lbutils: don't set USE_OPENAT and USE_URANDOM

these can be set explicitly in the compiler flags,
e.g.

make CC="cc -DUSE_OPENAT=1 -DUSE_URANDOM=1"

these options, if set to 1, will cause you to use
the code as if it were running on non-linux systems
such as openbsd. of course, some differences will
still exist, but this is useful for portability
testing when compiling on linux.

Signed-off-by: Leah Rowe <leah@libreboot.org>

util/libreboot-utils/Makefile

@@ -7,6 +7,7 @@
 
 CC = cc
 HELLCC = clang
+OLDCC = $(CC) -DUSE_URANDOM=1 -DUSE_OPENAT
 
 CFLAGS = -Os -Wall -Wextra -std=c99 -pedantic -Werror
 LDFLAGS =

util/libreboot-utils/include/common.h

@@ -34,13 +34,6 @@
 
 #define items(x) (sizeof((x)) / sizeof((x)[0]))
 
-/* system prototypes
- */
-
-#ifndef USE_URANDOM
-#define USE_URANDOM 0
-#endif
-
 #define MKHTEMP_RETRY_MAX 512
 #define MKHTEMP_SPIN_THRESHOLD 32
 

util/libreboot-utils/lib/file.c

@@ -22,12 +22,15 @@ long max = pathconf("/", _PC_PATH_MAX);
 
 /* for openat2: */
 #ifdef __linux__
+#if !defined(USE_OPENAT) || \
+    ((USE_OPENAT) < 1) /* if 1: use openat, not openat2 */
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE 1
 #endif
 #include <linux/openat2.h>
 #include <sys/syscall.h>
 #endif
+#endif
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -612,7 +615,8 @@ open_file_on_eintr(const char *path,
 }
 
 
-#ifdef __linux__ /* we use openat2 on linux */
+#if defined(__linux__) && \
+    ((USE_OPENAT) < 1) /* we use openat2 on linux */
 int
 openat_on_eintr(int dirfd, const char *path,
     int flags, mode_t mode)

util/libreboot-utils/lib/mkhtemp.c

@@ -10,6 +10,8 @@
 
 /* for openat2 / fast path: */
 #ifdef __linux__
+#if !defined(USE_OPENAT) || \
+    ((USE_OPENAT) < 1) /* if 1: use openat, not openat2 */
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE 1
 #endif
@@ -22,6 +24,7 @@
 #define AT_EMPTY_PATH 0x1000
 #endif
 #endif
+#endif
 
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -543,7 +546,8 @@ mkhtemp_try_create(int dirfd,
 		goto err;
 
 	if (type == MKHTEMP_FILE) {
-#ifdef __linux__
+#if defined(__linux__) && \
+    (!defined(USE_OPENAT) || ((USE_OPENAT) < 1))
 		/* try O_TMPFILE fast path */
 		if (mkhtemp_tmpfile_linux(dirfd,
 		    st_dir_first, fname_copy,
@@ -652,7 +656,8 @@ err:
    we still use openat() on bsd, which is
    still ok with our other mitigations
  */
-#ifdef __linux__
+#if defined(__linux__) && \
+    (!defined(USE_OPENAT) || ((USE_OPENAT) < 1))
 int
 mkhtemp_tmpfile_linux(int dirfd,
     struct stat *st_dir_first,

util/libreboot-utils/lib/rand.c

@@ -154,7 +154,7 @@ retry_rand: {
 
 	while (rw_retry(saved_errno,
 		rc = read_on_eintr(fd,
-		    (unsigned char *)buf + off, n - off, 0)));
+		    (unsigned char *)buf + off, n - off)));
 #elif defined(__linux__)
 	long rc;
 	while (sys_retry(saved_errno,
@@ -183,10 +183,6 @@ retry_rand: {
 	reset_caller_errno(0);
 	return;
 err:
-#if defined(USE_URANDOM) && \
-    ((USE_URANDOM) > 0)
-	close_on_eintr(&fd);
-#endif
 	(void) with_fallback_errno(ECANCELED);
 	exitf("Randomisierungsfehler");
 	exit(EXIT_FAILURE);