[RFA] sighandler backtrace on x86-64

[RFA] sighandler backtrace on x86-64

[Michal Ludvig]

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Hi all,
the attached patch enables backtrace through signal handlers on x86-64. 
It isn't yet complete, but this is the part that works.
Can someone approve it please?

Michal Ludvig
-- 
* SuSE CR, s.r.o     * mludvig@suse.cz
* +420 2 9654 5373   * http://www.suse.cz

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2002-09-18  Michal Ludvig  <mludvig@suse.cz>

	* dwarf2cfi.c (struct context)
	(struct context_reg): Moved to dwarf2cfi.h
	(context_alloc, frame_state_alloc, context_cpy):
	Made extern instead of static, removed prototypes.
	* dwarf2cfi.h (struct context)
	(struct context_reg): New, moved from dwarf2cfi.c
	(context_alloc, frame_state_alloc, context_cpy):
	New prototypes.
	* x86-64-linux-tdep.c (x86_64_linux_sigtramp_saved_pc):
	Changed from static to extern.
	(LINUX_SIGINFO_SIZE, LINUX_SIGCONTEXT_PC_OFFSET)
	(LINUX_SIGCONTEXT_FP_OFFSET)
	(LINUX_UCONTEXT_SIGCONTEXT_OFFSET): Adjusted.
	(x86_64_linux_in_sigtramp, x86_64_linux_frame_chain)
	(x86_64_init_frame_pc, x86_64_init_extra_frame_info): New.
	* x86-64-tdep.c (x86_64_gdbarch_init): Several
	set_gdbarch_*() calls now use x86-64 specific functions 
	instead of DWARF2 CFI ones.
	* x86-64-tdep.h (x86_64_linux_in_sigtramp)
	(x86_64_linux_frame_chain, x86_64_init_frame_pc)
	(x86_64_init_extra_frame_info): New prototypes.
	
Index: dwarf2cfi.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2cfi.c,v
retrieving revision 1.16
diff -u -p -r1.16 dwarf2cfi.c
--- dwarf2cfi.c	19 Jul 2002 09:40:51 -0000	1.16
+++ dwarf2cfi.c	18 Sep 2002 11:11:02 -0000
@@ -90,37 +90,6 @@ struct fde_array
   int array_size;
 };
 
-struct context_reg
-{
-  union
-  {
-    unsigned int reg;
-    long offset;
-    CORE_ADDR addr;
-  }
-  loc;
-  enum
-  {
-    REG_CTX_UNSAVED,
-    REG_CTX_SAVED_OFFSET,
-    REG_CTX_SAVED_REG,
-    REG_CTX_SAVED_ADDR,
-    REG_CTX_VALUE,
-  }
-  how;
-};
-
-/* This is the register and unwind state for a particular frame.  */
-struct context
-{
-  struct context_reg *reg;
-
-  CORE_ADDR cfa;
-  CORE_ADDR ra;
-  void *lsda;
-  int args_size;
-};
-
 struct frame_state_reg
 {
   union
@@ -208,11 +177,8 @@ static struct fde_unit *fde_unit_alloc (
 static struct cie_unit *cie_unit_alloc (void);
 static void fde_chunks_need_space ();
 
-static struct context *context_alloc ();
-static struct frame_state *frame_state_alloc ();
 static void unwind_tmp_obstack_init ();
 static void unwind_tmp_obstack_free ();
-static void context_cpy (struct context *dst, struct context *src);
 
 static unsigned int read_1u (bfd * abfd, char **p);
 static int read_1s (bfd * abfd, char **p);
@@ -286,7 +252,7 @@ fde_chunks_need_space (void)
 }
 
 /* Alocate a new `struct context' on temporary obstack.  */
-static struct context *
+struct context *
 context_alloc (void)
 {
   struct context *context;
@@ -303,7 +269,7 @@ context_alloc (void)
 }
 
 /* Alocate a new `struct frame_state' on temporary obstack.  */
-static struct frame_state *
+struct frame_state *
 frame_state_alloc (void)
 {
   struct frame_state *fs;
@@ -332,7 +298,7 @@ unwind_tmp_obstack_free (void)
   unwind_tmp_obstack_init ();
 }
 
