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 CA96EC369A1 for ; Wed, 9 Apr 2025 14:58:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=DIkoECFuaQxVCjnGwv8FG4r7r2U3GaRbiRXXaKB9upk=; b=B9v15F4f6Z87prxkJ5crODMgmA xGDHb1eB8TwFrL/1Ugakm7hYoUsvXujZqAQ4AITpg7CgNSs03dM5hWk+cJAhqIANhuWMwB1MJ3AOr E6454Gi3imwfxTRXgLCcEcsuYYTbETkb1nOOdzVpXU1Hdfgb49LwXJhf7HZyg6kQiU6dvYG6o2qS+ +IPQUInrWtIB9raciJvFBRkZl5GEuWNcofb9D8PKu3Vdxv2oSMcSiSlq+/yroazaqrykL+L1+LNXn 6T0vau/aiP7Xo5rHCyoFpfreFjQqOTfuqpisnpd42Rbx+l5Z5kAH849WgUrXTbIb/Zm+PB8uz0/rF 4nX/YQQg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2Wsi-00000007Zen-3LgQ; Wed, 09 Apr 2025 14:58:24 +0000 Received: from mail-pl1-x62a.google.com ([2607:f8b0:4864:20::62a]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2WPd-00000007SFl-3Y12 for linux-riscv@lists.infradead.org; Wed, 09 Apr 2025 14:28:23 +0000 Received: by mail-pl1-x62a.google.com with SMTP id d9443c01a7336-227b828de00so69212085ad.1 for ; Wed, 09 Apr 2025 07:28:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1744208901; x=1744813701; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=iKdsZVjEB+ld4A+96BXpcZU7N3NQ0asG+U4PZDEXS+s=; b=XXihYTskM2+wpn8MAI9MJEfWw1axm89j9/5L3LkXvNcMQgLjtLjsfHpr40c1cVB+kU IqvZ7hHWop1Ki/Klsgghq8ZOovO4d7z2vmsZvmoGXi75xb9DkF0m5UQ6NkLBjiCs5QYA sSUJCOud/JshZK9Hf2WsafhKNPyHyTGYDybRfYc4JlwRQYNkIBDB6vRpBbq8nfOC+Fzu 2/LMUbiY+BFSOcrKLnoJPNhQubfoOdULZOnqjX28N4jLXoixYpT4uFfyAVNZcVkxnFxY YNIs1DdBGNLy5ds2T+4iCHngzPxkGE6npqv0ryxgRjb8UUVxdLJb9ytD/9qKmOqSa65+ uRGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744208901; x=1744813701; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=iKdsZVjEB+ld4A+96BXpcZU7N3NQ0asG+U4PZDEXS+s=; b=GFcOD0425ZY6uzU0n+mdR+jr/euC2Tpz/4s39ViC6mb8OLxhUK0o4+LgtwfEcE50fu K+1IbcImCnWZivY5k72dcLpzxtVqOApyktx7YPJf8ofm/GtukJ+2olzJxgXNbPlJxHNQ gzxI/I5VowIKWLRjtw/v+r/fKVGH5zEhkaHMIw2Vlsm2fmmMCaKUV5lNuVI5xB1LO7ZT GTgzNJ0TDcagtxP4dSyvJi4Ti+MVxnnJwEW42H7XiH2rO7qAYjGmsFKbNGOfwgT0d1B5 BxPAVJHCMPKRk57jgYfVM2cTJSHbGXK3lkz2v3S41fKnOp0GAgTM1Jk4NTXdR8jWTS86 eH3Q== X-Forwarded-Encrypted: i=1; AJvYcCXYzPXQ6QydGuZIMoo3MuAHyoNZ+WPHLgA0ul7TPe0+3fJ9ipXWhwTy5MCIqdkgXFjE6G/pBh+4cBVApQ==@lists.infradead.org X-Gm-Message-State: AOJu0YzpM0ZAU+ZExZWw7ZOF/8Ko+pfOwojlpJavHVppyqYPbMpxWJ7F BQfTTFVsZLr/4d+yuksx+NS7i+HmuLwOj+D78nhDCOdukMlPCwHk0MTvwPRd9e0= X-Gm-Gg: ASbGnctHKxDuDUYMakQnfDcZiBjc9UL1pLUsk5eh49kiqRwgNz5Xfrw0L+Q3nDlCNyQ Wb/bu+wM12WdU7p2NjyToDQrA9gGErfBiwqhyW+WX4ugbkY0oq29KoVI5vEFmygoJ3Qy20gzwDJ VHI2/uirs2DTuKy47MrW40fqxo+TvqmC/U5/tYiOcEVxFyfQxegPdMU2Aza2VV8BxqhwvynjlRR dGZkoGsZL24YvzhqB3qHIigI/YDKyIa9qqJcS0lw+qzd1DCnp0Vzta18FqLqIKGS0+RpuAsz8uI GOgiKyMReKq9qlBlNZezFYzn5ktCXZSR7tVHEMX5NbtLH6/9NANmm4t/HF+SQA== X-Google-Smtp-Source: AGHT+IEZcb3DjiGcYzGFWX/udT1ybgSSFf/OKSBgPoOLDb9/c2yI1PJe1NZkwsT9h6HK1NAI3V+uKw== X-Received: by 2002:a17:903:1787:b0:224:1220:7f40 with SMTP id d9443c01a7336-22ac298441fmr44614275ad.3.1744208900819; Wed, 09 Apr 2025 07:28:20 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-22ac7cafdaasm12457775ad.165.2025.04.09.07.28.