From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 93064CAC597 for ; Thu, 18 Sep 2025 06:36:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=nd/aa+Cyw0z/Ul0/qN6NY/ef41tVXmadJuCUPt5tdFQ=; b=PgN2larOzPMuqvHrAz/fmbWb8d +ju5li7GmXkXjAkqMJYkpvFws3RaQJMGwc5vuFAr1UE1nMEkNjEgwWXnmvSw79ShO8E5ItKIIndcz 0t0AsBYeo0dcmfIYON8CTGisOlOXXPowQAKkDaiy13ln84Bv3nuageaTZ8BMk/E0BpXbTpO0QPvpy 19aIb5m8lvMP2uiE2IpkZdYHGPLZBgJlH/8gpy5aw0gnLDqewuVU+UFYeWgPKZVPtmY+nmfoEcDgC E/CDSrTUNco53WZpsgGl3VZ5cob2MKdfBE3jePog3KPlQrA2hXcjtpKEp5ho7KVGdwiPtDyusz+NI 55KH2L4w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uz8Fe-0000000GR1Z-2lY5; Thu, 18 Sep 2025 06:36:18 +0000 Received: from mail-wr1-x44a.google.com ([2a00:1450:4864:20::44a]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uz8FZ-0000000GQx6-4BVU for linux-arm-kernel@lists.infradead.org; Thu, 18 Sep 2025 06:36:15 +0000 Received: by mail-wr1-x44a.google.com with SMTP id ffacd0b85a97d-3e980eb1d3eso84882f8f.2 for ; Wed, 17 Sep 2025 23:36:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1758177372; x=1758782172; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=nd/aa+Cyw0z/Ul0/qN6NY/ef41tVXmadJuCUPt5tdFQ=; b=LbWpbihQvINNbJV1X7pXG/0Pumfm63PumHBuEKK6ypBBy49HkGrCZvjGqxzirAZ41B 3WZAt9WeXQgFU3p4MkPyT9rKelYQsQx7tmCra+YvtB4/WY9Ie+zIPARt+uWiu0LT0hd1 BuH5Bd8p2qgH4rvQb07tY8lx2mLaMX9mHzyiFBX5qdzsfg/mfUgRM1fy1C4cp4FFLUGw bFHB1M8jR13PTfiigTfAjIxrtniYunIK/rFwvB5f7zrFm+PS4FXQuR/rOwTrdSIfuKi+ q8vg/kjMqaHjU5JL+e2Ru4hqFLHJmeHFPUoYRQael2U889u0C+R5WXQSqAx4owXKx06Q 5hWA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758177372; x=1758782172; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=nd/aa+Cyw0z/Ul0/qN6NY/ef41tVXmadJuCUPt5tdFQ=; b=L09IyRI1ijJx58QTZAc3+dWe3J0Zv7wFtL0hATHqt47/0lQWAqw9OifLfd+HMRJbit atCvWMG+sEHmnRAmr3WS17FDV+vOzAVos1taM4qLApf+5HuJISoz0xV8kL6wEPO4VliH XaYtyREGIMbJoiRxtIpD7x0K01V+tXRw8wdQ0ltVFFLAS9ipm68ZL8o8Mb6nflZamYd9 3wUFySBupfCUKpzDJi6H8nGZyl1+hZDrjWKW3xFOVej8VW28raI3OknIuftTcrXS8U/P kpdIWw1JL0Iq03LpxT/IxoqN/i8uCvlD2sCEnPSrIOYTkVuU6wW3TCfAecVrUnkajFv3 glYA== X-Gm-Message-State: AOJu0YyZSKGdT3QaytBNrmW6r6X66TYpWpIImDh1SpphVq/VrUj+8Q07 qasFf+ukgQy4tBtLWQCHNfTBLySnqAZVU8ECDyopIhRGPPz5BwbjvLaAlKFVJhbEuBQYWSlchYi +5Zv6goHt/6DE6knLkOjEUW3WynEF5oGBaLdWGt/W7A2EOaoHS6d0jiioY3x1KimKquJKyl3F2d mI4l4bZxjUQDMJVOygptTdBMBFWJZ75t1endP8J9ARNRlb X-Google-Smtp-Source: AGHT+IEaYfwr01ZjRAssGnsJ1gUGd1rN8g5Gj0e5CjahKJgyizByZHhPk8uuPViunThk6UOOlyd5IgyT X-Received: from wrbbs28.prod.google.com ([2002:a05:6000:71c:b0:3eb:6104:3eb]) (user=ardb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:2284:b0:3ea:124c:8fc7 with SMTP id ffacd0b85a97d-3ecdfa1434dmr3783151f8f.39.1758177371854; Wed, 17 Sep 2025 23:36:11 -0700 (PDT) Date: Thu, 18 Sep 2025 08:35:44 +0200 In-Reply-To: <20250918063539.2640512-7-ardb+git@google.com> Mime-Version: 1.0 References: <20250918063539.2640512-7-ardb+git@google.com> X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-Developer-Signature: v=1; a=openpgp-sha256; l=2845; i=ardb@kernel.org; h=from:subject; bh=fbTmP4aG6tbBHGWrU82oUT6Reb9I9nyA/9uuGWnWHsA=; b=owGbwMvMwCVmkMcZplerG8N4Wi2JIeP0Cqcpcmo3s9lOdcud6TTT/3/e+Haah27JoTmrPn36k qtkYXWuo5SFQYyLQVZMkUVg9t93O09PlKp1niULM4eVCWQIAxenAEykPJyRYc9Ujxln1/M8UN0U