1652 lines
52 KiB
C
1652 lines
52 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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#include <ctype.h>
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#include <errno.h>
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#include <limits.h>
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#include <linux/oom.h>
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#include <stdbool.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/mman.h>
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#include <sys/mount.h>
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#include <sys/personality.h>
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#include <sys/prctl.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <syslog.h>
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#include <unistd.h>
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#if HAVE_VALGRIND_VALGRIND_H
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#include <valgrind/valgrind.h>
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#endif
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#include "alloc-util.h"
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#include "architecture.h"
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#include "env-util.h"
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#include "errno-util.h"
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#include "escape.h"
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#include "fd-util.h"
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#include "fileio.h"
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#include "fs-util.h"
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#include "ioprio.h"
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#include "locale-util.h"
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#include "log.h"
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#include "macro.h"
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#include "memory-util.h"
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#include "missing_sched.h"
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#include "missing_syscall.h"
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#include "namespace-util.h"
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#include "path-util.h"
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#include "process-util.h"
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#include "raw-clone.h"
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#include "rlimit-util.h"
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#include "signal-util.h"
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#include "stat-util.h"
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#include "stdio-util.h"
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#include "string-table.h"
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#include "string-util.h"
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#include "terminal-util.h"
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#include "user-util.h"
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#include "utf8.h"
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/* The kernel limits userspace processes to TASK_COMM_LEN (16 bytes), but allows higher values for its own
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* workers, e.g. "kworker/u9:3-kcryptd/253:0". Let's pick a fixed smallish limit that will work for the kernel.
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*/
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#define COMM_MAX_LEN 128
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static int get_process_state(pid_t pid) {
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_cleanup_free_ char *line = NULL;
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const char *p;
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char state;
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int r;
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assert(pid >= 0);
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/* Shortcut: if we are enquired about our own state, we are obviously running */
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if (pid == 0 || pid == getpid_cached())
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return (unsigned char) 'R';
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p = procfs_file_alloca(pid, "stat");
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r = read_one_line_file(p, &line);
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if (r == -ENOENT)
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return -ESRCH;
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if (r < 0)
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return r;
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p = strrchr(line, ')');
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if (!p)
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return -EIO;
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p++;
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if (sscanf(p, " %c", &state) != 1)
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return -EIO;
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return (unsigned char) state;
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}
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int get_process_comm(pid_t pid, char **ret) {
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_cleanup_free_ char *escaped = NULL, *comm = NULL;
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int r;
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assert(ret);
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assert(pid >= 0);
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if (pid == 0 || pid == getpid_cached()) {
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comm = new0(char, TASK_COMM_LEN + 1); /* Must fit in 16 byte according to prctl(2) */
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if (!comm)
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return -ENOMEM;
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if (prctl(PR_GET_NAME, comm) < 0)
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return -errno;
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} else {
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const char *p;
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p = procfs_file_alloca(pid, "comm");
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/* Note that process names of kernel threads can be much longer than TASK_COMM_LEN */
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r = read_one_line_file(p, &comm);
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if (r == -ENOENT)
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return -ESRCH;
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if (r < 0)
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return r;
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}
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escaped = new(char, COMM_MAX_LEN);
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if (!escaped)
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return -ENOMEM;
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/* Escape unprintable characters, just in case, but don't grow the string beyond the underlying size */
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cellescape(escaped, COMM_MAX_LEN, comm);
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*ret = TAKE_PTR(escaped);
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return 0;
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}
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int get_process_cmdline(pid_t pid, size_t max_columns, ProcessCmdlineFlags flags, char **line) {
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_cleanup_fclose_ FILE *f = NULL;
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_cleanup_free_ char *t = NULL, *ans = NULL;
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const char *p;
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int r;
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size_t k;
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/* This is supposed to be a safety guard against runaway command lines. */
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size_t max_length = sc_arg_max();
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assert(line);
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assert(pid >= 0);
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/* Retrieves a process' command line. Replaces non-utf8 bytes by replacement character (<28>). If
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* max_columns is != -1 will return a string of the specified console width at most, abbreviated with
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* an ellipsis. If PROCESS_CMDLINE_COMM_FALLBACK is specified in flags and the process has no command
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* line set (the case for kernel threads), or has a command line that resolves to the empty string
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* will return the "comm" name of the process instead. This will use at most _SC_ARG_MAX bytes of
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* input data.
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*
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* Returns -ESRCH if the process doesn't exist, and -ENOENT if the process has no command line (and
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* comm_fallback is false). Returns 0 and sets *line otherwise. */
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p = procfs_file_alloca(pid, "cmdline");
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r = fopen_unlocked(p, "re", &f);
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if (r == -ENOENT)
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return -ESRCH;
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if (r < 0)
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return r;
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/* We assume that each four-byte character uses one or two columns. If we ever check for combining
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* characters, this assumption will need to be adjusted. */
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if ((size_t) 4 * max_columns + 1 < max_columns)
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max_length = MIN(max_length, (size_t) 4 * max_columns + 1);
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t = new(char, max_length);
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if (!t)
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return -ENOMEM;
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k = fread(t, 1, max_length, f);
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if (k > 0) {
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/* Arguments are separated by NULs. Let's replace those with spaces. */
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for (size_t i = 0; i < k - 1; i++)
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if (t[i] == '\0')
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t[i] = ' ';
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t[k] = '\0'; /* Normally, t[k] is already NUL, so this is just a guard in case of short read */
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} else {
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/* We only treat getting nothing as an error. We *could* also get an error after reading some
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* data, but we ignore that case, as such an error is rather unlikely and we prefer to get
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* some data rather than none. */
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if (ferror(f))
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return -errno;
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if (!(flags & PROCESS_CMDLINE_COMM_FALLBACK))
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return -ENOENT;
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/* Kernel threads have no argv[] */
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_cleanup_free_ char *t2 = NULL;