-static void
+void
 context_cpy (struct context *dst, struct context *src)
 {
   int regs_size = sizeof (struct context_reg) * NUM_REGS;
Index: dwarf2cfi.h
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2cfi.h,v
retrieving revision 1.1
diff -u -p -r1.1 dwarf2cfi.h
--- dwarf2cfi.h	7 Dec 2001 12:10:15 -0000	1.1
+++ dwarf2cfi.h	18 Sep 2002 11:11:02 -0000
@@ -22,6 +22,37 @@
 #ifndef DWARF2CFI_H
 #define DWARF2CFI_H
 
+struct context_reg
+{
+  union
+  {
+    unsigned int reg;
+    long offset;
+    CORE_ADDR addr;
+  }
+  loc;
+  enum
+  {
+    REG_CTX_UNSAVED,
+    REG_CTX_SAVED_OFFSET,
+    REG_CTX_SAVED_REG,
+    REG_CTX_SAVED_ADDR,
+    REG_CTX_VALUE,
+  }
+  how;
+};
+
+/* This is the register and unwind state for a particular frame.  */
+struct context
+{
+  struct context_reg *reg;
+
+  CORE_ADDR cfa;
+  CORE_ADDR ra;
+  void *lsda;
+  int args_size;
+};
+
 /* Return the frame address.  */
 CORE_ADDR cfi_read_fp ();
 
@@ -63,4 +94,7 @@ void cfi_get_saved_register (char *raw_b
 void cfi_virtual_frame_pointer (CORE_ADDR pc, int *frame_regnum,
 				LONGEST * frame_offset);
 
+struct context *context_alloc ();
+void context_cpy (struct context *dst, struct context *src);
+struct frame_state *frame_state_alloc ();
 #endif
Index: x86-64-linux-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/x86-64-linux-tdep.c,v
retrieving revision 1.5
diff -u -p -r1.5 x86-64-linux-tdep.c
--- x86-64-linux-tdep.c	3 Sep 2002 13:06:33 -0000	1.5
+++ x86-64-linux-tdep.c	18 Sep 2002 11:11:02 -0000
@@ -35,8 +35,10 @@
 #define LINUX_SIGTRAMP_OFFSET1 (7)
 
 static const unsigned char linux_sigtramp_code[] = {
-  LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x89, 0x00, 0x00, 0x00,	/*  mov $0x89,%rax */
-  LINUX_SIGTRAMP_INSN1, 0x05	/* syscall */
+  /*  mov $__NR_rt_sigreturn,%rax */	
+  LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
+  /* syscall */
+  LINUX_SIGTRAMP_INSN1, 0x05
 };
 
 #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
@@ -68,17 +70,22 @@ x86_64_linux_sigtramp_start (CORE_ADDR p
   return pc;
 }
 
-#define LINUX_SIGINFO_SIZE 128
+#define LINUX_SIGINFO_SIZE 0
 
 /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>.  */
-#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET (36)
+#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
+
+/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
+#define LINUX_SIGCONTEXT_PC_OFFSET 128
+#define LINUX_SIGCONTEXT_FP_OFFSET 120
 
 /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
    address of the associated sigcontext structure.  */
-CORE_ADDR
+static CORE_ADDR
 x86_64_linux_sigcontext_addr (struct frame_info *frame)
 {
   CORE_ADDR pc;
+  ULONGEST rsp;
 
   pc = x86_64_linux_sigtramp_start (frame->pc);
   if (pc)
@@ -92,7 +99,8 @@ x86_64_linux_sigcontext_addr (struct fra
 
 
       /* This is the top frame. */
-      return read_register (SP_REGNUM) + LINUX_SIGINFO_SIZE +
+      rsp = read_register (SP_REGNUM);
+      return rsp + LINUX_SIGINFO_SIZE +
 	LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
 
     }
@@ -101,13 +109,10 @@ x86_64_linux_sigcontext_addr (struct fra
   return 0;
 }
 
-/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
-#define LINUX_SIGCONTEXT_PC_OFFSET (136)
-
 /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
    saved program counter.  */
 
