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crash/gdb_interface.c
Tao Liu 2145b2bb79 Let gdb get kernel module symbols info from crash 
Gdb will try to resolve an address to its corresponding symbol name such as
when printing a structure. It works fine for kernel symbols, because gdb can
find them through vmlinux. However as for kernel modules symbols, crash
resolves them by dig into "struct module", which gdb don't know. As a result,
gdb fails to translate a kernel module address to its symbol name without
"mod -s|-S" options. For example we can reproduce the issue as follows.

    crash> timer
    ....
    4331308176       336  ffff94ea24240860  ffffffffc03762c0  <estimation_timer>
    ....
    crash> sym 0xffffffffc03762c0
    ffffffffc03762c0 (t) estimation_timer [ip_vs]

Before patch:
    crash> timer_list ffff94ea24240860
    struct timer_list {
      ....
      function = 0xffffffffc03762c0,
      ....
    }

After patch:
    crash> timer_list ffff94ea24240860
    struct timer_list {
      ....
      function = 0xffffffffc03762c0 <estimation_timer>,
      ....
    }

In this patch, we add an interface for gdb, when gdb trying to build kernel
module's address symbolic, the info can be get from crash.

Signed-off-by: Tao Liu <ltao@redhat.com>
2022-09-01 11:03:52 +09:00

1097 lines
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/* gdb_interface.c - core analysis suite
*
* Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
* Copyright (C) 2002-2015,2018-2019 David Anderson
* Copyright (C) 2002-2015,2018-2019 Red Hat, Inc. All rights reserved.
*
* 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 2 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.
*/
#include "defs.h"
#ifndef GDB_10_2
static void exit_after_gdb_info(void);
#endif
static int is_restricted_command(char *, ulong);
static void strip_redirection(char *);
int get_frame_offset(ulong);
int *gdb_output_format;
unsigned int *gdb_print_max;
unsigned char *gdb_prettyprint_structs;
unsigned char *gdb_prettyprint_arrays;
unsigned int *gdb_repeat_count_threshold;
unsigned char *gdb_stop_print_at_null;
unsigned int *gdb_output_radix;
static void gdb_error_debug(void);
static ulong gdb_user_print_option_address(char *);
/*
* Called from main() this routine sets up the call-back hook such that
* gdb's main() routine -- renamed gdb_main() -- will call back to
* our main_loop() after gdb initializes.
*/
void
gdb_main_loop(int argc, char **argv)
{
argc = 1;
if (pc->flags & SILENT) {
if (pc->flags & READNOW)
argv[argc++] = "--readnow";
argv[argc++] = "--quiet";
argv[argc++] = pc->namelist_debug ?
pc->namelist_debug :
(pc->debuginfo_file && (st->flags & CRC_MATCHES) ?
pc->debuginfo_file : pc->namelist);
} else {
if (pc->flags & READNOW)
argv[argc++] = "--readnow";
argv[argc++] = pc->namelist_debug ?
pc->namelist_debug :
(pc->debuginfo_file && (st->flags & CRC_MATCHES) ?
pc->debuginfo_file : pc->namelist);
}
if (CRASHDEBUG(1)) {
int i;
fprintf(fp, "gdb ");
for (i = 1; i < argc; i++)
fprintf(fp, "%s ", argv[i]);
fprintf(fp, "\n");
}
optind = 0;
#ifndef GDB_10_2
#if defined(GDB_5_3) || defined(GDB_6_0) || defined(GDB_6_1)
command_loop_hook = main_loop;
#else
deprecated_command_loop_hook = main_loop;
#endif
#endif
gdb_main_entry(argc, argv);
}
/*
* Update any hooks that gdb has set.
*/
void
update_gdb_hooks(void)
{
#if defined(GDB_6_0) || defined(GDB_6_1)
command_loop_hook = pc->flags & VERSION_QUERY ?
exit_after_gdb_info : main_loop;
target_new_objfile_hook = NULL;
#endif
#if defined(GDB_7_0) || defined(GDB_7_3_1) || defined(GDB_7_6)
deprecated_command_loop_hook = pc->flags & VERSION_QUERY ?
exit_after_gdb_info : main_loop;
#endif
}
void
gdb_readnow_warning(void)
{
if ((THIS_GCC_VERSION >= GCC(3,4,0)) && (THIS_GCC_VERSION < GCC(4,0,0))
&& !(pc->flags & READNOW)) {
fprintf(stderr,
"WARNING: Because this kernel was compiled with gcc version %d.%d.%d, certain\n"
" commands or command options may fail unless crash is invoked with\n"
" the \"--readnow\" command line option.\n\n",
kt->gcc_version[0],
kt->gcc_version[1],
kt->gcc_version[2]);
}
}
/*
* Used only by the -v command line option, get gdb to initialize itself
* with no arguments, print its version and GPL paragraph, and then call
* back to exit_after_gdb_info().