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r = get_process_comm(pid, &t2);
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if (r < 0)
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return r;
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mfree(t);
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t = strjoin("[", t2, "]");
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if (!t)
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return -ENOMEM;
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}
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delete_trailing_chars(t, WHITESPACE);
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bool eight_bit = (flags & PROCESS_CMDLINE_USE_LOCALE) && !is_locale_utf8();
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ans = escape_non_printable_full(t, max_columns, eight_bit);
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if (!ans)
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return -ENOMEM;
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(void) str_realloc(&ans);
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*line = TAKE_PTR(ans);
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return 0;
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}
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static int update_argv(const char name[], size_t l) {
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static int can_do = -1;
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if (can_do == 0)
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return 0;
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can_do = false; /* We'll set it to true only if the whole process works */
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/* Let's not bother with this if we don't have euid == 0. Strictly speaking we should check for the
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* CAP_SYS_RESOURCE capability which is independent of the euid. In our own code the capability generally is
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* present only for euid == 0, hence let's use this as quick bypass check, to avoid calling mmap() if
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* PR_SET_MM_ARG_{START,END} fails with EPERM later on anyway. After all geteuid() is dead cheap to call, but
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* mmap() is not. */
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if (geteuid() != 0)
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return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
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"Skipping PR_SET_MM, as we don't have privileges.");
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static size_t mm_size = 0;
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static char *mm = NULL;
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int r;
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if (mm_size < l+1) {
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size_t nn_size;
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char *nn;
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nn_size = PAGE_ALIGN(l+1);
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nn = mmap(NULL, nn_size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
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if (nn == MAP_FAILED)
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return log_debug_errno(errno, "mmap() failed: %m");
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strncpy(nn, name, nn_size);
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/* Now, let's tell the kernel about this new memory */
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if (prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long) nn, 0, 0) < 0) {
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if (ERRNO_IS_PRIVILEGE(errno))
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return log_debug_errno(errno, "PR_SET_MM_ARG_START failed: %m");
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/* HACK: prctl() API is kind of dumb on this point. The existing end address may already be
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* below the desired start address, in which case the kernel may have kicked this back due
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* to a range-check failure (see linux/kernel/sys.c:validate_prctl_map() to see this in
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* action). The proper solution would be to have a prctl() API that could set both start+end
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* simultaneously, or at least let us query the existing address to anticipate this condition
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* and respond accordingly. For now, we can only guess at the cause of this failure and try
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* a workaround--which will briefly expand the arg space to something potentially huge before
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* resizing it to what we want. */
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log_debug_errno(errno, "PR_SET_MM_ARG_START failed, attempting PR_SET_MM_ARG_END hack: %m");
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if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) nn + l + 1, 0, 0) < 0) {
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r = log_debug_errno(errno, "PR_SET_MM_ARG_END hack failed, proceeding without: %m");
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(void) munmap(nn, nn_size);
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return r;
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}
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if (prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long) nn, 0, 0) < 0)
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return log_debug_errno(errno, "PR_SET_MM_ARG_START still failed, proceeding without: %m");
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} else {
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/* And update the end pointer to the new end, too. If this fails, we don't really know what
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* to do, it's pretty unlikely that we can rollback, hence we'll just accept the failure,
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* and continue. */
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if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) nn + l + 1, 0, 0) < 0)
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log_debug_errno(errno, "PR_SET_MM_ARG_END failed, proceeding without: %m");
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}
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if (mm)
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(void) munmap(mm, mm_size);
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mm = nn;
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mm_size = nn_size;
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} else {
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strncpy(mm, name, mm_size);
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/* Update the end pointer, continuing regardless of any failure. */
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if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) mm + l + 1, 0, 0) < 0)
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log_debug_errno(errno, "PR_SET_MM_ARG_END failed, proceeding without: %m");
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}
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can_do = true;
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return 0;
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}
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int rename_process(const char name[]) {
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bool truncated = false;
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/* This is a like a poor man's setproctitle(). It changes the comm field, argv[0], and also the glibc's
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* internally used name of the process. For the first one a limit of 16 chars applies; to the second one in
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* many cases one of 10 (i.e. length of "/sbin/init") — however if we have CAP_SYS_RESOURCES it is unbounded;
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* to the third one 7 (i.e. the length of "systemd". If you pass a longer string it will likely be
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* truncated.
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*
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* Returns 0 if a name was set but truncated, > 0 if it was set but not truncated. */
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if (isempty(name))
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return -EINVAL; /* let's not confuse users unnecessarily with an empty name */
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if (!is_main_thread())
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return -EPERM; /* Let's not allow setting the process name from other threads than the main one, as we
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* cache things without locking, and we make assumptions that PR_SET_NAME sets the
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* process name that isn't correct on any other threads */
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size_t l = strlen(name);
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/* First step, change the comm field. The main thread's comm is identical to the process comm. This means we
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* can use PR_SET_NAME, which sets the thread name for the calling thread. */
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if (prctl(PR_SET_NAME, name) < 0)
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log_debug_errno(errno, "PR_SET_NAME failed: %m");
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if (l >= TASK_COMM_LEN) /* Linux userspace process names can be 15 chars at max */
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truncated = true;
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/* Second step, change glibc's ID of the process name. */
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if (program_invocation_name) {
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size_t k;
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k = strlen(program_invocation_name);
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strncpy(program_invocation_name, name, k);
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if (l > k)
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truncated = true;
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}
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/* Third step, completely replace the argv[] array the kernel maintains for us. This requires privileges, but
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* has the advantage that the argv[] array is exactly what we want it to be, and not filled up with zeros at
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* the end. This is the best option for changing /proc/self/cmdline. */
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(void) update_argv(name, l);
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/* Fourth step: in all cases we'll also update the original argv[], so that our own code gets it right too if
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* it still looks here */
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if (saved_argc > 0) {
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if (saved_argv[0]) {
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size_t k;
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k = strlen(saved_argv[0]);
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strncpy(saved_argv[0], name, k);
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if (l > k)
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truncated = true;
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}
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for (int i = 1; i < saved_argc; i++) {
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if (!saved_argv[i])
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break;