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Apr 2025 07:28:20 -0700 (PDT) Date: Wed, 9 Apr 2025 07:28:17 -0700 From: Deepak Gupta To: Alexandre Ghiti Cc: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andrew Morton , "Liam R. Howlett" , Vlastimil Babka , Lorenzo Stoakes , Paul Walmsley , Palmer Dabbelt , Albert Ou , Conor Dooley , Rob Herring , Krzysztof Kozlowski , Arnd Bergmann , Christian Brauner , Peter Zijlstra , Oleg Nesterov , Eric Biederman , Kees Cook , Jonathan Corbet , Shuah Khan , Jann Horn , Conor Dooley , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, alistair.francis@wdc.com, richard.henderson@linaro.org, jim.shu@sifive.com, andybnac@gmail.com, kito.cheng@sifive.com, charlie@rivosinc.com, atishp@rivosinc.com, evan@rivosinc.com, cleger@rivosinc.com, alexghiti@rivosinc.com, samitolvanen@google.com, broonie@kernel.org, rick.p.edgecombe@intel.com, Zong Li Subject: Re: [PATCH v12 24/28] arch/riscv: compile vdso with landing pad Message-ID: References: <20250314-v5_user_cfi_series-v12-0-e51202b53138@rivosinc.com> <20250314-v5_user_cfi_series-v12-24-e51202b53138@rivosinc.com> <4f6a0c65-7c3a-4457-8b0b-cd39f40931c8@ghiti.fr> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4f6a0c65-7c3a-4457-8b0b-cd39f40931c8@ghiti.fr> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250409_072821_880822_FDB406A8 X-CRM114-Status: GOOD ( 17.45 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Tue, Apr 08, 2025 at 02:45:25PM +0200, Alexandre Ghiti wrote: > >On 14/03/2025 22:39, Deepak Gupta wrote: >>From: Jim Shu >> >>user mode tasks compiled with zicfilp may call indirectly into vdso (like >>hwprobe indirect calls). Add landing pad compile support in vdso. vdso >>with landing pad in it will be nop for tasks which have not enabled >>landing pad. >>This patch allows to run user mode tasks with cfi eanbled and do no harm. >> >>Future work can be done on this to do below >> - labeled landing pad on vdso functions (whenever labeling support shows >> up in gnu-toolchain) >> - emit shadow stack instructions only in vdso compiled objects as part of >> kernel compile. >> >>Signed-off-by: Jim Shu >>Reviewed-by: Zong Li >>Signed-off-by: Deepak Gupta >>--- >> arch/riscv/Makefile | 5 +++- >> arch/riscv/include/asm/assembler.h | 44 +++++++++++++++++++++++++++++++++++ >> arch/riscv/kernel/vdso/Makefile | 12 ++++++++++ >> arch/riscv/kernel/vdso/flush_icache.S | 4 ++++ >> arch/riscv/kernel/vdso/getcpu.S | 4 ++++ >> arch/riscv/kernel/vdso/rt_sigreturn.S | 4 ++++ >> arch/riscv/kernel/vdso/sys_hwprobe.S | 4 ++++ >> 7 files changed, 76 insertions(+), 1 deletion(-) >> >>diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile >>index 13fbc0f94238..eca94246cda6 100644 >>--- a/arch/riscv/Makefile >>+++ b/arch/riscv/Makefile >>@@ -88,9 +88,12 @@ riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZACAS) := $(riscv-march-y)_zacas >> # Check if the toolchain supports Zabha >> riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZABHA) := $(riscv-march-y)_zabha >>+KBUILD_BASE_ISA = -march=$(shell echo $(riscv-march-y) | sed -E 's/(rv32ima|rv64ima)fd([^v_]*)v?