srST+emhX57lN5vdFz69bBItdNUs9xHDP1OjzLYvG7QqeQXWeDWfFnstxjJ5Zu7xFo5XF1s+H1P byAcA X-Mailer: git-send-email 2.51.0.384.g4c02a37b29-goog Message-ID: <20250918063539.2640512-11-ardb+git@google.com> Subject: [PATCH 4/5] arm64/fpsimd: Require kernel NEON begin/end calls from the same scope From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, herbert@gondor.apana.org.au, ebiggers@kernel.org, Ard Biesheuvel , Marc Zyngier , Will Deacon , Mark Rutland , Kees Cook , Catalin Marinas , Mark Brown Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250917_233614_061264_FA689C8D X-CRM114-Status: GOOD ( 16.12 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Ard Biesheuvel In preparation for making kernel_neon_begin() allocate a stack based buffer for stashing the kernel mode FP/SIMD state on a context switch, redefine kernel_neon_begin() and kernel_neon_end() as macros, in a way that requires them to be called from the same scope, and therefore, running from the same stack frame. Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/neon.h | 7 +++++-- arch/arm64/kernel/fpsimd.c | 12 ++++++------ 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/arm64/include/asm/neon.h b/arch/arm64/include/asm/neon.h index d4b1d172a79b..4e24f1058b55 100644 --- a/arch/arm64/include/asm/neon.h +++ b/arch/arm64/include/asm/neon.h @@ -13,7 +13,10 @@ #define cpu_has_neon() system_supports_fpsimd() -void kernel_neon_begin(void); -void kernel_neon_end(void); +void __kernel_neon_begin(void); +void __kernel_neon_end(void); + +#define kernel_neon_begin() do { __kernel_neon_begin() +#define kernel_neon_end() __kernel_neon_end(); } while (0) #endif /* ! __ASM_NEON_H */ diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index c37f02d7194e..d7eb073d1366 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -1833,7 +1833,7 @@ void fpsimd_save_and_flush_cpu_state(void) * The caller may freely use the FPSIMD registers until kernel_neon_end() is * called. */ -void kernel_neon_begin(void) +void __kernel_neon_begin(void) { if (WARN_ON(!system_supports_fpsimd())) return; @@ -1875,7 +1875,7 @@ void kernel_neon_begin(void) put_cpu_fpsimd_context(); } -EXPORT_SYMBOL_GPL(kernel_neon_begin); +EXPORT_SYMBOL_GPL(__kernel_neon_begin); /* * kernel_neon_end(): give the CPU FPSIMD registers back to the current task @@ -1886,7 +1886,7 @@ EXPORT_SYMBOL_GPL(kernel_neon_begin); * The caller must not use the FPSIMD registers after this function is called, * unless kernel_neon_begin() is called again in the meantime. */ -void kernel_neon_end(void) +void __kernel_neon_end(void) { if (!system_supports_fpsimd()) return; @@ -1902,7 +1902,7 @@ void kernel_neon_end(void) else clear_thread_flag(TIF_KERNEL_FPSTATE); } -EXPORT_SYMBOL_GPL(kernel_neon_end); +EXPORT_SYMBOL_GPL(__kernel_neon_end); #ifdef CONFIG_EFI @@ -1936,7 +1936,7 @@ void __efi_fpsimd_begin(void) WARN_ON(preemptible()); if (may_use_simd()) { - kernel_neon_begin(); + __kernel_neon_begin(); } else { /* * If !efi_sve_state, SVE can't be in use yet and doesn't need @@ -1985,7 +1985,7 @@ void __efi_fpsimd_end(void) return; if (!efi_fpsimd_state_used) { - kernel_neon_end(); + __kernel_neon_end(); } else { if (system_supports_sve() && efi_sve_state_used) { bool ffr = true; -- 2.51.0.384.g4c02a37b29-goog