Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 595 insertions, 0 deletions

diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
new file mode 100644
index 000000000..d9db752c5
--- /dev/null
+++ b/arch/arm/include/asm/uaccess.h
@@ -0,0 +1,595 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  arch/arm/include/asm/uaccess.h
+ */
+#ifndef _ASMARM_UACCESS_H
+#define _ASMARM_UACCESS_H
+
+/*
+ * User space memory access functions
+ */
+#include <linux/string.h>
+#include <asm/memory.h>
+#include <asm/domain.h>
+#include <asm/unified.h>
+#include <asm/compiler.h>
+
+#include <asm/extable.h>
+
+/*
+ * These two functions allow hooking accesses to userspace to increase
+ * system integrity by ensuring that the kernel can not inadvertantly
+ * perform such accesses (eg, via list poison values) which could then
+ * be exploited for priviledge escalation.
+ */
+static __always_inline unsigned int uaccess_save_and_enable(void)
+{
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+	unsigned int old_domain = get_domain();
+
+	/* Set the current domain access to permit user accesses */
+	set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
+		   domain_val(DOMAIN_USER, DOMAIN_CLIENT));
+
+	return old_domain;
+#else
+	return 0;
+#endif
+}
+
+static __always_inline void uaccess_restore(unsigned int flags)
+{
+#ifdef CONFIG_CPU_SW_DOMAIN_PAN
+	/* Restore the user access mask */
+	set_domain(flags);
+#endif
+}
+
+/*
+ * These two are intentionally not defined anywhere - if the kernel
+ * code generates any references to them, that's a bug.
+ */
+extern int __get_user_bad(void);
+extern int __put_user_bad(void);
+
+/*
+ * Note that this is actually 0x1,0000,0000
+ */
+#define KERNEL_DS	0x00000000
+
+#ifdef CONFIG_MMU
+
+#define USER_DS		TASK_SIZE
+#define get_fs()	(current_thread_info()->addr_limit)
+
+static inline void set_fs(mm_segment_t fs)
+{
+	current_thread_info()->addr_limit = fs;
+
+	/*
+	 * Prevent a mispredicted conditional call to set_fs from forwarding
+	 * the wrong address limit to access_ok under speculation.
+	 */
+	dsb(nsh);
+	isb();
+
+	modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
+}
+
+#define uaccess_kernel()	(get_fs() == KERNEL_DS)
+
+/*
+ * We use 33-bit arithmetic here.  Success returns zero, failure returns
+ * addr_limit.  We take advantage that addr_limit will be zero for KERNEL_DS,
+ * so this will always return success in that case.
+ */
+#define __range_ok(addr, size) ({ \
+	unsigned long flag, roksum; \
+	__chk_user_ptr(addr);	\
+	__asm__(".syntax unified\n" \
+		"adds %1, %2, %3; sbcscc %1, %1, %0; movcc %0, #0" \
+		: "=&r" (flag), "=&r" (roksum) \
+		: "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
+		: "cc"); \
+	flag; })
+
+/*
+ * This is a type: either unsigned long, if the argument fits into
+ * that type, or otherwise unsigned long long.
+ */
+#define __inttype(x) \
+	__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
+
+/*
+ * Sanitise a uaccess pointer such that it becomes NULL if addr+size
+ * is above the current addr_limit.
+ */
+#define uaccess_mask_range_ptr(ptr, size)			\
+	((__typeof__(ptr))__uaccess_mask_range_ptr(ptr, size))
+static inline void __user *__uaccess_mask_range_ptr(const void __user *ptr,
+						    size_t size)
+{
+	void __user *safe_ptr = (void __user *)ptr;
+	unsigned long tmp;
+
+	asm volatile(
+	"	.syntax unified\n"
+	"	sub	%1, %3, #1\n"
+	"	subs	%1, %1, %0\n"
+	"	addhs	%1, %1, #1\n"
+	"	subshs	%1, %1, %2\n"
+	"	movlo	%0, #0\n"
+	: "+r" (safe_ptr), "=&r" (tmp)
+	: "r" (size), "r" (current_thread_info()->addr_limit)
+	: "cc");
+
+	csdb();
+	return safe_ptr;
+}
+
+/*
+ * Single-value transfer routines.  They automatically use the right
+ * size if we just have the right pointer type.  Note that the functions
+ * which read from user space (*get_*) need to take care not to leak
+ * kernel data even if the calling code is buggy and fails to check
+ * the return value.  This means zeroing out the destination variable
+ * or buffer on error.  Normally this is done out of line by the
+ * fixup code, but there are a few places where it intrudes on the
+ * main code path.  When we only write to user space, there is no
+ * problem.
