Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 216 insertions, 0 deletions

diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
new file mode 100644
index 000000000..a9d637bc3
--- /dev/null
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -0,0 +1,216 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_UACCESS_64_H
+#define _ASM_X86_UACCESS_64_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/compiler.h>
+#include <linux/lockdep.h>
+#include <linux/kasan-checks.h>
+#include <asm/alternative.h>
+#include <asm/cpufeatures.h>
+#include <asm/page.h>
+
+/*
+ * Copy To/From Userspace
+ */
+
+/* Handles exceptions in both to and from, but doesn't do access_ok */
+__must_check unsigned long
+copy_user_enhanced_fast_string(void *to, const void *from, unsigned len);
+__must_check unsigned long
+copy_user_generic_string(void *to, const void *from, unsigned len);
+__must_check unsigned long
+copy_user_generic_unrolled(void *to, const void *from, unsigned len);
+
+static __always_inline __must_check unsigned long
+copy_user_generic(void *to, const void *from, unsigned len)
+{
+	unsigned ret;
+
+	/*
+	 * If CPU has ERMS feature, use copy_user_enhanced_fast_string.
+	 * Otherwise, if CPU has rep_good feature, use copy_user_generic_string.
+	 * Otherwise, use copy_user_generic_unrolled.
+	 */
+	alternative_call_2(copy_user_generic_unrolled,
+			 copy_user_generic_string,
+			 X86_FEATURE_REP_GOOD,
+			 copy_user_enhanced_fast_string,
+			 X86_FEATURE_ERMS,
+			 ASM_OUTPUT2("=a" (ret), "=D" (to), "=S" (from),
+				     "=d" (len)),
+			 "1" (to), "2" (from), "3" (len)
+			 : "memory", "rcx", "r8", "r9", "r10", "r11");
+	return ret;
+}
+
+static __always_inline __must_check unsigned long
+copy_to_user_mcsafe(void *to, const void *from, unsigned len)
+{
+	unsigned long ret;
+
+	__uaccess_begin();
+	/*
+	 * Note, __memcpy_mcsafe() is explicitly used since it can
+	 * handle exceptions / faults.  memcpy_mcsafe() may fall back to
+	 * memcpy() which lacks this handling.
+	 */
+	ret = __memcpy_mcsafe(to, from, len);
+	__uaccess_end();
+	return ret;
+}
+
+static __always_inline __must_check unsigned long
+raw_copy_from_user(void *dst, const void __user *src, unsigned long size)
+{
+	int ret = 0;
+
+	if (!__builtin_constant_p(size))
+		return copy_user_generic(dst, (__force void *)src, size);
+	switch (size) {
+	case 1:
+		__uaccess_begin_nospec();
+		__get_user_asm_nozero(*(u8 *)dst, (u8 __user *)src,
+			      ret, "b", "b", "=q", 1);
+		__uaccess_end();
+		return ret;
+	case 2:
+		__uaccess_begin_nospec();
+		__get_user_asm_nozero(*(u16 *)dst, (u16 __user *)src,
+			      ret, "w", "w", "=r", 2);
+		__uaccess_end();
+		return ret;
+	case 4:
+		__uaccess_begin_nospec();
+		__get_user_asm_nozero(*(u32 *)dst, (u32 __user *)src,
+			      ret, "l", "k", "=r", 4);
+		__uaccess_end();
+		return ret;
+	case 8:
+		__uaccess_begin_nospec();
+		__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
+			      ret, "q", "", "=r", 8);
+		__uaccess_end();
+		return ret;
+	case 10:
+		__uaccess_begin_nospec();
+		__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
+			       ret, "q", "", "=r", 10);
+		if (likely(!ret))
+			__get_user_asm_nozero(*(u16 *)(8 + (char *)dst),
+				       (u16 __user *)(8 + (char __user *)src),
+				       ret, "w", "w", "=r", 2);
+		__uaccess_end();
+		return ret;
+	case 16:
+		__uaccess_begin_nospec();
+		__get_user_asm_nozero(*(u64 *)dst, (u64 __user *)src,
+			       ret, "q", "", "=r", 16);
+		if (likely(!ret))
+			__get_user_asm_nozero(*(u64 *)(8 + (char *)dst),
+				       (u64 __user *)(8 + (char __user *)src),
+				       ret, "q", "", "=r", 8);
+		__uaccess_end();
+		return ret;
+	default:
+		return copy_user_generic(dst, (__force void *)src, size);
+	}
+}
+
+static __always_inline __must_check unsigned long
+raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
+{
+	int ret = 0;
+
+	if (!__builtin_constant_p(size))
+		return copy_user_generic((__force void *)dst, src, size);
+	switch (size) {
+	case 1:
+		__uaccess_begin();
+		__put_user_asm(*(u8 *)src, (u8 __user *)dst,
+			      ret, "b", "b", "iq", 1);
+		__uaccess_end();
+		return ret;
+	case 2:
+		__uaccess_begin();
+		__put_user_asm(*(u16 *)src, (u16 __user *)dst,
+			      ret, "w", "w", "ir", 2);
+		__uaccess_end();
+		return ret;
+	case 4:
+		__uaccess_begin();
+		__put_user_asm(*(u32 *)src, (u32 __user *)dst,
+			      ret, "l", "k", "ir", 4);
+		__uaccess_end();
+		return ret;
+	case 8:
+		__uaccess_begin();
+		__put_user_asm(*(u64 *)src, (u64 __user *)dst,
+			      ret, "q", "", "er", 8);
+		__uaccess_end();
+		return ret;
+	case 10:
+		__uaccess_begin();
+		__put_user_asm(*(u64 *)src, (u64 __user *)dst,
+			       ret, "q", "", "er", 10);
+		if (likely(!ret)) {
+			asm("":::"memory");
+			__put_user_asm(4[(u16 *)src], 4 + (u16 __user *)dst,
+				       ret, "w", "w", "ir", 2);
+		}
+		__uaccess_end();
+		return ret;
+	case 16:
+		__uaccess_begin();
+		__put_user_asm(*(u64 *)src, (u64 __user *)dst,
+			       ret, "q", "", "er", 16);
+		if (likely(!ret)) {
+			asm("":::"memory");
+			__put_user_asm(1[(u64 *)src], 1 + (u64 __user *)dst,
+				       ret, "q", "", "er", 8);
+		}
+		__uaccess_end();
+		return ret;
+	default:
+		return copy_user_generic((__force void *)dst, src, size);
+	}
+}
+
+static __always_inline __must_check
+unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigned long size)
+{
+	return copy_user_generic((__force void *)dst,
+				 (__force void *)src, size);
+}
+
+extern long __copy_user_nocache(void *dst, const void __user *src,
+				unsigned size, int zerorest);
+
+extern long __copy_user_flushcache(void *dst, const void __user *src, unsigned size);
+extern void memcpy_page_flushcache(char *to, struct page *page, size_t offset,
+			   size_t len);
+
+static inline int
+__copy_from_user_inatomic_nocache(void *dst, const void __user *src,
+				  unsigned size)
+{
+	kasan_check_write(dst, size);
+	return __copy_user_nocache(dst, src, size, 0);
+}
+
+static inline int
+__copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
+{
+	kasan_check_write(dst, size);
+	return __copy_user_flushcache(dst, src, size);
+}
+
+unsigned long
+copy_user_handle_tail(char *to, char *from, unsigned len);
+
+unsigned long
+mcsafe_handle_tail(char *to, char *from, unsigned len);
+
+#endif /* _ASM_X86_UACCESS_64_H */