Add support for catching system calls to native FreeBSD targets.

[external/binutils.git] / gdb / fbsd-nat.c

diff --git a/gdb/fbsd-nat.c b/gdb/fbsd-nat.c
index dc65e29..c9548e9 100644 (file)
--- a/gdb/fbsd-nat.c
+++ b/gdb/fbsd-nat.c
@@ -779,6 +779,40 @@ fbsd_wait (struct target_ops *ops,
              return wptid;
            }
 #endif
+
+         /* Note that PL_FLAG_SCE is set for any event reported while
+            a thread is executing a system call in the kernel.  In
+            particular, signals that interrupt a sleep in a system
+            call will report this flag as part of their event.  Stops
+            explicitly for system call entry and exit always use
+            SIGTRAP, so only treat SIGTRAP events as system call
+            entry/exit events.  */
+         if (pl.pl_flags & (PL_FLAG_SCE | PL_FLAG_SCX)
+             && ourstatus->value.sig == SIGTRAP)
+           {
+#ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
+             if (catch_syscall_enabled ())
+               {
+                 if (catching_syscall_number (pl.pl_syscall_code))
+                   {
+                     if (pl.pl_flags & PL_FLAG_SCE)
+                       ourstatus->kind = TARGET_WAITKIND_SYSCALL_ENTRY;
+                     else
+                       ourstatus->kind = TARGET_WAITKIND_SYSCALL_RETURN;
+                     ourstatus->value.syscall_number = pl.pl_syscall_code;
+                     return wptid;
+                   }
+               }
+#endif
+             /* If the core isn't interested in this event, just
+                continue the process explicitly and wait for another
+                event.  Note that PT_SYSCALL is "sticky" on FreeBSD
+                and once system call stops are enabled on a process
+                it stops for all system call entries and exits.  */
+             if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1)
+               perror_with_name (("ptrace"));
+             continue;
+           }
        }
       return wptid;
     }
@@ -889,6 +923,19 @@ fbsd_remove_exec_catchpoint (struct target_ops *self, int pid)
   return 0;
 }
 #endif
+
+#ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
+static int
+fbsd_set_syscall_catchpoint (struct target_ops *self, int pid, int needed,
+                            int any_count, int table_size, int *table)
+{
+
+  /* Ignore the arguments.  inf-ptrace.c will use PT_SYSCALL which
+     will catch all system call entries and exits.  The system calls
+     are filtered by GDB rather than the kernel.  */
+  return 0;
+}
+#endif
 #endif
 
 void
@@ -925,6 +972,9 @@ fbsd_nat_add_target (struct target_ops *t)
   t->to_insert_exec_catchpoint = fbsd_insert_exec_catchpoint;
   t->to_remove_exec_catchpoint = fbsd_remove_exec_catchpoint;
 #endif
+#ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE
+  t->to_set_syscall_catchpoint = fbsd_set_syscall_catchpoint;
+#endif
 #endif
   add_target (t);
 }