From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B048E8F40; Wed, 2 Oct 2024 14:45:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727880322; cv=none; b=QmVmvFT2Hr70fHTDV/CGa+OzEX4YXN/pGMN1X9X80nC0WCd7Rvhbi8mqaPw+9tGctqvODwEviJO0NaTow/tiHIBSJhfAdMFW/bBIFdaXxYw5QnbGUi1PKfchZoC3qqSfUoo1i3Pudio2VG76uGXTDjVbQWJkn0HxEFaf0SV3XwI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727880322; c=relaxed/simple; bh=Z3jY6t8gQ9muyEEmk0ERc3dQLuCncxgGcwQ5WJ0LpIE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rRrWCQ7dnDdRos1BXWi531o8kuoqsZwhrJjJhp+pMBLe5iksV3YOuhhmESl/ez0rVDUc+1yzz89074g8ke1rGWsKL++rgei/WsZYx5T80M18J9VAyLZE7BF/rEPl9Qd/7TQRlQ5oHPv2mVwTqE9/05fNWFeokrCYqKlToNpvLq8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HcwZLXLh; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="HcwZLXLh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3851FC4CECE; Wed, 2 Oct 2024 14:45:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1727880322; bh=Z3jY6t8gQ9muyEEmk0ERc3dQLuCncxgGcwQ5WJ0LpIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HcwZLXLhWaJz66L3yt1kDv1T4MKWXa2XT1jQts/Dmg1BnsyeL3tcofXQQfmXfMz2m lweL7XXgIRyxg4YQsdZ2lDGx53PI/lkiGcSCOfXzw9NL/yReVJmyz+c7294T6Lop0I JTUYfAqfXKVRFNZk2PRDVOSZ7ZlmBA1NRVXJrLI4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stephen Rothwell , Mina Almasry , Segher Boessenkool , Michael Ellerman Subject: [PATCH 6.6 419/538] powerpc/atomic: Use YZ constraints for DS-form instructions Date: Wed, 2 Oct 2024 15:00:58 +0200 Message-ID: <20241002125808.972756782@linuxfoundation.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241002125751.964700919@linuxfoundation.org> References: <20241002125751.964700919@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Ellerman commit 39190ac7cff1fd15135fa8e658030d9646fdb5f2 upstream. The 'ld' and 'std' instructions require a 4-byte aligned displacement because they are DS-form instructions. But the "m" asm constraint doesn't enforce that. That can lead to build errors if the compiler chooses a non-aligned displacement, as seen with GCC 14: /tmp/ccuSzwiR.s: Assembler messages: /tmp/ccuSzwiR.s:2579: Error: operand out of domain (39 is not a multiple of 4) make[5]: *** [scripts/Makefile.build:229: net/core/page_pool.o] Error 1 Dumping the generated assembler shows: ld 8,39(8) # MEM[(const struct atomic64_t *)_29].counter, t Use the YZ constraints to tell the compiler either to generate a DS-form displacement, or use an X-form instruction, either of which prevents the build error. See commit 2d43cc701b96 ("powerpc/uaccess: Fix build errors seen with GCC 13/14") for more details on the constraint letters. Fixes: 9f0cbea0d8cc ("[POWERPC] Implement atomic{, 64}_{read, write}() without volatile") Cc: stable@vger.kernel.org # v2.6.24+ Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/all/20240913125302.0a06b4c7@canb.auug.org.au Tested-by: Mina Almasry Reviewed-by: Segher Boessenkool Signed-off-by: Michael Ellerman Link: https://msgid.link/20240916120510.2017749-1-mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/asm-compat.h | 6 ++++++ arch/powerpc/include/asm/atomic.h | 5 +++-- arch/powerpc/include/asm/uaccess.h | 7 +------ 3 files changed, 10 insertions(+), 8 deletions(-) --- a/arch/powerpc/include/asm/asm-compat.h +++ b/arch/powerpc/include/asm/asm-compat.h @@ -39,6 +39,12 @@ #define STDX_BE stringify_in_c(stdbrx) #endif +#ifdef CONFIG_CC_IS_CLANG +#define DS_FORM_CONSTRAINT "Z<>" +#else +#define DS_FORM_CONSTRAINT "YZ<>" +#endif + #else /* 32-bit */ /* operations for longs and pointers */ --- a/arch/powerpc/include/asm/atomic.h +++ b/arch/powerpc/include/asm/atomic.h @@ -11,6 +11,7 @@ #include #include #include +#include /* * Since *_return_relaxed and {cmp}xchg_relaxed are implemented with @@ -197,7 +198,7 @@ static __inline__ s64 arch_atomic64_read if (IS_ENABLED(CONFIG_PPC_KERNEL_PREFIXED)) __asm__ __volatile__("ld %0,0(%1)" : "=r"(t) : "b"(&v->counter)); else - __asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) : "m<>"(v->counter)); + __asm__ __volatile__("ld%U1%X1 %0,%1" : "=r"(t) : DS_FORM_CONSTRAINT (v->counter)); return t; } @@ -208,7 +209,7 @@ static __inline__ void arch_atomic64_set if (IS_ENABLED(CONFIG_PPC_KERNEL_PREFIXED)) __asm__ __volatile__("std %1,0(%2)" : "=m"(v->counter) : "r"(i), "b"(&v->counter)); else - __asm__ __volatile__("std%U0%X0 %1,%0" : "=m<>"(v->counter) : "r"(i)); + __asm__ __volatile__("std%U0%X0 %1,%0" : "=" DS_FORM_CONSTRAINT (v->counter) : "r"(i)); } #define ATOMIC64_OP(op, asm_op) \ --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -6,6 +6,7 @@ #include #include #include +#include #ifdef __powerpc64__ /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */ @@ -92,12 +93,6 @@ __pu_failed: \ : label) #endif -#ifdef CONFIG_CC_IS_CLANG -#define DS_FORM_CONSTRAINT "Z<>" -#else -#define DS_FORM_CONSTRAINT "YZ<>" -#endif - #ifdef __powerpc64__ #ifdef CONFIG_PPC_KERNEL_PREFIXED #define __put_user_asm2_goto(x, ptr, label) \