All of lore.kernel.org
 help / color / mirror / Atom feed
From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>, Shuah Khan <shuah@kernel.org>,
	Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kselftest@vger.kernel.org, Mark Brown <broonie@kernel.org>
Subject: [PATCH v4 2/6] tools compiler.h: Add OPTIMIZER_HIDE_VAR()
Date: Fri, 28 Jul 2023 00:26:13 +0100	[thread overview]
Message-ID: <20230728-arm64-signal-memcpy-fix-v4-2-0c1290db5d46@kernel.org> (raw)
In-Reply-To: <20230728-arm64-signal-memcpy-fix-v4-0-0c1290db5d46@kernel.org>

Port over the definition of OPTIMIZER_HIDE_VAR() so we can use it in
kselftests.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/include/linux/compiler.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h
index 9d36c8ce1fe7..f75cced41d59 100644
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -190,4 +190,10 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 #define ___PASTE(a, b) a##b
 #define __PASTE(a, b) ___PASTE(a, b)
 
+#ifndef OPTIMIZER_HIDE_VAR
+/* Make the optimizer believe the variable can be manipulated arbitrarily. */
+#define OPTIMIZER_HIDE_VAR(var)						\
+	__asm__ ("" : "=r" (var) : "0" (var))
+#endif
+
 #endif /* _TOOLS_LINUX_COMPILER_H */

-- 
2.30.2


WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>,
	 Will Deacon <will@kernel.org>, Shuah Khan <shuah@kernel.org>,
	 Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-kselftest@vger.kernel.org,  Mark Brown <broonie@kernel.org>
Subject: [PATCH v4 2/6] tools compiler.h: Add OPTIMIZER_HIDE_VAR()
Date: Fri, 28 Jul 2023 00:26:13 +0100	[thread overview]
Message-ID: <20230728-arm64-signal-memcpy-fix-v4-2-0c1290db5d46@kernel.org> (raw)
In-Reply-To: <20230728-arm64-signal-memcpy-fix-v4-0-0c1290db5d46@kernel.org>

Port over the definition of OPTIMIZER_HIDE_VAR() so we can use it in
kselftests.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/include/linux/compiler.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/include/linux/compiler.h b/tools/include/linux/compiler.h
index 9d36c8ce1fe7..f75cced41d59 100644
--- a/tools/include/linux/compiler.h
+++ b/tools/include/linux/compiler.h
@@ -190,4 +190,10 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
 #define ___PASTE(a, b) a##b
 #define __PASTE(a, b) ___PASTE(a, b)
 
+#ifndef OPTIMIZER_HIDE_VAR
+/* Make the optimizer believe the variable can be manipulated arbitrarily. */
+#define OPTIMIZER_HIDE_VAR(var)						\
+	__asm__ ("" : "=r" (var) : "0" (var))
+#endif
+
 #endif /* _TOOLS_LINUX_COMPILER_H */

-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  parent reply	other threads:[~2023-07-27 23:27 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-27 23:26 [PATCH v4 0/6] kselfest/arm64: Fix a SVE memcpy() issue and use tools/include Mark Brown
2023-07-27 23:26 ` Mark Brown
2023-07-27 23:26 ` [PATCH v4 1/6] kselftest/arm64: Exit streaming mode after collecting signal context Mark Brown
2023-07-27 23:26   ` Mark Brown
2023-07-27 23:26 ` Mark Brown [this message]
2023-07-27 23:26   ` [PATCH v4 2/6] tools compiler.h: Add OPTIMIZER_HIDE_VAR() Mark Brown
2023-07-27 23:26 ` [PATCH v4 3/6] tools include: Add some common function attributes Mark Brown
2023-07-27 23:26   ` Mark Brown
2023-07-27 23:26 ` [PATCH v4 4/6] kselftest/arm64: Make the tools/include headers available Mark Brown
2023-07-27 23:26   ` Mark Brown
2023-07-27 23:26 ` [PATCH v4 5/6] kselftest/arm64: Use shared OPTIMZER_HIDE_VAR() definiton Mark Brown
2023-07-27 23:26   ` Mark Brown
2023-07-27 23:26 ` [PATCH v4 6/6] kselftest/arm64: Use the tools/include compiler.h rather than our own Mark Brown
2023-07-27 23:26   ` Mark Brown
2023-08-04 18:10 ` [PATCH v4 0/6] kselfest/arm64: Fix a SVE memcpy() issue and use tools/include Will Deacon
2023-08-04 18:10   ` Will Deacon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230728-arm64-signal-memcpy-fix-v4-2-0c1290db5d46@kernel.org \
    --to=broonie@kernel.org \
    --cc=acme@redhat.com \
    --cc=catalin.marinas@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kselftest@vger.kernel.org \
    --cc=shuah@kernel.org \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.