From patchwork Mon Nov 25 12:08:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Christian_G=C3=B6ttsche?= X-Patchwork-Id: 13884865 Received: from server02.seltendoof.de (server02.seltendoof.de [168.119.48.163]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4EDFE19146E for ; Mon, 25 Nov 2024 12:08:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=168.119.48.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732536517; cv=none; b=t/ItmDGvnHvrLIBgvZFwGmiB/kyQfgfj7hKb3cbSxt9mV4RofqUwm8kPfuTmgwX6JbXfX7S6E6AZnyQp1C6bJQrVyfcWeEY3i9qUn1iV277Z6IRDBR4/qbrrLSz7e6iCtx6tg4RVk6ObgYmj3XP0rY/5GZgEd/UqFI5xhAb+fKo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732536517; c=relaxed/simple; bh=bXvpjErQRRdbbeiMPcmXQuv30Rsqtp5y083SK03qPkM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gK4tjUReqFC5aOGMFGPmHzWPNIw52/WgBE+sT1C4XK+kOcxWuZ5ObRmtMcvexo6mwAHeEMhihrQdRPNxidZ1lMa3NRw1LT83D3iIV5X2gEtGFt1m6NCLala3l0KAuBDttuAvc7XUlHr7T5iZMN2I5fmIrvumktzVPeaVLaLm1OM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=seltendoof.de; spf=pass smtp.mailfrom=seltendoof.de; dkim=pass (2048-bit key) header.d=seltendoof.de header.i=@seltendoof.de header.b=mS8K3d2G; arc=none smtp.client-ip=168.119.48.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=seltendoof.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=seltendoof.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=seltendoof.de header.i=@seltendoof.de header.b="mS8K3d2G" From: =?utf-8?q?Christian_G=C3=B6ttsche?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=seltendoof.de; s=2023072701; t=1732536513; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9rnw6I7U1VGY7u2k08l5bmVtiFwHF6AizdJ7OynI8Fs=; b=mS8K3d2GtnWsRVMyEiAFKgLDFm6sgcTMSFTIJy5a+eQcnhHL/7muuUjpYtJladNY6oB8oe BjIKo5s55EY/lGyhhzveORxTpsQAICCS0reZjJBVlNouOUtNwTVGFo9JcxA2+ya7PLPwP8 p+6caQbgzKKCeU7w4OQy1hPOAowIVCjZsLuO+/uia5IS+8b9b9KeV+mIGlQowJiyffFsS5 M34PlINKxQ1URnzD8+y3Zr4dzyptn8B8gijw98xeue48huv8xzu8dgCsxrxdZvf0kT9NyW QUjJcoEOeY+kH669+c9YrI+YSNBRbK8crzvieQJm90nAW1rU20dy4swHwiKuxA== To: selinux@vger.kernel.org Cc: =?utf-8?q?Christian_G=C3=B6ttsche?= Subject: [PATCH v2 2/3] libselinux: use vector instead of linked list for substitutions Date: Mon, 25 Nov 2024 13:08:26 +0100 Message-ID: <20241125120827.97332-2-cgoettsche@seltendoof.de> In-Reply-To: <20241125120827.97332-1-cgoettsche@seltendoof.de> References: <20241125120827.97332-1-cgoettsche@seltendoof.de> Reply-To: cgzones@googlemail.com Precedence: bulk X-Mailing-List: selinux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Christian Göttsche Utilize cache locality for the substitutions by storing them in contiguous memory instead of a linked list. Signed-off-by: Christian Göttsche --- v2: drop unnecessary check for zero length --- libselinux/src/label_file.c | 127 +++++++++++++++++++----------------- libselinux/src/label_file.h | 20 ++++-- 2 files changed, 80 insertions(+), 67 deletions(-) diff --git a/libselinux/src/label_file.c b/libselinux/src/label_file.c index 4e212aa4..c91a91f7 100644 --- a/libselinux/src/label_file.c +++ b/libselinux/src/label_file.c @@ -1120,28 +1120,27 @@ static int process_file(const char *path, const char *suffix, return -1; } -static void selabel_subs_fini(struct selabel_sub *ptr) +static void selabel_subs_fini(struct selabel_sub *subs, uint32_t num) { - struct selabel_sub *next; - - while (ptr) { - next = ptr->next; - free(ptr->src); - free(ptr->dst); - free(ptr); - ptr = next; + for (uint32_t i = 0; i < num; i++) { + free(subs[i].src); + free(subs[i].dst); } + + free(subs); } -static char *selabel_sub(const struct selabel_sub *ptr, const char *src) +static char *selabel_apply_subs(const struct selabel_sub *subs, uint32_t num, const char *src) { - char *dst = NULL; - unsigned int len; + char *dst; + uint32_t len; + + for (uint32_t i = 0; i < num; i++) { + const struct selabel_sub *ptr = &subs[i]; - while (ptr) { if (strncmp(src, ptr->src, ptr->slen) == 0 ) { if (src[ptr->slen] == '/' || - src[ptr->slen] == 0) { + src[ptr->slen] == '\0') { if ((src[ptr->slen] == '/') && (strcmp(ptr->dst, "/") == 0)) len = ptr->slen + 1; @@ -1152,34 +1151,38 @@ static char *selabel_sub(const struct selabel_sub *ptr, const char *src) return dst; } } - ptr = ptr->next; } + return NULL; } #if !defined(BUILD_HOST) && !defined(ANDROID) static int selabel_subs_init(const char *path, struct selabel_digest *digest, - struct selabel_sub **out_subs) + struct selabel_sub **out_subs, + uint32_t *out_num, uint32_t *out_alloc) { char buf[1024]; - FILE *cfg = fopen(path, "re"); - struct selabel_sub *list = NULL, *sub = NULL; + FILE *cfg; struct stat sb; - int status = -1; + struct selabel_sub *tmp = NULL; + uint32_t tmp_num = 0, tmp_alloc = 0; + char *src_cpy = NULL, *dst_cpy = NULL; + int rc; *out_subs = NULL; + *out_num = 0; + *out_alloc = 0; + + cfg = fopen(path, "re"); if (!cfg) { /* If the file does not exist, it is not fatal */ return (errno == ENOENT) ? 0 : -1; } - if (fstat(fileno(cfg), &sb) < 0) - goto out; - while (fgets_unlocked(buf, sizeof(buf) - 1, cfg)) { - char *ptr = NULL; + char *ptr; char *src = buf; - char *dst = NULL; + char *dst; size_t len; while (*src && isspace((unsigned char)*src)) @@ -1207,62 +1210,64 @@ static int selabel_subs_init(const char *path, struct selabel_digest *digest, goto err; } - sub = calloc(1, sizeof(*sub)); - if (! sub) + src_cpy = strdup(src); + if (!src_cpy) goto err; - sub->src = strdup(src); - if (! sub->src) + dst_cpy = strdup(dst); + if (!dst_cpy) goto err; - sub->dst = strdup(dst); - if (! sub->dst) + rc = GROW_ARRAY(tmp); + if (rc) goto err; - sub->slen = len; - sub->next = list; - list = sub; - sub = NULL; + tmp[tmp_num++] = (struct selabel_sub) { + .src = src_cpy, + .slen = len, + .dst = dst_cpy, + }; + src_cpy = NULL; + dst_cpy = NULL; } + rc = fstat(fileno(cfg), &sb); + if (rc < 0) + goto err; + if (digest_add_specfile(digest, cfg, NULL, sb.st_size, path) < 0) goto err; - *out_subs = list; - status = 0; + *out_subs = tmp; + *out_num = tmp_num; + *out_alloc = tmp_alloc; -out: fclose(cfg); - return status; + + return 0; + err: - if (sub) - free(sub->src); - free(sub); - while (list) { - sub = list->next; - free(list->src); - free(list->dst); - free(list); - list = sub; - } - goto out; + free(dst_cpy); + free(src_cpy); + free(tmp); + fclose_errno_safe(cfg); + return -1; } #endif static char *selabel_sub_key(const struct saved_data *data, const char *key) { - char *ptr = NULL; - char *dptr = NULL; + char *ptr, *dptr; - ptr = selabel_sub(data->subs, key); + ptr = selabel_apply_subs(data->subs, data->subs_num, key); if (ptr) { - dptr = selabel_sub(data->dist_subs, ptr); + dptr = selabel_apply_subs(data->dist_subs, data->dist_subs_num, ptr); if (dptr) { free(ptr); ptr = dptr; } } else { - ptr = selabel_sub(data->dist_subs, key); + ptr = selabel_apply_subs(data->dist_subs, data->dist_subs_num, key); } return ptr; @@ -1307,23 +1312,25 @@ static int init(struct selabel_handle *rec, const struct selinux_opt *opts, if (!path) { status = selabel_subs_init( selinux_file_context_subs_dist_path(), - rec->digest, &data->dist_subs); + rec->digest, + &data->dist_subs, &data->dist_subs_num, &data->dist_subs_alloc); if (status) goto finish; status = selabel_subs_init(selinux_file_context_subs_path(), - rec->digest, &data->subs); + rec->digest, + &data->subs, &data->subs_num, &data->subs_alloc); if (status) goto finish; path = selinux_file_context_path(); } else { snprintf(subs_file, sizeof(subs_file), "%s.subs_dist", path); status = selabel_subs_init(subs_file, rec->digest, - &data->dist_subs); + &data->dist_subs, &data->dist_subs_num, &data->dist_subs_alloc); if (status) goto finish; snprintf(subs_file, sizeof(subs_file), "%s.subs", path); status = selabel_subs_init(subs_file, rec->digest, - &data->subs); + &data->subs, &data->subs_num, &data->subs_alloc); if (status) goto finish; } @@ -1391,8 +1398,8 @@ static void closef(struct selabel_handle *rec) if (!data) return; - selabel_subs_fini(data->subs); - selabel_subs_fini(data->dist_subs); + selabel_subs_fini(data->subs, data->subs_num); + selabel_subs_fini(data->dist_subs, data->dist_subs_num); free_spec_node(data->root); free(data->root); diff --git a/libselinux/src/label_file.h b/libselinux/src/label_file.h index de8190f9..436982bf 100644 --- a/libselinux/src/label_file.h +++ b/libselinux/src/label_file.h @@ -67,11 +67,11 @@ extern struct lookup_result *lookup_all(struct selabel_handle *rec, const char * extern enum selabel_cmp_result cmp(const struct selabel_handle *h1, const struct selabel_handle *h2); #endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */ +/* A path substitution entry */ struct selabel_sub { - char *src; - unsigned int slen; - char *dst; - struct selabel_sub *next; + char *src; /* source path prefix */ + char *dst; /* substituted path prefix */ + uint32_t slen; /* length of source path prefix */ }; /* A regular expression file security context specification */ @@ -159,9 +159,17 @@ struct saved_data { struct mmap_area *mmap_areas; - /* substitution support */ + /* + * Array of distribution substitutions + */ struct selabel_sub *dist_subs; + uint32_t dist_subs_num, dist_subs_alloc; + + /* + * Array of local substitutions + */ struct selabel_sub *subs; + uint32_t subs_num, subs_alloc; }; static inline mode_t string_to_file_kind(const char *mode) @@ -811,8 +819,6 @@ static int insert_spec(const struct selabel_handle *rec, struct saved_data *data return 0; } -#undef GROW_ARRAY - static inline void free_spec_node(struct spec_node *node) { for (uint32_t i = 0; i < node->literal_specs_num; i++) {