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/*
* Copyright (C) 2009, Neil Horman <nhorman@redhat.com>
*
* This program file 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; version 2 of the License.
*
* 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 in a file named COPYING; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
/*
* This is a translator. given an input address, this will convert it into a
* symbolic name using /proc/kallsyms
*/
#include <stdlib.h>
#include <stdio.h>
#include <sys/utsname.h>
#include <bfd.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/queue.h>
#include "lookup.h"
struct symbol_entry {
char *sym_name;
__u64 start;
__u64 end;
LIST_ENTRY(symbol_entry) list;
};
LIST_HEAD(sym_list, symbol_entry);
/*
* This is our cache of symbols that we've previously looked up
*/
static struct sym_list sym_list_head = {NULL};
static int lookup_kas_cache( __u64 pc, struct loc_result *location)
{
struct symbol_entry *sym;
LIST_FOREACH(sym, &sym_list_head, list) {
if ((pc >= sym->start) &&
(pc <= sym->end)) {
location->symbol = sym->sym_name;
location->offset = (pc - sym->start);
return 0;
}
}
return 1;
}
static void kas_add_cache(__u64 start, __u64 end, char *name)
{
struct symbol_entry *sym = NULL;
sym = malloc(sizeof(struct symbol_entry));
if (!sym)
return;
sym->start = start;
sym->end = end;
sym->sym_name = name;
LIST_INSERT_HEAD(&sym_list_head, sym, list);
return;
}
static int lookup_kas_proc(__u64 pc, struct loc_result *location)
{
FILE *pf;
__u64 ppc;
__u64 uppc, ulpc, uipc;
char *name, *last_name;
pf = fopen("/proc/kallsyms", "r");
if (!pf)
return 1;
last_name = NULL;
uipc = pc;
ulpc = 0;
while (!feof(pf)) {
/*
* Each line of /proc/kallsyms is formatteded as:
* - "%pK %c %s\n" (for kernel internal symbols), or
* - "%pK %c %s\t[%s]\n" (for module-provided symbols)
*/
if (fscanf(pf, "%llx %*s %as [ %*[^]] ]", &ppc, &name) < 0) {
perror("Error Scanning File: ");
break;
}
uppc = (__u64)ppc;
if ((uipc >= ulpc) &&
(uipc < uppc)) {
/*
* The last symbol we looked at
* was a hit, record and return it
* Note that we don't free last_name
* here, because the cache is using it
*/
kas_add_cache(ulpc, uppc-1, last_name);
fclose(pf);
free(name);
return lookup_kas_cache(pc, location);
}
/*
* Advance all our state holders
*/
free(last_name);
last_name = name;
ulpc = uppc;
}
fclose(pf);
return 1;
}
static int lookup_kas_init(void)
{
printf("Initalizing kallsyms db\n");
return 0;
}
static int lookup_kas_sym(void *pc, struct loc_result *location)
{
__u64 pcv;
memset(&pcv, 0, sizeof(__u64));
memcpy(&pcv, &pc, sizeof(void *));
if (!lookup_kas_cache(pcv, location))
return 0;
return lookup_kas_proc(pcv, location);
}
struct lookup_methods kallsym_methods = {
lookup_kas_init,
lookup_kas_sym,
};
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