2004-04-08 Roland McGrath <roland@redhat.com>

	* strace.c (main) [LINUX]: When attaching for -p, look in
	/proc/PID/task for all threads and attach them as presumed
	CLONE_THREAD children.

diff --git a/strace.c b/strace.c
index 23d72c8d81bb65bc7cb6b92162fc2e75cd58ffc4..a8a1e400acb775f6b39e12e4622cca349cd552f0 100644 (file)
--- a/strace.c
+++ b/strace.c
@@ -44,6 +44,7 @@
 #include <grp.h>
 #include <string.h>
 #include <limits.h>
+#include <dirent.h>
 
 #if defined(IA64) && defined(LINUX)
 # include <asm/ptrace_offsets.h>
@@ -399,6 +400,64 @@ char *argv[];
                        continue;
                }
 #else /* !USE_PROCFS */
+# ifdef LINUX
+               if (tcp->flags & TCB_CLONE_THREAD)
+                       continue;
+               {
+                       char procdir[MAXPATHLEN];
+                       DIR *dir;
+                       sprintf(procdir, "/proc/%d/task", tcp->pid);
+                       dir = opendir(procdir);
+                       if (dir != NULL) {
+                               unsigned int ntid = 0, nerr = 0;
+                               struct dirent *de;
+                               int tid;
+                               while ((de = readdir(dir)) != NULL) {
+                                       if (de->d_fileno == 0 ||
+                                           de->d_name[0] == '.')
+                                               continue;
+                                       tid = atoi(de->d_name);
+                                       if (tid <= 0)
+                                               continue;
+                                       ++ntid;
+                                       if (ptrace(PTRACE_ATTACH, tid,
+                                                  (char *) 1, 0) < 0)
+                                               ++nerr;
+                                       else if (tid != tcbtab[c]->pid) {
+                                               tcp = alloctcb(tid);
+                                               if (tcp == NULL) {
+                                                       fprintf(stderr, "%s: out of memory\n",
+                                                               progname);
+                                                       exit(1);
+                                               }
+                                               tcp->flags |= TCB_ATTACHED|TCB_CLONE_THREAD|TCB_CLONE_DETACHED;
+                                               tcbtab[c]->nchildren++;
+                                               tcbtab[c]->nclone_threads++;
+                                               tcbtab[c]->nclone_detached++;
+                                               tcp->parent = tcbtab[c];
+                                       }
+                               }
+                               closedir(dir);
+                               if (nerr == ntid) {
+                                       perror("attach: ptrace(PTRACE_ATTACH, ...)");
+                                       droptcb(tcp);
+                                       continue;
+                               }
+                               if (!qflag) {
+                                       ntid -= nerr;
+                                       if (ntid > 1)
+                                               fprintf(stderr, "\
+Process %u attached with %u threads - interrupt to quit\n",
+                                                       tcp->pid, ntid);
+                                       else
+                                               fprintf(stderr, "\
+Process %u attached - interrupt to quit\n",
+                                                       tcp->pid);
+                               }
+                               continue;
+                       }
+               }
+# endif
                if (ptrace(PTRACE_ATTACH, tcp->pid, (char *) 1, 0) < 0) {
                        perror("attach: ptrace(PTRACE_ATTACH, ...)");
                        droptcb(tcp);