/\1\2/') >>+export KBUILD_BASE_ISA >>+ >> # Remove F,D,V from isa string for all. Keep extensions between "fd" and "v" by >> # matching non-v and non-multi-letter extensions out with the filter ([^v_]*) >>-KBUILD_CFLAGS += -march=$(shell echo $(riscv-march-y) | sed -E 's/(rv32ima|rv64ima)fd([^v_]*)v?/\1\2/') >>+KBUILD_CFLAGS += $(KBUILD_BASE_ISA) >> KBUILD_AFLAGS += -march=$(riscv-march-y) >>diff --git a/arch/riscv/include/asm/assembler.h b/arch/riscv/include/asm/assembler.h >>index 44b1457d3e95..a058ea5e9c58 100644 >>--- a/arch/riscv/include/asm/assembler.h >>+++ b/arch/riscv/include/asm/assembler.h >>@@ -80,3 +80,47 @@ >> .endm >> #endif /* __ASM_ASSEMBLER_H */ >>+ >>+#if defined(CONFIG_RISCV_USER_CFI) && (__riscv_xlen == 64) >>+.macro vdso_lpad >>+lpad 0 >>+.endm >>+#else >>+.macro vdso_lpad >>+.endm >>+#endif >>+ >>+/* >>+ * This macro emits a program property note section identifying >>+ * architecture features which require special handling, mainly for >>+ * use in assembly files included in the VDSO. >>+ */ >>+#define NT_GNU_PROPERTY_TYPE_0 5 >>+#define GNU_PROPERTY_RISCV_FEATURE_1_AND 0xc0000000 >>+ >>+#define GNU_PROPERTY_RISCV_FEATURE_1_ZICFILP (1U << 0) >>+#define GNU_PROPERTY_RISCV_FEATURE_1_ZICFISS (1U << 1) >>+ >>+#if defined(CONFIG_RISCV_USER_CFI) && (__riscv_xlen == 64) >>+#define GNU_PROPERTY_RISCV_FEATURE_1_DEFAULT \ >>+ (GNU_PROPERTY_RISCV_FEATURE_1_ZICFILP) >>+#endif >>+ >>+#ifdef GNU_PROPERTY_RISCV_FEATURE_1_DEFAULT >>+.macro emit_riscv_feature_1_and, feat = GNU_PROPERTY_RISCV_FEATURE_1_DEFAULT >>+ .pushsection .note.gnu.property, "a" >>+ .p2align 3 >>+ .word 4 >>+ .word 16 >>+ .word NT_GNU_PROPERTY_TYPE_0 >>+ .asciz "GNU" >>+ .word GNU_PROPERTY_RISCV_FEATURE_1_AND >>+ .word 4 >>+ .word \feat >>+ .word 0 >>+ .popsection >>+.endm >>+#else >>+.macro emit_riscv_feature_1_and, feat = 0 >>+.endm >>+#endif >>diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile >>index 9a1b555e8733..daa10c2b0dd1 100644 >>--- a/arch/riscv/kernel/vdso/Makefile >>+++ b/arch/riscv/kernel/vdso/Makefile >>@@ -13,12 +13,18 @@ vdso-syms += flush_icache >> vdso-syms += hwprobe >> vdso-syms += sys_hwprobe >>+ifdef CONFIG_RISCV_USER_CFI >>+LPAD_MARCH = _zicfilp >>+endif >>+ >> # Files to link into the vdso >> obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o >> ccflags-y := -fno-stack-protector >> ccflags-y += -DDISABLE_BRANCH_PROFILING >> ccflags-y += -fno-builtin >>+ccflags-y += $(KBUILD_BASE_ISA)$(LPAD_MARCH) >>+asflags-y += $(KBUILD_BASE_ISA)$(LPAD_MARCH) >> ifneq ($(c-gettimeofday-y),) >> CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y) >>@@ -40,6 +46,12 @@ endif >> CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) >> CFLAGS_REMOVE_hwprobe.o = $(CC_FLAGS_FTRACE) $(CC_FLAGS_SCS) >>+# Disable profiling and instrumentation for VDSO code >>+GCOV_PROFILE := n >>+KCOV_INSTRUMENT := n >>+KASAN_SANITIZE := n >>+UBSAN_SANITIZE := n > > >So I looked into this and it seems it is not needed. All the profilers >above only add their corresponding "clags" if the object >"is-kernel-object" (https://elixir.bootlin.com/linux/v6.14-rc6/source/scripts/Makefile.lib#L147) >which is not the case for hwprobe.c since it is not added to obj-y. Noted. Will remove it. > > >>+ >> # Force dependency >> $(obj)/vdso.o: $(obj)/vdso.so >>diff --git a/arch/riscv/kernel/vdso/flush_icache.S b/arch/riscv/kernel/vdso/flush_icache.S >>index 8f884227e8bc..e4c56970905e 100644 >>--- a/arch/riscv/kernel/vdso/flush_icache.S >>+++ b/arch/riscv/kernel/vdso/flush_icache.S >>@@ -5,11 +5,13 @@ >> #include >> #include >>+#include >> .text >> /* int __vdso_flush_icache(void *start, void *end, unsigned long flags); */ >> SYM_FUNC_START(__vdso_flush_icache) >> .cfi_startproc >>+ vdso_lpad >> #ifdef CONFIG_SMP >> li a7, __NR_riscv_flush_icache >> ecall >>@@ -20,3 +22,5 @@ SYM_FUNC_START(__vdso_flush_icache) >> ret >> .cfi_endproc >> SYM_FUNC_END(__vdso_flush_icache) >>+ >>+emit_riscv_feature_1_and >>diff --git a/arch/riscv/kernel/vdso/getcpu.S b/arch/riscv/kernel/vdso/getcpu.S >>index 9c1bd531907f..5c1ecc4e1465 100644 >>--- a/arch/riscv/kernel/vdso/getcpu.S >>+++ b/arch/riscv/kernel/vdso/getcpu.S >>@@ -5,14 +5,18 @@ >> #include >> #include >>+#include >> .text >> /* int __vdso_getcpu(unsigned *cpu, unsigned *node, void *unused); */ >> SYM_FUNC_START(__vdso_getcpu) >> .cfi_startproc >>+ vdso_lpad >> /* For now, just do the syscall. */ >> li a7, __NR_getcpu >> ecall >> ret >> .cfi_endproc >> SYM_FUNC_END(__vdso_getcpu) >>+ >>+emit_riscv_feature_1_and >>diff --git a/arch/riscv/kernel/vdso/rt_sigreturn.S b/arch/riscv/kernel/vdso/rt_sigreturn.S >>index 3dc022aa8931..e82987dc3739 100644 >>--- a/arch/riscv/kernel/vdso/rt_sigreturn.S >>+++ b/arch/riscv/kernel/vdso/rt_sigreturn.S >>@@ -5,12 +5,16 @@ >> #include >> #include >>+#include >> .text >> SYM_FUNC_START(__vdso_rt_sigreturn) >> .cfi_startproc >> .cfi_signal_frame >>+ vdso_lpad >> li a7, __NR_rt_sigreturn >> ecall >> .cfi_endproc >> SYM_FUNC_END(__vdso_rt_sigreturn) >>+ >>+emit_riscv_feature_1_and >>diff --git a/arch/riscv/kernel/vdso/sys_hwprobe.S b/arch/riscv/kernel/vdso/sys_hwprobe.S >>index 77e57f830521..f1694451a60c 100644 >>--- a/arch/riscv/kernel/vdso/sys_hwprobe.S >>+++ b/arch/riscv/kernel/vdso/sys_hwprobe.S >>@@ -3,13 +3,17 @@ >> #include >> #include >>+#include >> .text >> SYM_FUNC_START(riscv_hwprobe) >> .cfi_startproc >>+ vdso_lpad >> li a7, __NR_riscv_hwprobe >> ecall >> ret >> .cfi_endproc >> SYM_FUNC_END(riscv_hwprobe) >>+ >>+emit_riscv_feature_1_and >> _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv