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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builtin-buildid-cache.c (13248B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * builtin-buildid-cache.c
      4 *
      5 * Builtin buildid-cache command: Manages build-id cache
      6 *
      7 * Copyright (C) 2010, Red Hat Inc.
      8 * Copyright (C) 2010, Arnaldo Carvalho de Melo <acme@redhat.com>
      9 */
     10#include <sys/types.h>
     11#include <sys/time.h>
     12#include <time.h>
     13#include <dirent.h>
     14#include <errno.h>
     15#include <unistd.h>
     16#include "builtin.h"
     17#include "namespaces.h"
     18#include "util/debug.h"
     19#include "util/header.h"
     20#include <subcmd/pager.h>
     21#include <subcmd/parse-options.h>
     22#include "util/strlist.h"
     23#include "util/build-id.h"
     24#include "util/session.h"
     25#include "util/dso.h"
     26#include "util/symbol.h"
     27#include "util/time-utils.h"
     28#include "util/util.h"
     29#include "util/probe-file.h"
     30#include "util/config.h"
     31#include <linux/string.h>
     32#include <linux/err.h>
     33
     34static int build_id_cache__kcore_buildid(const char *proc_dir, char *sbuildid)
     35{
     36	char root_dir[PATH_MAX];
     37	char *p;
     38
     39	strlcpy(root_dir, proc_dir, sizeof(root_dir));
     40
     41	p = strrchr(root_dir, '/');
     42	if (!p)
     43		return -1;
     44	*p = '\0';
     45	return sysfs__sprintf_build_id(root_dir, sbuildid);
     46}
     47
     48static int build_id_cache__kcore_dir(char *dir, size_t sz)
     49{
     50	return fetch_current_timestamp(dir, sz);
     51}
     52
     53static bool same_kallsyms_reloc(const char *from_dir, char *to_dir)
     54{
     55	char from[PATH_MAX];
     56	char to[PATH_MAX];
     57	const char *name;
     58	u64 addr1 = 0, addr2 = 0;
     59	int i, err = -1;
     60
     61	scnprintf(from, sizeof(from), "%s/kallsyms", from_dir);
     62	scnprintf(to, sizeof(to), "%s/kallsyms", to_dir);
     63
     64	for (i = 0; (name = ref_reloc_sym_names[i]) != NULL; i++) {
     65		err = kallsyms__get_function_start(from, name, &addr1);
     66		if (!err)
     67			break;
     68	}
     69
     70	if (err)
     71		return false;
     72
     73	if (kallsyms__get_function_start(to, name, &addr2))
     74		return false;
     75
     76	return addr1 == addr2;
     77}
     78
     79static int build_id_cache__kcore_existing(const char *from_dir, char *to_dir,
     80					  size_t to_dir_sz)
     81{
     82	char from[PATH_MAX];
     83	char to[PATH_MAX];
     84	char to_subdir[PATH_MAX];
     85	struct dirent *dent;
     86	int ret = -1;
     87	DIR *d;
     88
     89	d = opendir(to_dir);
     90	if (!d)
     91		return -1;
     92
     93	scnprintf(from, sizeof(from), "%s/modules", from_dir);
     94
     95	while (1) {
     96		dent = readdir(d);
     97		if (!dent)
     98			break;
     99		if (dent->d_type != DT_DIR)
    100			continue;
    101		scnprintf(to, sizeof(to), "%s/%s/modules", to_dir,
    102			  dent->d_name);
    103		scnprintf(to_subdir, sizeof(to_subdir), "%s/%s",
    104			  to_dir, dent->d_name);
    105		if (!compare_proc_modules(from, to) &&
    106		    same_kallsyms_reloc(from_dir, to_subdir)) {
    107			strlcpy(to_dir, to_subdir, to_dir_sz);
    108			ret = 0;
    109			break;
    110		}
    111	}
    112
    113	closedir(d);
    114
    115	return ret;
    116}
    117