+ */
+extern int __get_user_1(void *);
+extern int __get_user_2(void *);
+extern int __get_user_4(void *);
+extern int __get_user_32t_8(void *);
+extern int __get_user_8(void *);
+extern int __get_user_64t_1(void *);
+extern int __get_user_64t_2(void *);
+extern int __get_user_64t_4(void *);
+
+#define __GUP_CLOBBER_1	"lr", "cc"
+#ifdef CONFIG_CPU_USE_DOMAINS
+#define __GUP_CLOBBER_2	"ip", "lr", "cc"
+#else
+#define __GUP_CLOBBER_2 "lr", "cc"
+#endif
+#define __GUP_CLOBBER_4	"lr", "cc"
+#define __GUP_CLOBBER_32t_8 "lr", "cc"
+#define __GUP_CLOBBER_8	"lr", "cc"
+
+#define __get_user_x(__r2, __p, __e, __l, __s)				\
+	   __asm__ __volatile__ (					\
+		__asmeq("%0", "r0") __asmeq("%1", "r2")			\
+		__asmeq("%3", "r1")					\
+		"bl	__get_user_" #__s				\
+		: "=&r" (__e), "=r" (__r2)				\
+		: "0" (__p), "r" (__l)					\
+		: __GUP_CLOBBER_##__s)
+
+/* narrowing a double-word get into a single 32bit word register: */
+#ifdef __ARMEB__
+#define __get_user_x_32t(__r2, __p, __e, __l, __s)			\
+	__get_user_x(__r2, __p, __e, __l, 32t_8)
+#else
+#define __get_user_x_32t __get_user_x
+#endif
+
+/*
+ * storing result into proper least significant word of 64bit target var,
+ * different only for big endian case where 64 bit __r2 lsw is r3:
+ */
+#ifdef __ARMEB__
+#define __get_user_x_64t(__r2, __p, __e, __l, __s)		        \
+	   __asm__ __volatile__ (					\
+		__asmeq("%0", "r0") __asmeq("%1", "r2")			\
+		__asmeq("%3", "r1")					\
+		"bl	__get_user_64t_" #__s				\
+		: "=&r" (__e), "=r" (__r2)				\
+		: "0" (__p), "r" (__l)					\
+		: __GUP_CLOBBER_##__s)
+#else
+#define __get_user_x_64t __get_user_x
+#endif
+
+
+#define __get_user_check(x, p)						\
+	({								\
+		unsigned long __limit = current_thread_info()->addr_limit - 1; \
+		register typeof(*(p)) __user *__p asm("r0") = (p);	\
+		register __inttype(x) __r2 asm("r2");			\
+		register unsigned long __l asm("r1") = __limit;		\
+		register int __e asm("r0");				\
+		unsigned int __ua_flags = uaccess_save_and_enable();	\
+		int __tmp_e;						\
+		switch (sizeof(*(__p))) {				\
+		case 1:							\
+			if (sizeof((x)) >= 8)				\
+				__get_user_x_64t(__r2, __p, __e, __l, 1); \
+			else						\
+				__get_user_x(__r2, __p, __e, __l, 1);	\
+			break;						\
+		case 2:							\
+			if (sizeof((x)) >= 8)				\
+				__get_user_x_64t(__r2, __p, __e, __l, 2); \
+			else						\
+				__get_user_x(__r2, __p, __e, __l, 2);	\
+			break;						\
+		case 4:							\
+			if (sizeof((x)) >= 8)				\
+				__get_user_x_64t(__r2, __p, __e, __l, 4); \
+			else						\
+				__get_user_x(__r2, __p, __e, __l, 4);	\
+			break;						\
+		case 8:							\
+			if (sizeof((x)) < 8)				\
+				__get_user_x_32t(__r2, __p, __e, __l, 4); \
+			else						\
+				__get_user_x(__r2, __p, __e, __l, 8);	\
+			break;						\
+		default: __e = __get_user_bad(); break;			\
+		}							\
+		__tmp_e = __e;						\
+		uaccess_restore(__ua_flags);				\
+		x = (typeof(*(p))) __r2;				\
+		__tmp_e;						\
+	})
+
+#define get_user(x, p)							\
+	({								\
+		might_fault();						\
+		__get_user_check(x, p);					\
+	 })
+
+extern int __put_user_1(void *, unsigned int);
+extern int __put_user_2(void *, unsigned int);
+extern int __put_user_4(void *, unsigned int);
+extern int __put_user_8(void *, unsigned long long);
+
+#define __put_user_check(__pu_val, __ptr, __err, __s)			\
+	({								\
+		unsigned long __limit = current_thread_info()->addr_limit - 1; \
+		register typeof(__pu_val) __r2 asm("r2") = __pu_val;	\
+		register const void __user *__p asm("r0") = __ptr;	\
+		register unsigned long __l asm("r1") = __limit;		\
+		register int __e asm("r0");				\
+		__asm__ __volatile__ (					\
+			__asmeq("%0", "r0") __asmeq("%2", "r2")		\
+			__asmeq("%3", "r1")				\
+			"bl	__put_user_" #__s			\
+			: "=&r" (__e)					\
+			: "0" (__p), "r" (__r2), "r" (__l)		\
+			: "ip", "lr", "cc");				\
+		__err = __e;						\
+	})
+
+#else /* CONFIG_MMU */
+
+/*
+ * uClinux has only one addr space, so has simplified address limits.
