Use a dynamic buffer to allow parsing scripts bigger than BUFSIZ.

ok jasper@

diff --git a/usr.sbin/btrace/btrace.c b/usr.sbin/btrace/btrace.c
index 7ed844a..b65fb58 100644 (file)
--- a/usr.sbin/btrace/btrace.c
+++ b/usr.sbin/btrace/btrace.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: btrace.c,v 1.50 2021/09/09 06:58:39 mpi Exp $ */
+/*     $OpenBSD: btrace.c,v 1.51 2021/09/09 07:03:10 mpi Exp $ */
 
 /*
  * Copyright (c) 2019 - 2021 Martin Pieuchot <mpi@openbsd.org>
@@ -18,6 +18,7 @@
 
 #include <sys/ioctl.h>
 #include <sys/exec_elf.h>
+#include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/queue.h>
 
@@ -53,7 +54,7 @@
 #define __PATH_DEVDT "/dev/dt"
 
 __dead void             usage(void);
-char                   *read_btfile(const char *);
+char                   *read_btfile(const char *, size_t *);
 
 /*
  * Retrieve & parse probe information.
@@ -133,6 +134,7 @@ main(int argc, char *argv[])
        int fd = -1, ch, error = 0;
        const char *filename = NULL, *btscript = NULL;
        int showprobes = 0, noaction = 0;
+       size_t btslen = 0;
 
        setlocale(LC_ALL, "");
 
@@ -145,6 +147,7 @@ main(int argc, char *argv[])
                switch (ch) {
                case 'e':
                        btscript = optarg;
+                       btslen = strlen(btscript);
                        break;
                case 'l':
                        showprobes = 1;
@@ -165,7 +168,7 @@ main(int argc, char *argv[])
 
        if (argc > 0 && btscript == NULL) {
                filename = argv[0];
-               btscript = read_btfile(filename);
+               btscript = read_btfile(filename, &btslen);
                argc--;
                argv++;
        }
@@ -177,7 +180,7 @@ main(int argc, char *argv[])
                usage();
 
        if (btscript != NULL) {
-               error = btparse(btscript, strlen(btscript), filename, 1);
+               error = btparse(btscript, btslen, filename, 1);
                if (error)
                        return error;
        }
@@ -214,25 +217,30 @@ usage(void)
 }
 
 char *
-read_btfile(const char *filename)
+read_btfile(const char *filename, size_t *len)
 {
-       static char fcontent[BUFSIZ];
-       long offset;
        FILE *fp;
+       char *fcontent;
+       struct stat st;
+       size_t fsize;
+
+       if (stat(filename, &st))
+               err(1, "can't stat '%s'", filename);
+
+       fsize = st.st_size;
+       fcontent = malloc(fsize);
+       if (fcontent == NULL)
+               err(1, "malloc");
 
        fp = fopen(filename, "r");
        if (fp == NULL)
                err(1, "can't open '%s'", filename);
 
-       if (fread(fcontent, sizeof(fcontent) - 1, 1, fp) == 0 && errno != 0)
+       if (fread(fcontent, 1, fsize, fp) != fsize)
                err(1, "can't read '%s'", filename);
 
-       fseek(fp, 0, SEEK_END);
-       offset = ftell(fp);
-       if ((size_t)offset >= sizeof(fcontent))
-               errx(1, "couldn't read all of '%s'", filename);
-
        fclose(fp);
+       *len = fsize;
        return fcontent;
 }