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memzero(saved_argv[i], strlen(saved_argv[i]));
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}
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}
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return !truncated;
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}
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int is_kernel_thread(pid_t pid) {
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_cleanup_free_ char *line = NULL;
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unsigned long long flags;
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size_t l, i;
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const char *p;
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char *q;
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int r;
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if (IN_SET(pid, 0, 1) || pid == getpid_cached()) /* pid 1, and we ourselves certainly aren't a kernel thread */
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return 0;
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if (!pid_is_valid(pid))
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return -EINVAL;
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p = procfs_file_alloca(pid, "stat");
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r = read_one_line_file(p, &line);
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if (r == -ENOENT)
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return -ESRCH;
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if (r < 0)
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return r;
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/* Skip past the comm field */
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q = strrchr(line, ')');
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if (!q)
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return -EINVAL;
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q++;
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/* Skip 6 fields to reach the flags field */
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for (i = 0; i < 6; i++) {
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l = strspn(q, WHITESPACE);
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if (l < 1)
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return -EINVAL;
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q += l;
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l = strcspn(q, WHITESPACE);
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if (l < 1)
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return -EINVAL;
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q += l;
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}
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/* Skip preceding whitespace */
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l = strspn(q, WHITESPACE);
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if (l < 1)
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return -EINVAL;
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q += l;
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/* Truncate the rest */
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l = strcspn(q, WHITESPACE);
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if (l < 1)
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return -EINVAL;
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q[l] = 0;
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r = safe_atollu(q, &flags);
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if (r < 0)
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return r;
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return !!(flags & PF_KTHREAD);
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}
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int get_process_capeff(pid_t pid, char **capeff) {
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const char *p;
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int r;
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assert(capeff);
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assert(pid >= 0);
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p = procfs_file_alloca(pid, "status");
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r = get_proc_field(p, "CapEff", WHITESPACE, capeff);
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if (r == -ENOENT)
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return -ESRCH;
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return r;
|
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}
|
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|
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static int get_process_link_contents(const char *proc_file, char **name) {
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int r;
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|
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assert(proc_file);
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assert(name);
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|
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r = readlink_malloc(proc_file, name);
|
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if (r == -ENOENT)
|
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return -ESRCH;
|
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if (r < 0)
|
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return r;
|
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|
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return 0;
|
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}
|
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|
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int get_process_exe(pid_t pid, char **name) {
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const char *p;
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char *d;
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int r;
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assert(pid >= 0);
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p = procfs_file_alloca(pid, "exe");
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r = get_process_link_contents(p, name);
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if (r < 0)
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return r;
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|
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d = endswith(*name, " (deleted)");
|
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if (d)
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*d = '\0';
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return 0;
|
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}
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|
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static int get_process_id(pid_t pid, const char *field, uid_t *uid) {
|
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_cleanup_fclose_ FILE *f = NULL;
|
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const char *p;
|
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int r;
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|
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assert(field);
|
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assert(uid);
|
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|
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if (pid < 0)
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return -EINVAL;
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p = procfs_file_alloca(pid, "status");
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r = fopen_unlocked(p, "re", &f);
|
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if (r == -ENOENT)
|
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return -ESRCH;
|
||
if (r < 0)
|
||
return r;
|
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|
||
for (;;) {
|
||
_cleanup_free_ char *line = NULL;
|
||
char *l;
|
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|
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r = read_line(f, LONG_LINE_MAX, &line);
|
||
if (r < 0)
|
||
return r;
|
||
if (r == 0)
|
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break;
|
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|
||
l = strstrip(line);
|
||
|
||
if (startswith(l, field)) {
|
||
l += strlen(field);
|
||
l += strspn(l, WHITESPACE);
|
||
|
||
l[strcspn(l, WHITESPACE)] = 0;
|
||
|
||
return parse_uid(l, uid);
|
||
}
|
||
}
|
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|
||
return -EIO;
|
||
}
|
||
|
||
int get_process_uid(pid_t pid, uid_t *uid) {
|
||
|
||
if (pid == 0 || pid == getpid_cached()) {
|
||
*uid = getuid();
|
||
return 0;
|
||
}
|
||
|
||
return get_process_id(pid, "Uid:", uid);
|
||
}
|
||
|
||
int get_process_gid(pid_t pid, gid_t *gid) {
|
||
|
||
if (pid == 0 || pid == getpid_cached()) {
|
||
*gid = getgid();
|
||
return 0;
|
||
}
|
||
|
||
assert_cc(sizeof(uid_t) == sizeof(gid_t));
|
||
return get_process_id(pid, "Gid:", gid);
|
||
}
|
||
|
||
int get_process_cwd(pid_t pid, char **cwd) {
|
||
const char *p;
|
||
|
||
assert(pid >= 0);
|
||
|
||
if (pid == 0 || pid == getpid_cached())
|
||
return safe_getcwd(cwd);
|
||
|
||
p = procfs_file_alloca(pid, "cwd");
|
||
|
||
return get_process_link_contents(p, cwd);
|
||
}
|
||
|
||
int get_process_root(pid_t pid, char **root) {
|
||
const char *p;
|
||
|
||
assert(pid >= 0);
|
||
|
||
p = procfs_file_alloca(pid, "root");
|
||
|
||
return get_process_link_contents(p, root);
|
||
}
|
||
|
||
#define ENVIRONMENT_BLOCK_MAX (5U*1024U*1024U)
|
||
|
||
int get_process_environ(pid_t pid, char **env) {
|
||
_cleanup_fclose_ FILE *f = NULL;
|
||
_cleanup_free_ char *outcome = NULL;
|
||
size_t allocated = 0, sz = 0;
|
||
const char *p;
|
||
int r;
|
||
|
||
assert(pid >= 0);
|
||
assert(env);
|
||
|
||
p = procfs_file_alloca(pid, "environ");
|
||
|
||
r = fopen_unlocked(p, "re", &f);
|
||
if (r == -ENOENT)
|
||
return -ESRCH;
|
||
if (r < 0)
|
||
return r;
|
||
|
||
for (;;) {
|
||
char c;
|
||
|
||
if (sz >= ENVIRONMENT_BLOCK_MAX)
|
||
return -ENOBUFS;
|
||
|
||
if (!GREEDY_REALLOC(outcome, allocated, sz + 5))
|
||
return -ENOMEM;
|
||
|
||
r = safe_fgetc(f, &c);
|
||
if (r < 0)
|
||
return r;
|
||
if (r == 0)
|
||
break;
|
||
|
||
if (c == '\0')
|
||
outcome[sz++] = '\n';
|
||
else
|
||
sz += cescape_char(c, outcome + sz);
|
||
}
|
||
|
||
outcome[sz] = '\0';
|
||
*env = TAKE_PTR(outcome);
|
||
|
||
return 0;
|
||
}
|
||
|
||
int get_process_ppid(pid_t pid, pid_t *_ppid) {
|
||
int r;
|
||
_cleanup_free_ char *line = NULL;
|
||
long unsigned ppid;
|
||
const char *p;
|
||
|
||
assert(pid >= 0);
|
||
assert(_ppid);
|
||
|
||
if (pid == 0 || pid == getpid_cached()) {
|
||
*_ppid = getppid();
|
||
return 0;
|
||
}
|
||
|
||
p = procfs_file_alloca(pid, "stat");
|
||
r = read_one_line_file(p, &line);
|
||
if (r == -ENOENT)
|
||
return -ESRCH;
|
||
if (r < 0)
|
||
return r;
|
||
|
||
/* Let's skip the pid and comm fields. The latter is enclosed
|
||
* in () but does not escape any () in its value, so let's
|
||
* skip over it manually */
|
||
|
||
p = strrchr(line, ')');
|
||
if (!p)
|
||
return -EIO;
|
||
|
||
p++;
|
||
|
||
if (sscanf(p, " "
|
||
"%*c " /* state */
|
||
"%lu ", /* ppid */
|
||
&ppid) != 1)
|
||
return -EIO;
|
||
|
||
if ((long unsigned) (pid_t) ppid != ppid)
|
||
return -ERANGE;
|
||
|
||
*_ppid = (pid_t) ppid;
|
||
|
||
return 0;
|
||
}
|
||
|
||
int get_process_umask(pid_t pid, mode_t *umask) {
|
||
_cleanup_free_ char *m = NULL;
|
||
const char *p;
|
||
int r;
|
||
|
||
assert(umask);
|
||
assert(pid >= 0);
|
||
|
||
p = procfs_file_alloca(pid, "status");
|
||
|
||
r = get_proc_field(p, "Umask", WHITESPACE, &m);
|
||
if (r == -ENOENT)
|
||
return -ESRCH;
|
||
|
||
return parse_mode(m, umask);
|
||
}
|
||
|
||
int wait_for_terminate(pid_t pid, siginfo_t *status) {
|
||
siginfo_t dummy;
|
||
|
||
assert(pid >= 1);
|
||
|
||
if (!status)
|
||
status = &dummy;
|
||
|
||
for (;;) {
|
||
zero(*status);
|
||
|
||
if (waitid(P_PID, pid, status, WEXITED) < 0) {
|
||
|
||
if (errno == EINTR)
|
||
continue;
|
||
|
||
return negative_errno();
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Return values:
|
||
* < 0 : wait_for_terminate() failed to get the state of the
|
||
* process, the process was terminated by a signal, or
|
||
* failed for an unknown reason.
|
||
* >=0 : The process terminated normally, and its exit code is
|
||
* returned.
