From: Emil Velikov <emil.l.velikov@gmail.com>
Date: Sat, 24 May 2025 11:06:13 +0000 (+0100)
Subject: libkmod: use strlen() for string literals
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=723bdadc9f100263f870e5a8dcef14d3fe3d9501;p=thirdparty%2Fkmod.git

libkmod: use strlen() for string literals

Older compilers had struggles expanding strlen(string-literal) to a
constant compile time expression. Thus our code-base used sizeof() - 1
instead.

This has been resolved for years, so let's use the correct function. As
a bonus point, we can remove a few variable making the code tad easier
to follow.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/354
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/libkmod/libkmod-config.c b/libkmod/libkmod-config.c
index 9e03f3c5..38b162d5 100644
--- a/libkmod/libkmod-config.c
+++ b/libkmod/libkmod-config.c
@@ -267,11 +267,10 @@ static int kmod_config_add_softdep(struct kmod_config *config, const char *modna
 		}
 		plen = s - p;
 
-		if (plen == sizeof("pre:") - 1 &&
-		    memcmp(p, "pre:", sizeof("pre:") - 1) == 0)
+		if (plen == strlen("pre:") && memcmp(p, "pre:", strlen("pre:")) == 0)
 			mode = S_PRE;
-		else if (plen == sizeof("post:") - 1 &&
-			 memcmp(p, "post:", sizeof("post:") - 1) == 0)
+		else if (plen == strlen("post:") &&
+			 memcmp(p, "post:", strlen("post:")) == 0)
 			mode = S_POST;
 		else if (*s != '\0' || (*s == '\0' && !was_space)) {
 			if (mode == S_PRE) {
@@ -352,11 +351,10 @@ static int kmod_config_add_softdep(struct kmod_config *config, const char *modna
 		}
 		plen = s - p;
 
-		if (plen == sizeof("pre:") - 1 &&
-		    memcmp(p, "pre:", sizeof("pre:") - 1) == 0)
+		if (plen == strlen("pre:") && memcmp(p, "pre:", strlen("pre:")) == 0)
 			mode = S_PRE;
-		else if (plen == sizeof("post:") - 1 &&
-			 memcmp(p, "post:", sizeof("post:") - 1) == 0)
+		else if (plen == strlen("post:") &&
+			 memcmp(p, "post:", strlen("post:")) == 0)
 			mode = S_POST;
 		else if (*s != '\0' || (*s == '\0' && !was_space)) {
 			if (mode == S_PRE) {
@@ -506,8 +504,6 @@ static int kmod_config_add_weakdep(struct kmod_config *config, const char *modna
 
 static char *softdep_to_char(struct kmod_softdep *dep)
 {
-	const size_t sz_preprefix = sizeof("pre: ") - 1;
-	const size_t sz_postprefix = sizeof("post: ") - 1;
 	size_t sz = 1; /* at least '\0' */
 	size_t sz_pre, sz_post;
 	const char *start, *end;
@@ -521,7 +517,7 @@ static char *softdep_to_char(struct kmod_softdep *dep)
 		start = dep->pre[0];
 		end = dep->pre[dep->n_pre - 1] + strlen(dep->pre[dep->n_pre - 1]);
 		sz_pre = end - start;
-		sz += sz_pre + sz_preprefix;
+		sz += sz_pre + strlen("pre: ");
 	} else
 		sz_pre = 0;
 
@@ -529,7 +525,7 @@ static char *softdep_to_char(struct kmod_softdep *dep)
 		start = dep->post[0];
 		end = dep->post[dep->n_post - 1] + strlen(dep->post[dep->n_post - 1]);
 		sz_post = end - start;
-		sz += sz_post + sz_postprefix;
+		sz += sz_post + strlen("post: ");
 	} else
 		sz_post = 0;
 
@@ -540,8 +536,8 @@ static char *softdep_to_char(struct kmod_softdep *dep)
 	if (sz_pre) {
 		char *p;
 
-		memcpy(itr, "pre: ", sz_preprefix);
-		itr += sz_preprefix;
+		memcpy(itr, "pre: ", strlen("pre: "));
+		itr += strlen("pre: ");
 
 		/* include last '\0' */
 		memcpy(itr, dep->pre[0], sz_pre + 1);
@@ -555,8 +551,8 @@ static char *softdep_to_char(struct kmod_softdep *dep)
 	if (sz_post) {
 		char *p;
 
-		memcpy(itr, "post: ", sz_postprefix);
-		itr += sz_postprefix;
+		memcpy(itr, "post: ", strlen("post: "));
+		itr += strlen("post: ");
 
 		/* include last '\0' */
 		memcpy(itr, dep->post[0], sz_post + 1);
diff --git a/libkmod/libkmod-elf.c b/libkmod/libkmod-elf.c
index 4775360d..23d27f02 100644
--- a/libkmod/libkmod-elf.c
+++ b/libkmod/libkmod-elf.c
@@ -640,8 +640,7 @@ static int elf_strip_vermagic(const struct kmod_elf *elf, uint8_t *changed)
 			continue;
 
 		s = strings + i;
-		len = sizeof("vermagic=") - 1;
-		if (i + len >= size)
+		if (i + strlen("vermagic=") >= size)
 			continue;
 		if (!strstartswith(s, "vermagic=")) {
 			i += strlen(s);
diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 796dafa1..3ca90c0c 100644
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -819,7 +819,7 @@ static int module_do_install_commands(struct kmod_module *mod, const char *optio
 
 	options_len = strlen(options);
 	cmdlen = strlen(command);
-	varlen = sizeof("$CMDLINE_OPTS") - 1;
+	varlen = strlen("$CMDLINE_OPTS");
 
 	cmd = memdup(command, cmdlen + 1);
 	if (cmd == NULL)
@@ -1432,9 +1432,9 @@ KMOD_EXPORT int kmod_module_get_initstate(const struct kmod_module *mod)
 		err = -errno;
 		DBG(mod->ctx, "could not open '%s': %m\n", path);
 
-		if (pathlen > (int)sizeof("/initstate") - 1) {
+		if (pathlen > (int)strlen("/initstate")) {
 			struct stat st;
-			path[pathlen - (sizeof("/initstate") - 1)] = '\0';
+			path[pathlen - strlen("/initstate")] = '\0';
 			if (stat(path, &st) == 0 && S_ISDIR(st.st_mode))
 				return KMOD_MODULE_COMING;