diff -r 000000000000 -r aa1a9fbd6eb8 patches/gdb/6.3/730-debian_gdb-fix-tracefork-check.patch --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/patches/gdb/6.3/730-debian_gdb-fix-tracefork-check.patch Thu May 17 16:22:51 2007 +0000 @@ -0,0 +1,225 @@ +Status: submitted for comments + +2004-11-12 Daniel Jacobowitz + + * linux-nat.c (my_waitpid): New function. + (linux_test_for_tracefork): Make more robust and verbose. Take + an ORIGINAL_PID argument and test for PTRACE_SETOPTIONS first. + (linux_supports_tracefork, linux_supports_tracevforkdone): Take a PID + argument. Update calls to linux_test_for_tracefork. + (linux_enable_event_reporting, child_follow_fork) + (child_insert_fork_catchpoint, child_insert_vfork_catchpoint) + (child_insert_exec_catchpoint): Update calls to + linux_supports_tracefork and linux_supports_tracevforkdone. + +Index: gdb-6.3/gdb/linux-nat.c +=================================================================== +--- gdb-6.3.orig/gdb/linux-nat.c 2004-10-08 16:29:47.000000000 -0400 ++++ gdb-6.3/gdb/linux-nat.c 2004-11-13 16:41:51.368720845 -0500 +@@ -150,18 +150,47 @@ linux_tracefork_child (void) + exit (0); + } + +-/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. We ++/* Wrapper function for waitpid which handles EINTR. */ ++ ++static int ++my_waitpid (int pid, int *status, int flags) ++{ ++ int ret; ++ do ++ { ++ ret = waitpid (pid, status, flags); ++ } ++ while (ret == -1 && errno == EINTR); ++ ++ return ret; ++} ++ ++/* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. ++ ++ First, we try to enable fork tracing on ORIGINAL_PID. If this fails, ++ we know that the feature is not available. This may change the tracing ++ options for ORIGINAL_PID, but we'll be setting them shortly anyway. ++ ++ However, if it succeeds, we don't know for sure that the feature is ++ available; old versions of PTRACE_SETOPTIONS ignored unknown options. We + create a child process, attach to it, use PTRACE_SETOPTIONS to enable +- fork tracing, and let it fork. If the process exits, we assume that +- we can't use TRACEFORK; if we get the fork notification, and we can +- extract the new child's PID, then we assume that we can. */ ++ fork tracing, and let it fork. If the process exits, we assume that we ++ can't use TRACEFORK; if we get the fork notification, and we can extract ++ the new child's PID, then we assume that we can. */ + + static void +-linux_test_for_tracefork (void) ++linux_test_for_tracefork (int original_pid) + { + int child_pid, ret, status; + long second_pid; + ++ linux_supports_tracefork_flag = 0; ++ linux_supports_tracevforkdone_flag = 0; ++ ++ ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK); ++ if (ret != 0) ++ return; ++ + child_pid = fork (); + if (child_pid == -1) + perror_with_name ("linux_test_for_tracefork: fork"); +@@ -169,7 +198,7 @@ linux_test_for_tracefork (void) + if (child_pid == 0) + linux_tracefork_child (); + +- ret = waitpid (child_pid, &status, 0); ++ ret = my_waitpid (child_pid, &status, 0); + if (ret == -1) + perror_with_name ("linux_test_for_tracefork: waitpid"); + else if (ret != child_pid) +@@ -177,13 +206,23 @@ linux_test_for_tracefork (void) + if (! WIFSTOPPED (status)) + error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status); + +- linux_supports_tracefork_flag = 0; +- + ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); + if (ret != 0) + { +- ptrace (PTRACE_KILL, child_pid, 0, 0); +- waitpid (child_pid, &status, 0); ++ ret = ptrace (PTRACE_KILL, child_pid, 0, 0); ++ if (ret != 0) ++ { ++ warning ("linux_test_for_tracefork: failed to kill child"); ++ return; ++ } ++ ++ ret = my_waitpid (child_pid, &status, 0); ++ if (ret != child_pid) ++ warning ("linux_test_for_tracefork: failed to wait for killed child"); ++ else if (!WIFSIGNALED (status)) ++ warning ("linux_test_for_tracefork: unexpected wait status 0x%x from " ++ "killed child", status); ++ + return; + } + +@@ -192,8 +231,12 @@ linux_test_for_tracefork (void) + PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE); + linux_supports_tracevforkdone_flag = (ret == 0); + +- ptrace (PTRACE_CONT, child_pid, 0, 0); +- ret = waitpid (child_pid, &status, 0); ++ ret = ptrace (PTRACE_CONT, child_pid, 0, 0); ++ if (ret != 0) ++ warning ("linux_test_for_tracefork: failed to resume child"); ++ ++ ret = my_waitpid (child_pid, &status, 0); ++ + if (ret == child_pid && WIFSTOPPED (status) + && status >> 16 == PTRACE_EVENT_FORK) + { +@@ -204,34 +247,38 @@ linux_test_for_tracefork (void) + int second_status; + + linux_supports_tracefork_flag = 1; +- waitpid (second_pid, &second_status, 0); +- ptrace (PTRACE_DETACH, second_pid, 0, 0); ++ my_waitpid (second_pid, &second_status, 0); ++ ret = ptrace (PTRACE_KILL, second_pid, 0, 0); ++ if (ret != 0) ++ warning ("linux_test_for_tracefork: failed to kill second child"); + } + } ++ else ++ warning ("linux_test_for_tracefork: unexpected result from waitpid " ++ "(%d, status 0x%x)", ret, status); + +- if (WIFSTOPPED (status)) +- { +- ptrace (PTRACE_DETACH, child_pid, 0, 0); +- waitpid (child_pid, &status, 0); +- } ++ ret = ptrace (PTRACE_KILL, child_pid, 0, 0); ++ if (ret != 0) ++ warning ("linux_test_for_tracefork: failed to kill child"); ++ my_waitpid (child_pid, &status, 0); + } + + /* Return non-zero iff we have tracefork functionality available. + This function also sets linux_supports_tracefork_flag. */ + + static int +-linux_supports_tracefork (void) ++linux_supports_tracefork (int pid) + { + if (linux_supports_tracefork_flag == -1) +- linux_test_for_tracefork (); ++ linux_test_for_tracefork (pid); + return linux_supports_tracefork_flag; + } + + static int +-linux_supports_tracevforkdone (void) ++linux_supports_tracevforkdone (int pid) + { + if (linux_supports_tracefork_flag == -1) +- linux_test_for_tracefork (); ++ linux_test_for_tracefork (pid); + return linux_supports_tracevforkdone_flag; + } + +@@ -242,12 +289,12 @@ linux_enable_event_reporting (ptid_t pti + int pid = ptid_get_pid (ptid); + int options; + +- if (! linux_supports_tracefork ()) ++ if (! linux_supports_tracefork (pid)) + return; + + options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC + | PTRACE_O_TRACECLONE; +- if (linux_supports_tracevforkdone ()) ++ if (linux_supports_tracevforkdone (pid)) + options |= PTRACE_O_TRACEVFORKDONE; + + /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support +@@ -308,7 +355,8 @@ child_follow_fork (int follow_child) + + if (has_vforked) + { +- if (linux_supports_tracevforkdone ()) ++ gdb_assert (linux_supports_tracefork_flag >= 0); ++ if (linux_supports_tracevforkdone (0)) + { + int status; + +@@ -476,7 +524,7 @@ linux_handle_extended_wait (int pid, int + int + child_insert_fork_catchpoint (int pid) + { +- if (! linux_supports_tracefork ()) ++ if (! linux_supports_tracefork (pid)) + error ("Your system does not support fork catchpoints."); + + return 0; +@@ -485,7 +533,7 @@ child_insert_fork_catchpoint (int pid) + int + child_insert_vfork_catchpoint (int pid) + { +- if (!linux_supports_tracefork ()) ++ if (!linux_supports_tracefork (pid)) + error ("Your system does not support vfork catchpoints."); + + return 0; +@@ -494,7 +542,7 @@ child_insert_vfork_catchpoint (int pid) + int + child_insert_exec_catchpoint (int pid) + { +- if (!linux_supports_tracefork ()) ++ if (!linux_supports_tracefork (pid)) + error ("Your system does not support exec catchpoints."); + + return 0;