diff mbox series

[02/14] sparc64: add __{get,put}_kernel_nocheck()

Message ID 20220214163452.1568807-3-arnd@kernel.org
State New
Headers show
Series clean up asm/uaccess.h, kill set_fs for good | expand

Commit Message

Arnd Bergmann Feb. 14, 2022, 4:34 p.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

sparc64 is one of the architectures that uses separate address
spaces for kernel and user addresses, so __get_kernel_nofault()
can not just call into the normal __get_user() without the
access_ok() check.

Instead duplicate __get_user() and __put_user() into their
in-kernel versions, with minor changes for the calling conventions
and leaving out the address space modifier on the assembler
instruction.

This could surely be written more elegantly, but duplicating it
gets the job done.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 arch/sparc/include/asm/uaccess_64.h | 78 +++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
diff mbox series

Patch

diff --git a/arch/sparc/include/asm/uaccess_64.h b/arch/sparc/include/asm/uaccess_64.h
index 30eb4c6414d1..b283798315b1 100644
--- a/arch/sparc/include/asm/uaccess_64.h
+++ b/arch/sparc/include/asm/uaccess_64.h
@@ -100,6 +100,42 @@  void __retl_efault(void);
 struct __large_struct { unsigned long buf[100]; };
 #define __m(x) ((struct __large_struct *)(x))
 
+#define __put_kernel_nofault(dst, src, type, label)			\
+do {									\
+	type *addr = (type __force *)(dst);				\
+	type data = *(type *)src;					\
+	register int __pu_ret;						\
+	switch (sizeof(type)) {						\
+	case 1: __put_kernel_asm(data, b, addr, __pu_ret); break;	\
+	case 2: __put_kernel_asm(data, h, addr, __pu_ret); break;	\
+	case 4: __put_kernel_asm(data, w, addr, __pu_ret); break;	\
+	case 8: __put_kernel_asm(data, x, addr, __pu_ret); break;	\
+	default: __pu_ret = __put_user_bad(); break;			\
+	}								\
+	if (__pu_ret)							\
+		goto label;						\
+} while (0)
+
+#define __put_kernel_asm(x, size, addr, ret)				\
+__asm__ __volatile__(							\
+		"/* Put kernel asm, inline. */\n"			\
+	"1:\t"	"st"#size " %1, [%2]\n\t"				\
+		"clr	%0\n"						\
+	"2:\n\n\t"							\
+		".section .fixup,#alloc,#execinstr\n\t"			\
+		".align	4\n"						\
+	"3:\n\t"							\
+		"sethi	%%hi(2b), %0\n\t"				\
+		"jmpl	%0 + %%lo(2b), %%g0\n\t"			\
+		" mov	%3, %0\n\n\t"					\
+		".previous\n\t"						\
+		".section __ex_table,\"a\"\n\t"				\
+		".align	4\n\t"						\
+		".word	1b, 3b\n\t"					\
+		".previous\n\n\t"					\
+	       : "=r" (ret) : "r" (x), "r" (__m(addr)),			\
+		 "i" (-EFAULT))
+
 #define __put_user_nocheck(data, addr, size) ({			\
 	register int __pu_ret;					\
 	switch (size) {						\
@@ -134,6 +170,48 @@  __asm__ __volatile__(							\
 
 int __put_user_bad(void);
 
+#define __get_kernel_nofault(dst, src, type, label)			     \
+do {									     \
+	type *addr = (type __force *)(src);		     		     \
+	register int __gu_ret;						     \
+	register unsigned long __gu_val;				     \
+	switch (sizeof(type)) {						     \
+		case 1: __get_kernel_asm(__gu_val, ub, addr, __gu_ret); break; \
+		case 2: __get_kernel_asm(__gu_val, uh, addr, __gu_ret); break; \
+		case 4: __get_kernel_asm(__gu_val, uw, addr, __gu_ret); break; \
+		case 8: __get_kernel_asm(__gu_val, x, addr, __gu_ret); break;  \
+		default:						     \
+			__gu_val = 0;					     \
+			__gu_ret = __get_user_bad();			     \
+			break;						     \
+	} 								     \
+	if (__gu_ret)							     \
+		goto label;						     \
+	*(type *)dst = (__force type) __gu_val;				     \
+} while (0)
+#define __get_kernel_asm(x, size, addr, ret)				\
+__asm__ __volatile__(							\
+		"/* Get kernel asm, inline. */\n"			\
+	"1:\t"	"ld"#size " [%2], %1\n\t"				\
+		"clr	%0\n"						\
+	"2:\n\n\t"							\
+		".section .fixup,#alloc,#execinstr\n\t"			\
+		".align	4\n"						\
+	"3:\n\t"							\
+		"sethi	%%hi(2b), %0\n\t"				\
+		"clr	%1\n\t"						\
+		"jmpl	%0 + %%lo(2b), %%g0\n\t"			\
+		" mov	%3, %0\n\n\t"					\
+		".previous\n\t"						\
+		".section __ex_table,\"a\"\n\t"				\
+		".align	4\n\t"						\
+		".word	1b, 3b\n\n\t"					\
+		".previous\n\t"						\
+	       : "=r" (ret), "=r" (x) : "r" (__m(addr)),		\
+		 "i" (-EFAULT))
+
+#define HAVE_GET_KERNEL_NOFAULT
+
 #define __get_user_nocheck(data, addr, size, type) ({			     \
 	register int __gu_ret;						     \
 	register unsigned long __gu_val;				     \