Teach gdb how to unwind i386 kernel trap frames.

3 files changed, 133 insertions, 49 deletions

diff --git a/gnu/usr.bin/binutils/gdb/Makefile.in b/gnu/usr.bin/binutils/gdb/Makefile.in
index 040db280e42..0a8351ba3ec 100644
--- a/gnu/usr.bin/binutils/gdb/Makefile.in
+++ b/gnu/usr.bin/binutils/gdb/Makefile.in
@@ -2028,9 +2028,10 @@ i386-nto-tdep.o: i386-nto-tdep.c $(gdb_string_h) $(gdb_assert_h) $(defs_h) \
 	$(nto_tdep_h) $(osabi_h) $(i387_tdep_h)
 i386obsd-nat.o: i386obsd-nat.c $(defs_h) $(i386_tdep_h)
 i386obsd-tdep.o: i386obsd-tdep.c $(defs_h) $(arch_utils_h) $(frame_h) \
-	$(gdbcore_h) $(regcache_h) $(regset_h) $(symtab_h) $(objfiles_h) \
-	$(osabi_h) $(target_h) $(gdb_assert_h) $(gdb_string_h) \
-	$(i386_tdep_h) $(i387_tdep_h) $(solib_svr4_h)
+	$(frame_unwind_h) $(gdbcore_h) $(regcache_h) $(regset_h) $(symtab_h) \
+	$(objfiles_h) $(osabi_h) $(target_h) $(trad_frame_h) $(gdb_assert_h) \
+	$(gdb_string_h) $(i386_tdep_h) $(i387_tdep_h) $(solib_svr4_h) \
+	$(bsd_uthread_h)
 i386-sol2-tdep.o: i386-sol2-tdep.c $(defs_h) $(value_h) $(osabi_h) \
 	$(gdb_string_h) $(i386_tdep_h) $(solib_svr4_h)
 i386-stub.o: i386-stub.c
diff --git a/gnu/usr.bin/binutils/gdb/i386-tdep.h b/gnu/usr.bin/binutils/gdb/i386-tdep.h
index 9cb87653e12..0a44db9b1d1 100644
--- a/gnu/usr.bin/binutils/gdb/i386-tdep.h
+++ b/gnu/usr.bin/binutils/gdb/i386-tdep.h
@@ -1,6 +1,6 @@
 /* Target-dependent code for the i386.
 
-   Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
+   Copyright 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -89,6 +89,9 @@ struct gdbarch_tdep
   CORE_ADDR sigtramp_start;
   CORE_ADDR sigtramp_end;
 
+  /* Detect sigtramp.  */
+  int (*sigtramp_p) (struct frame_info *);
+
   /* Get address of sigcontext for sigtramp.  */
   CORE_ADDR (*sigcontext_addr) (struct frame_info *);
 
@@ -108,48 +111,11 @@ struct gdbarch_tdep
    (at most) in the FPU, but are zero-extended to 32 bits in GDB's
    register cache.  */
 
-/* "Generic" floating point control register.  */
-#define FPC_REGNUM	(FP0_REGNUM + 8)
-
-/* FPU control word.  */
-#define FCTRL_REGNUM	FPC_REGNUM
-
-/* FPU status word.  */
-#define FSTAT_REGNUM	(FPC_REGNUM + 1)
-
-/* FPU register tag word.  */
-#define FTAG_REGNUM	(FPC_REGNUM + 2)
-
-/* FPU instruction's code segment selector, called "FPU Instruction
-   Pointer Selector" in the IA-32 manuals.  */
-#define FISEG_REGNUM	(FPC_REGNUM + 3)
-
-/* FPU instruction's offset within segment.  */
-#define FIOFF_REGNUM	(FPC_REGNUM + 4)
-
-/* FPU operand's data segment.  */
-#define FOSEG_REGNUM	(FPC_REGNUM + 5)
-
-/* FPU operand's offset within segment */
-#define FOOFF_REGNUM	(FPC_REGNUM + 6)
-
-/* FPU opcode, bottom eleven bits.  */
-#define FOP_REGNUM	(FPC_REGNUM + 7)
-
 /* Return non-zero if REGNUM matches the FP register and the FP
    register set is active.  */
 extern int i386_fp_regnum_p (int regnum);
 extern int i386_fpc_regnum_p (int regnum);
 
