From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:61062 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727476AbgIOPny (ORCPT ); Tue, 15 Sep 2020 11:43:54 -0400 From: Heiko Carstens Subject: [PATCH 3/4] s390/uaccess: implement HAVE_GET_KERNEL_NOFAULT support Date: Tue, 15 Sep 2020 17:43:39 +0200 Message-Id: <20200915154340.4215-4-hca@linux.ibm.com> In-Reply-To: <20200915154340.4215-1-hca@linux.ibm.com> References: <20200915154340.4215-1-hca@linux.ibm.com> Sender: linux-s390-owner@vger.kernel.org List-ID: To: Christoph Hellwig Cc: Vasily Gorbik , Christian Borntraeger , Harald Freudenberger , linux-s390@vger.kernel.org Signed-off-by: Heiko Carstens --- arch/s390/include/asm/uaccess.h | 111 ++++++++++++++++++++++++++++++++ 1 file changed, 111 insertions(+) diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h index f09444d6aeab..3ef424bca082 100644 --- a/arch/s390/include/asm/uaccess.h +++ b/arch/s390/include/asm/uaccess.h @@ -278,4 +278,115 @@ static inline unsigned long __must_check clear_user(void __user *to, unsigned lo int copy_to_user_real(void __user *dest, void *src, unsigned long count); void *s390_kernel_write(void *dst, const void *src, size_t size); +#define HAVE_GET_KERNEL_NOFAULT + +int __put_kernel_bad(void) __attribute__((noreturn)); + +#define __put_kernel_asm(val, to, insn) \ +({ \ + int __rc; \ + \ + asm volatile( \ + "0: " insn " %2,%1\n" \ + "1: xr %0,%0\n" \ + "2:\n" \ + ".pushsection .fixup, \"ax\"\n" \ + "3: lhi %0,%3\n" \ + " jg 2b\n" \ + ".popsection\n" \ + EX_TABLE(0b,3b) EX_TABLE(1b,3b) \ + : "=d" (__rc), "+Q" (*(to)) \ + : "d" (val), "K" (-EFAULT) \ + : "cc"); \ + __rc; \ +}) + +#define __put_kernel_nofault(dst, src, type, err_label) \ +do { \ + u64 __x = (u64)(*((type *)(src))); \ + int __pk_err; \ + \ + switch (sizeof(type)) { \ + case 1: \ + __pk_err = __put_kernel_asm(__x, (type *)(dst), "stc"); \ + break; \ + case 2: \ + __pk_err = __put_kernel_asm(__x, (type *)(dst), "sth"); \ + break; \ + case 4: \ + __pk_err = __put_kernel_asm(__x, (type *)(dst), "st"); \ + break; \ + case 8: \ + __pk_err = __put_kernel_asm(__x, (type *)(dst), "stg"); \ + break; \ + default: \ + __pk_err = __put_kernel_bad(); \ + break; \ + } \ + if (unlikely(__pk_err)) \ + goto err_label; \ +} while (0) + +int __get_kernel_bad(void) __attribute__((noreturn)); + +#define __get_kernel_asm(val, from, insn) \ +({ \ + int __rc; \ + \ + asm volatile( \ + "0: " insn " %1,%2\n" \ + "1: xr %0,%0\n" \ + "2:\n" \ + ".pushsection .fixup, \"ax\"\n" \ + "3: lhi %0,%3\n" \ + " jg 2b\n" \ + ".popsection\n" \ + EX_TABLE(0b,3b) EX_TABLE(1b,3b) \ + : "=d" (__rc), "+d" (val) \ + : "Q" (*(from)), "K" (-EFAULT) \ + : "cc"); \ + __rc; \ +}) + +#define __get_kernel_nofault(dst, src, type, err_label) \ +do { \ + int __gk_err = -EFAULT; \ + \ + switch (sizeof(type)) { \ + case 1: { \ + u8 __x = 0; \ + \ + __gk_err = __get_kernel_asm(__x, (type *)(src), "ic"); \ + *((type *)(dst)) = (type)__x; \ + break; \ + }; \ + case 2: { \ + u16 __x = 0; \ + \ + __gk_err = __get_kernel_asm(__x, (type *)(src), "lh"); \ + *((type *)(dst)) = (type)__x; \ + break; \ + }; \ + case 4: { \ + u32 __x = 0; \ + \ + __gk_err = __get_kernel_asm(__x, (type *)(src), "l"); \ + *((type *)(dst)) = (type)__x; \ + break; \ + }; \ + case 8: { \ + u64 __x = 0; \ + \ + __gk_err = __get_kernel_asm(__x, (type *)(src), "lg"); \ + *((type *)(dst)) = (type)__x; \ + break; \ + }; \ + default: \ + __gk_err = __get_kernel_bad(); \ + break; \ + } \ + if (unlikely(__gk_err)) \ + goto err_label; \ +} while (0) + #endif /* __S390_UACCESS_H */ -- 2.17.1