Implementing catch syscall.

* amd64-linux-tdep.c: Include xml-syscall.h header, define the XML
syscall name for the architecture.
(amd64_linux_get_syscall_number): New function.
(amd64_linux_init_abi): Register the correct functions for syscall
catchpoint; set the correct syscall file name.
* breakpoint.c: New include: xml-syscall.h.
(set_raw_breakpoint_without_location): Setting the parameters
for the catch syscall feature.
(insert_catch_syscall): New.
(remove_catch_syscall): New.
(breakpoint_hit_catch_syscall): New.
(print_it_catch_syscall): New.
(print_one_catch_syscall): New.
(print_mention_catch_syscall): New.
(catch_syscall_breakpoint_ops): New.
(syscall_catchpoint_p): New.
(create_catchpoint_without_mention): New.
(create_catchpoint): Modified in order to use
create_catchpoint_without_mention.
(create_syscall_event_catchpoint): New.
(clean_up_filters): New.
(catch_syscall_split_args): New.
(catch_syscall_command_1): New.
(delete_breakpoint): Add cleanup for catch syscall.
(is_syscall_catchpoint_enabled): New.
(catch_syscall_enabled): New.
(catching_syscall_number): New.
(catch_syscall_completer): New completer function.
(add_catch_command): Add the completer function for catchpoints.
* breakpoint.h (syscalls_to_be_caught): New vector.
(catch_syscall_enabled): New.
(catching_syscall_number): New.
* gdbarch.c: Regenerated.
* gdbarch.h: Regenerated.
* gdbarch.sh: Add syscall catchpoint functions and structures.
(get_syscall_number): New.
(UNKNOWN_SYSCALL): New definition.
* i386-linux-nat.c (i386_linux_resume): Select the proper request
to be made for ptrace() considering if we are catching syscalls
or not.
* i386-linux-tdep.c: Include xml-syscall.h header, define the XML
syscall name for the architecture.
(i386_linux_get_syscall_number): New.
(i386_linux_init_abi): Register the correct functions for syscall
catchpoint; set the correct syscall file name.
* inf-child.c (inf_child_set_syscall_catchpoint): New.
(inf_child_target): Assign default values to target_ops.
* inf-ptrace.c (inf_ptrace_resume): Select the proper request
to be made for ptrace() considering if we are catching syscalls
or not.
* inferior.h (struct inferior): Included new variables
any_syscall_count, syscalls_counts and total_syscalls_count,
used to keep track of requested syscall catchpoints.
* infrun.c (resume): Add syscall catchpoint.
(deal_with_syscall_event): New.
(handle_inferior_event): Add syscall entry/return events.
(inferior_has_called_syscall): New.
* linux-nat.c: Define some helpful variables to track wether we have
support for the needed ptrace option.
(linux_test_for_tracesysgood): New.
(linux_supports_tracesysgood): New.
(linux_enable_tracesysgood): New.
(linux_enable_event_reporting): Save the current used ptrace
options.
(linux_child_post_attach): Calling linux_enable_tracesysgood.
(linux_child_post_startup_inferior): Likewise.
(linux_child_set_syscall_catchpoint): New function.
(linux_handle_extended_wait): Handle the case which the inferior stops
because it has called or returned from a syscall.
(linux_target_install_ops): Install the necessary functions to handle
syscall catchpoints.
* linux-nat.h (struct lwp_info): Include syscall_state into the
structure, which indicates if we are in a syscall entry or return.
* ppc-linux-tdep.c: Include xml-syscall.h header, define the XML
syscall filename for the arch.
(ppc_linux_get_syscall_number): New.
(ppc_linux_init_abi): Register the correct functions for syscall
catchpoint; setting the correct name for the XML syscall file.
* target.c (update_current_target): Update/copy functions related to
syscall catchpoint.
(target_waitstatus_to_string): Add syscall catchpoint entry/return
events.
* target.h (struct target_waitstatus): Add syscall number.
(struct syscall): New struct to hold information about syscalls
in the system.
(struct target_ops): Add ops for syscall catchpoint.
(inferior_has_called_syscall): New.
(target_set_syscall_catchpoint): New.
* xml-support.c (xml_fetch_content_from_file): New function,
transferred from xml-tdesc.c.
* xml-support.h (xml_fetch_content_from_file): New.
* xml-tdesc.c (fetch_xml_from_file): Function removed;
transferred to xml-support.c.
(file_read_description_xml): Updated to use the new
xml_fetch_content_from_file function.
* syscalls/gdb-syscalls.dtd: New definition file for syscall's XML
support.
* syscalls/amd64-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use amd64 architecture.
* syscalls/i386-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use i386 architecture.
* syscalls/ppc-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use PPC architecture.
* syscalls/ppc64-linux.xml: New file containing information about
syscalls for GNU/Linux systems that use PPC64 architecture.
* xml-syscall.c: New file containing functions for manipulating
syscall's XML files.
* xml-syscall.h: New file, exporting the functions above mentioned.
* Makefile.in: Support for relocatable GDB datadir and XML
syscall.
* NEWS: Added information about the catch syscall feature.
* doc/gdb.texinfo (Set Catchpoints): Documentation about the new
feature.
* testsuite/Makefile.in: Inclusion of catch-syscall object.
* testsuite/gdb.base/catch-syscall.c: New file.
* testsuite/gdb.base/catch-syscall.exp: New file.