+ */
+#define USER_DS			KERNEL_DS
+
+#define uaccess_kernel()	(true)
+#define __addr_ok(addr)		((void)(addr), 1)
+#define __range_ok(addr, size)	((void)(addr), 0)
+#define get_fs()		(KERNEL_DS)
+
+static inline void set_fs(mm_segment_t fs)
+{
+}
+
+#define get_user(x, p)	__get_user(x, p)
+#define __put_user_check __put_user_nocheck
+
+#endif /* CONFIG_MMU */
+
+#define access_ok(addr, size)	(__range_ok(addr, size) == 0)
+
+#define user_addr_max() \
+	(uaccess_kernel() ? ~0UL : get_fs())
+
+#ifdef CONFIG_CPU_SPECTRE
+/*
+ * When mitigating Spectre variant 1, it is not worth fixing the non-
+ * verifying accessors, because we need to add verification of the
+ * address space there.  Force these to use the standard get_user()
+ * version instead.
+ */
+#define __get_user(x, ptr) get_user(x, ptr)
+#else
+
+/*
+ * The "__xxx" versions of the user access functions do not verify the
+ * address space - it must have been done previously with a separate
+ * "access_ok()" call.
+ *
+ * The "xxx_error" versions set the third argument to EFAULT if an
+ * error occurs, and leave it unchanged on success.  Note that these
+ * versions are void (ie, don't return a value as such).
+ */
+#define __get_user(x, ptr)						\
+({									\
+	long __gu_err = 0;						\
+	__get_user_err((x), (ptr), __gu_err);				\
+	__gu_err;							\
+})
+
+#define __get_user_err(x, ptr, err)					\
+do {									\
+	unsigned long __gu_addr = (unsigned long)(ptr);			\
+	unsigned long __gu_val;						\
+	unsigned int __ua_flags;					\
+	__chk_user_ptr(ptr);						\
+	might_fault();							\
+	__ua_flags = uaccess_save_and_enable();				\
+	switch (sizeof(*(ptr))) {					\
+	case 1:	__get_user_asm_byte(__gu_val, __gu_addr, err);	break;	\
+	case 2:	__get_user_asm_half(__gu_val, __gu_addr, err);	break;	\
+	case 4:	__get_user_asm_word(__gu_val, __gu_addr, err);	break;	\
+	default: (__gu_val) = __get_user_bad();				\
+	}								\
+	uaccess_restore(__ua_flags);					\
+	(x) = (__typeof__(*(ptr)))__gu_val;				\
+} while (0)
+
+#define __get_user_asm(x, addr, err, instr)			\
+	__asm__ __volatile__(					\
+	"1:	" TUSER(instr) " %1, [%2], #0\n"		\
+	"2:\n"							\
+	"	.pushsection .text.fixup,\"ax\"\n"		\
+	"	.align	2\n"					\
+	"3:	mov	%0, %3\n"				\
+	"	mov	%1, #0\n"				\
+	"	b	2b\n"					\
+	"	.popsection\n"					\
+	"	.pushsection __ex_table,\"a\"\n"		\
+	"	.align	3\n"					\
+	"	.long	1b, 3b\n"				\
+	"	.popsection"					\
+	: "+r" (err), "=&r" (x)					\
+	: "r" (addr), "i" (-EFAULT)				\
+	: "cc")
+
+#define __get_user_asm_byte(x, addr, err)			\
+	__get_user_asm(x, addr, err, ldrb)
+
+#if __LINUX_ARM_ARCH__ >= 6
+
+#define __get_user_asm_half(x, addr, err)			\
+	__get_user_asm(x, addr, err, ldrh)
+
+#else
+
+#ifndef __ARMEB__
+#define __get_user_asm_half(x, __gu_addr, err)			\
+({								\
+	unsigned long __b1, __b2;				\
+	__get_user_asm_byte(__b1, __gu_addr, err);		\
+	__get_user_asm_byte(__b2, __gu_addr + 1, err);		\
+	(x) = __b1 | (__b2 << 8);				\
+})
+#else
+#define __get_user_asm_half(x, __gu_addr, err)			\
+({								\
+	unsigned long __b1, __b2;				\
+	__get_user_asm_byte(__b1, __gu_addr, err);		\