-CORE_ADDR
+static CORE_ADDR
 x86_64_linux_sigtramp_saved_pc (struct frame_info *frame)
 {
   CORE_ADDR addr;
@@ -134,4 +139,62 @@ x86_64_linux_frame_saved_pc (struct fram
   if (frame->signal_handler_caller)
     return x86_64_linux_sigtramp_saved_pc (frame);
   return cfi_get_ra (frame);
+}
+
+/* Return whether PC is in a GNU/Linux sigtramp routine.  */
+
+int
+x86_64_linux_in_sigtramp (CORE_ADDR pc, char *name)
+{
+  if (name)
+    return STREQ ("__restore_rt", name);
+  
+  return (x86_64_linux_sigtramp_start (pc) != 0);
+}
+
+CORE_ADDR
+x86_64_linux_frame_chain (struct frame_info *fi)
+{
+	ULONGEST addr;
+	CORE_ADDR fp, pc;
+	
+	if (! fi->signal_handler_caller)
+	{
+		fp = cfi_frame_chain (fi);
+		if(fp)
+			return fp;
+		else
+			addr = fi->frame;
+	}
+	else
+		addr = fi->next->frame;
+
+	addr += LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
+	
+	fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8)+8;
+	
+	return fp;
+}
+
+void
+x86_64_init_frame_pc (int fromleaf, struct frame_info *fi)
+{
+	CORE_ADDR addr;
+
+	if(fi->next && fi->next->signal_handler_caller)
+	{
+		addr = fi->next->next->frame 
+			+ LINUX_SIGINFO_SIZE 
+			+ LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
+		fi->pc = read_memory_integer (addr 
+				+ LINUX_SIGCONTEXT_PC_OFFSET, 8);
+	}
+	else
+		cfi_init_frame_pc (fromleaf, fi);
+}
+
+void
+x86_64_init_extra_frame_info (int fromleaf, struct frame_info *fi)
+{
+	cfi_init_extra_frame_info (fromleaf, fi);
 }
Index: x86-64-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/x86-64-tdep.c,v
retrieving revision 1.27
diff -u -p -r1.27 x86-64-tdep.c
--- x86-64-tdep.c	12 Sep 2002 08:39:26 -0000	1.27
+++ x86-64-tdep.c	18 Sep 2002 11:11:03 -0000
@@ -1026,7 +1026,7 @@ x86_64_gdbarch_init (struct gdbarch_info
 
   /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
      chain-pointer.  */
-  set_gdbarch_frame_chain (gdbarch, cfi_frame_chain);
+  set_gdbarch_frame_chain (gdbarch, x86_64_linux_frame_chain);
 
   set_gdbarch_frameless_function_invocation (gdbarch,
 					     x86_64_frameless_function_invocation);
@@ -1041,10 +1041,10 @@ x86_64_gdbarch_init (struct gdbarch_info
   set_gdbarch_frame_init_saved_regs (gdbarch, x86_64_frame_init_saved_regs);
 
 /* Frame pc initialization is handled by unwind informations.  */
-  set_gdbarch_init_frame_pc (gdbarch, cfi_init_frame_pc);
+  set_gdbarch_init_frame_pc (gdbarch, x86_64_init_frame_pc);
 
 /* Initialization of unwind informations.  */
-  set_gdbarch_init_extra_frame_info (gdbarch, cfi_init_extra_frame_info);
+  set_gdbarch_init_extra_frame_info (gdbarch, x86_64_init_extra_frame_info);
 
 /* Getting saved registers is handled by unwind informations.  */
   set_gdbarch_get_saved_register (gdbarch, cfi_get_saved_register);
@@ -1054,8 +1054,7 @@ x86_64_gdbarch_init (struct gdbarch_info
 /* Cons up virtual frame pointer for trace */
   set_gdbarch_virtual_frame_pointer (gdbarch, cfi_virtual_frame_pointer);
 