*/
void
display_gdb_banner(void)
{
optind = 0;
#ifndef GDB_10_2
#if defined(GDB_5_3) || defined(GDB_6_0) || defined(GDB_6_1)
command_loop_hook = exit_after_gdb_info;
#else
deprecated_command_loop_hook = exit_after_gdb_info;
#endif
#endif
args[0] = "gdb";
args[1] = "-version";
gdb_main_entry(2, args);
}
#ifndef GDB_10_2
static void
exit_after_gdb_info(void)
{
fprintf(fp, "\n");
clean_exit(0);
}
#endif
/*
* Stash a copy of the gdb version locally. This can be called before
* gdb gets initialized, so bypass gdb_interface().
*/
void
get_gdb_version(void)
{
struct gnu_request request;
if (!pc->gdb_version) {
request.command = GNU_VERSION;
gdb_command_funnel(&request); /* bypass gdb_interface() */
pc->gdb_version = request.buf;
}
}
void
gdb_session_init(void)
{
struct gnu_request *req;
int debug_data_pulled_in;
if (!have_partial_symbols() && !have_full_symbols())
no_debugging_data(FATAL);
/*
* Restore the SIGINT and SIGPIPE handlers, which got temporarily
* re-assigned by gdb. The SIGINT call also initializes GDB's
* SIGINT sigaction.
*/
SIGACTION(SIGINT, restart, &pc->sigaction, &pc->gdb_sigaction);
SIGACTION(SIGPIPE, SIG_IGN, &pc->sigaction, NULL);
if (!(pc->flags & DROP_CORE))
SIGACTION(SIGSEGV, restart, &pc->sigaction, NULL);
/*
* Set up pointers to gdb variables.
*/
#if defined(GDB_5_3) || defined(GDB_6_0) || defined(GDB_6_1)
gdb_output_format = &output_format;
gdb_print_max = &print_max;
gdb_prettyprint_structs = &prettyprint_structs;
gdb_prettyprint_arrays = &prettyprint_arrays;
gdb_repeat_count_threshold = &repeat_count_threshold;
gdb_stop_print_at_null = &stop_print_at_null;
gdb_output_radix = &output_radix;
#else
gdb_output_format = (int *)
gdb_user_print_option_address("output_format");
gdb_print_max = (unsigned int *)
gdb_user_print_option_address("print_max");
gdb_prettyprint_structs = (unsigned char *)
gdb_user_print_option_address("prettyprint_structs");
gdb_prettyprint_arrays = (unsigned char *)
gdb_user_print_option_address("prettyprint_arrays");
gdb_repeat_count_threshold = (unsigned int *)
gdb_user_print_option_address("repeat_count_threshold");
gdb_stop_print_at_null = (unsigned char *)
gdb_user_print_option_address("stop_print_at_null");
gdb_output_radix = (unsigned int *)
gdb_user_print_option_address("output_radix");
#endif
/*
* If the output radix is set via the --hex or --dec command line
* option, then pc->output_radix will be non-zero; otherwise use
* the gdb default.
*/
if (pc->output_radix) {
*gdb_output_radix = pc->output_radix;
*gdb_output_format = (*gdb_output_radix == 10) ? 0 : 'x';
}
switch (*gdb_output_radix)
{
case 10:
case 16:
pc->output_radix = *gdb_output_radix;
break;
default:
pc->output_radix = *gdb_output_radix = 10;
*gdb_output_format = 0;
}
*gdb_prettyprint_structs = 1;
*gdb_repeat_count_threshold = 0x7fffffff;
*gdb_print_max = 256;
#ifdef GDB_5_3
gdb_disassemble_from_exec = 0;
#endif
pc->flags |= GDB_INIT; /* set here so gdb_interface will work */
req = (struct gnu_request *)GETBUF(sizeof(struct gnu_request));
req->buf = GETBUF(BUFSIZE);
/*
* Make sure the namelist has symbolic data. Later versions of
* gcc may require that debug data be pulled in by printing a
* static kernel data structure.
