scripts/kallsyms: remove KSYM_NAME_LEN_BUFFER

You do not need to decide the buffer size statically.

Use getline() to grow the line buffer as needed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <n.schier@avm.de>

diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c
index 8e97ac7..d387c93 100644 (file)
--- a/scripts/kallsyms.c
+++ b/scripts/kallsyms.c
@@ -19,6 +19,7 @@
  *
  */
 
+#include <errno.h>
 #include <getopt.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -29,24 +30,8 @@
 
 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
 
-#define _stringify_1(x)        #x
-#define _stringify(x)  _stringify_1(x)
-
 #define KSYM_NAME_LEN          512
 
-/*
- * A substantially bigger size than the current maximum.
- *
- * It cannot be defined as an expression because it gets stringified
- * for the fscanf() format string. Therefore, a _Static_assert() is
- * used instead to maintain the relationship with KSYM_NAME_LEN.
- */
-#define KSYM_NAME_LEN_BUFFER   2048
-_Static_assert(
-       KSYM_NAME_LEN_BUFFER == KSYM_NAME_LEN * 4,
-       "Please keep KSYM_NAME_LEN_BUFFER in sync with KSYM_NAME_LEN"
-);
-
 struct sym_entry {
        unsigned long long addr;
        unsigned int len;
@@ -136,24 +121,40 @@ static void check_symbol_range(const char *sym, unsigned long long addr,
        }
 }
 
-static struct sym_entry *read_symbol(FILE *in)
+static struct sym_entry *read_symbol(FILE *in, char **buf, size_t *buf_len)
 {
-       char name[KSYM_NAME_LEN_BUFFER+1], type;
+       char *name, type, *p;
        unsigned long long addr;
-       unsigned int len;
+       size_t len;
+       ssize_t readlen;
        struct sym_entry *sym;
-       int rc;
 
-       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");
+       readlen = getline(buf, buf_len, in);
+       if (readlen < 0) {
+               if (errno) {
+                       perror("read_symbol");
+                       exit(EXIT_FAILURE);
+               }
                return NULL;
        }
-       if (strlen(name) >= KSYM_NAME_LEN) {
+
+       if ((*buf)[readlen - 1] == '\n')
+               (*buf)[readlen - 1] = 0;
+
+       addr = strtoull(*buf, &p, 16);
+
+       if (*buf == p || *p++ != ' ' || !isascii((type = *p++)) || *p++ != ' ') {
+               fprintf(stderr, "line format error\n");
+               exit(EXIT_FAILURE);
+       }
+
+       name = p;
+       len = strlen(name);
+
+       if (len >= KSYM_NAME_LEN) {
                fprintf(stderr, "Symbol %s too long for kallsyms (%zu >= %d).\n"
                                "Please increase KSYM_NAME_LEN both in kernel and kallsyms.c\n",
-                       name, strlen(name), KSYM_NAME_LEN);
+                       name, len, KSYM_NAME_LEN);
                return NULL;
        }
 
@@ -169,8 +170,7 @@ static struct sym_entry *read_symbol(FILE *in)
 
        /* include the type field in the symbol name, so that it gets
         * compressed together */
-
-       len = strlen(name) + 1;
+       len++;
 
        sym = malloc(sizeof(*sym) + len + 1);
        if (!sym) {
@@ -257,6 +257,8 @@ static void read_map(const char *in)
 {
        FILE *fp;
        struct sym_entry *sym;
+       char *buf = NULL;
+       size_t buflen = 0;
 
        fp = fopen(in, "r");
        if (!fp) {
@@ -265,7 +267,7 @@ static void read_map(const char *in)
        }
 
        while (!feof(fp)) {
-               sym = read_symbol(fp);
+               sym = read_symbol(fp, &buf, &buflen);
                if (!sym)
                        continue;
 
@@ -284,6 +286,7 @@ static void read_map(const char *in)
                table[table_cnt++] = sym;
        }
 
+       free(buf);
        fclose(fp);
 }