-
-  set_gdbarch_frame_chain_valid (gdbarch, generic_file_frame_chain_valid);
+  set_gdbarch_frame_chain_valid (gdbarch, file_frame_chain_valid);
 
   set_gdbarch_use_generic_dummy_frames (gdbarch, 1);
   set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT);
@@ -1121,6 +1120,8 @@ x86_64_gdbarch_init (struct gdbarch_info
 /* Use dwarf2 debug frame informations.  */
   set_gdbarch_dwarf2_build_frame_info (gdbarch, dwarf2_build_frame_info);
   set_gdbarch_dwarf2_reg_to_regnum (gdbarch, x86_64_dwarf2_reg_to_regnum);
+
+  set_gdbarch_pc_in_sigtramp (gdbarch, x86_64_linux_in_sigtramp);
 
   return gdbarch;
 }
Index: x86-64-tdep.h
===================================================================
RCS file: /cvs/src/src/gdb/x86-64-tdep.h,v
retrieving revision 1.5
diff -u -p -r1.5 x86-64-tdep.h
--- x86-64-tdep.h	20 Jun 2002 13:08:12 -0000	1.5
+++ x86-64-tdep.h	18 Sep 2002 11:11:03 -0000
@@ -31,8 +31,12 @@ extern int x86_64_num_gregs;
 int x86_64_register_number (const char *name);
 const char *x86_64_register_name (int reg_nr);
 	
-
 gdbarch_frame_saved_pc_ftype x86_64_linux_frame_saved_pc;
 gdbarch_saved_pc_after_call_ftype x86_64_linux_saved_pc_after_call;
+gdbarch_pc_in_sigtramp_ftype x86_64_linux_in_sigtramp;
+CORE_ADDR x86_64_linux_frame_chain (struct frame_info *fi);
+void x86_64_init_frame_pc (int fromleaf, struct frame_info *fi);
+void x86_64_init_extra_frame_info (int fromleaf, struct frame_info *fi);
+
 
 #endif

Re: [RFA] sighandler backtrace on x86-64

[Elena Zannoni]

Michal Ludvig writes:
 > Hi all,
 > the attached patch enables backtrace through signal handlers on x86-64. 
 > It isn't yet complete, but this is the part that works.
 > Can someone approve it please?
 > 
 > Michal Ludvig
 > -- 
 > * SuSE CR, s.r.o     * mludvig@suse.cz
 > * +420 2 9654 5373   * http://www.suse.cz
 > 2002-09-18  Michal Ludvig  <mludvig@suse.cz>
 > 
 > 	* dwarf2cfi.c (struct context)
 > 	(struct context_reg): Moved to dwarf2cfi.h
 > 	(context_alloc, frame_state_alloc, context_cpy):
 > 	Made extern instead of static, removed prototypes.
 > 	* dwarf2cfi.h (struct context)
 > 	(struct context_reg): New, moved from dwarf2cfi.c
 > 	(context_alloc, frame_state_alloc, context_cpy):
 > 	New prototypes.


I don't see any uses of the structures and functions you are exporting.
Could you postpone these changes until they are actually used?
I have some comments anyway, see below.

