From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f171.google.com (mail-pg1-f171.google.com [209.85.215.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84B2617C20E for ; Fri, 21 Jun 2024 22:10:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719007849; cv=none; b=iwe39kdMakyB48PuAA/q7bwqcIti2poyXmb5lS+XNQVRIRfkq6icgEoAtw+ggMVKyLfe7+lc6H4Lf89Pwv5eKJiExPAJI3/lHNUTyiq+Ann9+4qGe+qeaQh1FFl4p08MqNMph5PeRCbtynAFinwGIXrHELbzO7kAvfQEE5YM+9Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719007849; c=relaxed/simple; bh=ZEyjg1DGdHfvMHVyn3oiXgYoAsPB9kPjfgjytYscvC8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=bchzGZ9F5fWc3ojbkM8aEe+KtHVfR4MPgYMKN0icpj+T/W2vLGXR3QwmngfzhvylkVbelrR28mOfM+Yk/h4FcR/fWPcGfW7qIAvJQEI2u2idPQdnjPm9fQn/FCi7FNO7qxm88vN0hdoLn7COpIMUdx37qbMiWIVHrDKdbcVm/Qo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com; spf=pass smtp.mailfrom=rivosinc.com; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b=HXM3+qjX; arc=none smtp.client-ip=209.85.215.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rivosinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rivosinc-com.20230601.gappssmtp.com header.i=@rivosinc-com.20230601.gappssmtp.com header.b="HXM3+qjX" Received: by mail-pg1-f171.google.com with SMTP id 41be03b00d2f7-70346ae2c43so2417576a12.1 for ; Fri, 21 Jun 2024 15:10:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1719007846; x=1719612646; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=W6zNTGp1aTwOtvLdnUXPrvSqBQrllJdVcW2FVVgDB5g=; b=HXM3+qjXxtXZ59+HmVscZ/hJS6if3zHHfXT84Pi+RsoH+Vteq9ece+6LBs+pm4XXDN ZqN5p91ivkN4iEO2UWDal+H9R/nkwhF0mnrNCZegFNcKlXvD6q+7wyRPnyXVge7W0HIx vG8rGq8j+Mq3qFbRKFaYO0RHGB5NYVAA4r+g5dafKAZbK8smEUBlUV63fPJHD61+BNZQ RxLqQvVIcISTeoWD1MsVcsPqDM+IpX1wtkws2YOeDnlInOjMIOlDMHE1x/PQRogVHsFL IhDVGv0Sd0oGzHWkaA6tpLOWLK+V105PqUmeputuqWPzU4aUBjR5qVSIZaP1Ab3tQta3 JSlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719007846; x=1719612646; h=in-reply-to:content-transfer-encoding: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=W6zNTGp1aTwOtvLdnUXPrvSqBQrllJdVcW2FVVgDB5g=; b=iHmdnbPCfXZmuQAw8CMFY21mytJ6xfBZkTIK9eWV2iVHkFiUpzCRs72fzTxc1cxh59 3Tn70oqgF11Q3FlbwvAnWYy23C1r08AQis2n1BOMlIBPDon9+XiHhvUlAeHwFOt75G2A cRYUhJFEScmZpn9vDQ48EU0anLFa6utbjHDKmSS8PxAPLMMvIyDseKnxszTF5pmshYMy gQuFTdfCdDtL03G7EMe3dzyDbmjEwYhPcTO9X1D+X5uI6DavDX7rXuddu8K15aKAJeEa 6NmjzLL5gI/0OAMvz8Q7qiG/Jr3BCB3Y/Vi0AIvA1YIEhJs09lDMuO1RF+4/U6x/Goxl N3yg== X-Forwarded-Encrypted: i=1; AJvYcCWI2lzW7fp3+0BjRPItsYVjl48G3+EXzM3bcc6yO+t6jf1nDTgphY2UjVVb4ysjCeNgPBpUBM6q/nkjjZWaU43dHbKj0SvnzDTAjNHA X-Gm-Message-State: AOJu0YyZvcYzK7RzVSI2YTOGw6oM7r3WMOeWH06VrO8RYNypfv+5I9nf j558AY9I2+eq8CWwdxNzs2QGNSm1P/1mTryCIba4TrgQ2m7eM0H61eqGOzSNAk4= X-Google-Smtp-Source: AGHT+IFodC/KHmQCg2O0jJBVOPuXhUN5lF51VkVlsO14ggFbC93W0YN4q838joM1PZnjh/NG3CSEVg== X-Received: by 2002:a17:902:e84d:b0:1f9:f906:9082 with SMTP id d9443c01a7336-1fa04a42126mr12275615ad.7.1719007845678; Fri, 21 Jun 2024 15:10:45 -0700 (PDT) Received: from ghost ([2601:647:5700:6860:e8dd:a296:71d5:2490]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1f9eb5e030dsm18868865ad.218.2024.06.21.15.10.