binutils-gdb/gdbserver/ax.h
Andrew Burgess 3812b38d8d gdbserver: allow agent expressions to fail with invalid memory access
This commit extends gdbserver to take account of a failed memory
access from agent_mem_read, and to return a new eval_result_type
expr_eval_invalid_memory_access.

I have only updated the agent_mem_read calls related directly to
reading memory, I have not updated any of the calls related to
tracepoint data collection.  This is just because I'm not familiar
with that area of gdb/gdbserver, and I don't want to break anything,
so leaving the existing behaviour untouched seems like the safest
approach.

I've then updated gdb.base/bp-cond-failure.exp to test evaluating the
breakpoints on the target, and have also extended the test so that it
checks for different sizes of memory access.
2023-04-03 14:46:32 +01:00

147 lines
4.6 KiB
C

/* Data structures and functions associated with agent expressions in GDB.
Copyright (C) 2009-2023 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 GDBSERVER_AX_H
#define GDBSERVER_AX_H
#include "regcache.h"
#ifdef IN_PROCESS_AGENT
#include "gdbsupport/agent.h"
#define debug_threads debug_agent
#endif
struct traceframe;
/* Enumeration of the different kinds of things that can happen during
agent expression evaluation. */
enum eval_result_type
{
expr_eval_no_error,
expr_eval_empty_expression,
expr_eval_empty_stack,
expr_eval_stack_overflow,
expr_eval_stack_underflow,
expr_eval_unhandled_opcode,
expr_eval_unrecognized_opcode,
expr_eval_divide_by_zero,
expr_eval_invalid_goto,
expr_eval_invalid_memory_access
};
struct agent_expr
{
int length;
unsigned char *bytes;
};
#ifndef IN_PROCESS_AGENT
/* The packet form of an agent expression consists of an 'X', number
of bytes in expression, a comma, and then the bytes. */
struct agent_expr *gdb_parse_agent_expr (const char **actparm);
/* Release an agent expression. */
void gdb_free_agent_expr (struct agent_expr *aexpr);
/* Convert the bytes of an agent expression back into hex digits, so
they can be printed or uploaded. This allocates the buffer,
callers should free when they are done with it. */
char *gdb_unparse_agent_expr (struct agent_expr *aexpr);
void emit_prologue (void);
void emit_epilogue (void);
enum eval_result_type compile_bytecodes (struct agent_expr *aexpr);
#endif
/* The context when evaluating agent expression. */
struct eval_agent_expr_context
{
/* The registers when evaluating agent expression. */
struct regcache *regcache;
/* The traceframe, if any, when evaluating agent expression. */
struct traceframe *tframe;
/* The tracepoint, if any, when evaluating agent expression. */
struct tracepoint *tpoint;
};
enum eval_result_type
gdb_eval_agent_expr (struct eval_agent_expr_context *ctx,
struct agent_expr *aexpr,
ULONGEST *rslt);
/* Bytecode compilation function vector. */
struct emit_ops
{
void (*emit_prologue) (void);
void (*emit_epilogue) (void);
void (*emit_add) (void);
void (*emit_sub) (void);
void (*emit_mul) (void);
void (*emit_lsh) (void);
void (*emit_rsh_signed) (void);
void (*emit_rsh_unsigned) (void);
void (*emit_ext) (int arg);
void (*emit_log_not) (void);
void (*emit_bit_and) (void);
void (*emit_bit_or) (void);
void (*emit_bit_xor) (void);
void (*emit_bit_not) (void);
void (*emit_equal) (void);
void (*emit_less_signed) (void);
void (*emit_less_unsigned) (void);
void (*emit_ref) (int size);
void (*emit_if_goto) (int *offset_p, int *size_p);
void (*emit_goto) (int *offset_p, int *size_p);
void (*write_goto_address) (CORE_ADDR from, CORE_ADDR to, int size);
void (*emit_const) (LONGEST num);
void (*emit_call) (CORE_ADDR fn);
void (*emit_reg) (int reg);
void (*emit_pop) (void);
void (*emit_stack_flush) (void);
void (*emit_zero_ext) (int arg);
void (*emit_swap) (void);
void (*emit_stack_adjust) (int n);
/* Emit code for a generic function that takes one fixed integer
argument and returns a 64-bit int (for instance, tsv getter). */
void (*emit_int_call_1) (CORE_ADDR fn, int arg1);
/* Emit code for a generic function that takes one fixed integer
argument and a 64-bit int from the top of the stack, and returns
nothing (for instance, tsv setter). */
void (*emit_void_call_2) (CORE_ADDR fn, int arg1);
/* Emit code specialized for common combinations of compare followed
by a goto. */
void (*emit_eq_goto) (int *offset_p, int *size_p);
void (*emit_ne_goto) (int *offset_p, int *size_p);
void (*emit_lt_goto) (int *offset_p, int *size_p);
void (*emit_le_goto) (int *offset_p, int *size_p);
void (*emit_gt_goto) (int *offset_p, int *size_p);
void (*emit_ge_goto) (int *offset_p, int *size_p);
};
extern CORE_ADDR current_insn_ptr;
extern int emit_error;
#endif /* GDBSERVER_AX_H */