    118static int build_id_cache__add_kcore(const char *filename, bool force)
    119{
    120	char dir[32], sbuildid[SBUILD_ID_SIZE];
    121	char from_dir[PATH_MAX], to_dir[PATH_MAX];
    122	char *p;
    123
    124	strlcpy(from_dir, filename, sizeof(from_dir));
    125
    126	p = strrchr(from_dir, '/');
    127	if (!p || strcmp(p + 1, "kcore"))
    128		return -1;
    129	*p = '\0';
    130
    131	if (build_id_cache__kcore_buildid(from_dir, sbuildid) < 0)
    132		return -1;
    133
    134	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s",
    135		  buildid_dir, DSO__NAME_KCORE, sbuildid);
    136
    137	if (!force &&
    138	    !build_id_cache__kcore_existing(from_dir, to_dir, sizeof(to_dir))) {
    139		pr_debug("same kcore found in %s\n", to_dir);
    140		return 0;
    141	}
    142
    143	if (build_id_cache__kcore_dir(dir, sizeof(dir)))
    144		return -1;
    145
    146	scnprintf(to_dir, sizeof(to_dir), "%s/%s/%s/%s",
    147		  buildid_dir, DSO__NAME_KCORE, sbuildid, dir);
    148
    149	if (mkdir_p(to_dir, 0755))
    150		return -1;
    151
    152	if (kcore_copy(from_dir, to_dir)) {
    153		/* Remove YYYYmmddHHMMSShh directory */
    154		if (!rmdir(to_dir)) {
    155			p = strrchr(to_dir, '/');
    156			if (p)
    157				*p = '\0';
    158			/* Try to remove buildid directory */
    159			if (!rmdir(to_dir)) {
    160				p = strrchr(to_dir, '/');
    161				if (p)
    162					*p = '\0';
    163				/* Try to remove [kernel.kcore] directory */
    164				rmdir(to_dir);
    165			}
    166		}
    167		return -1;
    168	}
    169
    170	pr_debug("kcore added to build-id cache directory %s\n", to_dir);
    171
    172	return 0;
    173}
    174
    175static int build_id_cache__add_file(const char *filename, struct nsinfo *nsi)
    176{
    177	char sbuild_id[SBUILD_ID_SIZE];
    178	struct build_id bid;
    179	int err;
    180	struct nscookie nsc;
    181
    182	nsinfo__mountns_enter(nsi, &nsc);
    183	err = filename__read_build_id(filename, &bid);
    184	nsinfo__mountns_exit(&nsc);
    185	if (err < 0) {
    186		pr_debug("Couldn't read a build-id in %s\n", filename);
    187		return -1;
    188	}
    189
    190	build_id__sprintf(&bid, sbuild_id);
    191	err = build_id_cache__add_s(sbuild_id, filename, nsi,
    192				    false, false);
    193	pr_debug("Adding %s %s: %s\n", sbuild_id, filename,
    194		 err ? "FAIL" : "Ok");
    195	return err;
    196}
    197
    198static int build_id_cache__remove_file(const char *filename, struct nsinfo *nsi)
    199{
    200	char sbuild_id[SBUILD_ID_SIZE];
    201	struct build_id bid;
    202	struct nscookie nsc;
    203
    204	int err;
    205
    206	nsinfo__mountns_enter(nsi, &nsc);
    207	err = filename__read_build_id(filename, &bid);
    208	nsinfo__mountns_exit(&nsc);
    209	if (err < 0) {
    210		pr_debug("Couldn't read a build-id in %s\n", filename);
    211		return -1;
    212	}
    213
    214	build_id__sprintf(&bid, sbuild_id);
    215	err = build_id_cache__remove_s(sbuild_id);
    216	pr_debug("Removing %s %s: %s\n", sbuild_id, filename,
    217		 err ? "FAIL" : "Ok");
    218
    219	return err;
    220}
    221
    222static int build_id_cache__purge_path(const char *pathname, struct nsinfo *nsi)
    223{
    224	struct strlist *list;
    225	struct str_node *pos;
    226	int err;
    227
    228	err = build_id_cache__list_build_ids(pathname, nsi, &list);
    229	if (err)
    230		goto out;
    231
