X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Flinux-fork.c;h=e7202dd8a53e0b3a430fd3f6853dded7ca727480;hb=8929ad8bbca9a8b036eba0397992d6f3b4d1966b;hp=35ca389867efba605c8b7cd5b9a27fc56bcdadf7;hpb=3cb5bea9340698c7f2316d68e4c9617929a84ccd;p=deliverable%2Fbinutils-gdb.git diff --git a/gdb/linux-fork.c b/gdb/linux-fork.c index 35ca389867..e7202dd8a5 100644 --- a/gdb/linux-fork.c +++ b/gdb/linux-fork.c @@ -1,6 +1,6 @@ /* GNU/Linux native-dependent code for debugging multiple forks. - Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. + Copyright (C) 2005-2016 Free Software Foundation, Inc. This file is part of GDB. @@ -20,19 +20,19 @@ #include "defs.h" #include "arch-utils.h" #include "inferior.h" +#include "infrun.h" #include "regcache.h" #include "gdbcmd.h" #include "infcall.h" #include "objfiles.h" -#include "gdb_assert.h" -#include "gdb_string.h" #include "linux-fork.h" #include "linux-nat.h" +#include "gdbthread.h" +#include "source.h" -#include +#include "nat/gdb_ptrace.h" #include "gdb_wait.h" -#include -#include "gdb_dirent.h" +#include #include struct fork_info *fork_list; @@ -41,15 +41,13 @@ static int highest_fork_num; /* Prevent warning from -Wmissing-prototypes. */ extern void _initialize_linux_fork (void); -int detach_fork = 1; /* Default behavior is to detach - newly forked processes (legacy). */ - /* Fork list data structure: */ struct fork_info { struct fork_info *next; ptid_t ptid; - int num; /* Convenient handle (GDB fork id) */ + ptid_t parent_ptid; + int num; /* Convenient handle (GDB fork id). */ struct regcache *savedregs; /* Convenient for info fork, saves having to actually switch contexts. */ int clobber_regs; /* True if we should restore saved regs. */ @@ -65,6 +63,21 @@ forks_exist_p (void) return (fork_list != NULL); } +/* Return the last fork in the list. */ + +static struct fork_info * +find_last_fork (void) +{ + struct fork_info *last; + + if (fork_list == NULL) + return NULL; + + for (last = fork_list; last->next != NULL; last = last->next) + ; + return last; +} + /* Add a fork to the internal fork list. */ struct fork_info * @@ -72,21 +85,29 @@ add_fork (pid_t pid) { struct fork_info *fp; - if (fork_list == NULL && pid != PIDGET (inferior_ptid)) + if (fork_list == NULL && pid != ptid_get_pid (inferior_ptid)) { /* Special case -- if this is the first fork in the list (the list is hitherto empty), and if this new fork is NOT the current inferior_ptid, then add inferior_ptid first, as a special zeroeth fork id. */ highest_fork_num = -1; - add_fork (PIDGET (inferior_ptid)); /* safe recursion */ + add_fork (ptid_get_pid (inferior_ptid)); /* safe recursion */ } - fp = XZALLOC (struct fork_info); + fp = XCNEW (struct fork_info); fp->ptid = ptid_build (pid, pid, 0); fp->num = ++highest_fork_num; - fp->next = fork_list; - fork_list = fp; + + if (fork_list == NULL) + fork_list = fp; + else + { + struct fork_info *last = find_last_fork (); + + last->next = fp; + } + return fp; } @@ -122,6 +143,8 @@ delete_fork (ptid_t ptid) fpprev = NULL; + linux_nat_forget_process (ptid_get_pid (ptid)); + for (fp = fork_list; fp; fpprev = fp, fp = fp->next) if (ptid_equal (fp->ptid, ptid)) break; @@ -267,7 +290,7 @@ fork_load_infrun_state (struct fork_info *fp) static void fork_save_infrun_state (struct fork_info *fp, int clobber_regs) { - char path[MAXPATHLEN]; + char path[PATH_MAX]; struct dirent *de; DIR *d; @@ -281,7 +304,8 @@ fork_save_infrun_state (struct fork_info *fp, int clobber_regs) { /* Now save the 'state' (file position) of all open file