binutils-gdb/gdb/arch-utils.h
Yao Qi 7eb895307f Skip unwritable frames in command "finish"
Nowadays, GDB can't insert breakpoint on the return address of the
exception handler on ARM M-profile, because the address is a magic
one 0xfffffff9,

 (gdb) bt
 #0  CT32B1_IRQHandler () at ../src/timer.c:67
 #1  <signal handler called>
 #2  main () at ../src/timer.c:127

(gdb) info frame
Stack level 0, frame at 0x200ffa8:
 pc = 0x4ec in CT32B1_IRQHandler (../src/timer.c:67); saved pc = 0xfffffff9
 called by frame at 0x200ffc8
 source language c.
 Arglist at 0x200ffa0, args:
 Locals at 0x200ffa0, Previous frame's sp is 0x200ffa8
 Saved registers:
  r7 at 0x200ffa0, lr at 0x200ffa4

(gdb) x/x 0xfffffff9
0xfffffff9:     Cannot access memory at address 0xfffffff9

(gdb) finish
Run till exit from #0  CT32B1_IRQHandler () at ../src/timer.c:67
Ed:15: Target error from Set break/watch: Et:96: Pseudo-address (0xFFFFFFxx) for EXC_RETURN is invalid (GDB error?)

Warning:
Cannot insert hardware breakpoint 0.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.

Command aborted.

even some debug probe can't set hardware breakpoint on the magic
address too,

(gdb) hbreak *0xfffffff9
Hardware assisted breakpoint 2 at 0xfffffff9
(gdb) c
Continuing.
Ed:15: Target error from Set break/watch: Et:96: Pseudo-address (0xFFFFFFxx) for EXC_RETURN is invalid (GDB error?)

Warning:
Cannot insert hardware breakpoint 2.
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.

Command aborted.

The problem described above is quite similar to PR 8841, in which GDB
can't set breakpoint on signal trampoline, which is mapped to a read-only
page by kernel.  The rationale of this patch is to skip "unwritable"
frames when looking for caller frames in command "finish", and a new
gdbarch method code_of_frame_writable is added.  This patch fixes
the problem on ARM cortex-m target, but it can be used to fix
PR 8841 too.

gdb:

2016-05-10  Yao Qi  <yao.qi@arm.com>

	* arch-utils.c (default_code_of_frame_writable): New function.
	* arch-utils.h (default_code_of_frame_writable): Declare.
	* arm-tdep.c (arm_code_of_frame_writable): New function.
	(arm_gdbarch_init): Install gdbarch method
	code_of_frame_writable if the target is M-profile.
	* frame.c (skip_unwritable_frames): New function.
	* frame.h (skip_unwritable_frames): Declare.
	* gdbarch.sh (code_of_frame_writable): New.
	* gdbarch.c, gdbarch.h: Re-generated.
	* infcmd.c (finish_command): Call skip_unwritable_frames.
2016-05-23 17:32:56 +01:00

