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systemd/SOURCES/0122-util.h-add-new-UNPROTE...

104 lines
3.0 KiB

From b05795bd3d8afcdcb765639a636ada8d36a2ee79 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 18 Jan 2019 20:04:13 +0100
Subject: [PATCH] util.h: add new UNPROTECT_ERRNO macro
THis is inspired by #11395, but much simpler.
(cherry picked from commit 840f606d88fef2f5d240b2d759ce7b951354d5bb)
Resolves: #1691691
---
src/basic/util.h | 9 +++++++++
src/test/test-fs-util.c | 6 +++---
src/test/test-util.c | 25 +++++++++++++++++++++++++
3 files changed, 37 insertions(+), 3 deletions(-)
diff --git a/src/basic/util.h b/src/basic/util.h
index 9699d228f9..27b5a09782 100644
--- a/src/basic/util.h
+++ b/src/basic/util.h
@@ -134,11 +134,20 @@ static inline void *mempset(void *s, int c, size_t n) {
}
static inline void _reset_errno_(int *saved_errno) {
+ if (*saved_errno < 0) /* Invalidated by UNPROTECT_ERRNO? */
+ return;
+
errno = *saved_errno;
}
#define PROTECT_ERRNO _cleanup_(_reset_errno_) __attribute__((unused)) int _saved_errno_ = errno
+#define UNPROTECT_ERRNO \
+ do { \
+ errno = _saved_errno_; \
+ _saved_errno_ = -1; \
+ } while (false)
+
static inline int negative_errno(void) {
/* This helper should be used to shut up gcc if you know 'errno' is
* negative. Instead of "return -errno;", use "return negative_errno();"
diff --git a/src/test/test-fs-util.c b/src/test/test-fs-util.c
index fc650b513e..7b7990bb70 100644
--- a/src/test/test-fs-util.c
+++ b/src/test/test-fs-util.c
@@ -322,11 +322,11 @@ static void test_unlink_noerrno(void) {
{
PROTECT_ERRNO;
- errno = -42;
+ errno = 42;
assert_se(unlink_noerrno(name) >= 0);
- assert_se(errno == -42);
+ assert_se(errno == 42);
assert_se(unlink_noerrno(name) < 0);
- assert_se(errno == -42);
+ assert_se(errno == 42);
}
}
diff --git a/src/test/test-util.c b/src/test/test-util.c
index 4d3e5c5b94..df60d89115 100644
--- a/src/test/test-util.c
+++ b/src/test/test-util.c
@@ -164,6 +164,30 @@ static void test_protect_errno(void) {
assert_se(errno == 12);
}
+static void test_unprotect_errno_inner_function(void) {
+ PROTECT_ERRNO;
+
+ errno = 2222;
+}
+
+static void test_unprotect_errno(void) {
+ log_info("/* %s */", __func__);
+
+ errno = 4711;
+
+ PROTECT_ERRNO;
+
+ errno = 815;
+
+ UNPROTECT_ERRNO;
+
+ assert_se(errno == 4711);
+
+ test_unprotect_errno_inner_function();
+
+ assert_se(errno == 4711);
+}
+
static void test_in_set(void) {
assert_se(IN_SET(1, 1));
assert_se(IN_SET(1, 1, 2, 3, 4));
@@ -307,6 +331,7 @@ int main(int argc, char *argv[]) {
test_div_round_up();
test_u64log2();
test_protect_errno();
+ test_unprotect_errno();
test_in_set();
test_log2i();
test_raw_clone();