diff options
Diffstat (limited to 'gdb/linux-nat.c')
| -rw-r--r-- | gdb/linux-nat.c | 181 |
1 files changed, 178 insertions, 3 deletions
diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index 61931c6..0dd83e7 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -56,6 +56,8 @@ #define __WALL 0x40000000 /* Wait for any child. */ #endif +extern struct target_ops child_ops; + struct simple_pid_list { int pid; @@ -189,13 +191,147 @@ linux_supports_tracefork (void) } +void +linux_enable_event_reporting (ptid_t ptid) +{ + int pid = ptid_get_pid (ptid); + int options; + + if (! linux_supports_tracefork ()) + return; + + options = PTRACE_O_TRACEFORK; + + ptrace (PTRACE_SETOPTIONS, pid, 0, options); +} + +void +child_post_attach (int pid) +{ + linux_enable_event_reporting (pid_to_ptid (pid)); +} + +void +linux_child_post_startup_inferior (ptid_t ptid) +{ + linux_enable_event_reporting (ptid); +} + +#ifndef LINUX_CHILD_POST_STARTUP_INFERIOR +void +child_post_startup_inferior (ptid_t ptid) +{ + linux_child_post_startup_inferior (ptid); +} +#endif + int -child_insert_fork_catchpoint (int pid) +child_follow_fork (int follow_child) { - if (linux_supports_tracefork ()) - error ("Fork catchpoints have not been implemented yet."); + ptid_t last_ptid; + struct target_waitstatus last_status; + int parent_pid, child_pid; + + get_last_target_status (&last_ptid, &last_status); + parent_pid = ptid_get_pid (last_ptid); + child_pid = last_status.value.related_pid; + + if (! follow_child) + { + /* We're already attached to the parent, by default. */ + + /* Before detaching from the child, remove all breakpoints from + it. (This won't actually modify the breakpoint list, but will + physically remove the breakpoints from the child.) */ + detach_breakpoints (child_pid); + + fprintf_filtered (gdb_stdout, + "Detaching after fork from child process %d.\n", + child_pid); + + ptrace (PTRACE_DETACH, child_pid, 0, 0); + } else + { + char child_pid_spelling[40]; + + /* Needed to keep the breakpoint lists in sync. */ + detach_breakpoints (child_pid); + + /* Before detaching from the parent, remove all breakpoints from it. */ + remove_breakpoints (); + + fprintf_filtered (gdb_stdout, + "Attaching after fork to child process %d.\n", + child_pid); + + target_detach (NULL, 0); + + inferior_ptid = pid_to_ptid (child_pid); + push_target (&child_ops); + + /* Reset breakpoints in the child as appropriate. */ + follow_inferior_reset_breakpoints (); + } + + return 0; +} + +ptid_t +linux_handle_extended_wait (int pid, int status, + struct target_waitstatus *ourstatus) +{ + int event = status >> 16; + + if (event == PTRACE_EVENT_CLONE) + internal_error (__FILE__, __LINE__, + "unexpected clone event"); + + if (event == PTRACE_EVENT_FORK) + { + unsigned long new_pid; + int ret; + + ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); + + /* If we haven't already seen the new PID stop, wait for it now. */ + if (! pull_pid_from_list (&stopped_pids, new_pid)) + { + /* The new child has a pending SIGSTOP. We can't affect it until it + hits the SIGSTOP, but we're already attached. + + It won't be a clone (we didn't ask for clones in the event mask) + so we can just call waitpid and wait for the SIGSTOP. */ + do { + ret = waitpid (new_pid, &status, 0); + } while (ret == -1 && errno == EINTR); + if (ret == -1) + perror_with_name ("waiting for new child"); + else if (ret != new_pid) + internal_error (__FILE__, __LINE__, + "wait returned unexpected PID %d", ret); + else if (!WIFSTOPPED (status) || WSTOPSIG (status) != SIGSTOP) + internal_error (__FILE__, __LINE__, + "wait returned unexpected status 0x%x", status); + } + + ourstatus->kind = TARGET_WAITKIND_FORKED; + ourstatus->value.related_pid = new_pid; + return inferior_ptid; + } + + internal_error (__FILE__, __LINE__, + "unknown ptrace event %d", event); +} + + +int +child_insert_fork_catchpoint (int pid) +{ + if (! linux_supports_tracefork ()) error ("Your system does not support fork catchpoints."); + + return 0; } int @@ -216,4 +352,43 @@ child_insert_exec_catchpoint (int pid) error ("Your system does not support exec catchpoints."); } +void +kill_inferior (void) +{ + int status; + int pid = PIDGET (inferior_ptid); + struct target_waitstatus last; + ptid_t last_ptid; + int ret; + + if (pid == 0) + return; + + /* If we're stopped while forking and we haven't followed yet, kill the + other task. We need to do this first because the parent will be + sleeping if this is a vfork. */ + + get_last_target_status (&last_ptid, &last); + if (last.kind == TARGET_WAITKIND_FORKED + || last.kind == TARGET_WAITKIND_VFORKED) + { + ptrace (PT_KILL, last.value.related_pid); + ptrace_wait (null_ptid, &status); + } + + /* Kill the current process. */ + ptrace (PT_KILL, pid, (PTRACE_ARG3_TYPE) 0, 0); + ret = ptrace_wait (null_ptid, &status); + + /* We might get a SIGCHLD instead of an exit status. This is + aggravated by the first kill above - a child has just died. */ + + while (ret == pid && WIFSTOPPED (status)) + { + ptrace (PT_KILL, pid, (PTRACE_ARG3_TYPE) 0, 0); + ret = ptrace_wait (null_ptid, &status); + } + + target_mourn_inferior (); +} |