| Message ID | 20200330180811.31381-3-sean.j.christopherson@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86/sgx: Make vDSO callable from C | expand |
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 <sean.j.christopherson@intel.com> > --- > 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
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 */
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 <sean.j.christopherson@intel.com> --- arch/x86/entry/vdso/vsgx_enter_enclave.S | 62 ------------------------ arch/x86/include/uapi/asm/sgx.h | 61 +++++++++++++++++++++++ 2 files changed, 61 insertions(+), 62 deletions(-)