    232	strlist__for_each_entry(pos, list) {
    233		err = build_id_cache__remove_s(pos->s);
    234		pr_debug("Removing %s %s: %s\n", pos->s, pathname,
    235			 err ? "FAIL" : "Ok");
    236		if (err)
    237			break;
    238	}
    239	strlist__delete(list);
    240
    241out:
    242	pr_debug("Purging %s: %s\n", pathname, err ? "FAIL" : "Ok");
    243
    244	return err;
    245}
    246
    247static int build_id_cache__purge_all(void)
    248{
    249	struct strlist *list;
    250	struct str_node *pos;
    251	int err = 0;
    252	char *buf;
    253
    254	list = build_id_cache__list_all(false);
    255	if (!list) {
    256		pr_debug("Failed to get buildids: -%d\n", errno);
    257		return -EINVAL;
    258	}
    259
    260	strlist__for_each_entry(pos, list) {
    261		buf = build_id_cache__origname(pos->s);
    262		err = build_id_cache__remove_s(pos->s);
    263		pr_debug("Removing %s (%s): %s\n", buf, pos->s,
    264			 err ? "FAIL" : "Ok");
    265		free(buf);
    266		if (err)
    267			break;
    268	}
    269	strlist__delete(list);
    270
    271	pr_debug("Purged all: %s\n", err ? "FAIL" : "Ok");
    272	return err;
    273}
    274
    275static bool dso__missing_buildid_cache(struct dso *dso, int parm __maybe_unused)
    276{
    277	char filename[PATH_MAX];
    278	struct build_id bid;
    279
    280	if (dso__build_id_filename(dso, filename, sizeof(filename), false) &&
    281	    filename__read_build_id(filename, &bid) == -1) {
    282		if (errno == ENOENT)
    283			return false;
    284
    285		pr_warning("Problems with %s file, consider removing it from the cache\n",
    286			   filename);
    287	} else if (memcmp(dso->bid.data, bid.data, bid.size)) {
    288		pr_warning("Problems with %s file, consider removing it from the cache\n",
    289			   filename);
    290	}
    291
    292	return true;
    293}
    294
    295static int build_id_cache__fprintf_missing(struct perf_session *session, FILE *fp)
    296{
    297	perf_session__fprintf_dsos_buildid(session, fp, dso__missing_buildid_cache, 0);
    298	return 0;
    299}
    300
    301static int build_id_cache__update_file(const char *filename, struct nsinfo *nsi)
    302{
    303	char sbuild_id[SBUILD_ID_SIZE];
    304	struct build_id bid;
    305	struct nscookie nsc;
    306
    307	int err;
    308
    309	nsinfo__mountns_enter(nsi, &nsc);
    310	err = filename__read_build_id(filename, &bid);
    311	nsinfo__mountns_exit(&nsc);
    312	if (err < 0) {
    313		pr_debug("Couldn't read a build-id in %s\n", filename);
    314		return -1;
    315	}
    316	err = 0;
    317
    318	build_id__sprintf(&bid, sbuild_id);
    319	if (build_id_cache__cached(sbuild_id))
    320		err = build_id_cache__remove_s(sbuild_id);
    321
    322	if (!err)
    323		err = build_id_cache__add_s(sbuild_id, filename, nsi, false,
    324					    false);
    325
    326	pr_debug("Updating %s %s: %s\n", sbuild_id, filename,
    327		 err ? "FAIL" : "Ok");
    328
    329	return err;
    330}
    331
    332static int build_id_cache__show_all(void)
    333{
    334	struct strlist *bidlist;
    335	struct str_node *nd;
    336	char *buf;
    337
    338	bidlist = build_id_cache__list_all(true);
    339	if (!bidlist) {
    340		pr_debug("Failed to get buildids: -%d\n", errno);
    341		return -1;
    342	}
    343	strlist__for_each_entry(nd, bidlist) {
    344		buf = build_id_cache__origname(nd->s);
    345		fprintf(stdout, "%s %s\n", nd->s, buf);
