fw_env: fix reading NVMEM device's "compatible" value
Call to fread() was changed to check for return value. The problem is it
can't be checked for returning 1 (as it is) to determine success.
We call fread() with buffer size as "size" argument. Reading any
"compatible" value shorter than buffer size will result in returning 0
even on success.
Modify code to use fstat() to determine expected read length.
This fixes regression that broke using fw_env with NVMEM devices.
Fixes: c059a22b7776 ("tools: env: fw_env: Fix unused-result warning")
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index c9a8774..bf8b7ba 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -1732,6 +1732,7 @@
}
while (!nvmem && (dent = readdir(dir))) {
+ struct stat s;
FILE *fp;
size_t size;
@@ -1749,14 +1750,22 @@
continue;
}
- size = fread(buf, sizeof(buf), 1, fp);
+ if (fstat(fileno(fp), &s)) {
+ fprintf(stderr, "Failed to fstat %s\n", comp);
+ goto next;
+ }
+
+ if (s.st_size >= sizeof(buf)) {
+ goto next;
+ }
+
+ size = fread(buf, s.st_size, 1, fp);
if (size != 1) {
fprintf(stderr,
"read failed about %s\n", comp);
- fclose(fp);
- return -EIO;
+ goto next;
}
-
+ buf[s.st_size] = '\0';
if (!strcmp(buf, "u-boot,env")) {
bytes = asprintf(&nvmem, "%s/%s/nvmem", path, dent->d_name);
@@ -1765,6 +1774,7 @@
}
}
+next:
fclose(fp);
}