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Jun 2024 15:10:45 -0700 (PDT) Date: Fri, 21 Jun 2024 15:10:42 -0700 From: Charlie Jenkins To: Jisheng Zhang Cc: Paul Walmsley , Palmer Dabbelt , Albert Ou , Ard Biesheuvel , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [PATCH] riscv: enable HAVE_ARCH_STACKLEAK Message-ID: References: <20240617123029.723-1-jszhang@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240617123029.723-1-jszhang@kernel.org> On Mon, Jun 17, 2024 at 08:30:29PM +0800, Jisheng Zhang wrote: > Add support for the stackleak feature. Whenever the kernel returns to user > space the kernel stack is filled with a poison value. > > At the same time, disables the plugin in EFI stub code because EFI stub > is out of scope for the protection. > > Tested on qemu and milkv duo: > / # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT > [ 38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING > [ 38.678448] lkdtm: stackleak stack usage: > [ 38.678448] high offset: 288 bytes > [ 38.678448] current: 496 bytes > [ 38.678448] lowest: 1328 bytes > [ 38.678448] tracked: 1328 bytes > [ 38.678448] untracked: 448 bytes > [ 38.678448] poisoned: 14312 bytes > [ 38.678448] low offset: 8 bytes > [ 38.689887] lkdtm: OK: the rest of the thread stack is properly erased > > Signed-off-by: Jisheng Zhang > --- > arch/riscv/Kconfig | 1 + > arch/riscv/kernel/entry.S | 4 ++++ > drivers/firmware/efi/libstub/Makefile | 3 ++- > 3 files changed, 7 insertions(+), 1 deletion(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 0525ee2d63c7..9cbfdffec96c 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -118,6 +118,7 @@ config RISCV > select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT > select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET > select HAVE_ARCH_SECCOMP_FILTER > + select HAVE_ARCH_STACKLEAK When this is selected, stackleak.h include arch/riscv/include/asm/thread_info.h without sizes.h and I hit: ./arch/riscv/include/asm/thread_info.h:30:33: error: ‘SZ_4K’ undeclared here (not in a function) 30 | #define OVERFLOW_STACK_SIZE SZ_4K | ^~~~~ Adding "#include " to thread_info.h resolves the issue. I am testing this based on 6.10-rc4. Did you encounter this? - Charlie > select HAVE_ARCH_THREAD_STRUCT_WHITELIST > select HAVE_ARCH_TRACEHOOK > select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU > diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S > index 68a24cf9481a..80ff55a26d13 100644 > --- a/arch/riscv/kernel/entry.S > +++ b/arch/riscv/kernel/entry.S > @@ -130,6 +130,10 @@ SYM_CODE_START_NOALIGN(ret_from_exception) > #endif > bnez s0, 1f > > +#ifdef CONFIG_GCC_PLUGIN_STACKLEAK > + call stackleak_erase_on_task_stack > +#endif > + > /* Save unwound kernel stack pointer in thread_info */ > addi s0, sp, PT_SIZE_ON_STACK > REG_S s0, TASK_TI_KERNEL_SP(tp) > diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile > index 06f0428a723c..3a9521c57641 100644 > --- a/drivers/firmware/efi/libstub/Makefile > +++ b/drivers/firmware/efi/libstub/Makefile > @@ -28,7 +28,8 @@ cflags-$(CONFIG_ARM) += -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \ > -DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \ > -DEFI_HAVE_STRCMP -fno-builtin -fpic \ > $(call cc-option,-mno-single-pic-base) > -cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE -mno-relax > +cflags-$(CONFIG_RISCV) += -fpic -DNO_ALTERNATIVE -mno-relax \ > + $(DISABLE_STACKLEAK_PLUGIN) > cflags-$(CONFIG_LOONGARCH) += -fpie > > cflags-$(CONFIG_EFI_PARAMS_FROM_FDT) += -I$(srctree)/scripts/dtc/libfdt > -- > 2.43.0 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv