[PATCH] Re: KDB in ameslab

linas at austin.ibm.com linas at austin.ibm.com
Tue Feb 24 08:21:01 EST 2004


On Mon, Feb 23, 2004 at 01:46:39PM -0600, linas at austin.ibm.com wrote:
> On Tue, Feb 17, 2004 at 03:35:27PM +1100, Anton Blanchard wrote:
> >
> > Hi,
> >
> > Linus had a nasty problem debugging what should have been a simple
> > problem but became a nightmare due to an incorrect debug hook. In
> > response to this I have cleaned up our debug hooks, it should be much
> > harder to screw up.
> >
> > A side effect of this is that KDB is probably broken. I started looking
> > into fixing it however I noticed it looks out of date. Does someone have
> > the urge to update it?
> I don't have the urge to update it but I'm motivated (today) to fix it
> up enough to work.  Do you want a patch on the mailing list, or just
> a bk push?

The atttachments below are the only changes I needed to
make to get kdb to compile & run with toadys (2.6.3)
ameslab bk tree.

The file include/linux/dis-asm.h seems to be missing from
the ameslab tree, I'm not sure why.  I append it below.
Its a copy of this file from the 2.4 trees (which seem
to be identical).

Please apply this patch & file to ameslab.


p.s. where is the "newest" KDB ?  I found
but googling KDB is such a sad experience that I'm not
convinced that something newer isn't hiding somewhere.

-------------- next part --------------

The atttachments below are the only changes I needed to
make to get kdb to compile & run with toadys (2.6.3)
ameslab bk tree.

The file include/linux/dis-asm.h seems to be missing from
the ameslab tree, I'm not sure why.  I append it below.
Its a copy of this file from the 2.4 trees (which seem
to be identical).

Please apply this patch & file to ameslab.


p.s. where is the "newest" KDB ?  I found
but googling KDB is such a sad experience that I'm not
convinced that something newer isn't hiding somewhere.

===== kdbasupport.c 1.5 vs edited =====
--- 1.5/arch/ppc64/kdb/kdbasupport.c	Thu Jan 22 00:11:58 2004
+++ edited/kdbasupport.c	Mon Feb 23 13:49:24 2004
@@ -732,7 +732,6 @@
 	asm volatile("sync; isync");

-extern void (*debugger_fault_handler)(struct pt_regs *);
 extern void longjmp(u_int *, int);

 unsigned long
@@ -2028,12 +2027,12 @@
 	kdb_map_scc();		/* map sysrq key */

-	debugger = kdb_debugger;
-	debugger_bpt = kdb_debugger_bpt;
-	debugger_sstep = kdb_debugger_sstep;
-	debugger_iabr_match = kdb_debugger_iabr_match;
-	debugger_dabr_match = kdb_debugger_dabr_match;
-	debugger_fault_handler = NULL; /* this guy is normally off. */
+	__debugger = kdb_debugger;
+	__debugger_bpt = kdb_debugger_bpt;
+	__debugger_sstep = kdb_debugger_sstep;
+	__debugger_iabr_match = kdb_debugger_iabr_match;
+	__debugger_dabr_match = kdb_debugger_dabr_match;
+	__debugger_fault_handler = NULL; /* this guy is normally off. */
 				    /* = kdb_debugger_fault_handler; */

-------------- next part --------------
/* Interface between the opcode library and its callers.
   Written by Cygnus Support, 1993.

   The opcode library (libopcodes.a) provides instruction decoders for
   a large variety of instruction sets, callable with an identical
   interface, for making instruction-processing programs more independent
   of the instruction set being processed.  */

/* Hacked by Scott Lurndal at SGI (02/1999) for linux kernel debugger */
/* Upgraded to cygnus CVS Keith Owens <kaos at sgi.com> 30 Oct 2000 */

#ifndef DIS_ASM_H
#define DIS_ASM_H

#ifdef __cplusplus
extern "C" {

	 * Misc definitions
#ifndef PARAMS
#define PARAMS(x)	x
#define PTR void *
#define FILE int
#if !defined(NULL)
#define NULL 0

#define abort()		dis_abort(__LINE__)

static inline void
dis_abort(int line)
	panic("Aborting disassembler @ line %d\n", line);

#include <linux/slab.h>
#include <asm/page.h>
#define xstrdup(string) ({ char *res = kdb_strdup(string, GFP_ATOMIC); if (!res) BUG(); res; })
#define xmalloc(size) ({ void *res = kmalloc(size, GFP_ATOMIC); if (!res) BUG(); res; })
#define free(address) kfree(address)

#include <bfd.h>

typedef int (*fprintf_ftype) PARAMS((PTR, const char*, ...));

enum dis_insn_type {
  dis_noninsn,			/* Not a valid instruction */
  dis_nonbranch,		/* Not a branch instruction */
  dis_branch,			/* Unconditional branch */
  dis_condbranch,		/* Conditional branch */
  dis_jsr,			/* Jump to subroutine */
  dis_condjsr,			/* Conditional jump to subroutine */
  dis_dref,			/* Data reference instruction */
  dis_dref2			/* Two data references in instruction */

/* This struct is passed into the instruction decoding routine,
   and is passed back out into each callback.  The various fields are used
   for conveying information from your main routine into your callbacks,
   for passing information into the instruction decoders (such as the
   addresses of the callback functions), or for passing information
   back from the instruction decoders to their callers.

