diff options
| -rw-r--r-- | src/basic/process-util.c | 90 | ||||
| -rw-r--r-- | src/test/test-process-util.c | 192 |
2 files changed, 270 insertions, 12 deletions
diff --git a/src/basic/process-util.c b/src/basic/process-util.c index 08fa98bb9e..b5b068ad38 100644 --- a/src/basic/process-util.c +++ b/src/basic/process-util.c @@ -110,6 +110,15 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * assert(line); assert(pid >= 0); + /* Retrieves a process' command line. Replaces unprintable characters while doing so by whitespace (coalescing + * multiple sequential ones into one). If max_length is != 0 will return a string of the specified size at most + * (the trailing NUL byte does count towards the length here!), abbreviated with a "..." ellipsis. If + * comm_fallback is true and the process has no command line set (the case for kernel threads), or has a + * command line that resolves to the empty string will return the "comm" name of the process instead. + * + * Returns -ESRCH if the process doesn't exist, and -ENOENT if the process has no command line (and + * comm_fallback is false). */ + p = procfs_file_alloca(pid, "cmdline"); f = fopen(p, "re"); @@ -119,12 +128,22 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * return -errno; } - if (max_length == 0) { + if (max_length == 1) { + + /* If there's only room for one byte, return the empty string */ + r = new0(char, 1); + if (!r) + return -ENOMEM; + + *line = r; + return 0; + + } else if (max_length == 0) { size_t len = 0, allocated = 0; while ((c = getc(f)) != EOF) { - if (!GREEDY_REALLOC(r, allocated, len+2)) { + if (!GREEDY_REALLOC(r, allocated, len+3)) { free(r); return -ENOMEM; } @@ -136,7 +155,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * } r[len++] = c; - } else + } else if (len > 0) space = true; } @@ -144,6 +163,7 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * r[len] = 0; } else { + bool dotdotdot = false; size_t left; r = new(char, max_length); @@ -155,28 +175,46 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * while ((c = getc(f)) != EOF) { if (isprint(c)) { + if (space) { - if (left <= 4) + if (left <= 2) { + dotdotdot = true; break; + } *(k++) = ' '; left--; space = false; } - if (left <= 4) + if (left <= 1) { + dotdotdot = true; break; + } *(k++) = (char) c; left--; - } else + } else if (k > r) space = true; } - if (left <= 4) { - size_t n = MIN(left-1, 3U); - memcpy(k, "...", n); - k[n] = 0; + if (dotdotdot) { + if (max_length <= 4) { + k = r; + left = max_length; + } else { + k = r + max_length - 4; + left = 4; + + /* Eat up final spaces */ + while (k > r && isspace(k[-1])) { + k--; + left++; + } + } + + strncpy(k, "...", left-1); + k[left] = 0; } else *k = 0; } @@ -195,7 +233,37 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * if (h < 0) return h; - r = strjoin("[", t, "]", NULL); + if (max_length == 0) + r = strjoin("[", t, "]", NULL); + else { + size_t l; + + l = strlen(t); + + if (l + 3 <= max_length) + r = strjoin("[", t, "]", NULL); + else if (max_length <= 6) { + + r = new(char, max_length); + if (!r) + return -ENOMEM; + + memcpy(r, "[...]", max_length-1); + r[max_length-1] = 0; + } else { + char *e; + + t[max_length - 6] = 0; + + /* Chop off final spaces */ + e = strchr(t, 0); + while (e > t && isspace(e[-1])) + e--; + *e = 0; + + r = strjoin("[", t, "...]", NULL); + } + } if (!r) return -ENOMEM; } diff --git a/src/test/test-process-util.c b/src/test/test-process-util.c index 8bb5f6e3a3..af2c9282d4 100644 --- a/src/test/test-process-util.c +++ b/src/test/test-process-util.c @@ -18,7 +18,10 @@ along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ +#include <sched.h> +#include <sys/mount.h> #include <sys/personality.h> +#include <sys/prctl.h> #include <sys/stat.h> #include <sys/types.h> #include <sys/wait.h> @@ -26,6 +29,7 @@ #include "alloc-util.h" #include "architecture.h" +#include "fd-util.h" #include "log.h" #include "macro.h" #include "parse-util.h" @@ -59,7 +63,11 @@ static void test_get_process_comm(pid_t pid) { log_info("PID"PID_FMT" cmdline: '%s'", pid, c); assert_se(get_process_cmdline(pid, 8, false, &d) >= 0); - log_info("PID"PID_FMT" cmdline truncated: '%s'", pid, d); + log_info("PID"PID_FMT" cmdline truncated to 8: '%s'", pid, d); + + free(d); + assert_se(get_process_cmdline(pid, 1, false, &d) >= 0); + log_info("PID"PID_FMT" cmdline truncated to 1: '%s'", pid, d); assert_se(get_process_ppid(pid, &e) >= 0); log_info("PID"PID_FMT" PPID: "PID_FMT, pid, e); @@ -147,6 +155,187 @@ static void test_personality(void) { #endif } +static void test_get_process_cmdline_harder(void) { + char path[] = "/tmp/test-cmdlineXXXXXX"; + _cleanup_close_ int fd = -1; + _cleanup_free_ char *line = NULL; + pid_t pid; + + if (geteuid() != 0) + return; + + pid = fork(); + if (pid > 0) { + siginfo_t si; + + (void) wait_for_terminate(pid, &si); + + assert_se(si.si_code == CLD_EXITED); + assert_se(si.si_status == 0); + + return; + } + + assert_se(pid == 0); + assert_se(unshare(CLONE_NEWNS) >= 0); + + fd = mkostemp(path, O_CLOEXEC); + assert_se(fd >= 0); + assert_se(mount(path, "/proc/self/cmdline", "bind", MS_BIND, NULL) >= 0); + assert_se(unlink(path) >= 0); + + assert_se(prctl(PR_SET_NAME, "testa") >= 0); + + assert_se(get_process_cmdline(getpid(), 0, false, &line) == -ENOENT); + + assert_se(get_process_cmdline(getpid(), 0, true, &line) >= 0); + assert_se(streq(line, "[testa]")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 1, true, &line) >= 0); + assert_se(streq(line, "")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 2, true, &line) >= 0); + assert_se(streq(line, "[")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 3, true, &line) >= 0); + assert_se(streq(line, "[.")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 4, true, &line) >= 0); + assert_se(streq(line, "[..")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 5, true, &line) >= 0); + assert_se(streq(line, "[...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 6, true, &line) >= 0); + assert_se(streq(line, "[...]")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 7, true, &line) >= 0); + assert_se(streq(line, "[t...]")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 8, true, &line) >= 0); + assert_se(streq(line, "[testa]")); + line = mfree(line); + + assert_se(write(fd, "\0\0\0\0\0\0\0\0\0", 10) == 10); + + assert_se(get_process_cmdline(getpid(), 0, false, &line) == -ENOENT); + + assert_se(get_process_cmdline(getpid(), 0, true, &line) >= 0); + assert_se(streq(line, "[testa]")); + line = mfree(line); + + assert_se(write(fd, "foo\0bar\0\0\0\0\0", 10) == 10); + + assert_se(get_process_cmdline(getpid(), 0, false, &line) >= 0); + assert_se(streq(line, "foo bar")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 0, true, &line) >= 0); + assert_se(streq(line, "foo bar")); + line = mfree(line); + + assert_se(write(fd, "quux", 4) == 4); + assert_se(get_process_cmdline(getpid(), 0, false, &line) >= 0); + assert_se(streq(line, "foo bar quux")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 0, true, &line) >= 0); + assert_se(streq(line, "foo bar quux")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 1, true, &line) >= 0); + assert_se(streq(line, "")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 2, true, &line) >= 0); + assert_se(streq(line, ".")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 3, true, &line) >= 0); + assert_se(streq(line, "..")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 4, true, &line) >= 0); + assert_se(streq(line, "...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 5, true, &line) >= 0); + assert_se(streq(line, "f...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 6, true, &line) >= 0); + assert_se(streq(line, "fo...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 7, true, &line) >= 0); + assert_se(streq(line, "foo...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 8, true, &line) >= 0); + assert_se(streq(line, "foo...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 9, true, &line) >= 0); + assert_se(streq(line, "foo b...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 10, true, &line) >= 0); + assert_se(streq(line, "foo ba...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 11, true, &line) >= 0); + assert_se(streq(line, "foo bar...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 12, true, &line) >= 0); + assert_se(streq(line, "foo bar...")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 13, true, &line) >= 0); + assert_se(streq(line, "foo bar quux")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 14, true, &line) >= 0); + assert_se(streq(line, "foo bar quux")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 1000, true, &line) >= 0); + assert_se(streq(line, "foo bar quux")); + line = mfree(line); + + assert_se(ftruncate(fd, 0) >= 0); + assert_se(prctl(PR_SET_NAME, "aaaa bbbb cccc") >= 0); + + assert_se(get_process_cmdline(getpid(), 0, false, &line) == -ENOENT); + + assert_se(get_process_cmdline(getpid(), 0, true, &line) >= 0); + assert_se(streq(line, "[aaaa bbbb cccc]")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 10, true, &line) >= 0); + assert_se(streq(line, "[aaaa...]")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 11, true, &line) >= 0); + assert_se(streq(line, "[aaaa...]")); + line = mfree(line); + + assert_se(get_process_cmdline(getpid(), 12, true, &line) >= 0); + assert_se(streq(line, "[aaaa b...]")); + line = mfree(line); + + safe_close(fd); + _exit(0); +} + int main(int argc, char *argv[]) { log_parse_environment(); log_open(); @@ -164,6 +353,7 @@ int main(int argc, char *argv[]) { test_pid_is_unwaited(); test_pid_is_alive(); test_personality(); + test_get_process_cmdline_harder(); return 0; } |