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From:   Miguel Ojeda <ojeda@kernel.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, patches@lists.linux.dev,
        Jarkko Sakkinen <jarkko@kernel.org>,
        Miguel Ojeda <ojeda@kernel.org>,
        Boqun Feng <boqun.feng@gmail.com>,
        Kees Cook <keescook@chromium.org>
Subject: [PATCH v10 02/27] kallsyms: avoid hardcoding buffer size
Date:   Tue, 27 Sep 2022 15:14:33 +0200
Message-Id: <20220927131518.30000-3-ojeda@kernel.org>
In-Reply-To: <20220927131518.30000-1-ojeda@kernel.org>
References: <20220927131518.30000-1-ojeda@kernel.org>
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From: Boqun Feng <boqun.feng@gmail.com>

This introduces `KSYM_NAME_LEN_BUFFER` in place of the previously
hardcoded size of the input buffer.

It will also make it easier to update the size in a single place
in a later patch.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 scripts/kallsyms.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 8551513f9311..25e2fe5fbcd4 100644
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -27,8 +27,14 @@
 
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
 
+#define _stringify_1(x)	#x
+#define _stringify(x)	_stringify_1(x)
+
 #define KSYM_NAME_LEN		128
 
+/* A substantially bigger size than the current maximum. */
+#define KSYM_NAME_LEN_BUFFER	499
+
 struct sym_entry {
 	unsigned long long addr;
 	unsigned int len;
@@ -198,13 +204,13 @@ static void check_symbol_range(const char *sym, unsigned long long addr,
 
 static struct sym_entry *read_symbol(FILE *in)
 {
-	char name[500], type;
+	char name[KSYM_NAME_LEN_BUFFER+1], type;
 	unsigned long long addr;
 	unsigned int len;
 	struct sym_entry *sym;
 	int rc;
 
-	rc = fscanf(in, "%llx %c %499s\n", &addr, &type, name);
+	rc = fscanf(in, "%llx %c %" _stringify(KSYM_NAME_LEN_BUFFER) "s\n", &addr, &type, name);
 	if (rc != 3) {
 		if (rc != EOF && fgets(name, ARRAY_SIZE(name), in) == NULL)
 			fprintf(stderr, "Read error or end of file.\n");
-- 
2.37.3