libdrgn: accept flattened KDUMP format

Support for the flattened KDUMP format was added in libkdumpfile-0.5.3.

Signed-off-by: Petr Tesarik <petr@tesarici.cz>

libdrgn/program.c

@@ -222,15 +222,9 @@ static struct drgn_error *has_kdump_signature(const char *path, int fd,
 	ssize_t r = pread_all(fd, signature, sizeof(signature), 0);
 	if (r < 0)
 		return drgn_error_create_os("pread", errno, path);
-	if (r >= FLATTENED_SIG_LEN
-	    && memcmp(signature, FLATTENED_SIGNATURE, FLATTENED_SIG_LEN) == 0) {
-		return drgn_error_create(DRGN_ERROR_INVALID_ARGUMENT,
-					 "the given file is in the makedumpfile flattened "
-					 "format, which drgn does not support; use "
-					 "'makedumpfile -R newfile <oldfile' to reassemble "
-					 "the file into a format drgn can read");
-	}
-	*ret = (r >= KDUMP_SIG_LEN
+	*ret = (r >= FLATTENED_SIG_LEN
+		&& memcmp(signature, FLATTENED_SIGNATURE, FLATTENED_SIG_LEN) == 0) ||
+	       (r >= KDUMP_SIG_LEN
 	        && memcmp(signature, KDUMP_SIGNATURE, KDUMP_SIG_LEN) == 0);
 	return NULL;
 }