|
||
*
|
||
* That is, success is indicated by a return value of zero, and an
|
||
* error is indicated by a non-zero value.
|
||
*
|
||
* A warning is emitted if the process terminates abnormally,
|
||
* and also if it returns non-zero unless check_exit_code is true.
|
||
*/
|
||
int wait_for_terminate_and_check(const char *name, pid_t pid, WaitFlags flags) {
|
||
_cleanup_free_ char *buffer = NULL;
|
||
siginfo_t status;
|
||
int r, prio;
|
||
|
||
assert(pid > 1);
|
||
|
||
if (!name) {
|
||
r = get_process_comm(pid, &buffer);
|
||
if (r < 0)
|
||
log_debug_errno(r, "Failed to acquire process name of " PID_FMT ", ignoring: %m", pid);
|
||
else
|
||
name = buffer;
|
||
}
|
||
|
||
prio = flags & WAIT_LOG_ABNORMAL ? LOG_ERR : LOG_DEBUG;
|
||
|
||
r = wait_for_terminate(pid, &status);
|
||
if (r < 0)
|
||
return log_full_errno(prio, r, "Failed to wait for %s: %m", strna(name));
|
||
|
||
if (status.si_code == CLD_EXITED) {
|
||
if (status.si_status != EXIT_SUCCESS)
|
||
log_full(flags & WAIT_LOG_NON_ZERO_EXIT_STATUS ? LOG_ERR : LOG_DEBUG,
|
||
"%s failed with exit status %i.", strna(name), status.si_status);
|
||
else
|
||
log_debug("%s succeeded.", name);
|
||
|
||
return status.si_status;
|
||
|
||
} else if (IN_SET(status.si_code, CLD_KILLED, CLD_DUMPED)) {
|
||
|
||
log_full(prio, "%s terminated by signal %s.", strna(name), signal_to_string(status.si_status));
|
||
return -EPROTO;
|
||
}
|
||
|
||
log_full(prio, "%s failed due to unknown reason.", strna(name));
|
||
return -EPROTO;
|
||
}
|
||
|
||
/*
|
||
* Return values:
|
||
*
|
||
* < 0 : wait_for_terminate_with_timeout() failed to get the state of the process, the process timed out, the process
|
||
* was terminated by a signal, or failed for an unknown reason.
|
||
*
|
||
* >=0 : The process terminated normally with no failures.
|
||
*
|
||
* Success is indicated by a return value of zero, a timeout is indicated by ETIMEDOUT, and all other child failure
|
||
* states are indicated by error is indicated by a non-zero value.
|
||
*
|
||
* This call assumes SIGCHLD has been blocked already, in particular before the child to wait for has been forked off
|
||
* to remain entirely race-free.
|
||
*/
|
||
int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout) {
|
||
sigset_t mask;
|
||
int r;
|
||
usec_t until;
|
||
|
||
assert_se(sigemptyset(&mask) == 0);
|
||
assert_se(sigaddset(&mask, SIGCHLD) == 0);
|
||
|
||
/* Drop into a sigtimewait-based timeout. Waiting for the
|
||
* pid to exit. */
|
||
until = now(CLOCK_MONOTONIC) + timeout;
|
||
for (;;) {
|
||
usec_t n;
|
||
siginfo_t status = {};
|
||
struct timespec ts;
|
||
|
||
n = now(CLOCK_MONOTONIC);
|
||
if (n >= until)
|
||
break;
|
||
|
||
r = sigtimedwait(&mask, NULL, timespec_store(&ts, until - n)) < 0 ? -errno : 0;
|
||
/* Assuming we woke due to the child exiting. */
|
||
if (waitid(P_PID, pid, &status, WEXITED|WNOHANG) == 0) {
|
||
if (status.si_pid == pid) {
|
||
/* This is the correct child.*/
|
||
if (status.si_code == CLD_EXITED)
|
||
return (status.si_status == 0) ? 0 : -EPROTO;
|
||
else
|
||
return -EPROTO;
|
||
}
|
||
}
|
||
/* Not the child, check for errors and proceed appropriately */
|
||
if (r < 0) {
|
||
switch (r) {
|
||
case -EAGAIN:
|
||
/* Timed out, child is likely hung. */
|
||
return -ETIMEDOUT;
|
||
case -EINTR:
|
||
/* Received a different signal and should retry */
|
||
continue;
|
||
default:
|
||
/* Return any unexpected errors */
|
||
return r;
|
||
}
|
||
}
|
||
}
|
||
|
||
return -EPROTO;
|
||
}
|
||
|
||
void sigkill_wait(pid_t pid) {
|
||
assert(pid > 1);
|
||
|
||
if (kill(pid, SIGKILL) >= 0)
|
||
(void) wait_for_terminate(pid, NULL);
|
||
}
|
||
|
||
void sigkill_waitp(pid_t *pid) {
|
||
PROTECT_ERRNO;
|
||
|
||
if (!pid)
|
||
return;
|
||
if (*pid <= 1)
|
||
return;
|
||
|
||
sigkill_wait(*pid);
|
||
}
|
||
|
||
void sigterm_wait(pid_t pid) {
|
||
assert(pid > 1);
|
||
|
||
if (kill_and_sigcont(pid, SIGTERM) >= 0)
|
||
(void) wait_for_terminate(pid, NULL);
|
||
}
|
||
|
||
int kill_and_sigcont(pid_t pid, int sig) {
|
||
int r;
|
||
|
||
r = kill(pid, sig) < 0 ? -errno : 0;
|
||
|
||
/* If this worked, also send SIGCONT, unless we already just sent a SIGCONT, or SIGKILL was sent which isn't
|
||
* affected by a process being suspended anyway. */
|
||
if (r >= 0 && !IN_SET(sig, SIGCONT, SIGKILL))
|
||
(void) kill(pid, SIGCONT);
|
||
|
||
return r;
|
||
}
|
||
|
||
int getenv_for_pid(pid_t pid, const char *field, char **ret) {
|
||
_cleanup_fclose_ FILE *f = NULL;
|
||
char *value = NULL;
|
||
const char *path;
|
||
size_t l, sum = 0;
|
||
int r;
|
||
|
||
assert(pid >= 0);
|
||
assert(field);
|
||
assert(ret);
|
||
|
||
if (pid == 0 || pid == getpid_cached()) {
|
||
const char *e;
|
||
|
||
e = getenv(field);
|
||
if (!e) {
|
||
*ret = NULL;
|
||
return 0;
|
||
}
|
||
|
||
value = strdup(e);
|
||
if (!value)
|
||
return -ENOMEM;
|
||
|
||
*ret = value;
|
||
return 1;
|
||
}
|
||
|
||
if (!pid_is_valid(pid))
|
||
return -EINVAL;
|
||
|
||
path = procfs_file_alloca(pid, "environ");
|
||
|
||
r = fopen_unlocked(path, "re", &f);
|
||
if (r == -ENOENT)
|
||
return -ESRCH;
|
||
if (r < 0)
|
||
return r;
|
||
|
||
l = strlen(field);
|
||
for (;;) {
|
||
_cleanup_free_ char *line = NULL;
|
||
|
||
if (sum > ENVIRONMENT_BLOCK_MAX) /* Give up searching eventually */
|
||
return -ENOBUFS;
|
||
|
||
r = read_nul_string(f, LONG_LINE_MAX, &line);
|
||
if (r < 0)
|
||
return r;
|
||
if (r == 0) /* EOF */
|
||
break;
|
||
|
||
sum += r;
|
||
|
||
if (strneq(line, field, l) && line[l] == '=') {
|
||
value = strdup(line + l + 1);
|
||
if (!value)
|
||
return -ENOMEM;
|
||
|
||
*ret = value;
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
*ret = NULL;
|
||
return 0;
|
||
}
|
||
|
||
int pid_is_my_child(pid_t pid) {
|
||
pid_t ppid;
|
||
int r;
|
||
|
||
if (pid <= 1)
|
||
return false;
|
||
|
||
r = get_process_ppid(pid, &ppid);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
return ppid == getpid_cached();
|
||
}
|
||
|
||
bool pid_is_unwaited(pid_t pid) {
|
||
/* Checks whether a PID is still valid at all, including a zombie */
|
||
|
||
if (pid < 0)
|
||
return false;
|
||
|
||
if (pid <= 1) /* If we or PID 1 would be dead and have been waited for, this code would not be running */
|
||
return true;
|
||
|
||
if (pid == getpid_cached())
|
||
return true;
|
||
|
||
if (kill(pid, 0) >= 0)
|
||
return true;
|
||
|
||
return errno != ESRCH;
|
||
}
|
||
|
||
bool pid_is_alive(pid_t pid) {
|
||
int r;
|
||
|
||
/* Checks whether a PID is still valid and not a zombie */
|
||
|
||
if (pid < 0)
|
||
return false;
|
||
|
||
if (pid <= 1) /* If we or PID 1 would be a zombie, this code would not be running */
|
||
return true;
|
||
|
||
if (pid == getpid_cached())
|
||
return true;
|
||
|
||
r = get_process_state(pid);
|
||
if (IN_SET(r, -ESRCH, 'Z'))
|
||
return false;
|
||
|
||
return true;
|
||
}
|
||
|
||
int pid_from_same_root_fs(pid_t pid) {
|
||
const char *root;
|
||
|
||
if (pid < 0)
|
||
return false;
|
||
|
||
if (pid == 0 || pid == getpid_cached())
|
||
return true;
|
||
|
||
root = procfs_file_alloca(pid, "root");
|
||
|
||
return files_same(root, "/proc/1/root", 0);
|
||
}
|
||
|
||
bool is_main_thread(void) {
|
||
static thread_local int cached = 0;
|
||
|
||
if (_unlikely_(cached == 0))
|
||
cached = getpid_cached() == gettid() ? 1 : -1;
|
||
|
||
return cached > 0;
|
||
}
|
||
|
||
_noreturn_ void freeze(void) {
|
||
|
||
log_close();
|
||
|
||
/* Make sure nobody waits for us on a socket anymore */
|
||
(void) close_all_fds(NULL, 0);
|
||
|
||
sync();
|
||
|
||
/* Let's not freeze right away, but keep reaping zombies. */
|
||
for (;;) {
|
||
int r;
|
||
siginfo_t si = {};
|
||
|
||
r = waitid(P_ALL, 0, &si, WEXITED);
|
||
if (r < 0 && errno != EINTR)
|
||
break;
|
||
}
|
||
|
||
/* waitid() failed with an unexpected error, things are really borked. Freeze now! */
|
||
for (;;)
|
||
pause();
|
||
}
|
||
|
||
bool oom_score_adjust_is_valid(int oa) {
|
||
return oa >= OOM_SCORE_ADJ_MIN && oa <= OOM_SCORE_ADJ_MAX;
|
||
}
|
||
|
||
unsigned long personality_from_string(const char *p) {
|
||
int architecture;
|
||
|
||
if (!p)
|
||
return PERSONALITY_INVALID;
|
||
|
||
/* Parse a personality specifier. We use our own identifiers that indicate specific ABIs, rather than just
|
||
* hints regarding the register size, since we want to keep things open for multiple locally supported ABIs for
|
||
* the same register size. */
|
||
|
||
architecture = architecture_from_string(p);
|
||
if (architecture < 0)
|
||
return PERSONALITY_INVALID;
|
||
|
||
if (architecture == native_architecture())
|
||
return PER_LINUX;
|
||
#ifdef SECONDARY_ARCHITECTURE
|
||
if (architecture == SECONDARY_ARCHITECTURE)
|
||
return PER_LINUX32;
|
||
#endif
|
||
|
||
return PERSONALITY_INVALID;
|
||
}
|
||
|
||
const char* personality_to_string(unsigned long p) {
|
||
int architecture = _ARCHITECTURE_INVALID;
|
||
|
||
if (p == PER_LINUX)
|
||
architecture = native_architecture();
|
||
#ifdef SECONDARY_ARCHITECTURE
|
||
else if (p == PER_LINUX32)
|
||
architecture = SECONDARY_ARCHITECTURE;
|
||
#endif
|
||
|
||
if (architecture < 0)
|
||
return NULL;
|
||
|
||
return architecture_to_string(architecture);
|
||
}
|
||
|
||
int safe_personality(unsigned long p) {
|
||
int ret;
|
||
|
||
/* So here's the deal, personality() is weirdly defined by glibc. In some cases it returns a failure via errno,
|
||
* and in others as negative return value containing an errno-like value. Let's work around this: this is a
|
||
* wrapper that uses errno if it is set, and uses the return value otherwise. And then it sets both errno and
|
||
* the return value indicating the same issue, so that we are definitely on the safe side.
|
||
*
|
||
* See https://github.com/systemd/systemd/issues/6737 */
|
||
|
||
errno = 0;
|
||
ret = personality(p);
|
||
if (ret < 0) {
|
||
if (errno != 0)
|
||
return -errno;
|
||
|
||
errno = -ret;
|
||
}
|
||
|
||
return ret;
|
||
}
|
||
|
||
int opinionated_personality(unsigned long *ret) {
|
||
int current;
|
||
|
||
/* Returns the current personality, or PERSONALITY_INVALID if we can't determine it. This function is a bit
|
||
* opinionated though, and ignores all the finer-grained bits and exotic personalities, only distinguishing the
|
||
* two most relevant personalities: PER_LINUX and PER_LINUX32. */
|
||
|
||
current = safe_personality(PERSONALITY_INVALID);
|
||
if (current < 0)
|
||
return current;
|
||
|
||
if (((unsigned long) current & 0xffff) == PER_LINUX32)
|
||
*ret = PER_LINUX32;
|
||
else
|
||
*ret = PER_LINUX;
|
||
|
||
return 0;
|
||
}
|
||
|
||
void valgrind_summary_hack(void) {
|
||
#if HAVE_VALGRIND_VALGRIND_H
|
||
if (getpid_cached() == 1 && RUNNING_ON_VALGRIND) {
|
||
pid_t pid;
|
||
pid = raw_clone(SIGCHLD);
|
||
if (pid < 0)
|
||
log_emergency_errno(errno, "Failed to fork off valgrind helper: %m");
|
||
else if (pid == 0)
|
||
exit(EXIT_SUCCESS);
|
||
else {
|
||
log_info("Spawned valgrind helper as PID "PID_FMT".", pid);
|
||
(void) wait_for_terminate(pid, NULL);
|
||
}
|
||
}
|
||
#endif
|
||
}
|
||
|
||
int pid_compare_func(const pid_t *a, const pid_t *b) {
|
||
/* Suitable for usage in qsort() */
|
||
return CMP(*a, *b);
|
||
}
|
||
|
||
int ioprio_parse_priority(const char *s, int *ret) {
|
||
int i, r;
|
||
|
||
assert(s);
|
||
assert(ret);
|
||
|
||
r = safe_atoi(s, &i);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
if (!ioprio_priority_is_valid(i))
|
||
return -EINVAL;
|
||
|
||
*ret = i;
|
||
return 0;
|
||
}
|
||
|
||
/* The cached PID, possible values:
|
||
*
|
||
* == UNSET [0] → cache not initialized yet
|
||
* == BUSY [-1] → some thread is initializing it at the moment
|
||
* any other → the cached PID
|
||
*/
|
||
|
||
#define CACHED_PID_UNSET ((pid_t) 0)
|
||
#define CACHED_PID_BUSY ((pid_t) -1)
|
||
|
||
static pid_t cached_pid = CACHED_PID_UNSET;
|
||
|
||
void reset_cached_pid(void) {
|
||
/* Invoked in the child after a fork(), i.e. at the first moment the PID changed */
|
||
cached_pid = CACHED_PID_UNSET;
|
||
}
|
||
|
||
/* We use glibc __register_atfork() + __dso_handle directly here, as they are not included in the glibc
|
||
* headers. __register_atfork() is mostly equivalent to pthread_atfork(), but doesn't require us to link against
|
||
* libpthread, as it is part of glibc anyway. */
|
||
extern int __register_atfork(void (*prepare) (void), void (*parent) (void), void (*child) (void), void *dso_handle);
|
||
extern void* __dso_handle _weak_;
|
||
|
||
pid_t getpid_cached(void) {
|
||
static bool installed = false;
|
||
pid_t current_value;
|
||
|
||
/* getpid_cached() is much like getpid(), but caches the value in local memory, to avoid having to invoke a
|
||
* system call each time. This restores glibc behaviour from before 2.24, when getpid() was unconditionally
|
||
* cached. Starting with 2.24 getpid() started to become prohibitively expensive when used for detecting when
|
||
* objects were used across fork()s. With this caching the old behaviour is somewhat restored.
|
||
*
|
||
* https://bugzilla.redhat.com/show_bug.cgi?id=1443976
|
||
* https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=c579f48edba88380635ab98cb612030e3ed8691e
|
||
*/
|
||
|
||
current_value = __sync_val_compare_and_swap(&cached_pid, CACHED_PID_UNSET, CACHED_PID_BUSY);
|
||
|
||
switch (current_value) {
|
||
|
||
case CACHED_PID_UNSET: { /* Not initialized yet, then do so now */
|
||
pid_t new_pid;
|
||
|
||
new_pid = raw_getpid();
|
||
|
||
if (!installed) {
|
||
/* __register_atfork() either returns 0 or -ENOMEM, in its glibc implementation. Since it's
|
||
* only half-documented (glibc doesn't document it but LSB does — though only superficially)
|
||
* we'll check for errors only in the most generic fashion possible. */
|
||
|
||
if (__register_atfork(NULL, NULL, reset_cached_pid, __dso_handle) != 0) {
|
||
/* OOM? Let's try again later */
|
||
cached_pid = CACHED_PID_UNSET;
|
||
return new_pid;
|
||
}
|
||
|
||
installed = true;
|
||
}
|
||
|
||
cached_pid = new_pid;
|
||
return new_pid;
|
||
}
|
||
|
||
case CACHED_PID_BUSY: /* Somebody else is currently initializing */
|
||
return raw_getpid();
|
||
|
||
default: /* Properly initialized */
|
||
return current_value;
|
||
}
|
||
}
|
||
|
||
int must_be_root(void) {
|
||
|
||
if (geteuid() == 0)
|
||
return 0;
|
||
|
||
return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Need to be root.");
|
||
}
|
||
|
||
static void restore_sigsetp(sigset_t **ssp) {
|
||
if (*ssp)
|
||
(void) sigprocmask(SIG_SETMASK, *ssp, NULL);
|
||
}
|
||
|
||
int safe_fork_full(
|
||
const char *name,
|
||
const int except_fds[],
|
||
size_t n_except_fds,
|
||
ForkFlags flags,
|
||
pid_t *ret_pid) {
|
||
|
||
pid_t original_pid, pid;
|
||
sigset_t saved_ss, ss;
|
||
_cleanup_(restore_sigsetp) sigset_t *saved_ssp = NULL;
|
||
bool block_signals = false, block_all = false;
|
||
int prio, r;
|
||
|
||
/* A wrapper around fork(), that does a couple of important initializations in addition to mere forking. Always
|
||
* returns the child's PID in *ret_pid. Returns == 0 in the child, and > 0 in the parent. */
|
||
|
||
prio = flags & FORK_LOG ? LOG_ERR : LOG_DEBUG;
|
||
|
||
original_pid = getpid_cached();
|
||
|
||
if (flags & (FORK_RESET_SIGNALS|FORK_DEATHSIG)) {
|
||
/* We temporarily block all signals, so that the new child has them blocked initially. This way, we can
|
||
* be sure that SIGTERMs are not lost we might send to the child. */
|
||
|
||
assert_se(sigfillset(&ss) >= 0);
|
||
block_signals = block_all = true;
|
||
|
||
} else if (flags & FORK_WAIT) {
|
||
/* Let's block SIGCHLD at least, so that we can safely watch for the child process */
|
||
|
||
assert_se(sigemptyset(&ss) >= 0);