*/
debug_data_pulled_in = FALSE;
retry:
BZERO(req->buf, BUFSIZE);
req->command = GNU_GET_DATATYPE;
req->name = XEN_HYPER_MODE() ? "page_info" : "task_struct";
req->flags = GNU_RETURN_ON_ERROR;
gdb_interface(req);
if (req->flags & GNU_COMMAND_FAILED) {
if (XEN_HYPER_MODE())
no_debugging_data(WARNING); /* just bail out */
if (!debug_data_pulled_in) {
if (CRASHDEBUG(1))
error(INFO,
"gdb_session_init: pulling in debug data by accessing init_mm.mmap %s\n",
symbol_exists("sysfs_mount") ?
"and syfs_mount" : "");
debug_data_pulled_in = TRUE;
req->command = GNU_PASS_THROUGH;
req->flags = GNU_RETURN_ON_ERROR|GNU_NO_READMEM;
req->name = NULL;
if (symbol_exists("sysfs_mount"))
sprintf(req->buf, "print sysfs_mount, init_mm.mmap");
else
sprintf(req->buf, "print init_mm.mmap");
gdb_interface(req);
if (!(req->flags & GNU_COMMAND_FAILED))
goto retry;
}
no_debugging_data(WARNING);
}
if (pc->flags & KERNEL_DEBUG_QUERY) {
fprintf(fp, "\n%s: %s: contains debugging data\n\n",
pc->program_name, pc->namelist);
if (REMOTE())
remote_exit();
clean_exit(0);
}
/*
* Set up any pre-ordained gdb settings here that can't be
* accessed directly.
*/
req->command = GNU_PASS_THROUGH;
req->name = NULL, req->flags = 0;
sprintf(req->buf, "set height 0");
gdb_interface(req);
req->command = GNU_PASS_THROUGH;
req->name = NULL, req->flags = 0;
sprintf(req->buf, "set width 0");
gdb_interface(req);
#ifdef GDB_10_2
req->command = GNU_PASS_THROUGH;
req->name = NULL, req->flags = 0;
sprintf(req->buf, "set max-value-size unlimited");
gdb_interface(req);
req->command = GNU_PASS_THROUGH;
req->name = NULL, req->flags = 0;
sprintf(req->buf, "set max-completions unlimited");
gdb_interface(req);
#endif
#if 0
/*
* Patch gdb's symbol values with the correct values from either
* the System.map or non-debug vmlinux, whichever is in effect.
*/
if ((pc->flags & SYSMAP) || (kt->flags & (RELOC_SET|RELOC_FORCE)) ||
(pc->namelist_debug && !pc->debuginfo_file)) {
req->command = GNU_PATCH_SYMBOL_VALUES;
req->flags = GNU_RETURN_ON_ERROR;
gdb_interface(req);
if (req->flags & GNU_COMMAND_FAILED)
error(FATAL, "patching of gdb symbol values failed\n");
} else if (!(pc->flags & SILENT))
#else
if (!(pc->flags & SILENT))
#endif
fprintf(fp, "\n");
FREEBUF(req->buf);
FREEBUF(req);
}
/*
* Quickest way to gdb -- just pass a command string to pass through.
*/
int
gdb_pass_through(char *cmd, FILE *fptr, ulong flags)
{
struct gnu_request *req;
int retval;
if (CRASHDEBUG(1))
console("gdb_pass_through: [%s]\n", cmd);
req = (struct gnu_request *)GETBUF(sizeof(struct gnu_request));
req->buf = cmd;
if (fptr)
req->fp = fptr;
req->command = GNU_PASS_THROUGH;
req->flags = flags;
gdb_interface(req);
if ((req->flags & (GNU_RETURN_ON_ERROR|GNU_COMMAND_FAILED)) ==
(GNU_RETURN_ON_ERROR|GNU_COMMAND_FAILED))
retval = FALSE;
else
retval = TRUE;
FREEBUF(req);
return retval;
}
/*
* General purpose routine for passing commands to gdb. All gdb commands
* come through here, where they are passed to gdb_command_funnel().