+	__get_user_asm_byte(__b2, __gu_addr + 1, err);		\
+	(x) = (__b1 << 8) | __b2;				\
+})
+#endif
+
+#endif /* __LINUX_ARM_ARCH__ >= 6 */
+
+#define __get_user_asm_word(x, addr, err)			\
+	__get_user_asm(x, addr, err, ldr)
+#endif
+
+
+#define __put_user_switch(x, ptr, __err, __fn)				\
+	do {								\
+		const __typeof__(*(ptr)) __user *__pu_ptr = (ptr);	\
+		__typeof__(*(ptr)) __pu_val = (x);			\
+		unsigned int __ua_flags;				\
+		might_fault();						\
+		__ua_flags = uaccess_save_and_enable();			\
+		switch (sizeof(*(ptr))) {				\
+		case 1: __fn(__pu_val, __pu_ptr, __err, 1); break;	\
+		case 2:	__fn(__pu_val, __pu_ptr, __err, 2); break;	\
+		case 4:	__fn(__pu_val, __pu_ptr, __err, 4); break;	\
+		case 8:	__fn(__pu_val, __pu_ptr, __err, 8); break;	\
+		default: __err = __put_user_bad(); break;		\
+		}							\
+		uaccess_restore(__ua_flags);				\
+	} while (0)
+
+#define put_user(x, ptr)						\
+({									\
+	int __pu_err = 0;						\
+	__put_user_switch((x), (ptr), __pu_err, __put_user_check);	\
+	__pu_err;							\
+})
+
+#ifdef CONFIG_CPU_SPECTRE
+/*
+ * When mitigating Spectre variant 1.1, all accessors need to include
+ * verification of the address space.
+ */
+#define __put_user(x, ptr) put_user(x, ptr)
+
+#else
+#define __put_user(x, ptr)						\
+({									\
+	long __pu_err = 0;						\
+	__put_user_switch((x), (ptr), __pu_err, __put_user_nocheck);	\
+	__pu_err;							\
+})
+
+#define __put_user_nocheck(x, __pu_ptr, __err, __size)			\
+	do {								\
+		unsigned long __pu_addr = (unsigned long)__pu_ptr;	\
+		__put_user_nocheck_##__size(x, __pu_addr, __err);	\
+	} while (0)
+
+#define __put_user_nocheck_1 __put_user_asm_byte
+#define __put_user_nocheck_2 __put_user_asm_half
+#define __put_user_nocheck_4 __put_user_asm_word
+#define __put_user_nocheck_8 __put_user_asm_dword
+
+#define __put_user_asm(x, __pu_addr, err, instr)		\
+	__asm__ __volatile__(					\
+	"1:	" TUSER(instr) " %1, [%2], #0\n"		\
+	"2:\n"							\
+	"	.pushsection .text.fixup,\"ax\"\n"		\
+	"	.align	2\n"					\
+	"3:	mov	%0, %3\n"				\
+	"	b	2b\n"					\
+	"	.popsection\n"					\
+	"	.pushsection __ex_table,\"a\"\n"		\
+	"	.align	3\n"					\
+	"	.long	1b, 3b\n"				\
+	"	.popsection"					\
+	: "+r" (err)						\
+	: "r" (x), "r" (__pu_addr), "i" (-EFAULT)		\
+	: "cc")
+
+#define __put_user_asm_byte(x, __pu_addr, err)			\
+	__put_user_asm(x, __pu_addr, err, strb)
+
+#if __LINUX_ARM_ARCH__ >= 6
+
+#define __put_user_asm_half(x, __pu_addr, err)			\
+	__put_user_asm(x, __pu_addr, err, strh)
+
+#else
+
+#ifndef __ARMEB__
+#define __put_user_asm_half(x, __pu_addr, err)			\
+({								\
+	unsigned long __temp = (__force unsigned long)(x);	\
+	__put_user_asm_byte(__temp, __pu_addr, err);		\
+	__put_user_asm_byte(__temp >> 8, __pu_addr + 1, err);	\
+})
+#else
+#define __put_user_asm_half(x, __pu_addr, err)			\
+({								\
+	unsigned long __temp = (__force unsigned long)(x);	\
+	__put_user_asm_byte(__temp >> 8, __pu_addr, err);	\
+	__put_user_asm_byte(__temp, __pu_addr + 1, err);	\
+})
+#endif
+
+#endif /* __LINUX_ARM_ARCH__ >= 6 */
+