|
||
assert_se(sigaddset(&ss, SIGCHLD) >= 0);
|
||
block_signals = true;
|
||
}
|
||
|
||
if (block_signals) {
|
||
if (sigprocmask(SIG_SETMASK, &ss, &saved_ss) < 0)
|
||
return log_full_errno(prio, errno, "Failed to set signal mask: %m");
|
||
saved_ssp = &saved_ss;
|
||
}
|
||
|
||
if (flags & FORK_NEW_MOUNTNS)
|
||
pid = raw_clone(SIGCHLD|CLONE_NEWNS);
|
||
else
|
||
pid = fork();
|
||
if (pid < 0)
|
||
return log_full_errno(prio, errno, "Failed to fork: %m");
|
||
if (pid > 0) {
|
||
/* We are in the parent process */
|
||
|
||
log_debug("Successfully forked off '%s' as PID " PID_FMT ".", strna(name), pid);
|
||
|
||
if (flags & FORK_WAIT) {
|
||
if (block_all) {
|
||
/* undo everything except SIGCHLD */
|
||
ss = saved_ss;
|
||
assert_se(sigaddset(&ss, SIGCHLD) >= 0);
|
||
(void) sigprocmask(SIG_SETMASK, &ss, NULL);
|
||
}
|
||
|
||
r = wait_for_terminate_and_check(name, pid, (flags & FORK_LOG ? WAIT_LOG : 0));
|
||
if (r < 0)
|
||
return r;
|
||
if (r != EXIT_SUCCESS) /* exit status > 0 should be treated as failure, too */
|
||
return -EPROTO;
|
||
}
|
||
|
||
if (ret_pid)
|
||
*ret_pid = pid;
|
||
|
||
return 1;
|
||
}
|
||
|
||
/* We are in the child process */
|
||
|
||
/* Restore signal mask manually */
|
||
saved_ssp = NULL;
|
||
|
||
if (flags & FORK_REOPEN_LOG) {
|
||
/* Close the logs if requested, before we log anything. And make sure we reopen it if needed. */
|
||
log_close();
|
||
log_set_open_when_needed(true);
|
||
}
|
||
|
||
if (name) {
|
||
r = rename_process(name);
|
||
if (r < 0)
|
||
log_full_errno(flags & FORK_LOG ? LOG_WARNING : LOG_DEBUG,
|
||
r, "Failed to rename process, ignoring: %m");
|
||
}
|
||
|
||
if (flags & (FORK_DEATHSIG|FORK_DEATHSIG_SIGINT))
|
||
if (prctl(PR_SET_PDEATHSIG, (flags & FORK_DEATHSIG_SIGINT) ? SIGINT : SIGTERM) < 0) {
|
||
log_full_errno(prio, errno, "Failed to set death signal: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
if (flags & FORK_RESET_SIGNALS) {
|
||
r = reset_all_signal_handlers();
|
||
if (r < 0) {
|
||
log_full_errno(prio, r, "Failed to reset signal handlers: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
/* This implicitly undoes the signal mask stuff we did before the fork()ing above */
|
||
r = reset_signal_mask();
|
||
if (r < 0) {
|
||
log_full_errno(prio, r, "Failed to reset signal mask: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
} else if (block_signals) { /* undo what we did above */
|
||
if (sigprocmask(SIG_SETMASK, &saved_ss, NULL) < 0) {
|
||
log_full_errno(prio, errno, "Failed to restore signal mask: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
if (flags & FORK_DEATHSIG) {
|
||
pid_t ppid;
|
||
/* Let's see if the parent PID is still the one we started from? If not, then the parent
|
||
* already died by the time we set PR_SET_PDEATHSIG, hence let's emulate the effect */
|
||
|
||
ppid = getppid();
|
||
if (ppid == 0)
|
||
/* Parent is in a different PID namespace. */;
|
||
else if (ppid != original_pid) {
|
||
log_debug("Parent died early, raising SIGTERM.");
|
||
(void) raise(SIGTERM);
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
if (FLAGS_SET(flags, FORK_NEW_MOUNTNS | FORK_MOUNTNS_SLAVE)) {
|
||
|
||
/* Optionally, make sure we never propagate mounts to the host. */
|
||
|
||
if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0) {
|
||
log_full_errno(prio, errno, "Failed to remount root directory as MS_SLAVE: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
if (flags & FORK_CLOSE_ALL_FDS) {
|
||
/* Close the logs here in case it got reopened above, as close_all_fds() would close them for us */
|
||
log_close();
|
||
|
||
r = close_all_fds(except_fds, n_except_fds);
|
||
if (r < 0) {
|
||
log_full_errno(prio, r, "Failed to close all file descriptors: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
/* When we were asked to reopen the logs, do so again now */
|
||
if (flags & FORK_REOPEN_LOG) {
|
||
log_open();
|
||
log_set_open_when_needed(false);
|
||
}
|
||
|
||
if (flags & FORK_NULL_STDIO) {
|
||
r = make_null_stdio();
|
||
if (r < 0) {
|
||
log_full_errno(prio, r, "Failed to connect stdin/stdout to /dev/null: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
} else if (flags & FORK_STDOUT_TO_STDERR) {
|
||
if (dup2(STDERR_FILENO, STDOUT_FILENO) < 0) {
|
||
log_full_errno(prio, errno, "Failed to connect stdout to stderr: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
if (flags & FORK_RLIMIT_NOFILE_SAFE) {
|
||
r = rlimit_nofile_safe();
|
||
if (r < 0) {
|
||
log_full_errno(prio, r, "Failed to lower RLIMIT_NOFILE's soft limit to 1K: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
}
|
||
|
||
if (ret_pid)
|
||
*ret_pid = getpid_cached();
|
||
|
||
return 0;
|
||
}
|
||
|
||
int namespace_fork(
|
||
const char *outer_name,
|
||
const char *inner_name,
|
||
const int except_fds[],
|
||
size_t n_except_fds,
|
||
ForkFlags flags,
|
||
int pidns_fd,
|
||
int mntns_fd,
|
||
int netns_fd,
|
||
int userns_fd,
|
||
int root_fd,
|
||
pid_t *ret_pid) {
|
||
|
||
int r;
|
||
|
||
/* This is much like safe_fork(), but forks twice, and joins the specified namespaces in the middle
|
||
* process. This ensures that we are fully a member of the destination namespace, with pidns an all, so that
|
||
* /proc/self/fd works correctly. */
|
||
|
||
r = safe_fork_full(outer_name, except_fds, n_except_fds, (flags|FORK_DEATHSIG) & ~(FORK_REOPEN_LOG|FORK_NEW_MOUNTNS|FORK_MOUNTNS_SLAVE), ret_pid);
|
||
if (r < 0)
|
||
return r;
|
||
if (r == 0) {
|
||
pid_t pid;
|
||
|
||
/* Child */
|
||
|
||
r = namespace_enter(pidns_fd, mntns_fd, netns_fd, userns_fd, root_fd);
|
||
if (r < 0) {
|
||
log_full_errno(FLAGS_SET(flags, FORK_LOG) ? LOG_ERR : LOG_DEBUG, r, "Failed to join namespace: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
/* We mask a few flags here that either make no sense for the grandchild, or that we don't have to do again */
|
||
r = safe_fork_full(inner_name, except_fds, n_except_fds, flags & ~(FORK_WAIT|FORK_RESET_SIGNALS|FORK_CLOSE_ALL_FDS|FORK_NULL_STDIO), &pid);