 > 	* x86-64-linux-tdep.c (x86_64_linux_sigtramp_saved_pc):
 > 	Changed from static to extern.
 > 	(LINUX_SIGINFO_SIZE, LINUX_SIGCONTEXT_PC_OFFSET)
 > 	(LINUX_SIGCONTEXT_FP_OFFSET)
 > 	(LINUX_UCONTEXT_SIGCONTEXT_OFFSET): Adjusted.
 > 	(x86_64_linux_in_sigtramp, x86_64_linux_frame_chain)
 > 	(x86_64_init_frame_pc, x86_64_init_extra_frame_info): New.
 > 	* x86-64-tdep.c (x86_64_gdbarch_init): Several
 > 	set_gdbarch_*() calls now use x86-64 specific functions 
 > 	instead of DWARF2 CFI ones.
 > 	* x86-64-tdep.h (x86_64_linux_in_sigtramp)
 > 	(x86_64_linux_frame_chain, x86_64_init_frame_pc)
 > 	(x86_64_init_extra_frame_info): New prototypes.
 > 	
 > Index: dwarf2cfi.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/dwarf2cfi.c,v
 > retrieving revision 1.16
 > diff -u -p -r1.16 dwarf2cfi.c
 > --- dwarf2cfi.c	19 Jul 2002 09:40:51 -0000	1.16
 > +++ dwarf2cfi.c	18 Sep 2002 11:11:02 -0000
 > @@ -90,37 +90,6 @@ struct fde_array
 >    int array_size;
 >  };
 >  
 > -struct context_reg
 > -{
 > -  union
 > -  {
 > -    unsigned int reg;
 > -    long offset;
 > -    CORE_ADDR addr;
 > -  }
 > -  loc;
 > -  enum
 > -  {
 > -    REG_CTX_UNSAVED,
 > -    REG_CTX_SAVED_OFFSET,
 > -    REG_CTX_SAVED_REG,
 > -    REG_CTX_SAVED_ADDR,
 > -    REG_CTX_VALUE,
 > -  }
 > -  how;
 > -};
 > -
 > -/* This is the register and unwind state for a particular frame.  */
 > -struct context
 > -{
 > -  struct context_reg *reg;
 > -
 > -  CORE_ADDR cfa;
 > -  CORE_ADDR ra;
 > -  void *lsda;
 > -  int args_size;
 > -};
 > -
 >  struct frame_state_reg
 >  {
 >    union
 > @@ -208,11 +177,8 @@ static struct fde_unit *fde_unit_alloc (
 >  static struct cie_unit *cie_unit_alloc (void);
 >  static void fde_chunks_need_space ();
 >  
 > -static struct context *context_alloc ();
 > -static struct frame_state *frame_state_alloc ();
 >  static void unwind_tmp_obstack_init ();
 >  static void unwind_tmp_obstack_free ();
 > -static void context_cpy (struct context *dst, struct context *src);
 >  
 >  static unsigned int read_1u (bfd * abfd, char **p);
 >  static int read_1s (bfd * abfd, char **p);
 > @@ -286,7 +252,7 @@ fde_chunks_need_space (void)
 >  }
 >  
 >  /* Alocate a new `struct context' on temporary obstack.  */
 > -static struct context *
 > +struct context *
 >  context_alloc (void)
 >  {
 >    struct context *context;
 > @@ -303,7 +269,7 @@ context_alloc (void)
 >  }
 >  
 >  /* Alocate a new `struct frame_state' on temporary obstack.  */
 > -static struct frame_state *
 > +struct frame_state *
 >  frame_state_alloc (void)
 >  {
 >    struct frame_state *fs;
 > @@ -332,7 +298,7 @@ unwind_tmp_obstack_free (void)
 >    unwind_tmp_obstack_init ();
 >  }
 >  
 > -static void
 > +void
 >  context_cpy (struct context *dst, struct context *src)
 >  {
 >    int regs_size = sizeof (struct context_reg) * NUM_REGS;
 > Index: dwarf2cfi.h
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/dwarf2cfi.h,v
 > retrieving revision 1.1
 > diff -u -p -r1.1 dwarf2cfi.h
 > --- dwarf2cfi.h	7 Dec 2001 12:10:15 -0000	1.1
 > +++ dwarf2cfi.h	18 Sep 2002 11:11:02 -0000
 > @@ -22,6 +22,37 @@
 >  #ifndef DWARF2CFI_H
 >  #define DWARF2CFI_H
 >  
 > +struct context_reg
 > +{
 > +  union
 > +  {
 > +    unsigned int reg;
 > +    long offset;
 > +    CORE_ADDR addr;
 > +  }
 > +  loc;
 > +  enum
 > +  {
 > +    REG_CTX_UNSAVED,
 > +    REG_CTX_SAVED_OFFSET,
 > +    REG_CTX_SAVED_REG,
 > +    REG_CTX_SAVED_ADDR,
 > +    REG_CTX_VALUE,
 > +  }
 > +  how;
 > +};
 > +
 > +/* This is the register and unwind state for a particular frame.  */
 > +struct context
 > +{
 > +  struct context_reg *reg;
 > +
 > +  CORE_ADDR cfa;
 > +  CORE_ADDR ra;
 > +  void *lsda;
 > +  int args_size;
 > +};
 > +


Do you need to make the whole structure accessible? would it be enough
for your purposes to just add
struct context;
struct context_reg;

to the .h file?


 >  /* Return the frame address.  */
 >  CORE_ADDR cfi_read_fp ();
 >  
 > @@ -63,4 +94,7 @@ void cfi_get_saved_register (char *raw_b
 >  void cfi_virtual_frame_pointer (CORE_ADDR pc, int *frame_regnum,
 >  				LONGEST * frame_offset);
 >  
 > +struct context *context_alloc ();
 > +void context_cpy (struct context *dst, struct context *src);
 > +struct frame_state *frame_state_alloc ();

'extern' keyword?

