔
21
22	r = read_one_line_file("/proc/sys/kernel/pid_max", &value);	6,914✔
23	if (r < 0)	6,914✔
24	return r;
25
26	return safe_atou64(value, ret);	6,914✔
27	}
28
29	int procfs_get_threads_max(uint64_t *ret) {	6,913✔
30	_cleanup_free_ char *value = NULL;	6,913✔
31	int r;	6,913✔
32
33	assert(ret);	6,913✔
34
35	r = read_one_line_file("/proc/sys/kernel/threads-max", &value);	6,913✔
36	if (r < 0)	6,913✔
37	return r;
38
39	return safe_atou64(value, ret);	6,913✔
40	}
41
42	int procfs_tasks_set_limit(uint64_t limit) {	2✔
43	char buffer[DECIMAL_STR_MAX(uint64_t)+1];	2✔
44	uint64_t pid_max;	2✔
45	int r;	2✔
46
47	if (limit == 0) /* This makes no sense, we are userspace and hence count as tasks too, and we want to live,	2✔
48	* hence the limit conceptually has to be above 0. Also, most likely if anyone asks for a zero
49	* limit they probably mean "no limit", hence let's better refuse this to avoid
50	* confusion. */
51	return -EINVAL;	2✔
52
53	/* The Linux kernel doesn't allow this value to go below 20, hence don't allow this either, higher values than
54	* TASKS_MAX are not accepted by the pid_max sysctl. We'll treat anything this high as "unbounded" and hence
55	* set it to the maximum. */
56	limit = CLAMP(limit, 20U, TASKS_MAX);	2✔
57
58	r = procfs_get_pid_max(&pid_max);	2✔
59	if (r < 0)	2✔
60	return r;
61
62	/* As pid_max is about the numeric pid_t range we'll bump it if necessary, but only ever increase it, never
63	* decrease it, as threads-max is the much more relevant sysctl. */
64	if (limit > pid_max-1) {	2✔
UNCOV 65	xsprintf(buffer, "%" PRIu64, limit+1); /* Add one, since PID 0 is not a valid PID */	×
66	r = write_string_file("/proc/sys/kernel/pid_max", buffer, WRITE_STRING_FILE_DISABLE_BUFFER);	×
67	if (r < 0)	×
68	return r;
69	}
70
71	xsprintf(buffer, "%" PRIu64, limit);	2✔
72	r = write_string_file("/proc/sys/kernel/threads-max", buffer, WRITE_STRING_FILE_DISABLE_BUFFER);	2✔
73	if (r < 0) {	2✔
74	uint64_t threads_max;	2✔
75
76	/* Hmm, we couldn't write this? If so, maybe it was already set properly? In that case let's not
77	* generate an error */
78
79	if (procfs_get_threads_max(&threads_max) < 0)	2✔
80	return r; /* return original error */	1✔
81
82	if (MIN(pid_max - 1, threads_max) != limit)	2✔
83	return r; /* return original error */
84
85	/* Yay! Value set already matches what we were trying to set, hence consider this a success. */
86	}
87
88	return 0;
89	}
90
91	int procfs_tasks_get_current(uint64_t *ret) {	1✔
92	_cleanup_free_ char *value = NULL;	1✔
93	const char p, nr;	1✔
94	size_t n;	1✔
95	int r;	1✔
96
97	assert(ret);	1✔
98
99	r = read_one_line_file("/proc/loadavg", &value);	1✔
100	if (r < 0)	1✔
101	return r;
102
103	/* Look for the second part of the fourth field, which is separated by a slash from the first part. None of the
104	* earlier fields use a slash, hence let's use this to find the right spot. */
105	p = strchr(value, '/');	1✔
106	if (!p)	1✔
107	return -EINVAL;
108
109	p++;	1✔
110	n = strspn(p, DIGITS);	1✔
111	nr = strndupa_safe(p, n);	1✔
112
113	return safe_atou64(nr, ret);	1✔
114	}
115
116	static uint64_t calc_gcd64(uint64_t a, uint64_t b) {	1✔
117
118	while (b > 0) {	2✔
119	uint64_t t;	1✔
120
121	t = a % b;	1✔
122
123	a = b;	1✔
124	b = t;	1✔
125	}
126
127	return a;	1✔
128	}
129
130	int procfs_cpu_get_usage(nsec_t *ret) {	1✔
131	_cleanup_free_ char *first_line = NULL;	1✔