    346		free(buf);
    347	}
    348	strlist__delete(bidlist);
    349	return 0;
    350}
    351
    352static int perf_buildid_cache_config(const char *var, const char *value, void *cb)
    353{
    354	struct perf_debuginfod *di = cb;
    355
    356	if (!strcmp(var, "buildid-cache.debuginfod")) {
    357		di->urls = strdup(value);
    358		if (!di->urls)
    359			return -ENOMEM;
    360		di->set = true;
    361	}
    362
    363	return 0;
    364}
    365
    366int cmd_buildid_cache(int argc, const char **argv)
    367{
    368	struct strlist *list;
    369	struct str_node *pos;
    370	int ret, ns_id = -1;
    371	bool force = false;
    372	bool list_files = false;
    373	bool opts_flag = false;
    374	bool purge_all = false;
    375	char const *add_name_list_str = NULL,
    376		   *remove_name_list_str = NULL,
    377		   *purge_name_list_str = NULL,
    378		   *missing_filename = NULL,
    379		   *update_name_list_str = NULL,
    380		   *kcore_filename = NULL;
    381	struct perf_debuginfod debuginfod = { };
    382	char sbuf[STRERR_BUFSIZE];
    383
    384	struct perf_data data = {
    385		.mode  = PERF_DATA_MODE_READ,
    386	};
    387	struct perf_session *session = NULL;
    388	struct nsinfo *nsi = NULL;
    389
    390	const struct option buildid_cache_options[] = {
    391	OPT_STRING('a', "add", &add_name_list_str,
    392		   "file list", "file(s) to add"),
    393	OPT_STRING('k', "kcore", &kcore_filename,
    394		   "file", "kcore file to add"),
    395	OPT_STRING('r', "remove", &remove_name_list_str, "file list",
    396		    "file(s) to remove"),
    397	OPT_STRING('p', "purge", &purge_name_list_str, "file list",
    398		    "file(s) to remove (remove old caches too)"),
    399	OPT_BOOLEAN('P', "purge-all", &purge_all, "purge all cached files"),
    400	OPT_BOOLEAN('l', "list", &list_files, "list all cached files"),
    401	OPT_STRING('M', "missing", &missing_filename, "file",
    402		   "to find missing build ids in the cache"),
    403	OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
    404	OPT_STRING('u', "update", &update_name_list_str, "file list",
    405		    "file(s) to update"),
    406	OPT_STRING_OPTARG_SET(0, "debuginfod", &debuginfod.urls,
    407			&debuginfod.set, "debuginfod urls",
    408			"Enable debuginfod data retrieval from DEBUGINFOD_URLS or specified urls",
    409			"system"),
    410	OPT_INCR('v', "verbose", &verbose, "be more verbose"),
    411	OPT_INTEGER(0, "target-ns", &ns_id, "target pid for namespace context"),
    412	OPT_END()
    413	};
    414	const char * const buildid_cache_usage[] = {
    415		"perf buildid-cache [<options>]",
    416		NULL
    417	};
    418
    419	ret = perf_config(perf_buildid_cache_config, &debuginfod);
    420	if (ret)
    421		return ret;
    422
    423	argc = parse_options(argc, argv, buildid_cache_options,
    424			     buildid_cache_usage, 0);
    425
    426	opts_flag = add_name_list_str || kcore_filename ||
    427		remove_name_list_str || purge_name_list_str ||
    428		missing_filename || update_name_list_str ||
    429		purge_all;
    430
    431	if (argc || !(list_files || opts_flag))
    432		usage_with_options(buildid_cache_usage, buildid_cache_options);
    433
    434	perf_debuginfod_setup(&debuginfod);
    435
    436	/* -l is exclusive. It can not be used with other options. */
    437	if (list_files && opts_flag) {
    438		usage_with_options_msg(buildid_cache_usage,
