systemd/SOURCES/0679-macro-add-generic-IS_ALIGNED32-anf-friends.patch

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2024-04-30 11:42:21 +00:00
From 925a5adafed2d17c4f2c50460d4e571ca509f54e Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Wed, 7 Dec 2022 18:31:27 +0100
Subject: [PATCH] macro: add generic IS_ALIGNED32() anf friends
Let's generalize (and invert) the UNALIGNED32_P() macro from the sha256
code, and let's add a test for it.
(cherry picked from commit 4f07388360a3513b9fc8d2773568b8def941f4a4)
Related: RHEL-16952
---
src/fundamental/macro-fundamental.h | 9 +++++
src/test/test-macro.c | 53 +++++++++++++++++++++++++++++
2 files changed, 62 insertions(+)
diff --git a/src/fundamental/macro-fundamental.h b/src/fundamental/macro-fundamental.h
index e0665d9dcb..dd0de328cb 100644
--- a/src/fundamental/macro-fundamental.h
+++ b/src/fundamental/macro-fundamental.h
@@ -334,14 +334,23 @@ static inline size_t ALIGN_TO(size_t l, size_t ali) {
return ((l + ali - 1) & ~(ali - 1));
}
+#define ALIGN2(l) ALIGN_TO(l, 2)
#define ALIGN4(l) ALIGN_TO(l, 4)
#define ALIGN8(l) ALIGN_TO(l, 8)
+#define ALIGN2_PTR(p) ((void*) ALIGN2((uintptr_t) p))
+#define ALIGN4_PTR(p) ((void*) ALIGN4((uintptr_t) p))
+#define ALIGN8_PTR(p) ((void*) ALIGN8((uintptr_t) p))
#ifndef SD_BOOT
/* libefi also provides ALIGN, and we do not use them in sd-boot explicitly. */
#define ALIGN(l) ALIGN_TO(l, sizeof(void*))
#define ALIGN_PTR(p) ((void*) ALIGN((uintptr_t) (p)))
#endif
+/* Checks if the specified pointer is aligned as appropriate for the specific type */
+#define IS_ALIGNED16(p) (((uintptr_t) p) % __alignof__(uint16_t) == 0)
+#define IS_ALIGNED32(p) (((uintptr_t) p) % __alignof__(uint32_t) == 0)
+#define IS_ALIGNED64(p) (((uintptr_t) p) % __alignof__(uint64_t) == 0)
+
/* Same as ALIGN_TO but callable in constant contexts. */
#define CONST_ALIGN_TO(l, ali) \
__builtin_choose_expr( \
diff --git a/src/test/test-macro.c b/src/test/test-macro.c
index bb79ea0dbe..a1618c3105 100644
--- a/src/test/test-macro.c
+++ b/src/test/test-macro.c
@@ -755,4 +755,57 @@ TEST(FOREACH_ARRAY) {
assert_se(n == 0);
}
+TEST(ALIGNED) {
+ assert_se(IS_ALIGNED16(NULL));
+ assert_se(IS_ALIGNED32(NULL));
+ assert_se(IS_ALIGNED64(NULL));
+
+ uint64_t u64;
+ uint32_t u32;
+ uint16_t u16;
+
+ assert_se(IS_ALIGNED16(&u16));
+ assert_se(IS_ALIGNED16(&u32));
+ assert_se(IS_ALIGNED16(&u64));
+ assert_se(IS_ALIGNED32(&u32));
+ assert_se(IS_ALIGNED32(&u64));
+ assert_se(IS_ALIGNED64(&u64));
+
+ _align_(32) uint8_t ua256;
+ _align_(8) uint8_t ua64;
+ _align_(4) uint8_t ua32;
+ _align_(2) uint8_t ua16;
+
+ assert_se(IS_ALIGNED16(&ua256));
+ assert_se(IS_ALIGNED32(&ua256));
+ assert_se(IS_ALIGNED64(&ua256));
+
+ assert_se(IS_ALIGNED16(&ua64));
+ assert_se(IS_ALIGNED32(&ua64));
+ assert_se(IS_ALIGNED64(&ua64));
+
+ assert_se(IS_ALIGNED16(&ua32));
+ assert_se(IS_ALIGNED32(&ua32));
+
+ assert_se(IS_ALIGNED16(&ua16));
+
+#ifdef __x86_64__
+ /* Conditionalized on x86-64, since there we know for sure that all three types are aligned to
+ * their size. Too lazy to figure it out for other archs */
+ void *p = UINT_TO_PTR(1); /* definitely not aligned */
+ assert_se(!IS_ALIGNED16(p));
+ assert_se(!IS_ALIGNED32(p));
+ assert_se(!IS_ALIGNED64(p));
+
+ assert_se(IS_ALIGNED16(ALIGN2_PTR(p)));
+ assert_se(IS_ALIGNED32(ALIGN4_PTR(p)));
+ assert_se(IS_ALIGNED64(ALIGN8_PTR(p)));
+
+ p = UINT_TO_PTR(-1); /* also definitely not aligned */
+ assert_se(!IS_ALIGNED16(p));
+ assert_se(!IS_ALIGNED32(p));
+ assert_se(!IS_ALIGNED64(p));
+#endif
+}
+
DEFINE_TEST_MAIN(LOG_INFO);