Elena


 >  #endif
 > Index: x86-64-linux-tdep.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/x86-64-linux-tdep.c,v
 > retrieving revision 1.5
 > diff -u -p -r1.5 x86-64-linux-tdep.c
 > --- x86-64-linux-tdep.c	3 Sep 2002 13:06:33 -0000	1.5
 > +++ x86-64-linux-tdep.c	18 Sep 2002 11:11:02 -0000
 > @@ -35,8 +35,10 @@
 >  #define LINUX_SIGTRAMP_OFFSET1 (7)
 >  
 >  static const unsigned char linux_sigtramp_code[] = {
 > -  LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x89, 0x00, 0x00, 0x00,	/*  mov $0x89,%rax */
 > -  LINUX_SIGTRAMP_INSN1, 0x05	/* syscall */
 > +  /*  mov $__NR_rt_sigreturn,%rax */	
 > +  LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00,
 > +  /* syscall */
 > +  LINUX_SIGTRAMP_INSN1, 0x05
 >  };
 >  
 >  #define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
 > @@ -68,17 +70,22 @@ x86_64_linux_sigtramp_start (CORE_ADDR p
 >    return pc;
 >  }
 >  
 > -#define LINUX_SIGINFO_SIZE 128
 > +#define LINUX_SIGINFO_SIZE 0
 >  
 >  /* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>.  */
 > -#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET (36)
 > +#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
 > +
 > +/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
 > +#define LINUX_SIGCONTEXT_PC_OFFSET 128
 > +#define LINUX_SIGCONTEXT_FP_OFFSET 120
 >  
 >  /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
 >     address of the associated sigcontext structure.  */
 > -CORE_ADDR
 > +static CORE_ADDR
 >  x86_64_linux_sigcontext_addr (struct frame_info *frame)
 >  {
 >    CORE_ADDR pc;
 > +  ULONGEST rsp;
 >  
 >    pc = x86_64_linux_sigtramp_start (frame->pc);
 >    if (pc)
 > @@ -92,7 +99,8 @@ x86_64_linux_sigcontext_addr (struct fra
 >  
 >  
 >        /* This is the top frame. */
 > -      return read_register (SP_REGNUM) + LINUX_SIGINFO_SIZE +
 > +      rsp = read_register (SP_REGNUM);
 > +      return rsp + LINUX_SIGINFO_SIZE +
 >  	LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
 >  
 >      }
 > @@ -101,13 +109,10 @@ x86_64_linux_sigcontext_addr (struct fra
 >    return 0;
 >  }
 >  
 > -/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>.  */
 > -#define LINUX_SIGCONTEXT_PC_OFFSET (136)
 > -
 >  /* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
 >     saved program counter.  */
 >  
 > -CORE_ADDR
 > +static CORE_ADDR
 >  x86_64_linux_sigtramp_saved_pc (struct frame_info *frame)
 >  {
 >    CORE_ADDR addr;
 > @@ -134,4 +139,62 @@ x86_64_linux_frame_saved_pc (struct fram
 >    if (frame->signal_handler_caller)
 >      return x86_64_linux_sigtramp_saved_pc (frame);
 >    return cfi_get_ra (frame);
 > +}
 > +
 > +/* Return whether PC is in a GNU/Linux sigtramp routine.  */
 > +
 > +int
 > +x86_64_linux_in_sigtramp (CORE_ADDR pc, char *name)
 > +{
 > +  if (name)
 > +    return STREQ ("__restore_rt", name);
 > +  
 > +  return (x86_64_linux_sigtramp_start (pc) != 0);
 > +}
 > +
 > +CORE_ADDR
 > +x86_64_linux_frame_chain (struct frame_info *fi)
 > +{
 > +	ULONGEST addr;
 > +	CORE_ADDR fp, pc;
 > +	
 > +	if (! fi->signal_handler_caller)
 > +	{
 > +		fp = cfi_frame_chain (fi);
 > +		if(fp)
 > +			return fp;
 > +		else
 > +			addr = fi->frame;
 > +	}
 > +	else
 > +		addr = fi->next->frame;
 > +
 > +	addr += LINUX_SIGINFO_SIZE + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
 > +	
 > +	fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8)+8;
 > +	
 > +	return fp;
 > +}
 > +
 > +void
 > +x86_64_init_frame_pc (int fromleaf, struct frame_info *fi)
 > +{
 > +	CORE_ADDR addr;
 > +
