*** empty log message ***

[deliverable/binutils-gdb.git] / gdb / i386obsd-tdep.c

diff --git a/gdb/i386obsd-tdep.c b/gdb/i386obsd-tdep.c
index f30924430832533687ecc61611748f984518088c..f1ce0477d356d5b97b953b6ff3a538879b9dafbf 100644 (file)
--- a/gdb/i386obsd-tdep.c
+++ b/gdb/i386obsd-tdep.c
@@ -1,7 +1,7 @@
 /* Target-dependent code for OpenBSD/i386.
 
    Copyright (C) 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
-   2003, 2004, 2005
+   2003, 2004, 2005, 2006
    Free Software Foundation, Inc.
 
    This file is part of GDB.
@@ -24,6 +24,7 @@
 #include "defs.h"
 #include "arch-utils.h"
 #include "frame.h"
+#include "frame-unwind.h"
 #include "gdbcore.h"
 #include "regcache.h"
 #include "regset.h"
@@ -31,6 +32,7 @@
 #include "objfiles.h"
 #include "osabi.h"
 #include "target.h"
+#include "trad-frame.h"
 
 #include "gdb_assert.h"
 #include "gdb_string.h"
@@ -265,7 +267,6 @@ i386obsd_supply_uthread (struct regcache *regcache,
          regcache_raw_supply (regcache, i, buf);
        }
     }
-
 }
 
 static void
@@ -313,6 +314,132 @@ i386obsd_collect_uthread (const struct regcache *regcache,
        }
     }
 }
+\f
+/* Kernel debugging support.  */
+
+/* From <machine/frame.h>.  Note that %esp and %ess are only saved in
+   a trap frame when entering the kernel from user space.  */
+static int i386obsd_tf_reg_offset[] =
+{
+  10 * 4,                      /* %eax */
+  9 * 4,                       /* %ecx */
+  8 * 4,                       /* %edx */
+  7 * 4,                       /* %ebx */
+  -1,                          /* %esp */
+  6 * 4,                       /* %ebp */
+  5 * 4,                       /* %esi */
+  4 * 4,                       /* %edi */
+  13 * 4,                      /* %eip */
+  15 * 4,                      /* %eflags */
+  14 * 4,                      /* %cs */
+  -1,                          /* %ss */
+  3 * 4,                       /* %ds */
+  2 * 4,                       /* %es */
+  0 * 4,                       /* %fs */
+  1 * 4                                /* %gs */
+};
+
+static struct trad_frame_cache *
+i386obsd_trapframe_cache(struct frame_info *next_frame, void **this_cache)
+{
+  struct trad_frame_cache *cache;
+  CORE_ADDR func, sp, addr;
+  ULONGEST cs;
+  char *name;
+  int i;
+
+  if (*this_cache)
+    return *this_cache;
+
+  cache = trad_frame_cache_zalloc (next_frame);
+  *this_cache = cache;
+
+  func = frame_func_unwind (next_frame);
+  sp = frame_unwind_register_unsigned (next_frame, I386_ESP_REGNUM);
+
+  find_pc_partial_function (func, &name, NULL, NULL);
+  if (name && strncmp (name, "Xintr", 5) == 0)
+    addr = sp + 8;             /* It's an interrupt frame.  */
+  else
+    addr = sp;
+
+  for (i = 0; i < ARRAY_SIZE (i386obsd_tf_reg_offset); i++)
+    if (i386obsd_tf_reg_offset[i] != -1)
+      trad_frame_set_reg_addr (cache, i, addr + i386obsd_tf_reg_offset[i]);
+
+  /* Read %cs from trap frame.  */
+  addr += i386obsd_tf_reg_offset[I386_CS_REGNUM];
+  cs = read_memory_unsigned_integer (addr, 4); 
+  if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
+    {
+      /* Trap from user space; terminate backtrace.  */
+      trad_frame_set_id (cache, null_frame_id);
+    }
+  else
+    {
+      /* Construct the frame ID using the function start.  */
+      trad_frame_set_id (cache, frame_id_build (sp + 8, func));
+    }
+
+  return cache;
+}
+
+static void
+i386obsd_trapframe_this_id (struct frame_info *next_frame,
+                           void **this_cache, struct frame_id *this_id)
+{
+  struct trad_frame_cache *cache =
+    i386obsd_trapframe_cache (next_frame, this_cache);
+  
+  trad_frame_get_id (cache, this_id);
+}
+
+static void
+i386obsd_trapframe_prev_register (struct frame_info *next_frame,
+                                 void **this_cache, int regnum,
+                                 int *optimizedp, enum lval_type *lvalp,
+                                 CORE_ADDR *addrp, int *realnump,
+                                 gdb_byte *valuep)
+{
+  struct trad_frame_cache *cache =
+    i386obsd_trapframe_cache (next_frame, this_cache);
+
+  trad_frame_get_register (cache, next_frame, regnum,
+                          optimizedp, lvalp, addrp, realnump, valuep);
+}
+
+static int
+i386obsd_trapframe_sniffer (const struct frame_unwind *self,
+                           struct frame_info *next_frame,
+                           void **this_prologue_cache)
+{
+  ULONGEST cs;
+  char *name;
+
+  /* Check Current Privilege Level and bail out if we're not executing
+     in kernel space.  */
+  cs = frame_unwind_register_unsigned (next_frame, I386_CS_REGNUM);
+  if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
+    return 0;
+
+  find_pc_partial_function (frame_pc_unwind (next_frame), &name, NULL, NULL);
+  return (name && (strcmp (name, "calltrap") == 0
+                  || strcmp (name, "syscall1") == 0
+                  || strncmp (name, "Xintr", 5) == 0
+                  || strncmp (name, "Xsoft", 5) == 0));
+}
+
+static const struct frame_unwind i386obsd_trapframe_unwind = {
+  /* FIXME: kettenis/20051219: This really is more like an interrupt
+     frame, but SIGTRAMP_FRAME would print <signal handler called>,
+     which really is not what we want here.  */
+  NORMAL_FRAME,
+  i386obsd_trapframe_this_id,
+  i386obsd_trapframe_prev_register,
+  NULL,
+  i386obsd_trapframe_sniffer
+};
+\f
 
 static void 
 i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -343,6 +470,9 @@ i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
   /* OpenBSD provides a user-level threads implementation.  */
   bsd_uthread_set_supply_uthread (gdbarch, i386obsd_supply_uthread);
   bsd_uthread_set_collect_uthread (gdbarch, i386obsd_collect_uthread);
+
+  /* Unwind kernel trap frames correctly.  */
+  frame_unwind_prepend_unwinder (gdbarch, &i386obsd_trapframe_unwind);
 }
 
 /* OpenBSD a.out.  */