From: Emil Velikov <emil.l.velikov@gmail.com>
Date: Sat, 5 Apr 2025 10:39:42 +0000 (+0100)
Subject: Use sizeof() over PATH_MAX in snprintf() contexts
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0fd84a53abf5af8621b1fbd420622a85dc3297e4;p=thirdparty%2Fkmod.git

Use sizeof() over PATH_MAX in snprintf() contexts

Bunch of our codebase uses sizeof() while the rest hard-coded length for
the destination buffer. Converge on the former since it makes for more
obvious and less error prone code.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/345
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/libkmod/libkmod-builtin.c b/libkmod/libkmod-builtin.c
index f354d455..b32848d9 100644
--- a/libkmod/libkmod-builtin.c
+++ b/libkmod/libkmod-builtin.c
@@ -44,7 +44,7 @@ static bool kmod_builtin_info_init(struct kmod_builtin_info *info, struct kmod_c
 		errno = ENAMETOOLONG;
 		return false;
 	}
-	snprintf(path, PATH_MAX, "%s/" MODULES_BUILTIN_MODINFO, dirname);
+	snprintf(path, sizeof(path), "%s/" MODULES_BUILTIN_MODINFO, dirname);
 
 	fp = fopen(path, "r");
 	if (fp == NULL)
diff --git a/shared/tmpfile-util.c b/shared/tmpfile-util.c
index 4d6fc557..c9c20d23 100644
--- a/shared/tmpfile-util.c
+++ b/shared/tmpfile-util.c
@@ -31,8 +31,8 @@ FILE *tmpfile_openat(int dirfd, mode_t mode, struct tmpfile *file)
 	if (targetdir == NULL)
 		goto create_fail;
 
-	n = snprintf(tmpfile_path, PATH_MAX, "%s/%s", targetdir, tmpname_tmpl);
-	if (n < 0 || n >= PATH_MAX)
+	n = snprintf(tmpfile_path, sizeof(tmpfile_path), "%s/%s", targetdir, tmpname_tmpl);
+	if (n < 0 || n >= (int)sizeof(tmpfile_path))
 		goto create_fail;
 
 	fd = mkstemp(tmpfile_path);
diff --git a/tools/depmod.c b/tools/depmod.c
index fb5d426a..cd29bf4f 100644
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -3011,17 +3011,17 @@ static int do_depmod(int argc, char *argv[])
 	while (module_directory[0] == '/')
 		module_directory++;
 
-	cfg.dirnamelen = snprintf(cfg.dirname, PATH_MAX, "%s/%s/%s", root,
+	cfg.dirnamelen = snprintf(cfg.dirname, sizeof(cfg.dirname), "%s/%s/%s", root,
 				  module_directory, cfg.kversion);
-	if (cfg.dirnamelen >= PATH_MAX) {
+	if (cfg.dirnamelen >= sizeof(cfg.dirname)) {
 		ERR("Bad directory %s/%s/%s: path too long\n", root, module_directory,
 		    cfg.kversion);
 		goto cmdline_failed;
 	}
 
-	cfg.outdirnamelen = snprintf(cfg.outdirname, PATH_MAX, "%s/%s/%s",
+	cfg.outdirnamelen = snprintf(cfg.outdirname, sizeof(cfg.outdirname), "%s/%s/%s",
 				     out_root ?: root, module_directory, cfg.kversion);
-	if (cfg.outdirnamelen >= PATH_MAX) {
+	if (cfg.outdirnamelen >= sizeof(cfg.outdirname)) {
 		ERR("Bad directory %s/%s/%s: path too long\n", out_root ?: root,
 		    module_directory, cfg.kversion);
 		goto cmdline_failed;