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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5DC05C43331 for ; Mon, 30 Mar 2020 21:10:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 334A720714 for ; Mon, 30 Mar 2020 21:10:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728376AbgC3VKN (ORCPT ); Mon, 30 Mar 2020 17:10:13 -0400 Received: from mga14.intel.com ([192.55.52.115]:50018 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728317AbgC3VKM (ORCPT ); Mon, 30 Mar 2020 17:10:12 -0400 IronPort-SDR: F9EZN1ztr3s0q1tzwT2UxhMCl773iREmiSZ3HNYpN6/4KzV72ZGwzRXeov2/4+IQTBEDIV+ByO eIysRq5ZbxMg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Mar 2020 14:10:10 -0700 IronPort-SDR: FrrgQmLwwpmnF53SHLtpZGKt2HyV7Z6tW/4GDuJVBQl+wwWMS0OiNh7z0Ls+W1Jo426tYHUnsj U8q0GX8p5phQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,325,1580803200"; d="scan'208";a="294729076" Received: from plachner-mobl.ger.corp.intel.com (HELO localhost) ([10.252.35.129]) by FMSMGA003.fm.intel.com with ESMTP; 30 Mar 2020 14:10:06 -0700 Date: Tue, 31 Mar 2020 00:10:05 +0300 From: Jarkko Sakkinen To: Sean Christopherson Cc: Nathaniel McCallum , Cedric Xing , Jethro Beekman , Andy Lutomirski , linux-sgx@vger.kernel.org Subject: Re: [PATCH for_v29 v2 2/5] x86/sgx: vdso: Define a typedef for __vdso_sgx_enter_enclave Message-ID: <20200330210952.GK1384380@linux.intel.com> References: <20200330180811.31381-1-sean.j.christopherson@intel.com> <20200330180811.31381-3-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200330180811.31381-3-sean.j.christopherson@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-sgx-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Mon, Mar 30, 2020 at 11:08:08AM -0700, Sean Christopherson wrote: > Define a typedef for the __vdso_sgx_enter_enclave() prototype and move > the entire function comment from the assembly code to the uAPI header, > dropping the kernel doc hack along the way. > > Signed-off-by: Sean Christopherson > --- > arch/x86/entry/vdso/vsgx_enter_enclave.S | 62 ------------------------ > arch/x86/include/uapi/asm/sgx.h | 61 +++++++++++++++++++++++ > 2 files changed, 61 insertions(+), 62 deletions(-) > > diff --git a/arch/x86/entry/vdso/vsgx_enter_enclave.S b/arch/x86/entry/vdso/vsgx_enter_enclave.S > index c56064fb36bc..be7e467e1efb 100644 > --- a/arch/x86/entry/vdso/vsgx_enter_enclave.S > +++ b/arch/x86/entry/vdso/vsgx_enter_enclave.S > @@ -15,68 +15,6 @@ > .code64 > .section .text, "ax" > > -/** > - * __vdso_sgx_enter_enclave() - Enter an SGX enclave > - * @rdi: Pass-through value for RDI > - * @rsi: Pass-through value for RSI > - * @rdx: Pass-through value for RDX > - * @leaf: ENCLU leaf, must be EENTER or ERESUME > - * @r8: Pass-through value for R8 > - * @r9: Pass-through value for R9 > - * @tcs: TCS, must be non-NULL > - * @e: Optional struct sgx_enclave_exception instance > - * @handler: Optional enclave exit handler > - * > - * **Important!** __vdso_sgx_enter_enclave() does not ensure full compliance > - * with the x86-64 ABI, e.g. doesn't explicitly clear EFLAGS.DF after EEXIT. > - * Except for non-volatile general purpose registers, preserving/setting state > - * in accordance with the x86-64 ABI is the responsibility of the enclave and > - * its runtime, i.e. __vdso_sgx_enter_enclave() cannot be called from C code > - * without careful consideration by both the enclave and its runtime. > - * > - * All general purpose registers except RAX, RBX and RCX are passed as-is to > - * the enclave. RAX, RBX and RCX are consumed by EENTER and ERESUME and are > - * loaded with @leaf, asynchronous exit pointer, and @tcs respectively. > - * > - * RBP and the stack are used to anchor __vdso_sgx_enter_enclave() to the > - * pre-enclave state, e.g. to retrieve @e and @handler after an enclave exit. > - * All other registers are available for use by the enclave and its runtime, > - * e.g. an enclave can push additional data onto the stack (and modify RSP) to > - * pass information to the optional exit handler (see below). > - * > - * Most exceptions reported on ENCLU, including those that occur within the > - * enclave, are fixed up and reported synchronously instead of being delivered > - * via a standard signal. Debug Exceptions (#DB) and Breakpoints (#BP) are > - * never fixed up and are always delivered via standard signals. On synchrously > - * reported exceptions, -EFAULT is returned and details about the exception are > - * recorded in @e, the optional sgx_enclave_exception struct. > - > - * If an exit handler is provided, the handler will be invoked on synchronous > - * exits from the enclave and for all synchronously reported exceptions. In > - * latter