mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-27 13:55:23 +07:00
c512c69187
In commit9f79b78ef7("Convert filldir[64]() from __put_user() to unsafe_put_user()") I made filldir() use unsafe_put_user(), which improves code generation on x86 enormously. But because we didn't have a "unsafe_copy_to_user()", the dirent name copy was also done by hand with unsafe_put_user() in a loop, and it turns out that a lot of other architectures didn't like that, because unlike x86, they have various alignment issues. Most non-x86 architectures trap and fix it up, and some (like xtensa) will just fail unaligned put_user() accesses unconditionally. Which makes that "copy using put_user() in a loop" not work for them at all. I could make that code do explicit alignment etc, but the architectures that don't like unaligned accesses also don't really use the fancy "user_access_begin/end()" model, so they might just use the regular old __copy_to_user() interface. So this commit takes that looping implementation, turns it into the x86 version of "unsafe_copy_to_user()", and makes other architectures implement the unsafe copy version as __copy_to_user() (the same way they do for the other unsafe_xyz() accessor functions). Note that it only does this for the copying _to_ user space, and we still don't have a unsafe version of copy_from_user(). That's partly because we have no current users of it, but also partly because the copy_from_user() case is slightly different and cannot efficiently be implemented in terms of a unsafe_get_user() loop (because gcc can't do asm goto with outputs). It would be trivial to do this using "rep movsb", which would work really nicely on newer x86 cores, but really badly on some older ones. Al Viro is looking at cleaning up all our user copy routines to make this all a non-issue, but for now we have this simple-but-stupid version for x86 that works fine for the dirent name copy case because those names are short strings and we simply don't need anything fancier. Fixes:9f79b78ef7("Convert filldir[64]() from __put_user() to unsafe_put_user()") Reported-by: Guenter Roeck <linux@roeck-us.net> Reported-and-tested-by: Tony Luck <tony.luck@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
762 lines
22 KiB
C
762 lines
22 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_X86_UACCESS_H
|
|
#define _ASM_X86_UACCESS_H
|
|
/*
|
|
* User space memory access functions
|
|
*/
|
|
#include <linux/compiler.h>
|
|
#include <linux/kasan-checks.h>
|
|
#include <linux/string.h>
|
|
#include <asm/asm.h>
|
|
#include <asm/page.h>
|
|
#include <asm/smap.h>
|
|
#include <asm/extable.h>
|
|
|
|
/*
|
|
* The fs value determines whether argument validity checking should be
|
|
* performed or not. If get_fs() == USER_DS, checking is performed, with
|
|
* get_fs() == KERNEL_DS, checking is bypassed.
|
|
*
|
|
* For historical reasons, these macros are grossly misnamed.
|
|
*/
|
|
|
|
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
|
|
|
|
#define KERNEL_DS MAKE_MM_SEG(-1UL)
|
|
#define USER_DS MAKE_MM_SEG(TASK_SIZE_MAX)
|
|
|
|
#define get_fs() (current->thread.addr_limit)
|
|
static inline void set_fs(mm_segment_t fs)
|
|
{
|
|
current->thread.addr_limit = fs;
|
|
/* On user-mode return, check fs is correct */
|
|
set_thread_flag(TIF_FSCHECK);
|
|
}
|
|
|
|
#define segment_eq(a, b) ((a).seg == (b).seg)
|
|
#define user_addr_max() (current->thread.addr_limit.seg)
|
|
|
|
/*
|
|
* Test whether a block of memory is a valid user space address.
|
|
* Returns 0 if the range is valid, nonzero otherwise.
|
|
*/
|
|
static inline bool __chk_range_not_ok(unsigned long addr, unsigned long size, unsigned long limit)
|
|
{
|
|
/*
|
|
* If we have used "sizeof()" for the size,
|
|
* we know it won't overflow the limit (but
|
|
* it might overflow the 'addr', so it's
|
|
* important to subtract the size from the
|
|
* limit, not add it to the address).
