From patchwork Fri Jan 10 15:23:46 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= X-Patchwork-Id: 13935003 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 9BB91211A2B; Fri, 10 Jan 2025 15:23:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736522640; cv=none; b=Unht7F+Rha/nRTdxMO8fX+IdkHibbO/u8TLPW3bRPOnLEFNfiRMfuhVtF/Aoyt+HCvjNEW9RR1WOILImAdhYQf2gtJbo1IOgG2sZBXeBC/leqW91uhKxzI/G8iRgZue4whR+LH/Mm4koJFGz/apY9B5if7rDPwd6CQ0R8yy0bBQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736522640; c=relaxed/simple; bh=2OGLOTIn3mrK94nEr9eCVL0nPgn4S3w/pFtDFpXzfrI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=XIAr4PXOHX0F2/hVMLgihpXmTDZZig6KBOzXkXM41Q9v8o8hpek5gBJEWMYBjkna/EBD4ir0s1Ixlzxyw02CdKNfFN4FRsrJ3CNIF7iDNnCueVyOKJV9ouWLI4stbv9gVTNwiAhok+LbUoAa6AHSfd2e+UQogK8m1gxbg61oQoo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=4QuV6WLv; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=6C/eB/zj; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="4QuV6WLv"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="6C/eB/zj" From: =?utf-8?q?Thomas_Wei=C3=9Fschuh?= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1736522635; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2hF0doQ8ABpgn/aNZsNNVwp/0/3UT02lIHINaA5tvUM=; b=4QuV6WLv+qM0NFq/bU50gvu9jHJbGQqi8ZhB1pWOJo78K7X8EMY2cqzf+A0eJ3euP6AoM0 3ZgoB397PR5qBYy4Ji2YF5V5UlQDbEFyfk4u8GXDBtnxZE2qjnL+2jmv4vuaIsaezwXOSZ hwdc3Iqa+1S91NJqKlHixWQY9bBHOG+dGCoc8F1rFRxxvjDF5+usOvgWMbZs+TZP/R8CjB c5zeenPso/iK5Muu0FVxXZzMwgvBPwh6VwzXRiz9M+2AobY70sdWEN9azGRgZEoT3kGFN5 GE1kIR8fbyssrgwer81DVIhdrwGGYCCC0p5dNAeLcv8MU05MrLi78ZR4Qu9StA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1736522635; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2hF0doQ8ABpgn/aNZsNNVwp/0/3UT02lIHINaA5tvUM=; b=6C/eB/zjdtEzQvYPxdxc0wgWqNTengxBY22KHhSipUPGZt0oE+VYTtMiCbpmEs2qO3htJ6 bAtCMpTjfRigOvCQ== Date: Fri, 10 Jan 2025 16:23:46 +0100 Subject: [PATCH v2 07/18] vdso: Add generic architecture-specific data storage Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250110-vdso-store-rng-v2-7-350c9179bbf1@linutronix.de> References: <20250110-vdso-store-rng-v2-0-350c9179bbf1@linutronix.de> In-Reply-To: <20250110-vdso-store-rng-v2-0-350c9179bbf1@linutronix.de> To: "James E.J. Bottomley" , Helge Deller , Andy Lutomirski , Thomas Gleixner , Vincenzo Frascino , Anna-Maria Behnsen , Frederic Weisbecker , Andrew Morton , Catalin Marinas , Will Deacon , Theodore Ts'o , "Jason A. Donenfeld" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Huacai Chen , WANG Xuerui , Russell King , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Bogendoerfer , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Naveen N Rao , Madhavan Srinivasan , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Arnd Bergmann , Guo Ren Cc: linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, loongarch@lists.linux.dev, linux-s390@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org, Nam Cao , =?utf-8?q?Thom?= =?utf-8?q?as_Wei=C3=9Fschuh?= , linux-csky@vger.kernel.org X-Developer-Signature: v=1; a=ed25519-sha256; t=1736522629; l=4823; i=thomas.weissschuh@linutronix.de; s=20240209; h=from:subject:message-id; bh=2OGLOTIn3mrK94nEr9eCVL0nPgn4S3w/pFtDFpXzfrI=; b=BWqHXYbHF2N14HCyKEALbacHP4B4k0Olfuqv1Ny6/4qxq5QHetPRa9vRN0DxHlVRIYSAWu+an Ie7iC4RpCs5CHpDT8JL7bXGs/W4j5ZDMEXMmBF0IlVo9oyq1D256JK5 X-Developer-Key: i=thomas.weissschuh@linutronix.de; a=ed25519; pk=pfvxvpFUDJV2h2nY0FidLUml22uGLSjByFbM6aqQQws= Some architectures need to architecture-specific data to the vDSO. Enable the generic vDSO storage mechanism to both store and map this data. Some architectures require more than a single page, like LoongArch, so prepare for that usecase, too. Signed-off-by: Thomas Weißschuh --- arch/Kconfig | 4 ++++ include/vdso/datapage.h | 25 +++++++++++++++++++++++++ lib/vdso/datastore.c | 14 ++++++++++++++ 3 