*/
void
gdb_interface(struct gnu_request *req)
{
if (!(pc->flags & GDB_INIT))
error(FATAL, "gdb_interface: gdb not initialized?\n");
if (output_closed())
restart(0);
if (!req->fp) {
req->fp = ((pc->flags & RUNTIME) || (pc->flags2 & ALLOW_FP)) ?
fp : CRASHDEBUG(1) ? fp : pc->nullfp;
}
pc->cur_req = req;
pc->cur_gdb_cmd = req->command;
if (CRASHDEBUG(2))
dump_gnu_request(req, IN_GDB);
if (!(pc->flags & DROP_CORE))
SIGACTION(SIGSEGV, restart, &pc->sigaction, NULL);
else
SIGACTION(SIGSEGV, SIG_DFL, &pc->sigaction, NULL);
if (interruptible()) {
SIGACTION(SIGINT, pc->gdb_sigaction.sa_handler,
&pc->gdb_sigaction, NULL);
} else {
SIGACTION(SIGINT, SIG_IGN, &pc->sigaction, NULL);
SIGACTION(SIGPIPE, SIG_IGN, &pc->sigaction, NULL);
}
pc->flags |= IN_GDB;
gdb_command_funnel(req);
pc->flags &= ~IN_GDB;
SIGACTION(SIGINT, restart, &pc->sigaction, NULL);
SIGACTION(SIGSEGV, SIG_DFL, &pc->sigaction, NULL);
if (req->flags & GNU_COMMAND_FAILED)
gdb_error_debug();
if (CRASHDEBUG(2))
dump_gnu_request(req, !IN_GDB);
pc->last_gdb_cmd = pc->cur_gdb_cmd;
pc->cur_gdb_cmd = 0;
pc->cur_req = NULL;
}
/*
* help -g output
*/
void
dump_gdb_data(void)
{
fprintf(fp, " prettyprint_arrays: %d\n", *gdb_prettyprint_arrays);
fprintf(fp, " prettyprint_structs: %d\n", *gdb_prettyprint_structs);
fprintf(fp, "repeat_count_threshold: %x\n", *gdb_repeat_count_threshold);
fprintf(fp, " stop_print_at_null: %d\n", *gdb_stop_print_at_null);
fprintf(fp, " print_max: %d\n", *gdb_print_max);
fprintf(fp, " output_radix: %d\n", *gdb_output_radix);
fprintf(fp, " output_format: ");
switch (*gdb_output_format)
{
case 'x':
fprintf(fp, "hex\n"); break;
case 'o':
fprintf(fp, "octal\n"); break;
case 0:
fprintf(fp, "decimal\n"); break;
}
}
void
dump_gnu_request(struct gnu_request *req, int in_gdb)
{
int others;
char buf[BUFSIZE];
if (pc->flags & KERNEL_DEBUG_QUERY)
return;
console("%scommand: %d (%s)\n", in_gdb ? "GDB IN: " : "GDB OUT: ",
req->command, gdb_command_string(req->command, buf, TRUE));
console("buf: %lx ", req->buf);
if (req->buf && ascii_string(req->buf))
console(" \"%s\"", req->buf);
console("\n");
console("fp: %lx ", req->fp);
if (req->fp == pc->nullfp)
console("(pc->nullfp) ");
if (req->fp == pc->stdpipe)
console("(pc->stdpipe) ");
if (req->fp == pc->pipe)
console("(pc->pipe) ");
if (req->fp == pc->ofile)
console("(pc->ofile) ");
if (req->fp == pc->ifile)
console("(pc->ifile) ");
if (req->fp == pc->ifile_pipe)
console("(pc->ifile_pipe) ");
if (req->fp == pc->ifile_ofile)
console("(pc->ifile_ofile) ");
if (req->fp == pc->tmpfile)
console("(pc->tmpfile) ");
if (req->fp == pc->saved_fp)
console("(pc->saved_fp) ");
if (req->fp == pc->tmp_fp)
console("(pc->tmp_fp) ");
console("flags: %lx (", req->flags);
others = 0;
if (req->flags & GNU_PRINT_LINE_NUMBERS)
console("%sGNU_PRINT_LINE_NUMBERS", others++ ? "|" : "");
if (req->flags & GNU_FUNCTION_ONLY)
console("%sGNU_FUNCTION_ONLY", others++ ? "|" : "");
if (req->flags & GNU_PRINT_ENUMERATORS)
console("%sGNU_PRINT_ENUMERATORS", others++ ? "|" : "");
if (req->flags & GNU_RETURN_ON_ERROR)
console("%sGNU_RETURN_ON_ERROR", others++ ? "|" : "");
if (req->flags & GNU_FROM_TTY_OFF)
console("%sGNU_FROM_TTY_OFF", others++ ? "|" : "");
if (req->flags & GNU_NO_READMEM)
console("%sGNU_NO_READMEM", others++ ? "|" : "");
if (req->flags & GNU_VAR_LENGTH_TYPECODE)
console("%sGNU_VAR_LENGTH_TYPECODE", others++ ? "|" : "");
