From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Subject: [RFC PATCH 2/3] selftests/rseq: Fix arm64 buggy load-acquire/store-release macros
Date: Wed, 3 May 2023 16:13:23 -0400 [thread overview]
Message-ID: <20230503201324.1587003-2-mathieu.desnoyers@efficios.com> (raw)
In-Reply-To: <20230503201324.1587003-1-mathieu.desnoyers@efficios.com>
The arm64 load-acquire/store-release macros from the Linux kernel rseq
selftests are buggy. Remplace them by a working implementation.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
---
tools/testing/selftests/rseq/rseq-arm64.h | 58 ++++++++++++-----------
1 file changed, 30 insertions(+), 28 deletions(-)
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index 85b90977e7e6..21e1626a7235 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -27,59 +27,61 @@
#define rseq_smp_load_acquire(p) \
__extension__ ({ \
- __typeof(*p) ____p1; \
- switch (sizeof(*p)) { \
+ union { rseq_unqual_scalar_typeof(*(p)) __val; char __c[sizeof(*(p))]; } __u; \
+ switch (sizeof(*(p))) { \
case 1: \
- asm volatile ("ldarb %w0, %1" \
- : "=r" (*(__u8 *)p) \
- : "Q" (*p) : "memory"); \
+ __asm__ __volatile__ ("ldarb %w0, %1" \
+ : "=r" (*(__u8 *)__u.__c) \
+ : "Q" (*(p)) : "memory"); \
break; \
case 2: \
- asm volatile ("ldarh %w0, %1" \
- : "=r" (*(__u16 *)p) \
- : "Q" (*p) : "memory"); \
+ __asm__ __volatile__ ("ldarh %w0, %1" \
+ : "=r" (*(__u16 *)__u.__c) \
+ : "Q" (*(p)) : "memory"); \
break; \
case 4: \
- asm volatile ("ldar %w0, %1" \
- : "=r" (*(__u32 *)p) \
- : "Q" (*p) : "memory"); \
+ __asm__ __volatile__ ("ldar %w0, %1" \
+ : "=r" (*(__u32 *)__u.__c) \
+ : "Q" (*(p)) : "memory"); \
break; \
case 8: \
- asm volatile ("ldar %0, %1" \
- : "=r" (*(__u64 *)p) \
- : "Q" (*p) : "memory"); \
+ __asm__ __volatile__ ("ldar %0, %1" \
+ : "=r" (*(__u64 *)__u.__c) \
+ : "Q" (*(p)) : "memory"); \
break; \
} \
- ____p1; \
+ (rseq_unqual_scalar_typeof(*(p)))__u.__val; \
})
#define rseq_smp_acquire__after_ctrl_dep() rseq_smp_rmb()
#define rseq_smp_store_release(p, v) \
do { \
- switch (sizeof(*p)) { \
+ union { rseq_unqual_scalar_typeof(*(p)) __val; char __c[sizeof(*(p))]; } __u = \
+ { .__val = (rseq_unqual_scalar_typeof(*(p))) (v) }; \
+ switch (sizeof(*(p))) { \
case 1: \
- asm volatile ("stlrb %w1, %0" \
- : "=Q" (*p) \
- : "r" ((__u8)v) \
+ __asm__ __volatile__ ("stlrb %w1, %0" \
+ : "=Q" (*(p)) \
+ : "r" (*(__u8 *)__u.__c) \
: "memory"); \
break; \
case 2: \
- asm volatile ("stlrh %w1, %0" \
- : "=Q" (*p) \
- : "r" ((__u16)v) \
+ __asm__ __volatile__ ("stlrh %w1, %0" \
+ : "=Q" (*(p)) \
+ : "r" (*(__u16 *)__u.__c) \
: "memory"); \
break; \
case 4: \
- asm volatile ("stlr %w1, %0" \
- : "=Q" (*p) \
- : "r" ((__u32)v) \
+ __asm__ __volatile__ ("stlr %w1, %0" \
+ : "=Q" (*(p)) \
+ : "r" (*(__u32 *)__u.__c) \
: "memory"); \
break; \
case 8: \
- asm volatile ("stlr %1, %0" \
- : "=Q" (*p) \
- : "r" ((__u64)v) \
+ __asm__ __volatile__ ("stlr %1, %0" \
+ : "=Q" (*(p)) \
+ : "r" (*(__u64 *)__u.__c) \
: "memory"); \
break; \
} \
--
2.25.1
next prev parent reply other threads:[~2023-05-03 20:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-03 20:13 [RFC PATCH 1/3] selftests/rseq: Implement rseq_unqual_scalar_typeof Mathieu Desnoyers
2023-05-03 20:13 ` Mathieu Desnoyers [this message]
2023-05-03 20:13 ` [RFC PATCH 3/3] selftests/rseq: Use rseq_unqual_scalar_typeof in macros Mathieu Desnoyers
2023-05-04 6:09 ` [RFC PATCH 1/3] selftests/rseq: Implement rseq_unqual_scalar_typeof Peter Zijlstra
2023-05-04 14:36 ` Mathieu Desnoyers
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