-/* SSE registers.  */
-
-/* First SSE data register.  */
-#define XMM0_REGNUM	(FPC_REGNUM + 8)
-
-/* SSE control/status register.  */
-#define MXCSR_REGNUM \
-  (XMM0_REGNUM + gdbarch_tdep (current_gdbarch)->num_xmm_regs)
-
 /* Register numbers of various important registers.  */
 
 enum i386_regnum
@@ -183,12 +149,16 @@ enum i386_regnum
 /* Size of the largest register.  */
 #define I386_MAX_REGISTER_SIZE	16
 
+/* Segment selectors.  */
+#define I386_SEL_RPL	0x0003  /* Requester's Privilege Level mask.  */
+#define I386_SEL_UPL	0x0003	/* User Privilige Level. */
+#define I386_SEL_KPL	0x0000	/* Kernel Privilige Level. */
+
 /* Functions exported from i386-tdep.c.  */
 extern CORE_ADDR i386_pe_skip_trampoline_code (CORE_ADDR pc, char *name);
-extern int i386_frameless_signal_p (struct frame_info *frame);
 
-/* Return the name of register REG.  */
-extern char const *i386_register_name (int reg);
+/* Return the name of register REGNUM.  */
+extern char const *i386_register_name (int regnum);
 
 /* Return non-zero if REGNUM is a member of the specified group.  */
 extern int i386_register_reggroup_p (struct gdbarch *gdbarch, int regnum,
@@ -217,9 +187,6 @@ extern void i386_svr4_init_abi (struct gdbarch_info, struct gdbarch *);
 /* Functions and variables exported from i386bsd-tdep.c.  */
 
 extern void i386bsd_init_abi (struct gdbarch_info, struct gdbarch *);
-extern int i386bsd_pc_in_sigtramp (CORE_ADDR pc, char *name);
-extern CORE_ADDR i386bsd_sigtramp_start (CORE_ADDR pc);
-extern CORE_ADDR i386bsd_sigtramp_end (CORE_ADDR pc);
 extern CORE_ADDR i386fbsd_sigtramp_start_addr;
 extern CORE_ADDR i386fbsd_sigtramp_end_addr;
 extern CORE_ADDR i386obsd_sigtramp_start_addr;
diff --git a/gnu/usr.bin/binutils/gdb/i386obsd-tdep.c b/gnu/usr.bin/binutils/gdb/i386obsd-tdep.c
index 5b23e93c0e7..27b82448fee 100644
--- a/gnu/usr.bin/binutils/gdb/i386obsd-tdep.c
+++ b/gnu/usr.bin/binutils/gdb/i386obsd-tdep.c
@@ -1,7 +1,7 @@
 /* Target-dependent code for OpenBSD/i386.
 
    Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
-   2003, 2004
+   2003, 2004, 2005
    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"
@@ -258,7 +260,6 @@ i386obsd_supply_uthread (struct regcache *regcache,
 	  regcache_raw_supply (regcache, i, buf);
 	}
     }
-
 }
 
 static void
@@ -306,6 +307,118 @@ i386obsd_collect_uthread (const struct regcache *regcache,
 	}
     }
 }
+/* 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;
+  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);
+  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, sp + i386obsd_tf_reg_offset[i]);
+
+  /* Read %cs from trap frame.  */
+  addr = sp + i386obsd_tf_reg_offset[I386_CS_REGNUM];
+  cs = read_memory_unsigned_integer (addr, 4); 
+  if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
+    {
+      /* Trap from use 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,
+				  void *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 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
+};
+
+static const struct frame_unwind *
+i386obsd_trapframe_sniffer (struct frame_info *next_frame)
+{
+  ULONGEST cs;
+  char *name;
+
+  cs = frame_unwind_register_unsigned (next_frame, I386_CS_REGNUM);
+  if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
+    return NULL;
+
+  find_pc_partial_function (frame_pc_unwind (next_frame), &name, NULL, NULL);
+  if (name && ((strcmp ("calltrap", name) == 0)
+	       || (strcmp ("syscall1", name) == 0)))
+    return &i386obsd_trapframe_unwind;
+
+  return NULL;
+}
+
 
 static void 
 i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
@@ -336,6 +449,9 @@ 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_append_sniffer (gdbarch, i386obsd_trapframe_sniffer);
 }
 
 /* OpenBSD a.out.  */