console(")\n");
console("addr: %lx ", req->addr);
console("addr2: %lx ", req->addr2);
console("count: %ld\n", req->count);
if ((ulong)req->name > (ulong)PATCH_KERNEL_SYMBOLS_STOP)
console("name: \"%s\" ", req->name);
else
console("name: %lx ", (ulong)req->name);
console("length: %ld ", req->length);
console("typecode: %d\n", req->typecode);
#if defined(GDB_5_3) || defined(GDB_6_0) || defined(GDB_6_1) || defined(GDB_7_0)
console("typename: %s\n", req->typename);
#else
console("type_name: %s\n", req->type_name);
#endif
console("target_typename: %s\n", req->target_typename);
console("target_length: %ld ", req->target_length);
console("target_typecode: %d ", req->target_typecode);
console("is_typedef: %d ", req->is_typedef);
console("member: \"%s\" ", req->member);
console("member_offset: %ld\n", req->member_offset);
console("member_length: %ld\n", req->member_length);
console("member_typecode: %d\n", req->member_typecode);
console("member_main_type_name: %s\n", req->member_main_type_name);
console("member_main_type_tag_name: %s\n", req->member_main_type_tag_name);
console("member_target_type_name: %s\n", req->member_target_type_name);
console("member_target_type_tag_name: %s\n", req->member_target_type_tag_name);
console("value: %lx ", req->value);
console("tagname: \"%s\" ", req->tagname);
console("pc: %lx ", req->pc);
if (is_kernel_text(req->pc))
console("(%s)", value_to_symstr(req->pc, buf, 0));
console("\n");
console("sp: %lx ", req->sp);
console("ra: %lx ", req->ra);
console("frame: %ld ", req->frame);
console("prevsp: %lx\n", req->prevsp);
console("prevpc: %lx ", req->prevpc);
console("lastsp: %lx ", req->lastsp);
console("task: %lx ", req->task);
console("debug: %lx\n", req->debug);
console("\n");
}
char *
gdb_command_string(int cmd, char *buf, int live)
{
switch (cmd)
{
case GNU_PASS_THROUGH:
sprintf(buf, "GNU_PASS_THROUGH");
break;
case GNU_DATATYPE_INIT:
sprintf(buf, "GNU_DATATYPE_INIT");
break;
case GNU_DISASSEMBLE:
sprintf(buf, "GNU_DISASSEMBLE");
break;
case GNU_GET_LINE_NUMBER:
sprintf(buf, "GNU_GET_LINE_NUMBER");
break;
case GNU_GET_DATATYPE:
if (live)
sprintf(buf, "GNU_GET_DATATYPE[%s]",
pc->cur_req->name ? pc->cur_req->name : "?");
else
sprintf(buf, "GNU_GET_DATATYPE");
break;
case GNU_STACK_TRACE:
sprintf(buf, "GNU_STACK_TRACE");
break;
case GNU_ALPHA_FRAME_OFFSET:
sprintf(buf, "GNU_ALPHA_FRAME_OFFSET");
break;
case GNU_COMMAND_EXISTS:
sprintf(buf, "GNU_COMMAND_EXISTS");
break;
case GNU_FUNCTION_NUMARGS:
sprintf(buf, "GNU_FUNCTION_NUMARGS");
break;
case GNU_RESOLVE_TEXT_ADDR:
sprintf(buf, "GNU_RESOLVE_TEXT_ADDR");
break;
case GNU_DEBUG_COMMAND:
sprintf(buf, "GNU_DEBUG_COMMAND");
break;
case GNU_ADD_SYMBOL_FILE:
sprintf(buf, "GNU_ADD_SYMBOL_FILE");
break;
case GNU_DELETE_SYMBOL_FILE:
sprintf(buf, "GNU_DELETE_SYMBOL_FILE");
break;
case GNU_VERSION:
sprintf(buf, "GNU_VERSION");
break;
case GNU_GET_SYMBOL_TYPE:
sprintf(buf, "GNU_GET_SYMBOL_TYPE");
break;
case GNU_PATCH_SYMBOL_VALUES:
sprintf(buf, "GNU_PATCH_SYMBOL_VALUES");
break;
case GNU_USER_PRINT_OPTION:
sprintf(buf, "GNU_USER_PRINT_OPTION");
break;
case GNU_SET_CRASH_BLOCK:
sprintf(buf, "GNU_SET_CRASH_BLOCK");
break;
case GNU_GET_FUNCTION_RANGE:
sprintf(buf, "GNU_GET_FUNCTION_RANGE");
break;
case 0:
buf[0] = NULLCHAR;
break;
default:
sprintf(buf, "(?)\n");
break;
}
return buf;
}
/*
* Restore known gdb state.
