cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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objtool.c (2870B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
      4 */
      5
      6#include <stdio.h>
      7#include <stdbool.h>
      8#include <string.h>
      9#include <stdlib.h>
     10#include <unistd.h>
     11#include <subcmd/exec-cmd.h>
     12#include <subcmd/pager.h>
     13#include <linux/kernel.h>
     14
     15#include <objtool/builtin.h>
     16#include <objtool/objtool.h>
     17#include <objtool/warn.h>
     18
     19bool help;
     20
     21const char *objname;
     22static struct objtool_file file;
     23
     24static bool objtool_create_backup(const char *_objname)
     25{
     26	int len = strlen(_objname);
     27	char *buf, *base, *name = malloc(len+6);
     28	int s, d, l, t;
     29
     30	if (!name) {
     31		perror("failed backup name malloc");
     32		return false;
     33	}
     34
     35	strcpy(name, _objname);
     36	strcpy(name + len, ".orig");
     37
     38	d = open(name, O_CREAT|O_WRONLY|O_TRUNC, 0644);
     39	if (d < 0) {
     40		perror("failed to create backup file");
     41		return false;
     42	}
     43
     44	s = open(_objname, O_RDONLY);
     45	if (s < 0) {
     46		perror("failed to open orig file");
     47		return false;
     48	}
     49
     50	buf = malloc(4096);
     51	if (!buf) {
     52		perror("failed backup data malloc");
     53		return false;
     54	}
     55
     56	while ((l = read(s, buf, 4096)) > 0) {
     57		base = buf;
     58		do {
     59			t = write(d, base, l);
     60			if (t < 0) {
     61				perror("failed backup write");
     62				return false;
     63			}
     64			base += t;
     65			l -= t;
     66		} while (l);
     67	}
     68
     69	if (l < 0) {
     70		perror("failed backup read");
     71		return false;
     72	}
     73
     74	free(name);
     75	free(buf);
     76	close(d);
     77	close(s);
     78
     79	return true;
     80}
     81
     82struct objtool_file *objtool_open_read(const char *_objname)
     83{
     84	if (objname) {
     85		if (strcmp(objname, _objname)) {
     86			WARN("won't handle more than one file at a time");
     87			return NULL;
     88		}
     89		return &file;
     90	}
     91	objname = _objname;
     92
     93	file.elf = elf_open_read(objname, O_RDWR);
     94	if (!file.elf)
     95		return NULL;
     96
     97	if (opts.backup && !objtool_create_backup(objname)) {
     98		WARN("can't create backup file");
     99		return NULL;
    100	}
    101
    102	INIT_LIST_HEAD(&file.insn_list);
    103	hash_init(file.insn_hash);
    104	INIT_LIST_HEAD(&file.retpoline_call_list);
    105	INIT_LIST_HEAD(&file.static_call_list);
    106	INIT_LIST_HEAD(&file.mcount_loc_list);
    107	INIT_LIST_HEAD(&file.endbr_list);
    108	file.ignore_unreachables = opts.no_unreachable;
    109	file.hints = false;
    110
    111	return &file;
    112}
    113
    114void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func)
    115{
    116	if (!opts.noinstr)
    117		return;
    118
    119	if (!f->pv_ops) {
    120		WARN("paravirt confusion");
    121		return;
    122	}
    123
    124	/*
    125	 * These functions will be patched into native code,
    126	 * see paravirt_patch().
    127	 */
    128	if (!strcmp(func->name, "_paravirt_nop") ||
    129	    !strcmp(func->name, "_paravirt_ident_64"))
    130		return;
    131
    132	/* already added this function */
    133	if (!list_empty(&func->pv_target))
    134		return;
    135
    136	list_add(&func->pv_target, &f->pv_ops[idx].targets);
    137	f->pv_ops[idx].clean = false;
    138}
    139
    140int main(int argc, const char **argv)
    141{
    142	static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
    143
    144	/* libsubcmd init */
    145	exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
    146	pager_init(UNUSED);
    147
    148	objtool_run(argc, argv);
    149
    150	return 0;
    151}