132	unsigned long user_ticks, nice_ticks, system_ticks, irq_ticks, softirq_ticks,	1✔
133	guest_ticks = 0, guest_nice_ticks = 0;	1✔
134	long ticks_per_second;	1✔
135	uint64_t sum, gcd, a, b;	1✔
136	const char *p;	1✔
137	int r;	1✔
138
139	assert(ret);	1✔
140
141	r = read_one_line_file("/proc/stat", &first_line);	1✔
142	if (r < 0)	1✔
143	return r;
144
145	p = first_word(first_line, "cpu");	1✔
146	if (!p)	1✔
147	return -EINVAL;
148
149	if (sscanf(p, "%lu %lu %lu %u %u %lu %lu %*u %lu %lu",	1✔
150	&user_ticks,
151	&nice_ticks,
152	&system_ticks,
153	&irq_ticks,
154	&softirq_ticks,
155	&guest_ticks,
156	&guest_nice_ticks) < 5) /* we only insist on the first five fields */
157	return -EINVAL;
158
159	ticks_per_second = sysconf(_SC_CLK_TCK);	1✔
160	if (ticks_per_second < 0)	1✔
UNCOV 161	return -errno;	×
162	assert(ticks_per_second > 0);	1✔
163
164	sum = (uint64_t) user_ticks + (uint64_t) nice_ticks + (uint64_t) system_ticks +	1✔
165	(uint64_t) irq_ticks + (uint64_t) softirq_ticks +	1✔
166	(uint64_t) guest_ticks + (uint64_t) guest_nice_ticks;	1✔
167
168	/* Let's reduce this fraction before we apply it to avoid overflows when converting this to μsec */
169	gcd = calc_gcd64(NSEC_PER_SEC, ticks_per_second);	1✔
170
171	a = (uint64_t) NSEC_PER_SEC / gcd;	1✔
172	b = (uint64_t) ticks_per_second / gcd;	1✔
173
174	ret = DIV_ROUND_UP((nsec_t) sum (nsec_t) a, (nsec_t) b);	1✔
175	return 0;	1✔
176	}
177
178	int convert_meminfo_value_to_uint64_bytes(const char s, uint64_t ret) {	223✔
179	_cleanup_free_ char *w = NULL;	223✔
180	uint64_t v;	223✔
181	int r;	223✔
182
183	assert(s);	223✔
184	assert(ret);	223✔
185
186	r = extract_first_word(&s, &w, /* separators = / NULL, / flags = */ 0);	223✔
187	if (r < 0)	223✔
188	return r;
189	if (r == 0)	223✔
190	return -EINVAL;
191
192	/* Ensure the line ends in "kB" */
193	if (!streq(s, "kB"))	223✔
194	return -EINVAL;
195
196	r = safe_atou64(w, &v);	222✔
197	if (r < 0)	222✔
198	return r;
199	if (v == UINT64_MAX)	222✔
200	return -EINVAL;
201
202	if (!MUL_ASSIGN_SAFE(&v, U64_KB))	222✔
203	return -EOVERFLOW;
204
205	*ret = v;	222✔
206	return 0;	222✔
207	}
208
209	int procfs_memory_get(uint64_t ret_total, uint64_t ret_used) {	29✔
210	uint64_t mem_total = UINT64_MAX, mem_available = UINT64_MAX;	29✔
211	_cleanup_fclose_ FILE *f = NULL;	29✔
212	int r;	29✔
213
214	f = fopen("/proc/meminfo", "re");	29✔
215	if (!f)	29✔
UNCOV 216	return -errno;	×
217
218	for (;;) {	87✔
219	_cleanup_free_ char *line = NULL;	58✔
220	uint64_t *v;	87✔
221	char *p;	87✔
222
223	r = read_line(f, LONG_LINE_MAX, &line);	87✔
224	if (r < 0)	87✔
225	return r;
226	if (r == 0)	87✔
227	return -EINVAL; /* EOF: Couldn't find one or both fields? */
228
229	p = first_word(line, "MemTotal:");	87✔
230	if (p)	87✔
231	v = &mem_total;
232	else {
233	p = first_word(line, "MemAvailable:");	58✔
234	if (p)	58✔
235	v = &mem_available;
236	else
237	continue;	29✔
238	}
239
240	r = convert_meminfo_value_to_uint64_bytes(p, v);	58✔
241	if (r < 0)	58✔
242	return r;
243
244	if (mem_total != UINT64_MAX && mem_available != UINT64_MAX)	58✔
245	break;
246	}
247
248	if (mem_available > mem_total)	29✔
249	return -EINVAL;
250
251	if (ret_total)	29✔
252	*ret_total = mem_total;	26✔
253	if (ret_used)	29✔
254	*ret_used = mem_total - mem_available;	3✔
255	return 0;
256	}

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