+#define __put_user_asm_word(x, __pu_addr, err)			\
+	__put_user_asm(x, __pu_addr, err, str)
+
+#ifndef __ARMEB__
+#define	__reg_oper0	"%R2"
+#define	__reg_oper1	"%Q2"
+#else
+#define	__reg_oper0	"%Q2"
+#define	__reg_oper1	"%R2"
+#endif
+
+#define __put_user_asm_dword(x, __pu_addr, err)			\
+	__asm__ __volatile__(					\
+ ARM(	"1:	" TUSER(str) "	" __reg_oper1 ", [%1], #4\n"	) \
+ ARM(	"2:	" TUSER(str) "	" __reg_oper0 ", [%1]\n"	) \
+ THUMB(	"1:	" TUSER(str) "	" __reg_oper1 ", [%1]\n"	) \
+ THUMB(	"2:	" TUSER(str) "	" __reg_oper0 ", [%1, #4]\n"	) \
+	"3:\n"							\
+	"	.pushsection .text.fixup,\"ax\"\n"		\
+	"	.align	2\n"					\
+	"4:	mov	%0, %3\n"				\
+	"	b	3b\n"					\
+	"	.popsection\n"					\
+	"	.pushsection __ex_table,\"a\"\n"		\
+	"	.align	3\n"					\
+	"	.long	1b, 4b\n"				\
+	"	.long	2b, 4b\n"				\
+	"	.popsection"					\
+	: "+r" (err), "+r" (__pu_addr)				\
+	: "r" (x), "i" (-EFAULT)				\
+	: "cc")
+
+#endif /* !CONFIG_CPU_SPECTRE */
+
+#ifdef CONFIG_MMU
+extern unsigned long __must_check
+arm_copy_from_user(void *to, const void __user *from, unsigned long n);
+
+static inline unsigned long __must_check
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	unsigned int __ua_flags;
+
+	__ua_flags = uaccess_save_and_enable();
+	n = arm_copy_from_user(to, from, n);
+	uaccess_restore(__ua_flags);
+	return n;
+}
+
+extern unsigned long __must_check
+arm_copy_to_user(void __user *to, const void *from, unsigned long n);
+extern unsigned long __must_check
+__copy_to_user_std(void __user *to, const void *from, unsigned long n);
+
+static inline unsigned long __must_check
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+#ifndef CONFIG_UACCESS_WITH_MEMCPY
+	unsigned int __ua_flags;
+	__ua_flags = uaccess_save_and_enable();
+	n = arm_copy_to_user(to, from, n);
+	uaccess_restore(__ua_flags);
+	return n;
+#else
+	return arm_copy_to_user(to, from, n);
+#endif
+}
+
+extern unsigned long __must_check
+arm_clear_user(void __user *addr, unsigned long n);
+extern unsigned long __must_check
+__clear_user_std(void __user *addr, unsigned long n);
+
+static inline unsigned long __must_check
+__clear_user(void __user *addr, unsigned long n)
+{
+	unsigned int __ua_flags = uaccess_save_and_enable();
+	n = arm_clear_user(addr, n);
+	uaccess_restore(__ua_flags);
+	return n;
+}
+
+#else
+static inline unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+	memcpy(to, (const void __force *)from, n);
+	return 0;
+}
+static inline unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+	memcpy((void __force *)to, from, n);
+	return 0;
+}
+#define __clear_user(addr, n)		(memset((void __force *)addr, 0, n), 0)
+#endif
+#define INLINE_COPY_TO_USER
+#define INLINE_COPY_FROM_USER
+
+static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
+{
+	if (access_ok(to, n))
+		n = __clear_user(to, n);
+	return n;
+}
+
+/* These are from lib/ code, and use __get_user() and friends */
+extern long strncpy_from_user(char *dest, const char __user *src, long count);
+
+extern __must_check long strnlen_user(const char __user *str, long n);
+
+#endif /* _ASMARM_UACCESS_H */