case, @e is filled prior to invoking the handler. > - * > - * The exit handler's return value is interpreted as follows: > - * >0: continue, restart __vdso_sgx_enter_enclave() with @ret as @leaf > - * 0: success, return @ret to the caller > - * <0: error, return @ret to the caller > - * > - * The exit handler may transfer control, e.g. via longjmp() or C++ exception, > - * without returning to __vdso_sgx_enter_enclave(). > - * > - * Return: > - * 0 on success, > - * -EINVAL if ENCLU leaf is not allowed, > - * -EFAULT if an exception occurs on ENCLU or within the enclave > - * -errno for all other negative values returned by the userspace exit handler > - */ > -#ifdef SGX_KERNEL_DOC > -/* C-style function prototype to coerce kernel-doc into parsing the comment. */ > -int __vdso_sgx_enter_enclave(unsigned long rdi, unsigned long rsi, > - unsigned long rdx, unsigned int leaf, > - unsigned long r8, unsigned long r9, void *tcs, > - struct sgx_enclave_exception *e, > - sgx_enclave_exit_handler_t handler); > -#endif > SYM_FUNC_START(__vdso_sgx_enter_enclave) > /* Prolog */ > .cfi_startproc > diff --git a/arch/x86/include/uapi/asm/sgx.h b/arch/x86/include/uapi/asm/sgx.h > index e196cfd44b70..8ca9ef7ea50a 100644 > --- a/arch/x86/include/uapi/asm/sgx.h > +++ b/arch/x86/include/uapi/asm/sgx.h > @@ -111,4 +111,65 @@ typedef int (*sgx_enclave_exit_handler_t)(long rdi, long rsi, long rdx, > void *tcs, int ret, > struct sgx_enclave_exception *e); > > +/** > + * __vdso_sgx_enter_enclave() - Enter an SGX enclave > + * @rdi: Pass-through value for RDI > + * @rsi: Pass-through value for RSI > + * @rdx: Pass-through value for RDX > + * @leaf: ENCLU leaf, must be EENTER or ERESUME > + * @r8: Pass-through value for R8 > + * @r9: Pass-through value for R9 > + * @tcs: TCS, must be non-NULL > + * @e: Optional struct sgx_enclave_exception instance > + * @handler: Optional enclave exit handler > + * > + * **Important!** __vdso_sgx_enter_enclave() does not ensure full compliance > + * with the x86-64 ABI, e.g. doesn't explicitly clear EFLAGS.DF after EEXIT. > + * Except for non-volatile general purpose registers, preserving/setting state > + * in accordance with the x86-64 ABI is the responsibility of the enclave and > + * its runtime, i.e. __vdso_sgx_enter_enclave() cannot be called from C code > + * without careful consideration by both the enclave and its runtime. > + * > + * All general purpose registers except RAX, RBX and RCX are passed as-is to > + * the enclave. RAX, RBX and RCX are consumed by EENTER and ERESUME and are > + * loaded with @leaf, asynchronous exit pointer, and @tcs respectively. > + * > + * RBP and the stack are used to anchor __vdso_sgx_enter_enclave() to the > + * pre-enclave state, e.g. to retrieve @e and @handler after an enclave exit. > + * All other registers are available for use by the enclave and its runtime, > + * e.g. an enclave can push additional data onto the stack (and modify RSP) to > + * pass information to the optional exit handler (see below). > + * > + * Most exceptions reported on ENCLU, including those that occur within the > + * enclave, are fixed up and reported synchronously instead of being delivered > + * via a standard signal. Debug Exceptions (#DB) and Breakpoints (#BP) are > + * never fixed up and are always delivered via standard signals. On synchrously > + * reported exceptions, -EFAULT is returned and details about the exception are > + * recorded in @e, the optional sgx_enclave_exception struct. > + > + * If an exit handler is provided, the handler will be invoked on synchronous > + * exits from the enclave and for all synchronously reported exceptions. In > + * latter case, @e is filled prior to invoking the handler. > + * > + * The exit handler's return value is interpreted as follows: > + * >0: continue, restart __vdso_sgx_enter_enclave() with @ret as @leaf > + * 0: success, return @ret to the caller > + * <0: error, return @ret to the caller > + * > + * The exit handler may transfer control, e.g. via longjmp() or C++ exception, > + * without returning to __vdso_sgx_enter_enclave(). > + * > + * Return: > + * 0 on success, > + * -EINVAL if ENCLU leaf is not allowed, > + * -EFAULT if an exception occurs on ENCLU or within the enclave > + * -errno for all other negative values returned by the userspace exit handler > + */ > +typedef int (*vdso_sgx_enter_enclave_t)(unsigned long rdi, unsigned long rsi, > + unsigned long rdx, unsigned int leaf, > + unsigned long r8, unsigned long r9, > + void *tcs, > + struct sgx_enclave_exception *e, > + sgx_enclave_exit_handler_t handler); > + > #endif /* _UAPI_ASM_X86_SGX_H */ > -- > 2.24.1 > Most probaby agree with this. /Jarkko