|
||
if (r < 0)
|
||
_exit(EXIT_FAILURE);
|
||
if (r == 0) {
|
||
/* Child */
|
||
if (ret_pid)
|
||
*ret_pid = pid;
|
||
return 0;
|
||
}
|
||
|
||
r = wait_for_terminate_and_check(inner_name, pid, FLAGS_SET(flags, FORK_LOG) ? WAIT_LOG : 0);
|
||
if (r < 0)
|
||
_exit(EXIT_FAILURE);
|
||
|
||
_exit(r);
|
||
}
|
||
|
||
return 1;
|
||
}
|
||
|
||
int fork_agent(const char *name, const int except[], size_t n_except, pid_t *ret_pid, const char *path, ...) {
|
||
bool stdout_is_tty, stderr_is_tty;
|
||
size_t n, i;
|
||
va_list ap;
|
||
char **l;
|
||
int r;
|
||
|
||
assert(path);
|
||
|
||
/* Spawns a temporary TTY agent, making sure it goes away when we go away */
|
||
|
||
r = safe_fork_full(name, except, n_except, FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_CLOSE_ALL_FDS, ret_pid);
|
||
if (r < 0)
|
||
return r;
|
||
if (r > 0)
|
||
return 0;
|
||
|
||
/* In the child: */
|
||
|
||
stdout_is_tty = isatty(STDOUT_FILENO);
|
||
stderr_is_tty = isatty(STDERR_FILENO);
|
||
|
||
if (!stdout_is_tty || !stderr_is_tty) {
|
||
int fd;
|
||
|
||
/* Detach from stdout/stderr. and reopen
|
||
* /dev/tty for them. This is important to
|
||
* ensure that when systemctl is started via
|
||
* popen() or a similar call that expects to
|
||
* read EOF we actually do generate EOF and
|
||
* not delay this indefinitely by because we
|
||
* keep an unused copy of stdin around. */
|
||
fd = open("/dev/tty", O_WRONLY);
|
||
if (fd < 0) {
|
||
log_error_errno(errno, "Failed to open /dev/tty: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
if (!stdout_is_tty && dup2(fd, STDOUT_FILENO) < 0) {
|
||
log_error_errno(errno, "Failed to dup2 /dev/tty: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
if (!stderr_is_tty && dup2(fd, STDERR_FILENO) < 0) {
|
||
log_error_errno(errno, "Failed to dup2 /dev/tty: %m");
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
safe_close_above_stdio(fd);
|
||
}
|
||
|
||
(void) rlimit_nofile_safe();
|
||
|
||
/* Count arguments */
|
||
va_start(ap, path);
|
||
for (n = 0; va_arg(ap, char*); n++)
|
||
;
|
||
va_end(ap);
|
||
|
||
/* Allocate strv */
|
||
l = newa(char*, n + 1);
|
||
|
||
/* Fill in arguments */
|
||
va_start(ap, path);
|
||
for (i = 0; i <= n; i++)
|
||
l[i] = va_arg(ap, char*);
|
||
va_end(ap);
|
||
|
||
execv(path, l);
|
||
_exit(EXIT_FAILURE);
|
||
}
|
||
|
||
int set_oom_score_adjust(int value) {
|
||
char t[DECIMAL_STR_MAX(int)];
|
||
|
||
sprintf(t, "%i", value);
|
||
|
||
return write_string_file("/proc/self/oom_score_adj", t,
|
||
WRITE_STRING_FILE_VERIFY_ON_FAILURE|WRITE_STRING_FILE_DISABLE_BUFFER);
|
||
}
|
||
|
||
int pidfd_get_pid(int fd, pid_t *ret) {
|
||
char path[STRLEN("/proc/self/fdinfo/") + DECIMAL_STR_MAX(int)];
|
||
_cleanup_free_ char *fdinfo = NULL;
|
||
char *p;
|
||
int r;
|
||
|
||
if (fd < 0)
|
||
return -EBADF;
|
||
|
||
xsprintf(path, "/proc/self/fdinfo/%i", fd);
|
||
|
||
r = read_full_file(path, &fdinfo, NULL);
|
||
if (r == -ENOENT) /* if fdinfo doesn't exist we assume the process does not exist */
|
||
return -ESRCH;
|
||
if (r < 0)
|
||
return r;
|
||
|
||
p = startswith(fdinfo, "Pid:");
|
||
if (!p) {
|
||
p = strstr(fdinfo, "\nPid:");
|
||
if (!p)
|
||
return -ENOTTY; /* not a pidfd? */
|
||
|
||
p += 5;
|
||
}
|
||
|
||
p += strspn(p, WHITESPACE);
|
||
p[strcspn(p, WHITESPACE)] = 0;
|
||
|
||
return parse_pid(p, ret);
|
||
}
|
||
|
||
static int rlimit_to_nice(rlim_t limit) {
|
||
if (limit <= 1)
|
||
return PRIO_MAX-1; /* i.e. 19 */
|
||
|
||
if (limit >= -PRIO_MIN + PRIO_MAX)
|
||
return PRIO_MIN; /* i.e. -20 */
|
||
|
||
return PRIO_MAX - (int) limit;
|
||
}
|
||
|
||
int setpriority_closest(int priority) {
|
||
int current, limit, saved_errno;
|
||
struct rlimit highest;
|
||
|
||
/* Try to set requested nice level */
|
||
if (setpriority(PRIO_PROCESS, 0, priority) >= 0)
|
||
return 1;
|
||
|
||
/* Permission failed */
|
||
saved_errno = -errno;
|
||
if (!ERRNO_IS_PRIVILEGE(saved_errno))
|
||
return saved_errno;
|
||
|
||
errno = 0;
|
||
current = getpriority(PRIO_PROCESS, 0);
|
||
if (errno != 0)
|
||
return -errno;
|
||
|
||
if (priority == current)
|
||
return 1;
|
||
|
||
/* Hmm, we'd expect that raising the nice level from our status quo would always work. If it doesn't,
|
||
* then the whole setpriority() system call is blocked to us, hence let's propagate the error
|
||
* right-away */
|
||
if (priority > current)
|
||
return saved_errno;
|
||
|
||
if (getrlimit(RLIMIT_NICE, &highest) < 0)
|
||
return -errno;
|
||
|
||
limit = rlimit_to_nice(highest.rlim_cur);
|
||
|
||
/* We are already less nice than limit allows us */
|
||
if (current < limit) {
|
||
log_debug("Cannot raise nice level, permissions and the resource limit do not allow it.");
|
||
return 0;
|
||
}
|
||
|
||
/* Push to the allowed limit */
|
||
if (setpriority(PRIO_PROCESS, 0, limit) < 0)
|
||
return -errno;
|
||
|
||
log_debug("Cannot set requested nice level (%i), used next best (%i).", priority, limit);
|
||
return 0;
|
||
}
|
||
|
||
static const char *const ioprio_class_table[] = {
|
||
[IOPRIO_CLASS_NONE] = "none",
|
||
[IOPRIO_CLASS_RT] = "realtime",
|
||
[IOPRIO_CLASS_BE] = "best-effort",
|
||
[IOPRIO_CLASS_IDLE] = "idle",
|
||
};
|
||
|
||
DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ioprio_class, int, IOPRIO_N_CLASSES);
|
||
|
||
static const char *const sigchld_code_table[] = {
|
||
[CLD_EXITED] = "exited",
|
||
[CLD_KILLED] = "killed",
|
||
[CLD_DUMPED] = "dumped",
|
||
[CLD_TRAPPED] = "trapped",
|
||
[CLD_STOPPED] = "stopped",
|
||
[CLD_CONTINUED] = "continued",
|
||
};
|
||
|
||
DEFINE_STRING_TABLE_LOOKUP(sigchld_code, int);
|
||
|
||
static const char* const sched_policy_table[] = {
|
||
[SCHED_OTHER] = "other",
|
||
[SCHED_BATCH] = "batch",
|
||
[SCHED_IDLE] = "idle",
|
||
[SCHED_FIFO] = "fifo",
|
||
[SCHED_RR] = "rr",
|
||
};
|
||
|
||
DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(sched_policy, int, INT_MAX);
|