*/
void
restore_gdb_sanity(void)
{
if (!(pc->flags & GDB_INIT))
return;
if (pc->output_radix) {
*gdb_output_radix = pc->output_radix;
*gdb_output_format = (*gdb_output_radix == 10) ? 0 : 'x';
}
*gdb_prettyprint_structs = 1; /* these may piss somebody off... */
*gdb_repeat_count_threshold = 0x7fffffff;
if (st->flags & ADD_SYMBOL_FILE) {
error(INFO,
"%s\n gdb add-symbol-file command failed\n",
st->current->mod_namelist);
delete_load_module(st->current->mod_base);
st->flags &= ~ADD_SYMBOL_FILE;
}
if (pc->cur_gdb_cmd) {
pc->last_gdb_cmd = pc->cur_gdb_cmd;
pc->cur_gdb_cmd = 0;
}
}
/*
* Check whether string in args[0] is a valid gdb command.
*/
int
is_gdb_command(int merge_orig_args, ulong flags)
{
int retval;
struct gnu_request *req;
if (!args[0])
return FALSE;
if (STREQ(args[0], "Q")) {
args[0] = "q";
return TRUE;
}
if (is_restricted_command(args[0], flags))
return FALSE;
req = (struct gnu_request *)GETBUF(sizeof(struct gnu_request));
req->buf = GETBUF(strlen(args[0])+1);
req->command = GNU_COMMAND_EXISTS;
req->name = args[0];
req->flags = GNU_RETURN_ON_ERROR;
req->fp = pc->nullfp;
gdb_interface(req);
if (req->flags & GNU_COMMAND_FAILED)
retval = FALSE;
else
retval = req->value;
FREEBUF(req->buf);
FREEBUF(req);
if (retval && merge_orig_args) {
int i;
for (i = argcnt; i; i--)
args[i] = args[i-1];
args[0] = "gdb";
argcnt++;
}
return retval;
}
/*
* Check whether a command is on the gdb-prohibited list.
*/
static char *prohibited_list[] = {
"run", "r", "break", "b", "tbreak", "hbreak", "thbreak", "rbreak",
"watch", "rwatch", "awatch", "attach", "continue", "c", "fg", "detach",
"finish", "handle", "interrupt", "jump", "kill", "next", "nexti",
"signal", "step", "s", "stepi", "target", "until", "delete",
"clear", "disable", "enable", "condition", "ignore", "frame", "catch",
"tcatch", "return", "file", "exec-file", "core-file", "symbol-file",
"load", "si", "ni", "shell", "sy",
NULL /* must be last */
};
static char *restricted_list[] = {
"define", "document", "while", "if",
NULL /* must be last */
};
#define RESTRICTED_GDB_COMMAND \
"restricted gdb command: %s\n%s\"%s\" may only be used in a .gdbinit file or in a command file.\n%sThe .gdbinit file is read automatically during %s initialization.\n%sOther user-defined command files may be read interactively during\n%s%s runtime by using the gdb \"source\" command.\n"
static int
is_restricted_command(char *cmd, ulong flags)
{
int i;
char *newline;
for (i = 0; prohibited_list[i]; i++) {
if (STREQ(prohibited_list[i], cmd)) {
if (flags == RETURN_ON_ERROR)
return TRUE;
pc->curcmd = pc->program_name;
error(FATAL, "prohibited gdb command: %s\n", cmd);
}
}
for (i = 0; restricted_list[i]; i++) {
if (STREQ(restricted_list[i], cmd)) {
if (flags == RETURN_ON_ERROR)
return TRUE;
newline = space(strlen(pc->program_name)+2);
pc->curcmd = pc->program_name;
error(FATAL, RESTRICTED_GDB_COMMAND,
cmd, newline, cmd,
newline, pc->program_name,
newline, newline, pc->program_name);
}
}
return FALSE;
}
/*
* Remove pipe/redirection stuff from the end of the command line.
*/
static void
strip_redirection(char *buf)
{
char *p1, *p2;
p1 = strstr_rightmost(buf, args[argcnt-1]);
p2 = p1 + strlen(args[argcnt-1]);
console("strip_redirection: [%s]\n", p2);
if ((p1 = strpbrk(p2, "|!>")))
*p1 = NULLCHAR;
strip_ending_whitespace(buf);
}
/*
* Command for passing strings directly to gdb.