files changed, 43 insertions(+) diff --git a/arch/Kconfig b/arch/Kconfig index 6682b2a53e342cbacc05b70ef99cb1c47efe55e8..48f37e6c00674f433a0d6e6e05ce72c27cf000b7 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1576,6 +1576,10 @@ config HAVE_SPARSE_SYSCALL_NR entries at 4000, 5000 and 6000 locations. This option turns on syscall related optimizations for a given architecture. +config ARCH_HAS_VDSO_ARCH_DATA + depends on GENERIC_VDSO_DATA_STORE + bool + config ARCH_HAS_VDSO_TIME_DATA bool diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h index 7dbc8797e3b8923c06f4b6b34790766e68b2abd2..46658b39c28250e977f5a3454224c3ed0fb4c81d 100644 --- a/include/vdso/datapage.h +++ b/include/vdso/datapage.h @@ -9,11 +9,13 @@ #include #include +#include #include #include #include #include #include +#include #include #include #include @@ -25,6 +27,15 @@ struct arch_vdso_time_data {}; #endif +#if defined(CONFIG_ARCH_HAS_VDSO_ARCH_DATA) +#include +#elif defined(CONFIG_GENERIC_VDSO_DATA_STORE) +struct vdso_arch_data { + /* Needed for the generic code, never actually used at runtime */ + char __unused; +}; +#endif + #define VDSO_BASES (CLOCK_TAI + 1) #define VDSO_HRES (BIT(CLOCK_REALTIME) | \ BIT(CLOCK_MONOTONIC) | \ @@ -145,9 +156,11 @@ extern struct vdso_rng_data _vdso_rng_data __attribute__((visibility("hidden"))) #else extern struct vdso_time_data vdso_u_time_data[CS_BASES] __attribute__((visibility("hidden"))); extern struct vdso_rng_data vdso_u_rng_data __attribute__((visibility("hidden"))); +extern struct vdso_arch_data vdso_u_arch_data __attribute__((visibility("hidden"))); extern struct vdso_time_data *vdso_k_time_data; extern struct vdso_rng_data *vdso_k_rng_data; +extern struct vdso_arch_data *vdso_k_arch_data; #endif /** @@ -160,10 +173,15 @@ union vdso_data_store { #ifdef CONFIG_GENERIC_VDSO_DATA_STORE +#define VDSO_ARCH_DATA_SIZE ALIGN(sizeof(struct vdso_arch_data), PAGE_SIZE) +#define VDSO_ARCH_DATA_PAGES (VDSO_ARCH_DATA_SIZE >> PAGE_SHIFT) + enum vdso_pages { VDSO_TIME_PAGE_OFFSET, VDSO_TIMENS_PAGE_OFFSET, VDSO_RNG_PAGE_OFFSET, + VDSO_ARCH_PAGES_START, + VDSO_ARCH_PAGES_END = VDSO_ARCH_PAGES_START + VDSO_ARCH_DATA_PAGES - 1, VDSO_NR_PAGES }; @@ -193,10 +211,17 @@ enum vdso_pages { #define __vdso_u_rng_data #endif +#ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA +#define __vdso_u_arch_data PROVIDE(vdso_u_arch_data = vdso_u_data + 3 * PAGE_SIZE); +#else +#define __vdso_u_arch_data +#endif + #define VDSO_VVAR_SYMS \ PROVIDE(vdso_u_data = . - __VDSO_PAGES * PAGE_SIZE); \ PROVIDE(vdso_u_time_data = vdso_u_data); \ __vdso_u_rng_data \ + __vdso_u_arch_data \ #endif /* !__ASSEMBLY__ */ diff --git a/lib/vdso/datastore.c b/lib/vdso/datastore.c index 9260b00dc8520af109bd9dd05ac7f7504eafbea0..0959d62d78586ef458eb5f7c1e152f6b5d4cbf85 100644 --- a/lib/vdso/datastore.c +++ b/lib/vdso/datastore.c @@ -26,6 +26,14 @@ struct vdso_rng_data *vdso_k_rng_data = &vdso_rng_data_store.data; static_assert(sizeof(vdso_rng_data_store) == PAGE_SIZE); #endif /* CONFIG_VDSO_GETRANDOM */ +#ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA +static union { + struct vdso_arch_data data; + u8 page[VDSO_ARCH_DATA_SIZE]; +} vdso_arch_data_store __page_aligned_data; +struct vdso_arch_data *vdso_k_arch_data = &vdso_arch_data_store.data; +#endif /* CONFIG_ARCH_HAS_VDSO_ARCH_DATA */ + static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, struct vm_area_struct *vma, struct vm_fault *vmf) { @@ -67,6 +75,12 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm, return VM_FAULT_SIGBUS; pfn = __phys_to_pfn(__pa_symbol(vdso_k_rng_data)); break; + case VDSO_ARCH_PAGES_START ... VDSO_ARCH_PAGES_END: + if (!IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA)) + return VM_FAULT_SIGBUS; + pfn = __phys_to_pfn(__pa_symbol(vdso_k_arch_data)) + + vmf->pgoff - VDSO_ARCH_PAGES_START; + break; default: return VM_FAULT_SIGBUS; }