peekfd: Allow attaching to all threads in group

Signed-off-by: Jeff Smith <whydoubt@gmail.com>

diff --git a/src/peekfd.c b/src/peekfd.c
index 7cf05e09f2adb139a51ef77a98eb187af0ae6a0a..5aa990a76630900d92fdbbf1ca4812bc8da4f0b3 100644 (file)
--- a/src/peekfd.c
+++ b/src/peekfd.c
@@ -34,6 +34,7 @@
 #include <stdlib.h>
 #include <getopt.h>
 #include <ctype.h>
+#include <dirent.h>
 
 #include "i18n.h"
 
@@ -132,6 +133,7 @@ void usage() {
          "    -8, --eight-bit-clean        output 8 bit clean streams.\n"
          "    -n, --no-headers             don't display read/write from fd headers.\n"
          "    -c, --follow                 peek at any new child processes too.\n"
+         "    -t, --tgid                   peek at all threads where tgid equals <pid>.\n"
          "    -d, --duplicates-removed     remove duplicate read/writes from the output.\n"
          "    -V, --version                prints version info.\n"
          "    -h, --help                   prints this help.\n"
@@ -153,6 +155,7 @@ int main(int argc, char **argv)
        int no_headers = 0;
        int follow_forks = 0;
        int follow_clones = 0;
+       int tgid = 0;
        int remove_duplicates = 0;
        int optc;
     int target_pid = 0;
@@ -164,6 +167,7 @@ int main(int argc, char **argv)
       {"eight-bit-clean", 0, NULL, '8'},
       {"no-headers", 0, NULL, 'n'},
       {"follow", 0, NULL, 'c'},
+      {"tgid", 0, NULL, 't'},
       {"duplicates-removed", 0, NULL, 'd'},
       {"help", 0, NULL, 'h'},
       {"version", 0, NULL, 'V'},
@@ -181,7 +185,7 @@ int main(int argc, char **argv)
                return 1;
        }
 
-       while ((optc = getopt_long(argc, argv, "8ncdhV",options, NULL)) != -1) {
+       while ((optc = getopt_long(argc, argv, "8nctdhV", options, NULL)) != -1) {
                switch(optc) {
                        case '8':
                                eight_bit_clean = 1;
@@ -193,6 +197,10 @@ int main(int argc, char **argv)
                                follow_forks = 1;
                                follow_clones = 1;
                                break;
+                       case 't':
+                               tgid = 1;
+                               follow_clones = 1;
+                               break;
                        case 'd':
                                remove_duplicates = 1;
                                break;
@@ -220,12 +228,31 @@ int main(int argc, char **argv)
     }
 
        attach(target_pid);
+
+       if (tgid) {
+               DIR *taskdir;
+               struct dirent *dt;
+               char taskpath[24];
+
+               snprintf(taskpath, 24, "/proc/%d/task", target_pid);
+
+               if ((taskdir = opendir(taskpath)) != 0) {
+                       while ((dt = readdir(taskdir)) != NULL) {
+                               int thread = atoi(dt->d_name);
+                               if ((thread != 0) && (thread != target_pid))
+                                       attach(thread);
+                       }
+                       closedir(taskdir);
+               }
+       }
+
        if (num_attached_pids == 0)
                return 1;
 
        signal(SIGINT, detach);
 
-       ptrace(PTRACE_SYSCALL, attached_pids[0], 0, 0);
+       for (i = 0; i < num_attached_pids; i++)
+               ptrace(PTRACE_SYSCALL, attached_pids[i], 0, 0);
 
        /*int count = 0;*/
        int lastfd = numfds > 0 ? fds[0] : 0;
@@ -273,8 +300,12 @@ int main(int argc, char **argv)
                                        if ((int)regs.REG_PARAM1 != lastfd || (int)regs.REG_ORIG_ACCUM != lastdir) {
                                                lastfd = regs.REG_PARAM1;
                                                lastdir = regs.REG_ORIG_ACCUM;
-                                               if (!no_headers)
-                                                       printf("\n%sing fd %i:\n", regs.REG_ORIG_ACCUM == SYS_read ? "read" : "writ", lastfd);
+                                               if (!no_headers) {
+                                                       printf("\n%sing fd %i", regs.REG_ORIG_ACCUM == SYS_read ? "read" : "writ", lastfd);
+                                                       if (tgid)
+                                                               printf(" (thread %d)", pid);
+                                                       printf(":\n");
+                                               }
                                        }
                                        if (!remove_duplicates || lastbuf == NULL
                                                        ||  last_buf_size != regs.REG_PARAM3 ||