*/
void
cmd_gdb(void)
{
char buf[BUFSIZE];
char **argv;
argv = STREQ(args[0], "gdb") ? &args[1] : &args[0];
if (*argv == NULL)
cmd_usage(pc->curcmd, SYNOPSIS);
if (STREQ(*argv, "set") && argv[1]) {
/*
* Intercept set commands in case something has to be done
* here or elsewhere.
*/
if (STREQ(argv[1], "gdb")) {
cmd_set();
return;
}
if (STREQ(argv[1], "output-radix") && argv[2])
pc->output_radix = stol(argv[2], FAULT_ON_ERROR, NULL);
}
/*
* If the command is not restricted, pass it on.
*/
if (!is_restricted_command(*argv, FAULT_ON_ERROR)) {
if (STREQ(pc->command_line, "gdb")) {
strcpy(buf, first_space(pc->orig_line));
strip_beginning_whitespace(buf);
} else
strcpy(buf, pc->orig_line);
if (pc->redirect & (REDIRECT_TO_FILE|REDIRECT_TO_PIPE))
strip_redirection(buf);
if (!gdb_pass_through(buf, NULL, GNU_RETURN_ON_ERROR))
error(INFO, "gdb request failed: %s\n", buf);
}
}
/*
* The gdb target_xfer_memory() has a hook installed to re-route
* all memory accesses back here; reads of 1 or 4 bytes come primarily
* from text disassembly requests, and are diverted to the text cache.
*/
int
gdb_readmem_callback(ulong addr, void *buf, int len, int write)
{
char locbuf[SIZEOF_32BIT], *p1;
int memtype;
ulong readflags;
if (write)
return FALSE;
if (!(pc->cur_req)) {
return(readmem(addr, KVADDR, buf, len,
"gdb_readmem_callback", RETURN_ON_ERROR));
}
if (pc->cur_req->flags & GNU_NO_READMEM)
return TRUE;
readflags = pc->curcmd_flags & PARTIAL_READ_OK ?
RETURN_ON_ERROR|RETURN_PARTIAL : RETURN_ON_ERROR;
if (STREQ(pc->curcmd, "bpf") && pc->curcmd_private &&
(addr > (ulong)pc->curcmd_private))
readflags |= QUIET;
if (pc->curcmd_flags & MEMTYPE_UVADDR)
memtype = UVADDR;
else if (pc->curcmd_flags & MEMTYPE_FILEADDR)
memtype = FILEADDR;
else if (!IS_KVADDR(addr)) {
if (STREQ(pc->curcmd, "gdb") &&
STRNEQ(pc->cur_req->buf, "x/")) {
memtype = UVADDR;
} else {
if (CRASHDEBUG(1))
console("gdb_readmem_callback: %lx %d FAILED\n",
addr, len);
return FALSE;
}
} else
memtype = KVADDR;
if (CRASHDEBUG(1))
console("gdb_readmem_callback[%d]: %lx %d\n",
memtype, addr, len);
if (memtype == FILEADDR)
return(readmem(pc->curcmd_private, memtype, buf, len,
"gdb_readmem_callback", readflags));
switch (len)
{
case SIZEOF_8BIT:
if (STREQ(pc->curcmd, "bt")) {
if (readmem(addr, memtype, buf, SIZEOF_8BIT,
"gdb_readmem_callback", readflags))
return TRUE;
}
p1 = (char *)buf;
if (!readmem(addr, memtype, locbuf, SIZEOF_32BIT,
"gdb_readmem_callback", readflags))
return FALSE;
*p1 = locbuf[0];
return TRUE;
case SIZEOF_32BIT:
if (STREQ(pc->curcmd, "bt")) {
if (readmem(addr, memtype, buf, SIZEOF_32BIT,
"gdb_readmem_callback", readflags))
return TRUE;
}
if (!readmem(addr, memtype, buf, SIZEOF_32BIT,
"gdb_readmem callback", readflags))
return FALSE;
return TRUE;
}
return(readmem(addr, memtype, buf, len,
"gdb_readmem_callback", readflags));
}
/*
* Machine-specific line-number pc section range verifier.
*/
int
gdb_line_number_callback(ulong pc, ulong low, ulong high)
{
if (machdep->verify_line_number)
return machdep->verify_line_number(pc, low, high);
return TRUE;
}
/*
* Prevent gdb from trying to translate and print pointers
* that are not kernel virtual addresses.
