tools: bpf_jit_disasm: Handle large images.

Dynamically allocate memory so that JIT images larger than the size of
the statically allocated array can be handled.

Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/tools/net/bpf_jit_disasm.c b/tools/net/bpf_jit_disasm.c
index ad572e6cdbd0f47cfa947f18451a253977ff6c64..422d9abd666a60a2c526eeb6581ea83a5fc577b7 100644 (file)
--- a/tools/net/bpf_jit_disasm.c
+++ b/tools/net/bpf_jit_disasm.c
@@ -159,8 +159,8 @@ static void put_log_buff(char *buff)
        free(buff);
 }
 
-static unsigned int get_last_jit_image(char *haystack, size_t hlen,
-                                      uint8_t *image, size_t ilen)
+static uint8_t *get_last_jit_image(char *haystack, size_t hlen,
+                                  unsigned int *ilen)
 {
        char *ptr, *pptr, *tmp;
        off_t off = 0;
@@ -168,9 +168,10 @@ static unsigned int get_last_jit_image(char *haystack, size_t hlen,
        regmatch_t pmatch[1];
        unsigned long base;
        regex_t regex;
+       uint8_t *image;
 
        if (hlen == 0)
-               return 0;
+               return NULL;
 
        ret = regcomp(&regex, "flen=[[:alnum:]]+ proglen=[[:digit:]]+ "
                      "pass=[[:digit:]]+ image=[[:xdigit:]]+", REG_EXTENDED);
@@ -194,11 +195,22 @@ static unsigned int get_last_jit_image(char *haystack, size_t hlen,
                     &flen, &proglen, &pass, &base);
        if (ret != 4) {
                regfree(&regex);
-               return 0;
+               return NULL;
+       }
+       if (proglen > 1000000) {
+               printf("proglen of %d too big, stopping\n", proglen);
+               return NULL;
        }
 
+       image = malloc(proglen);
+       if (!image) {
+               printf("Out of memory\n");
+               return NULL;
+       }
+       memset(image, 0, proglen);
+
        tmp = ptr = haystack + off;
-       while ((ptr = strtok(tmp, "\n")) != NULL && ulen < ilen) {
+       while ((ptr = strtok(tmp, "\n")) != NULL && ulen < proglen) {
                tmp = NULL;
                if (!strstr(ptr, "JIT code"))
                        continue;
@@ -208,10 +220,12 @@ static unsigned int get_last_jit_image(char *haystack, size_t hlen,
                ptr = pptr;
                do {
                        image[ulen++] = (uint8_t) strtoul(pptr, &pptr, 16);
-                       if (ptr == pptr || ulen >= ilen) {
+                       if (ptr == pptr) {
                                ulen--;
                                break;
                        }
+                       if (ulen >= proglen)
+                               break;
                        ptr = pptr;
                } while (1);
        }
@@ -222,7 +236,8 @@ static unsigned int get_last_jit_image(char *haystack, size_t hlen,
        printf("%lx + <x>:\n", base);
 
        regfree(&regex);
-       return ulen;
+       *ilen = ulen;
+       return image;
 }
 
 static void usage(void)
@@ -237,12 +252,12 @@ static void usage(void)
 int main(int argc, char **argv)
 {
        unsigned int len, klen, opt, opcodes = 0;
-       static uint8_t image[32768];
        char *kbuff, *file = NULL;
        char *ofile = NULL;
        int ofd;
        ssize_t nr;
        uint8_t *pos;
+       uint8_t *image = NULL;
 
        while ((opt = getopt(argc, argv, "of:O:")) != -1) {
                switch (opt) {
@@ -262,7 +277,6 @@ int main(int argc, char **argv)
        }
 
        bfd_init();
-       memset(image, 0, sizeof(image));
 
        kbuff = get_log_buff(file, &klen);
        if (!kbuff) {
@@ -270,8 +284,8 @@ int main(int argc, char **argv)
                return -1;
        }
 
-       len = get_last_jit_image(kbuff, klen, image, sizeof(image));
-       if (len <= 0) {
+       image = get_last_jit_image(kbuff, klen, &len);
+       if (!image) {
                fprintf(stderr, "No JIT image found!\n");
                goto done;
        }
@@ -301,5 +315,6 @@ int main(int argc, char **argv)
 
 done:
        put_log_buff(kbuff);
+       free(image);
        return 0;
 }