Drop lying to the compiler in the fletcher4 code

This is probably the uncontroversial part of openzfs#13631, which fixes a real problem people are having. There's still things to improve in our code after this is merged, but it should stop the breakage that people have reported, where we lie about a type always being aligned and then pass in stack objects with no alignment requirement and hope for the best. Of course, our SIMD code was written with unaligned accesses, so it doesn't care if we drop this...but some auto-vectorized code that gcc emits sure does, since we told it it can assume they're aligned. Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
andrewc12 · Mar 20, 2023 · 3f91db2 · 3f91db2
1 parent 1428f38
commit 3f91db2
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Showing 8 changed files with 4 additions and 40 deletions.
diff --git a/include/zfs_fletcher.h b/include/zfs_fletcher.h
@@ -76,19 +76,19 @@ typedef struct zfs_fletcher_superscalar {
 } zfs_fletcher_superscalar_t;
 
 typedef struct zfs_fletcher_sse {
-	uint64_t v[2] __attribute__((aligned(16)));
+	uint64_t v[2];
 } zfs_fletcher_sse_t;
 
 typedef struct zfs_fletcher_avx {
-	uint64_t v[4] __attribute__((aligned(32)));
+	uint64_t v[4];
 } zfs_fletcher_avx_t;
 
 typedef struct zfs_fletcher_avx512 {
-	uint64_t v[8] __attribute__((aligned(64)));
+	uint64_t v[8];
 } zfs_fletcher_avx512_t;
 
 typedef struct zfs_fletcher_aarch64_neon {
-	uint64_t v[2] __attribute__((aligned(16)));
+	uint64_t v[2];
 } zfs_fletcher_aarch64_neon_t;
 
 
@@ -161,20 +161,4 @@ _ZFS_FLETCHER_H const fletcher_4_ops_t fletcher_4_aarch64_neon_ops;
 }
 #endif
 
-#if	defined(ZFS_UBSAN_ENABLED)
-#if	defined(__has_attribute)
-#if	__has_attribute(no_sanitize_undefined)
-#define	ZFS_NO_SANITIZE_UNDEFINED __attribute__((no_sanitize_undefined))
-#elif	__has_attribute(no_sanitize)
-#define	ZFS_NO_SANITIZE_UNDEFINED __attribute__((no_sanitize("undefined")))
-#else
-#error	"Compiler has to support attribute "
-	"`no_sanitize_undefined` or `no_sanitize(\"undefined\")`"
-	"when compiling with UBSan enabled"
-#endif	/* __has_attribute(no_sanitize_undefined) */
-#endif	/* defined(__has_attribute) */
-#else
-#define	ZFS_NO_SANITIZE_UNDEFINED
-#endif	/* defined(ZFS_UBSAN_ENABLED) */
-
 #endif	/* _ZFS_FLETCHER_H */
diff --git a/module/zcommon/zfs_fletcher.c b/module/zcommon/zfs_fletcher.c
@@ -301,21 +301,18 @@ fletcher_2_byteswap(const void *buf, uint64_t size,
 	(void) fletcher_2_incremental_byteswap((void *) buf, size, zcp);
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_scalar_init(fletcher_4_ctx_t *ctx)
 {
 	ZIO_SET_CHECKSUM(&ctx->scalar, 0, 0, 0, 0);
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_scalar_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 {
 	memcpy(zcp, &ctx->scalar, sizeof (zio_cksum_t));
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_scalar_native(fletcher_4_ctx_t *ctx, const void *buf,
     uint64_t size)
@@ -339,7 +336,6 @@ fletcher_4_scalar_native(fletcher_4_ctx_t *ctx, const void *buf,
 	ZIO_SET_CHECKSUM(&ctx->scalar, a, b, c, d);
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_scalar_byteswap(fletcher_4_ctx_t *ctx, const void *buf,
     uint64_t size)

diff --git a/module/zcommon/zfs_fletcher_aarch64_neon.c b/module/zcommon/zfs_fletcher_aarch64_neon.c
@@ -48,14 +48,12 @@
 #include <sys/string.h>
 #include <zfs_fletcher.h>
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_aarch64_neon_init(fletcher_4_ctx_t *ctx)
 {
 	memset(ctx->aarch64_neon, 0, 4 * sizeof (zfs_fletcher_aarch64_neon_t));
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_aarch64_neon_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 {

diff --git a/module/zcommon/zfs_fletcher_avx512.c b/module/zcommon/zfs_fletcher_avx512.c
@@ -35,14 +35,12 @@
 #define	__asm __asm__ __volatile__
 #endif
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_avx512f_init(fletcher_4_ctx_t *ctx)
 {
 	memset(ctx->avx512, 0, 4 * sizeof (zfs_fletcher_avx512_t));
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_avx512f_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 {

diff --git a/module/zcommon/zfs_fletcher_intel.c b/module/zcommon/zfs_fletcher_intel.c
@@ -47,14 +47,12 @@
 #include <sys/simd.h>
 #include <zfs_fletcher.h>
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_avx2_init(fletcher_4_ctx_t *ctx)
 {
 	memset(ctx->avx, 0, 4 * sizeof (zfs_fletcher_avx_t));
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_avx2_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 {

diff --git a/module/zcommon/zfs_fletcher_sse.c b/module/zcommon/zfs_fletcher_sse.c
@@ -49,14 +49,12 @@
 #include <sys/byteorder.h>
 #include <zfs_fletcher.h>
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_sse2_init(fletcher_4_ctx_t *ctx)
 {
 	memset(ctx->sse, 0, 4 * sizeof (zfs_fletcher_sse_t));
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_sse2_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 {

diff --git a/module/zcommon/zfs_fletcher_superscalar.c b/module/zcommon/zfs_fletcher_superscalar.c
@@ -47,14 +47,12 @@
 #include <sys/string.h>
 #include <zfs_fletcher.h>
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar_init(fletcher_4_ctx_t *ctx)
 {
 	memset(ctx->superscalar, 0, 4 * sizeof (zfs_fletcher_superscalar_t));
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 {
@@ -70,7 +68,6 @@ fletcher_4_superscalar_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 	ZIO_SET_CHECKSUM(zcp, A, B, C, D);
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar_native(fletcher_4_ctx_t *ctx,
     const void *buf, uint64_t size)
@@ -110,7 +107,6 @@ fletcher_4_superscalar_native(fletcher_4_ctx_t *ctx,
 	ctx->superscalar[3].v[1] = d2;
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar_byteswap(fletcher_4_ctx_t *ctx,
     const void *buf, uint64_t size)

diff --git a/module/zcommon/zfs_fletcher_superscalar4.c b/module/zcommon/zfs_fletcher_superscalar4.c
@@ -47,14 +47,12 @@
 #include <sys/string.h>
 #include <zfs_fletcher.h>
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar4_init(fletcher_4_ctx_t *ctx)
 {
 	memset(ctx->superscalar, 0, 4 * sizeof (zfs_fletcher_superscalar_t));
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar4_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 {
@@ -84,7 +82,6 @@ fletcher_4_superscalar4_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
 	ZIO_SET_CHECKSUM(zcp, A, B, C, D);
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar4_native(fletcher_4_ctx_t *ctx,
     const void *buf, uint64_t size)
@@ -150,7 +147,6 @@ fletcher_4_superscalar4_native(fletcher_4_ctx_t *ctx,
 	ctx->superscalar[3].v[3] = d4;
 }
 
-ZFS_NO_SANITIZE_UNDEFINED
 static void
 fletcher_4_superscalar4_byteswap(fletcher_4_ctx_t *ctx,
     const void *buf, uint64_t size)