descriptors. Unfortunately fork does not take care of that for us... */ - snprintf (path, MAXPATHLEN, "/proc/%ld/fd", (long) PIDGET (fp->ptid)); + snprintf (path, PATH_MAX, "/proc/%ld/fd", + (long) ptid_get_pid (fp->ptid)); if ((d = opendir (path)) != NULL) { long tmp; @@ -296,8 +320,7 @@ fork_save_infrun_state (struct fork_info *fp, int clobber_regs) fp->maxfd = tmp; } /* Allocate array of file positions. */ - fp->filepos = xrealloc (fp->filepos, - (fp->maxfd + 1) * sizeof (*fp->filepos)); + fp->filepos = XRESIZEVEC (off_t, fp->filepos, fp->maxfd + 1); /* Initialize to -1 (invalid). */ for (tmp = 0; tmp <= fp->maxfd; tmp++) @@ -332,7 +355,7 @@ linux_fork_killall (void) for (fp = fork_list; fp; fp = fp->next) { - pid = PIDGET (fp->ptid); + pid = ptid_get_pid (fp->ptid); do { /* Use SIGKILL instead of PTRACE_KILL because the former works even if the thread is running, while the later doesn't. */ @@ -353,12 +376,13 @@ linux_fork_killall (void) void linux_fork_mourn_inferior (void) { + struct fork_info *last; + int status; + /* Wait just one more time to collect the inferior's exit status. Do not check whether this succeeds though, since we may be dealing with a process that we attached to. Such a process will only report its exit status to its original parent. */ - int status; - waitpid (ptid_get_pid (inferior_ptid), &status, 0); /* OK, presumably inferior_ptid is the one who has exited. @@ -371,7 +395,8 @@ linux_fork_mourn_inferior (void) inferior_ptid yet. */ gdb_assert (fork_list); - fork_load_infrun_state (fork_list); + last = find_last_fork (); + fork_load_infrun_state (last); printf_filtered (_("[Switching to %s]\n"), target_pid_to_str (inferior_ptid)); @@ -385,13 +410,13 @@ linux_fork_mourn_inferior (void) the first available. */ void -linux_fork_detach (char *args, int from_tty) +linux_fork_detach (const char *args, int from_tty) { /* OK, inferior_ptid is the one we are detaching from. We need to delete it from the fork_list, and switch to the next available fork. */ - if (ptrace (PTRACE_DETACH, PIDGET (inferior_ptid), 0, 0)) + if (ptrace (PTRACE_DETACH, ptid_get_pid (inferior_ptid), 0, 0)) error (_("Unable to detach %s"), target_pid_to_str (inferior_ptid)); delete_fork (inferior_ptid); @@ -412,12 +437,79 @@ linux_fork_detach (char *args, int from_tty) delete_fork (inferior_ptid); } +static void +inferior_call_waitpid_cleanup (void *fp) +{ + struct fork_info *oldfp = (struct fork_info *) fp; + + if (oldfp) + { + /* Switch back to inferior_ptid. */ + remove_breakpoints (); + fork_load_infrun_state (oldfp); + insert_breakpoints (); + } +} + +static int +inferior_call_waitpid (ptid_t pptid, int pid) +{ + struct objfile *waitpid_objf; + struct value *waitpid_fn = NULL; + struct value *argv[4], *retv; + struct gdbarch *gdbarch = get_current_arch (); + struct fork_info *oldfp = NULL, *newfp = NULL; + struct cleanup *old_cleanup; + int ret = -1; + + if (!ptid_equal (pptid, inferior_ptid)) + { + /* Switch to pptid. */ + oldfp = find_fork_ptid (inferior_ptid); + gdb_assert (oldfp != NULL); + newfp = find_fork_ptid (pptid); + gdb_assert (newfp != NULL); + fork_save_infrun_state (oldfp, 1); + remove_breakpoints (); + fork_load_infrun_state (newfp); + insert_breakpoints (); + } + + old_cleanup = make_cleanup (inferior_call_waitpid_cleanup, oldfp); + + /* Get the waitpid_fn. */ + if (lookup_minimal_symbol ("waitpid", NULL, NULL).minsym != NULL) + waitpid_fn = find_function_in_inferior ("waitpid", &waitpid_objf); + if (!waitpid_fn + && lookup_minimal_symbol ("_waitpid", NULL, NULL).minsym != NULL) + waitpid_fn = find_function_in_inferior ("_waitpid", &waitpid_objf); + if (!waitpid_fn) + goto out; + + /* Get the argv. */ + argv[0] = value_from_longest (builtin_type (gdbarch)->builtin_int, pid); + argv[1] = value_from_pointer (builtin_type (gdbarch)->builtin_data_ptr, 0); + argv[2] = value_from_longest (builtin_type (gdbarch)->builtin_int, 0); + argv[3] = 0; + + retv = call_function_by_hand (waitpid_fn, 3, argv); + if (value_as_long (retv) < 0) + goto out; + + ret = 0; + +out: + do_cleanups (old_cleanup); + return ret; +} + /* Fork list <-> user interface. */ static void delete_checkpoint_command (char *args, int from_tty) { - ptid_t ptid; + ptid_t ptid, pptid; + struct fork_info *fi; if (!args || !*args) error (_("Requires argument (checkpoint id to delete)")); @@ -430,13 +522,28 @@ delete_checkpoint_command (char *args, int from_tty) error (_("\ Please switch to another checkpoint before deleting the current one")); - if (ptrace (PTRACE_KILL, PIDGET (ptid), 0, 0)) + if (ptrace (PTRACE_KILL, ptid_get_pid (ptid), 0, 0)) error (_("Unable to kill pid %s"), target_pid_to_str (ptid)); + fi = find_fork_ptid (ptid); + gdb_assert (fi); + pptid = fi->parent_ptid; + if (from_tty) printf_filtered (_("Killed %s\n"), target_pid_to_str (ptid)); delete_fork (ptid); + + /* If fi->parent_ptid is not a part of lwp but it's a part of checkpoint + list, waitpid the ptid. + If fi->parent_ptid is a part of lwp and it is stoped, waitpid the + ptid. */ + if ((!find_thread_ptid (pptid) && find_fork_ptid (pptid)) + || (find_thread_ptid (pptid) && is_stopped (pptid))) + { + if (inferior_call_waitpid (pptid, ptid_get_pid (ptid))) + warning (_("Unable to wait pid %s"), target_pid_to_str (ptid)); + } } static void @@ -455,7 +562,7 @@ detach_checkpoint_command (char *args, int from_tty) error (_("\ Please switch to another checkpoint before detaching the current one")); - if (ptrace (PTRACE_DETACH, PIDGET (ptid), 0, 0)) + if (ptrace (PTRACE_DETACH, ptid_get_pid (ptid), 0, 0)) error (_("Unable to detach %s"), target_pid_to_str (ptid)); if (from_tty) @@ -470,11 +577,8 @@ static void info_checkpoints_command (char *arg, int from_tty) { struct gdbarch *gdbarch = get_current_arch (); - struct frame_info *cur_frame; struct symtab_and_line sal; - struct symtab *cur_symtab; struct fork_info *fp; - int cur_line; ULONGEST pc; int requested = -1; struct fork_info *printed = NULL; @@ -506,23 +610,17 @@ info_checkpoints_command (char *arg, int from_tty) sal = find_pc_line (pc, 0); if (sal.symtab) - { - char *tmp = strrchr (sal.symtab->filename, '/'); - - if (tmp) - printf_filtered (_(", file %s"), tmp + 1); - else - printf_filtered (_(", file %s"), sal.symtab->filename); - } + printf_filtered (_(", file %s"), + symtab_to_filename_for_display (sal.symtab)); if (sal.line) printf_filtered (_(", line %d"), sal.line); if (!sal.symtab && !sal.line) { - struct minimal_symbol *msym; + struct bound_minimal_symbol msym; msym = lookup_minimal_symbol_by_pc (pc); - if (msym) - printf_filtered (", <%s>", SYMBOL_LINKAGE_NAME (msym)); + if (msym.minsym) + printf_filtered (", <%s>", MSYMBOL_LINKAGE_NAME (msym.minsym)); } putchar_filtered ('\n'); @@ -545,6 +643,33 @@ linux_fork_checkpointing_p (int pid) return (checkpointing_pid == pid); } +/* Callback for iterate over threads. Used to check whether + the current inferior is multi-threaded. Returns true as soon + as it sees the second thread of the current inferior. */ + +static int +inf_has_multiple_thread_cb (struct thread_info *tp, void *data) +{ + int *count_p = (int *) data; + + if (current_inferior ()->pid == ptid_get_pid (tp->ptid)) + (*count_p)++; + + /* Stop the iteration if multiple threads have been detected. */ + return *count_p > 1; +} + +/* Return true if the current inferior is multi-threaded. */ + +static int +inf_has_multiple_threads (void) +{ + int count = 0; + + iterate_over_threads (inf_has_multiple_thread_cb, &count); + return (count > 1); +} + static void checkpoint_command (char *args, int from_tty) { @@ -556,14 +681,21 @@ checkpoint_command (char *args, int from_tty) struct fork_info *fp; pid_t retpid; struct cleanup *old_chain; - long i; + if (!target_has_execution) + error (_("The program is not being run.")); + + /* Ensure that the inferior is not multithreaded. */ + update_thread_list (); + if (inf_has_multiple_threads ()) + error (_("checkpoint: can't checkpoint multiple threads.")); + /* Make the inferior fork, record its (and gdb's) state. */ - if (lookup_minimal_symbol ("fork", NULL, NULL) != NULL) + if (lookup_minimal_symbol ("fork", NULL, NULL).minsym != NULL) fork_fn = find_function_in_inferior ("fork", &fork_objf); if (!fork_fn) - if (lookup_minimal_symbol ("_fork", NULL, NULL) != NULL) + if (lookup_minimal_symbol ("_fork", NULL, NULL).minsym != NULL) fork_fn = find_function_in_inferior ("fork", &fork_objf); if (!fork_fn) error (_("checkpoint: can't find fork function in inferior.")); @@ -573,7 +705,7 @@ checkpoint_command (char *args, int from_tty) /* Tell linux-nat.c that we're checkpointing this inferior. */ old_chain = make_cleanup_restore_integer (&checkpointing_pid); - checkpointing_pid = PIDGET (inferior_ptid); + checkpointing_pid = ptid_get_pid (inferior_ptid); ret = call_function_by_hand (fork_fn, 0, &ret); do_cleanups (old_chain); @@ -582,12 +714,15 @@ checkpoint_command (char *args, int from_tty) retpid = value_as_long (ret); get_last_target_status (&last_target_ptid, &last_target_waitstatus); + + fp = find_fork_pid (retpid); + if (from_tty) { int parent_pid; - printf_filtered (_("checkpoint: fork returned pid %ld.\n"), - (long) retpid); + printf_filtered (_("checkpoint %d: fork returned pid %ld.\n"), + fp != NULL ? fp->num : -1, (long) retpid); if (info_verbose) { parent_pid = ptid_get_lwp (last_target_ptid); @@ -598,10 +733,10 @@ checkpoint_command (char *args, int from_tty) } } - fp = find_fork_pid (retpid); if (!fp) error (_("Failed to find new fork")); fork_save_infrun_state (fp, 1); + fp->parent_ptid = last_target_ptid; } static void @@ -609,8 +744,6 @@ linux_fork_context (struct fork_info *newfp, int from_tty) { /* Now we attempt to switch processes. */ struct fork_info *oldfp; - ptid_t ptid; - int id, i; gdb_assert (newfp != NULL); @@ -625,7 +758,7 @@ linux_fork_context (struct fork_info *newfp, int from_tty) printf_filtered (_("Switching to %s\n"), target_pid_to_str (inferior_ptid)); - print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC); + print_stack_frame (get_selected_frame (NULL), 1, SRC_AND_LOC, 1); } /* Switch inferior process (checkpoint) context, by checkpoint id. */ @@ -648,14 +781,6 @@ _initialize_linux_fork (void) { init_fork_list (); - /* Set/show detach-on-fork: user-settable mode. */ - - add_setshow_boolean_cmd ("detach-on-fork", class_obscure, &detach_fork, _("\ -Set whether gdb will detach the child of a fork."), _("\ -Show whether gdb will detach the child of a fork."), _("\ -Tells gdb whether to detach the child of a fork."), - NULL, NULL, &setlist, &showlist); - /* Checkpoint command: create a fork of the inferior process and set it aside for later debugging. */