1 files changed, 82 insertions, 6 deletions

diff --git a/gdb/infrun.c b/gdb/infrun.c
index a6ca2e3..1a83a25 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -2042,6 +2042,10 @@ wait_for_inferior (int treat_exec_as_sigtrap)
 	 state.  */
       old_chain = make_cleanup (finish_thread_state_cleanup, &minus_one_ptid);
 
+      if (ecs->ws.kind == TARGET_WAITKIND_SYSCALL_ENTRY
+          || ecs->ws.kind == TARGET_WAITKIND_SYSCALL_RETURN)
+        ecs->ws.value.syscall_number = UNKNOWN_SYSCALL;
+
       /* Now figure out what to do with the result of the result.  */
       handle_inferior_event (ecs);
 
@@ -2378,6 +2382,56 @@ stepped_in_from (struct frame_info *frame, struct frame_id step_frame_id)
   return 0;
 }
 
+/* Auxiliary function that handles syscall entry/return events.
+   It returns 1 if the inferior should keep going (and GDB
+   should ignore the event), or 0 if the event deserves to be
+   processed.  */
+static int
+deal_with_syscall_event (struct execution_control_state *ecs)
+{
+  struct regcache *regcache = get_thread_regcache (ecs->ptid);
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  int syscall_number = gdbarch_get_syscall_number (gdbarch,
+                                                   ecs->ptid);
+  target_last_waitstatus.value.syscall_number = syscall_number;
+
+  if (catch_syscall_enabled () > 0
+      && catching_syscall_number (syscall_number) > 0)
+    {
+      if (debug_infrun)
+        fprintf_unfiltered (gdb_stdlog, "infrun: syscall number = '%d'\n",
+                            syscall_number);
+      ecs->event_thread->stop_signal = TARGET_SIGNAL_TRAP;
+
+      if (!ptid_equal (ecs->ptid, inferior_ptid))
+        {
+          context_switch (ecs->ptid);
+          reinit_frame_cache ();
+        }
+
+      stop_pc = regcache_read_pc (get_thread_regcache (ecs->ptid));
+
+      ecs->event_thread->stop_bpstat = bpstat_stop_status (stop_pc, ecs->ptid);
+
+      ecs->random_signal = !bpstat_explains_signal (ecs->event_thread->stop_bpstat);
+
+      /* If no catchpoint triggered for this, then keep going.  */
+      if (ecs->random_signal)
+        {
+          ecs->event_thread->stop_signal = TARGET_SIGNAL_0;
+          keep_going (ecs);
+          return 1;
+        }
+      return 0;
+    }
+  else
+    {
+      resume (0, TARGET_SIGNAL_0);
+      prepare_to_wait (ecs);
+      return 1;
+    }
+}
+
 /* Given an execution control state that has been freshly filled in
    by an event from the inferior, figure out what it means and take
    appropriate action.  */
@@ -2698,9 +2752,11 @@ handle_inferior_event (struct execution_control_state *ecs)
     case TARGET_WAITKIND_SYSCALL_ENTRY:
       if (debug_infrun)
         fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
-      resume (0, TARGET_SIGNAL_0);
-      prepare_to_wait (ecs);
-      return;
+      /* Getting the current syscall number */
+      if (deal_with_syscall_event (ecs) != 0)
+        return;
+      goto process_event_stop_test;
+      break;
 
       /* Before examining the threads further, step this thread to
          get it entirely out of the syscall.  (We get notice of the
@@ -2710,9 +2766,10 @@ handle_inferior_event (struct execution_control_state *ecs)
     case TARGET_WAITKIND_SYSCALL_RETURN:
       if (debug_infrun)
         fprintf_unfiltered (gdb_stdlog, "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
-      target_resume (ecs->ptid, 1, TARGET_SIGNAL_0);
-      prepare_to_wait (ecs);
-      return;
+      if (deal_with_syscall_event (ecs) != 0)
+        return;
+      goto process_event_stop_test;
+      break;
 
     case TARGET_WAITKIND_STOPPED:
       if (debug_infrun)
@@ -5626,6 +5683,25 @@ inferior_has_execd (ptid_t pid, char **execd_pathname)
   return 1;
 }
 
+int
+inferior_has_called_syscall (ptid_t pid, int *syscall_number)
+{
+  struct target_waitstatus last;
+  ptid_t last_ptid;
+
+  get_last_target_status (&last_ptid, &last);
+
+  if (last.kind != TARGET_WAITKIND_SYSCALL_ENTRY &&
+      last.kind != TARGET_WAITKIND_SYSCALL_RETURN)
+    return 0;
+
+  if (!ptid_equal (last_ptid, pid))
+    return 0;
+
+  *syscall_number = last.value.syscall_number;
+  return 1;
+}
+
 /* Oft used ptids */
 ptid_t null_ptid;
 ptid_t minus_one_ptid;