   It must be initialized before it is first passed; this can be done
   by hand, or using one of the initialization macros below.  */

typedef struct disassemble_info {
  fprintf_ftype fprintf_func;
  fprintf_ftype fprintf_dummy;
  PTR stream;
  PTR application_data;

  /* Target description.  We could replace this with a pointer to the bfd,
     but that would require one.  There currently isn't any such requirement
     so to avoid introducing one we record these explicitly.  */
  /* The bfd_flavour.  This can be bfd_target_unknown_flavour.  */
  enum bfd_flavour flavour;
  /* The bfd_arch value.  */
  enum bfd_architecture arch;
  /* The bfd_mach value.  */
  unsigned long mach;
  /* Endianness (for bi-endian cpus).  Mono-endian cpus can ignore this.  */
  enum bfd_endian endian;

  /* An array of pointers to symbols either at the location being disassembled
     or at the start of the function being disassembled.  The array is sorted
     so that the first symbol is intended to be the one used.  The others are
     present for any misc. purposes.  This is not set reliably, but if it is
     not NULL, it is correct.  */
  asymbol **symbols;
  /* Number of symbols in array.  */
  int num_symbols;

  /* For use by the disassembler.
     The top 16 bits are reserved for public use (and are documented here).
     The bottom 16 bits are for the internal use of the disassembler.  */
  unsigned long flags;
#define INSN_HAS_RELOC	0x80000000
  PTR private_data;

  /* Function used to get bytes to disassemble.  MEMADDR is the
     address of the stuff to be disassembled, MYADDR is the address to
     put the bytes in, and LENGTH is the number of bytes to read.
     INFO is a pointer to this struct.
     Returns an errno value or 0 for success.  */
  int (*read_memory_func)
    PARAMS ((bfd_vma memaddr, bfd_byte *myaddr, unsigned int length,
	     struct disassemble_info *info));

  /* Function which should be called if we get an error that we can't
     recover from.  STATUS is the errno value from read_memory_func and
     MEMADDR is the address that we were trying to read.  INFO is a
     pointer to this struct.  */
  void (*memory_error_func)
    PARAMS ((int status, bfd_vma memaddr, struct disassemble_info *info));

  /* Function called to print ADDR.  */
  void (*print_address_func)
    PARAMS ((bfd_vma addr, struct disassemble_info *info));

  /* Function called to determine if there is a symbol at the given ADDR.
     If there is, the function returns 1, otherwise it returns 0.
     This is used by ports which support an overlay manager where
     the overlay number is held in the top part of an address.  In
     some circumstances we want to include the overlay number in the
     address, (normally because there is a symbol associated with
     that address), but sometimes we want to mask out the overlay bits.  */
  int (* symbol_at_address_func)
    PARAMS ((bfd_vma addr, struct disassemble_info * info));

  /* These are for buffer_read_memory.  */
  bfd_byte *buffer;
  bfd_vma buffer_vma;
  unsigned int buffer_length;

  /* This variable may be set by the instruction decoder.  It suggests
      the number of bytes objdump should display on a single line.  If
      the instruction decoder sets this, it should always set it to
      the same value in order to get reasonable looking output.  */
  int bytes_per_line;

  /* the next two variables control the way objdump displays the raw data */
  /* For example, if bytes_per_line is 8 and bytes_per_chunk is 4, the */
  /* output will look like this:
     00:   00000000 00000000
     with the chunks displayed according to "display_endian". */
  int bytes_per_chunk;
  enum bfd_endian display_endian;

  /* Number of octets per incremented target address
     Normally one, but some DSPs have byte sizes of 16 or 32 bits
  unsigned int octets_per_byte;

  /* Results from instruction decoders.  Not all decoders yet support
     this information.  This info is set each time an instruction is
     decoded, and is only valid for the last such instruction.

