| 1 | #include "git-compat-util.h" |
| 2 | #include "strbuf.h" |
| 3 | #include "strvec.h" |
| 4 | #include "trace2.h" |
| 5 | #include <sys/sysctl.h> |
| 6 | |
| 7 | /* |
| 8 | * An arbitrarily chosen value to limit the depth of the ancestor chain. |
| 9 | */ |
| 10 | #define NR_PIDS_LIMIT 10 |
| 11 | |
| 12 | /* |
| 13 | * Get the process name and parent PID for a given PID using sysctl(). |
| 14 | * Returns 0 on success, -1 on failure. |
| 15 | */ |
| 16 | static int get_proc_info(pid_t pid, struct strbuf *name, pid_t *ppid) |
| 17 | { |
| 18 | int mib[4]; |
| 19 | struct kinfo_proc proc; |
| 20 | size_t size = sizeof(proc); |
| 21 | |
| 22 | mib[0] = CTL_KERN; |
| 23 | mib[1] = KERN_PROC; |
| 24 | mib[2] = KERN_PROC_PID; |
| 25 | mib[3] = pid; |
| 26 | |
| 27 | if (sysctl(mib, 4, &proc, &size, NULL, 0) < 0) |
| 28 | return -1; |
| 29 | |
| 30 | if (size == 0) |
| 31 | return -1; |
| 32 | |
| 33 | strbuf_addstr(name, proc.kp_proc.p_comm); |
| 34 | *ppid = proc.kp_eproc.e_ppid; |
| 35 | |
| 36 | return 0; |
| 37 | } |
| 38 | |
| 39 | /* |
| 40 | * Recursively push process names onto the ancestry array. |
| 41 | * We guard against cycles by limiting the depth to NR_PIDS_LIMIT. |
| 42 | */ |
| 43 | static void push_ancestry_name(struct strvec *names, pid_t pid, int depth) |
| 44 | { |
| 45 | struct strbuf name = STRBUF_INIT; |
| 46 | pid_t ppid; |
| 47 | |
| 48 | if (depth >= NR_PIDS_LIMIT) |
| 49 | return; |
| 50 | |
| 51 | if (pid <= 0) |
| 52 | return; |
| 53 | |
| 54 | if (get_proc_info(pid, &name, &ppid) < 0) |
| 55 | goto cleanup; |
| 56 | |
| 57 | strvec_push(names, name.buf); |
| 58 | |
| 59 | /* |
| 60 | * Recurse to the parent process. Stop if ppid not valid |
| 61 | * or if we've reached ourselves (cycle). |
| 62 | */ |
| 63 | if (ppid && ppid != pid) |
| 64 | push_ancestry_name(names, ppid, depth + 1); |
| 65 | |
| 66 | cleanup: |
| 67 | strbuf_release(&name); |
| 68 | } |
| 69 | |
| 70 | void trace2_collect_process_info(enum trace2_process_info_reason reason) |
| 71 | { |
| 72 | struct strvec names = STRVEC_INIT; |
| 73 | |
| 74 | if (!trace2_is_enabled()) |
| 75 | return; |
| 76 | |
| 77 | switch (reason) { |
| 78 | case TRACE2_PROCESS_INFO_STARTUP: |
| 79 | push_ancestry_name(&names, getppid(), 0); |
| 80 | if (names.nr) |
| 81 | trace2_cmd_ancestry(names.v); |
| 82 | |
| 83 | strvec_clear(&names); |
| 84 | break; |
| 85 | |
| 86 | case TRACE2_PROCESS_INFO_EXIT: |
| 87 | /* |
| 88 | * The Windows version of this calls its |
| 89 | * get_peak_memory_info() here. We may want to insert |
| 90 | * similar process-end statistics here in the future. |
| 91 | */ |
| 92 | break; |
| 93 | |
| 94 | default: |
| 95 | BUG("trace2_collect_process_info: unknown reason '%d'", reason); |
| 96 | } |
| 97 | } |