    439			buildid_cache_options, "-l is exclusive.\n");
    440	}
    441
    442	if (ns_id > 0)
    443		nsi = nsinfo__new(ns_id);
    444
    445	if (missing_filename) {
    446		data.path  = missing_filename;
    447		data.force = force;
    448
    449		session = perf_session__new(&data, NULL);
    450		if (IS_ERR(session))
    451			return PTR_ERR(session);
    452	}
    453
    454	if (symbol__init(session ? &session->header.env : NULL) < 0)
    455		goto out;
    456
    457	setup_pager();
    458
    459	if (list_files) {
    460		ret = build_id_cache__show_all();
    461		goto out;
    462	}
    463
    464	if (add_name_list_str) {
    465		list = strlist__new(add_name_list_str, NULL);
    466		if (list) {
    467			strlist__for_each_entry(pos, list)
    468				if (build_id_cache__add_file(pos->s, nsi)) {
    469					if (errno == EEXIST) {
    470						pr_debug("%s already in the cache\n",
    471							 pos->s);
    472						continue;
    473					}
    474					pr_warning("Couldn't add %s: %s\n",
    475						   pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
    476				}
    477
    478			strlist__delete(list);
    479		}
    480	}
    481
    482	if (remove_name_list_str) {
    483		list = strlist__new(remove_name_list_str, NULL);
    484		if (list) {
    485			strlist__for_each_entry(pos, list)
    486				if (build_id_cache__remove_file(pos->s, nsi)) {
    487					if (errno == ENOENT) {
    488						pr_debug("%s wasn't in the cache\n",
    489							 pos->s);
    490						continue;
    491					}
    492					pr_warning("Couldn't remove %s: %s\n",
    493						   pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
    494				}
    495
    496			strlist__delete(list);
    497		}
    498	}
    499
    500	if (purge_name_list_str) {
    501		list = strlist__new(purge_name_list_str, NULL);
    502		if (list) {
    503			strlist__for_each_entry(pos, list)
    504				if (build_id_cache__purge_path(pos->s, nsi)) {
    505					if (errno == ENOENT) {
    506						pr_debug("%s wasn't in the cache\n",
    507							 pos->s);
    508						continue;
    509					}
    510					pr_warning("Couldn't remove %s: %s\n",
    511						   pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
    512				}
    513
    514			strlist__delete(list);
    515		}
    516	}
    517
    518	if (purge_all) {
    519		if (build_id_cache__purge_all()) {
    520			pr_warning("Couldn't remove some caches. Error: %s.\n",
    521				str_error_r(errno, sbuf, sizeof(sbuf)));
    522		}
    523	}
    524
    525	if (missing_filename)
    526		ret = build_id_cache__fprintf_missing(session, stdout);
    527
    528	if (update_name_list_str) {
    529		list = strlist__new(update_name_list_str, NULL);
    530		if (list) {
    531			strlist__for_each_entry(pos, list)
    532				if (build_id_cache__update_file(pos->s, nsi)) {
    533					if (errno == ENOENT) {
    534						pr_debug("%s wasn't in the cache\n",
    535							 pos->s);
    536						continue;
    537					}
    538					pr_warning("Couldn't update %s: %s\n",
    539						   pos->s, str_error_r(errno, sbuf, sizeof(sbuf)));
    540				}
    541
    542			strlist__delete(list);
    543		}
    544	}
    545
    546	if (kcore_filename && build_id_cache__add_kcore(kcore_filename, force))
    547		pr_warning("Couldn't add %s\n", kcore_filename);
    548
    549out:
    550	perf_session__delete(session);
    551	nsinfo__zput(nsi);
    552
    553	return ret;
    554}