     To determine whether this decoder supports this information, set
     insn_info_valid to 0, decode an instruction, then check it.  */

  char insn_info_valid;		/* Branch info has been set. */
  char branch_delay_insns;	/* How many sequential insn's will run before
				   a branch takes effect.  (0 = normal) */
  char data_size;		/* Size of data reference in insn, in bytes */
  enum dis_insn_type insn_type;	/* Type of instruction */
  bfd_vma target;		/* Target address of branch or dref, if known;
				   zero if unknown.  */
  bfd_vma target2;		/* Second target address for dref2 */

  /* Command line options specific to the target disassembler.  */
  char * disassembler_options;

} disassemble_info;

/* Standard disassemblers.  Disassemble one instruction at the given
   target address.  Return number of bytes processed.  */
typedef int (*disassembler_ftype)
     PARAMS((bfd_vma, disassemble_info *));

extern int print_insn_big_mips		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_little_mips	PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_i386_att		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_i386_intel	PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_ia64		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_i370		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_m68hc11		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_m68hc12		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_m68k		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_z8001		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_z8002		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_h8300		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_h8300h		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_h8300s		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_h8500		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_alpha		PARAMS ((bfd_vma, disassemble_info*));
extern disassembler_ftype arc_get_disassembler PARAMS ((int, int));
extern int print_insn_big_arm		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_little_arm	PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_sparc		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_big_a29k		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_little_a29k	PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_i860		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_i960		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_sh		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_shl		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_hppa		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_fr30		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_m32r		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_m88k		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_mcore		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_mn10200		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_mn10300		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_ns32k		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_big_powerpc	PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_little_powerpc	PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_rs6000		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_w65		PARAMS ((bfd_vma, disassemble_info*));
extern disassembler_ftype cris_get_disassembler PARAMS ((bfd *));
extern int print_insn_d10v		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_d30v		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_v850		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_tic30		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_vax		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_tic54x		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_tic80		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_pj		PARAMS ((bfd_vma, disassemble_info*));
extern int print_insn_avr		PARAMS ((bfd_vma, disassemble_info*));

extern void print_arm_disassembler_options PARAMS ((FILE *));
extern void parse_arm_disassembler_option  PARAMS ((char *));
extern int  get_arm_regname_num_options    PARAMS ((void));
extern int  set_arm_regname_option         PARAMS ((int));
extern int  get_arm_regnames               PARAMS ((int, const char **, const char **, const char ***));

/* Fetch the disassembler for a given BFD, if that support is available.  */
extern disassembler_ftype disassembler	PARAMS ((bfd *));

/* Document any target specific options available from the disassembler.  */
extern void disassembler_usage          PARAMS ((FILE *));

/* This block of definitions is for particular callers who read instructions
   into a buffer before calling the instruction decoder.  */

/* Here is a function which callers may wish to use for read_memory_func.
   It gets bytes from a buffer.  */
extern int buffer_read_memory
  PARAMS ((bfd_vma, bfd_byte *, unsigned int, struct disassemble_info *));

/* This function goes with buffer_read_memory.
   It prints a message using info->fprintf_func and info->stream.  */
extern void perror_memory PARAMS ((int, bfd_vma, struct disassemble_info *));

/* Just print the address in hex.  This is included for completeness even
   though both GDB and objdump provide their own (to print symbolic
   addresses).  */
extern void generic_print_address
  PARAMS ((bfd_vma, struct disassemble_info *));

/* Always true.  */
extern int generic_symbol_at_address
  PARAMS ((bfd_vma, struct disassemble_info *));

/* Macro to initialize a disassemble_info struct.  This should be called
   by all applications creating such a struct.  */
  (INFO).flavour = bfd_target_unknown_flavour, \
  (INFO).arch = bfd_arch_unknown, \
  (INFO).mach = 0, \
  (INFO).octets_per_byte = 1, \

/* Call this macro to initialize only the internal variables for the
   disassembler.  Architecture dependent things such as byte order, or machine
   variant are not touched by this macro.  This makes things much easier for
   GDB which must initialize these things separately.  */

  (INFO).fprintf_func = (fprintf_ftype)(FPRINTF_FUNC), \
  (INFO).stream = (PTR)(STREAM), \
  (INFO).symbols = NULL, \
  (INFO).num_symbols = 0, \
  (INFO).buffer = NULL, \
  (INFO).buffer_vma = 0, \
  (INFO).buffer_length = 0, \
  (INFO).read_memory_func = buffer_read_memory, \
  (INFO).memory_error_func = perror_memory, \
  (INFO).print_address_func = generic_print_address, \
  (INFO).symbol_at_address_func = generic_symbol_at_address, \
  (INFO).flags = 0, \
  (INFO).bytes_per_line = 0, \
  (INFO).bytes_per_chunk = 0, \
  (INFO).display_endian = BFD_ENDIAN_UNKNOWN, \
  (INFO).insn_info_valid = 0

#ifdef __cplusplus

#endif /* ! defined (DIS_ASM_H) */

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