 > +	if(fi->next && fi->next->signal_handler_caller)
 > +	{
 > +		addr = fi->next->next->frame 
 > +			+ LINUX_SIGINFO_SIZE 
 > +			+ LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
 > +		fi->pc = read_memory_integer (addr 
 > +				+ LINUX_SIGCONTEXT_PC_OFFSET, 8);
 > +	}
 > +	else
 > +		cfi_init_frame_pc (fromleaf, fi);
 > +}
 > +
 > +void
 > +x86_64_init_extra_frame_info (int fromleaf, struct frame_info *fi)
 > +{
 > +	cfi_init_extra_frame_info (fromleaf, fi);
 >  }
 > Index: x86-64-tdep.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/x86-64-tdep.c,v
 > retrieving revision 1.27
 > diff -u -p -r1.27 x86-64-tdep.c
 > --- x86-64-tdep.c	12 Sep 2002 08:39:26 -0000	1.27
 > +++ x86-64-tdep.c	18 Sep 2002 11:11:03 -0000
 > @@ -1026,7 +1026,7 @@ x86_64_gdbarch_init (struct gdbarch_info
 >  
 >    /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
 >       chain-pointer.  */
 > -  set_gdbarch_frame_chain (gdbarch, cfi_frame_chain);
 > +  set_gdbarch_frame_chain (gdbarch, x86_64_linux_frame_chain);
 >  
 >    set_gdbarch_frameless_function_invocation (gdbarch,
 >  					     x86_64_frameless_function_invocation);
 > @@ -1041,10 +1041,10 @@ x86_64_gdbarch_init (struct gdbarch_info
 >    set_gdbarch_frame_init_saved_regs (gdbarch, x86_64_frame_init_saved_regs);
 >  
 >  /* Frame pc initialization is handled by unwind informations.  */
 > -  set_gdbarch_init_frame_pc (gdbarch, cfi_init_frame_pc);
 > +  set_gdbarch_init_frame_pc (gdbarch, x86_64_init_frame_pc);
 >  
 >  /* Initialization of unwind informations.  */
 > -  set_gdbarch_init_extra_frame_info (gdbarch, cfi_init_extra_frame_info);
 > +  set_gdbarch_init_extra_frame_info (gdbarch, x86_64_init_extra_frame_info);
 >  
 >  /* Getting saved registers is handled by unwind informations.  */
 >    set_gdbarch_get_saved_register (gdbarch, cfi_get_saved_register);
 > @@ -1054,8 +1054,7 @@ x86_64_gdbarch_init (struct gdbarch_info
 >  /* Cons up virtual frame pointer for trace */
 >    set_gdbarch_virtual_frame_pointer (gdbarch, cfi_virtual_frame_pointer);
 >  
 > -
 > -  set_gdbarch_frame_chain_valid (gdbarch, generic_file_frame_chain_valid);
 > +  set_gdbarch_frame_chain_valid (gdbarch, file_frame_chain_valid);
 >  
 >    set_gdbarch_use_generic_dummy_frames (gdbarch, 1);
 >    set_gdbarch_call_dummy_location (gdbarch, AT_ENTRY_POINT);
 > @@ -1121,6 +1120,8 @@ x86_64_gdbarch_init (struct gdbarch_info
 >  /* Use dwarf2 debug frame informations.  */
 >    set_gdbarch_dwarf2_build_frame_info (gdbarch, dwarf2_build_frame_info);
 >    set_gdbarch_dwarf2_reg_to_regnum (gdbarch, x86_64_dwarf2_reg_to_regnum);
 > +
 > +  set_gdbarch_pc_in_sigtramp (gdbarch, x86_64_linux_in_sigtramp);
 >  
 >    return gdbarch;
 >  }
 > Index: x86-64-tdep.h
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/x86-64-tdep.h,v
 > retrieving revision 1.5
 > diff -u -p -r1.5 x86-64-tdep.h
 > --- x86-64-tdep.h	20 Jun 2002 13:08:12 -0000	1.5
 > +++ x86-64-tdep.h	18 Sep 2002 11:11:03 -0000
 > @@ -31,8 +31,12 @@ extern int x86_64_num_gregs;
 >  int x86_64_register_number (const char *name);
 >  const char *x86_64_register_name (int reg_nr);
 >  	
 > -
 >  gdbarch_frame_saved_pc_ftype x86_64_linux_frame_saved_pc;
 >  gdbarch_saved_pc_after_call_ftype x86_64_linux_saved_pc_after_call;
 > +gdbarch_pc_in_sigtramp_ftype x86_64_linux_in_sigtramp;
 > +CORE_ADDR x86_64_linux_frame_chain (struct frame_info *fi);
 > +void x86_64_init_frame_pc (int fromleaf, struct frame_info *fi);
 > +void x86_64_init_extra_frame_info (int fromleaf, struct frame_info *fi);
 > +
 >  
 >  #endif