*/
int
gdb_print_callback(ulong addr)
{
if (!addr)
return FALSE;
else
return IS_KVADDR(addr);
}
char *
gdb_lookup_module_symbol(ulong addr, ulong *offset)
{
struct syment *sp;
if ((sp = value_search_module(addr, offset))) {
return sp->name;
} else {
return NULL;
}
}
/*
* Used by gdb_interface() to catch gdb-related errors, if desired.
*/
static void
gdb_error_debug(void)
{
char buf1[BUFSIZE];
char buf2[BUFSIZE];
int buffers;
if (CRASHDEBUG(2)) {
sprintf(buf2, "\n");
if (CRASHDEBUG(5) && (buffers = get_embedded()))
sprintf(buf2, "(%d buffer%s in use)\n",
buffers, buffers > 1 ? "s" : "");
fprintf(stderr, "%s: returned via gdb_error_hook %s",
gdb_command_string(pc->cur_gdb_cmd, buf1, TRUE), buf2);
console("%s: returned via gdb_error_hook %s",
gdb_command_string(pc->cur_gdb_cmd, buf1, TRUE), buf2);
}
}
/*
* gdb callback to access debug mode.
*/
int
gdb_CRASHDEBUG(ulong dval)
{
if (CRASHDEBUG(dval))
return TRUE;
return (pc->cur_req && (pc->cur_req->debug >= dval));
}
static ulong
gdb_user_print_option_address(char *name)
{
struct gnu_request request;
request.command = GNU_USER_PRINT_OPTION;
request.name = name;
gdb_command_funnel(&request);
return request.addr;
}
/*
* Try to set a crash scope block based upon the vaddr.
*/
int
gdb_set_crash_scope(ulong vaddr, char *arg)
{
struct gnu_request request, *req = &request;
char name[BUFSIZE];
struct load_module *lm;
if (vaddr) {
if (!is_kernel_text(vaddr)) {
error(INFO, "invalid text address: %s\n", arg);
return FALSE;
}
if (module_symbol(vaddr, NULL, &lm, name, 0)) {
if (!(lm->mod_flags & MOD_LOAD_SYMS)) {
error(INFO, "attempting to find/load \"%s\" module debuginfo\n",
lm->mod_name);
if (!load_module_symbols_helper(lm->mod_name)) {
error(INFO, "cannot find/load \"%s\" module debuginfo\n",
lm->mod_name);
return FALSE;
}
}
}
}
req->command = GNU_SET_CRASH_BLOCK;
req->addr = vaddr;
req->flags = 0;
req->addr2 = 0;
req->fp = pc->nullfp;
gdb_command_funnel(req);
if (CRASHDEBUG(1))
fprintf(fp,
"gdb_set_crash_scope: %s addr: %lx block: %lx\n",
req->flags & GNU_COMMAND_FAILED ? "FAILED" : "OK",
req->addr, req->addr2);
if (req->flags & GNU_COMMAND_FAILED) {
error(INFO,
"gdb cannot find text block for address: %s\n", arg);
return FALSE;
}
return TRUE;
}
#ifndef ALPHA
/*
* Stub routine needed for resolution by non-alpha, modified gdb code.
*/
int
get_frame_offset(ulong pc)
{
return (error(FATAL,
"get_frame_offset: invalid request for non-alpha systems!\n"));
}
#endif /* !ALPHA */
unsigned long crash_get_kaslr_offset(void);
unsigned long crash_get_kaslr_offset(void)
{
return kt->relocate * -1;
}
/* Callbacks for crash_target */
int crash_get_nr_cpus(void);
int crash_get_cpu_reg (int cpu, int regno, const char *regname,
int regsize, void *val);
int crash_get_nr_cpus(void)
{
if (SADUMP_DUMPFILE())
return sadump_get_nr_cpus();
else if (DISKDUMP_DUMPFILE())
return diskdump_get_nr_cpus();
else if (KDUMP_DUMPFILE())
return kdump_get_nr_cpus();
else if (VMSS_DUMPFILE())
return vmware_vmss_get_nr_cpus();
/* Just CPU #0 */
return 1;
}
int crash_get_cpu_reg (int cpu, int regno, const char *regname,
int regsize, void *value)
{
if (!machdep->get_cpu_reg)
return FALSE;
return machdep->get_cpu_reg(cpu, regno, regname, regsize, value);
}
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