215 lines
8.2 KiB
C

/* Dynamic architecture support for GDB, the GNU debugger.
Copyright (C) 1998-2016 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#ifndef GDBARCH_UTILS_H
#define GDBARCH_UTILS_H
struct gdbarch;
struct frame_info;
struct minimal_symbol;
struct type;
struct gdbarch_info;
/* An implementation of gdbarch_displaced_step_copy_insn for
processors that don't need to modify the instruction before
single-stepping the displaced copy.
Simply copy gdbarch_max_insn_length (ARCH) bytes from FROM to TO.
The closure is an array of that many bytes containing the
instruction's bytes, allocated with xmalloc. */
extern struct displaced_step_closure *
simple_displaced_step_copy_insn (struct gdbarch *gdbarch,
CORE_ADDR from, CORE_ADDR to,
struct regcache *regs);
/* Simple implementation of gdbarch_displaced_step_free_closure: Call
xfree.
This is appropriate for use with simple_displaced_step_copy_insn. */
extern void
simple_displaced_step_free_closure (struct gdbarch *gdbarch,
struct displaced_step_closure *closure);
/* Default implementation of gdbarch_displaced_hw_singlestep. */
extern int
default_displaced_step_hw_singlestep (struct gdbarch *,
struct displaced_step_closure *);
/* Possible value for gdbarch_displaced_step_location:
Place displaced instructions at the program's entry point,
leaving space for inferior function call return breakpoints. */
extern CORE_ADDR displaced_step_at_entry_point (struct gdbarch *gdbarch);
/* The only possible cases for inner_than. */
extern int core_addr_lessthan (CORE_ADDR lhs, CORE_ADDR rhs);
extern int core_addr_greaterthan (CORE_ADDR lhs, CORE_ADDR rhs);
/* Identity functions on a CORE_ADDR. Just return the "addr". */
extern CORE_ADDR core_addr_identity (struct gdbarch *gdbarch, CORE_ADDR addr);
extern gdbarch_convert_from_func_ptr_addr_ftype convert_from_func_ptr_addr_identity;
/* No-op conversion of reg to regnum. */
extern int no_op_reg_to_regnum (struct gdbarch *gdbarch, int reg);
/* Do nothing version of coff_make_msymbol_special. */
void default_coff_make_msymbol_special (int val, struct minimal_symbol *msym);
/* Do nothing default implementation of gdbarch_make_symbol_special. */
void default_make_symbol_special (struct symbol *sym, struct objfile *objfile);
/* Do nothing default implementation of gdbarch_adjust_dwarf2_addr. */
CORE_ADDR default_adjust_dwarf2_addr (CORE_ADDR pc);
/* Do nothing default implementation of gdbarch_adjust_dwarf2_line. */
CORE_ADDR default_adjust_dwarf2_line (CORE_ADDR addr, int rel);
/* Version of cannot_fetch_register() / cannot_store_register() that
always fails. */
int cannot_register_not (struct gdbarch *gdbarch, int regnum);
/* Legacy version of target_virtual_frame_pointer(). Assumes that
there is an gdbarch_deprecated_fp_regnum and that it is the same, cooked or
raw. */
extern gdbarch_virtual_frame_pointer_ftype legacy_virtual_frame_pointer;
extern CORE_ADDR generic_skip_trampoline_code (struct frame_info *frame,
CORE_ADDR pc);
extern CORE_ADDR generic_skip_solib_resolver (struct gdbarch *gdbarch,
CORE_ADDR pc);
extern int generic_in_solib_return_trampoline (struct gdbarch *gdbarch,
CORE_ADDR pc, const char *name);
extern int generic_stack_frame_destroyed_p (struct gdbarch *gdbarch,
CORE_ADDR pc);
extern int default_code_of_frame_writable (struct gdbarch *gdbarch,
struct frame_info *frame);
/* By default, registers are not convertible. */
extern int generic_convert_register_p (struct gdbarch *gdbarch, int regnum,
struct type *type);
extern int default_stabs_argument_has_addr (struct gdbarch *gdbarch,
struct type *type);
extern int generic_instruction_nullified (struct gdbarch *gdbarch,
struct regcache *regcache);
int default_remote_register_number (struct gdbarch *gdbarch,
int regno);
/* For compatibility with older architectures, returns
(LEGACY_SIM_REGNO_IGNORE) when the register doesn't have a valid
name. */
extern int legacy_register_sim_regno (struct gdbarch *gdbarch, int regnum);
/* Return the selected byte order, or BFD_ENDIAN_UNKNOWN if no byte
order was explicitly selected. */
extern enum bfd_endian selected_byte_order (void);
/* Return the selected architecture's name, or NULL if no architecture
was explicitly selected. */
extern const char *selected_architecture_name (void);
/* Initialize a ``struct info''. Can't use memset(0) since some
default values are not zero. "fill" takes all available
information and fills in any unspecified fields. */
extern void gdbarch_info_init (struct gdbarch_info *info);
/* Similar to init, but this time fill in the blanks. Information is
obtained from the global "set ..." options and explicitly
initialized INFO fields. */
extern void gdbarch_info_fill (struct gdbarch_info *info);
/* Return the architecture for ABFD. If no suitable architecture
could be find, return NULL. */
extern struct gdbarch *gdbarch_from_bfd (bfd *abfd);
/* Return "current" architecture. If the target is running, this is the
architecture of the selected frame. Otherwise, the "current" architecture
defaults to the target architecture.
This function should normally be called solely by the command interpreter
routines to determine the architecture to execute a command in. */
extern struct gdbarch *get_current_arch (void);
extern int default_has_shared_address_space (struct gdbarch *);
extern int default_fast_tracepoint_valid_at (struct gdbarch *gdbarch,
CORE_ADDR addr, char **msg);
extern void default_remote_breakpoint_from_pc (struct gdbarch *,
CORE_ADDR *pcptr, int *kindptr);
extern void default_gen_return_address (struct gdbarch *gdbarch,
struct agent_expr *ax,
struct axs_value *value,
CORE_ADDR scope);
extern const char *default_auto_charset (void);
extern const char *default_auto_wide_charset (void);
extern int default_return_in_first_hidden_param_p (struct gdbarch *,
struct type *);
extern int default_insn_is_call (struct gdbarch *, CORE_ADDR);
extern int default_insn_is_ret (struct gdbarch *, CORE_ADDR);
extern int default_insn_is_jump (struct gdbarch *, CORE_ADDR);
/* Do-nothing version of vsyscall_range. Returns false. */
extern int default_vsyscall_range (struct gdbarch *gdbarch, struct mem_range *range);
/* Default way to advance the PC to the next instruction in order to
skip a permanent breakpoint. Increments the PC by the size of a
software breakpoint instruction, as determined with
gdbarch_breakpoint_from_pc. This matches how the breakpoints
module determines whether a breakpoint is permanent. */
extern void default_skip_permanent_breakpoint (struct regcache *regcache);
/* Symbols for gdbarch_infcall_mmap; their Linux PROT_* system
definitions would be dependent on compilation host. */
#define GDB_MMAP_PROT_READ 0x1 /* Page can be read. */
#define GDB_MMAP_PROT_WRITE 0x2 /* Page can be written. */
#define GDB_MMAP_PROT_EXEC 0x4 /* Page can be executed. */
extern CORE_ADDR default_infcall_mmap (CORE_ADDR size, unsigned prot);
extern void default_infcall_munmap (CORE_ADDR addr, CORE_ADDR size);
extern char *default_gcc_target_options (struct gdbarch *gdbarch);
extern const char *default_gnu_triplet_regexp (struct gdbarch *gdbarch);
extern int default_addressable_memory_unit_size (struct gdbarch *gdbarch);
extern void default_guess_tracepoint_registers (struct gdbarch *gdbarch,
struct regcache *regcache,
CORE_ADDR addr);
#endif