Re: [RFA] sighandler backtrace on x86-64

[Michal Ludvig]

Elena Zannoni wrote:
> Do you need to make the whole structure accessible? would it be enough
> for your purposes to just add
> struct context;
> struct context_reg;
> to the .h file?

Hmm, I don't think so. I'm afraid I'll have to artifically create the 
content of context_reg for the sighandler caller frame.

 > I don't see any uses of the structures and functions you are
 > exporting.
 > Could you postpone these changes until they are actually used?

Sure I can. Anyway having all structures in .h isn't a bad habit, is it?

>  > +struct context *context_alloc ();
>  > +void context_cpy (struct context *dst, struct context *src);
>  > +struct frame_state *frame_state_alloc ();
> 
> 'extern' keyword?

It is the default for function declarations, and AFAIK is never used for 
them in gdb's headers.

Can I commit without the struct context movement?

Michal Ludvig
-- 
* SuSE CR, s.r.o     * mludvig@suse.cz
* +420 2 9654 5373   * http://www.suse.cz

Re: [RFA] sighandler backtrace on x86-64

[Elena Zannoni]

Michal Ludvig writes:
 > Elena Zannoni wrote:
 > > Do you need to make the whole structure accessible? would it be enough
 > > for your purposes to just add
 > > struct context;
 > > struct context_reg;
 > > to the .h file?
 > 
 > Hmm, I don't think so. I'm afraid I'll have to artifically create the 
 > content of context_reg for the sighandler caller frame.
 > 

If you need to access the fields of the structure later on, then it's fine.

 >  > I don't see any uses of the structures and functions you are
 >  > exporting.
 >  > Could you postpone these changes until they are actually used?
 > 
 > Sure I can. Anyway having all structures in .h isn't a bad habit, is it?
 > 

No, having the whole structure is fine, if it is used. If you just
need it for passing paramters around, w/o accessing the internal
fields, then it's better not exporting the whole struct, to keep the
interface a bit tighter.

 > >  > +struct context *context_alloc ();
 > >  > +void context_cpy (struct context *dst, struct context *src);
 > >  > +struct frame_state *frame_state_alloc ();
 > > 
 > > 'extern' keyword?
 > 
 > It is the default for function declarations, and AFAIK is never used for 
 > them in gdb's headers.
 > 

Hmmm, it is customary to use it. 

 > Can I commit without the struct context movement?
 > 

Yes, but I have noticed a few non-gnu style problems in x86-64.c:
 > +            if(fp)
 > +    fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8)+8;
 > +    if(fi->next && fi->next->signal_handler_caller)


Could you fix them before committing?

Thanks
Elena


 > Michal Ludvig
 > -- 
 > * SuSE CR, s.r.o     * mludvig@suse.cz
 > * +420 2 9654 5373   * http://www.suse.cz

Re: [RFA] sighandler backtrace on x86-64

[Michal Ludvig]

Elena Zannoni wrote:
> Michal Ludvig writes:
>  > +            if(fp)
>  > +    fp = read_memory_integer (addr + LINUX_SIGCONTEXT_FP_OFFSET, 8)+8;
>  > +    if(fi->next && fi->next->signal_handler_caller)
> 
> Could you fix them before committing?

Reindented and committed. Thanks.

Michal Ludvig
-- 
* SuSE CR, s.r.o     * mludvig@suse.cz
* (+420) 296.545.373 * http://www.suse.cz