|
|
*/
|
|
if (__builtin_constant_p(size))
|
|
return unlikely(addr > limit - size);
|
|
|
|
/* Arbitrary sizes? Be careful about overflow */
|
|
addr += size;
|
|
if (unlikely(addr < size))
|
|
return true;
|
|
return unlikely(addr > limit);
|
|
}
|
|
|
|
#define __range_not_ok(addr, size, limit) \
|
|
({ \
|
|
__chk_user_ptr(addr); \
|
|
__chk_range_not_ok((unsigned long __force)(addr), size, limit); \
|
|
})
|
|
|
|
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
|
|
static inline bool pagefault_disabled(void);
|
|
# define WARN_ON_IN_IRQ() \
|
|
WARN_ON_ONCE(!in_task() && !pagefault_disabled())
|
|
#else
|
|
# define WARN_ON_IN_IRQ()
|
|
#endif
|
|
|
|
/**
|
|
* access_ok - Checks if a user space pointer is valid
|
|
* @addr: User space pointer to start of block to check
|
|
* @size: Size of block to check
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* Checks if a pointer to a block of memory in user space is valid.
|
|
*
|
|
* Note that, depending on architecture, this function probably just
|
|
* checks that the pointer is in the user space range - after calling
|
|
* this function, memory access functions may still return -EFAULT.
|
|
*
|
|
* Return: true (nonzero) if the memory block may be valid, false (zero)
|
|
* if it is definitely invalid.
|
|
*/
|
|
#define access_ok(addr, size) \
|
|
({ \
|
|
WARN_ON_IN_IRQ(); \
|
|
likely(!__range_not_ok(addr, size, user_addr_max())); \
|
|
})
|
|
|
|
/*
|
|
* These are the main single-value transfer routines. They automatically
|
|
* use the right size if we just have the right pointer type.
|
|
*
|
|
* This gets kind of ugly. We want to return _two_ values in "get_user()"
|
|
* and yet we don't want to do any pointers, because that is too much
|
|
* of a performance impact. Thus we have a few rather ugly macros here,
|
|
* and hide all the ugliness from the user.
|
|
*
|
|
* The "__xxx" versions of the user access functions are versions that
|
|
* do not verify the address space, that must have been done previously
|
|
* with a separate "access_ok()" call (this is used when we do multiple
|
|
* accesses to the same area of user memory).
|
|
*/
|
|
|
|
extern int __get_user_1(void);
|
|
extern int __get_user_2(void);
|
|
extern int __get_user_4(void);
|
|
extern int __get_user_8(void);
|
|
extern int __get_user_bad(void);
|
|
|
|
#define __uaccess_begin() stac()
|
|
#define __uaccess_end() clac()
|
|
#define __uaccess_begin_nospec() \
|
|
({ \
|
|
stac(); \
|
|
barrier_nospec(); \
|
|
})
|
|
|
|
/*
|
|
* 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))
|
|
|
|
/**
|
|
* get_user - Get a simple variable from user space.
|
|
* @x: Variable to store result.
|
|
* @ptr: Source address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple variable from user space to kernel
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and the result of
|
|
* dereferencing @ptr must be assignable to @x without a cast.
|
|
*
|
|
* Return: zero on success, or -EFAULT on error.
|
|
* On error, the variable @x is set to zero.
|
|
*/
|
|
/*
|
|
* Careful: we have to cast the result to the type of the pointer
|
|
* for sign reasons.
|
|
*
|
|
* The use of _ASM_DX as the register specifier is a bit of a
|
|
* simplification, as gcc only cares about it as the starting point
|
|
* and not size: for a 64-bit value it will use %ecx:%edx on 32 bits
|
|
* (%ecx being the next register in gcc's x86 register sequence), and
|
|
* %rdx on 64 bits.
|
|
*
|
|
* Clang/LLVM cares about the size of the register, but still wants
|
|
* the base register for something that ends up being a pair.
|
|
*/
|
|
#define get_user(x, ptr) \
|
|
({ \
|
|
int __ret_gu; \
|
|
register __inttype(*(ptr)) __val_gu asm("%"_ASM_DX); \
|
|
__chk_user_ptr(ptr); \
|
|
might_fault(); \
|
|
asm volatile("call __get_user_%P4" \
|
|
: "=a" (__ret_gu), "=r" (__val_gu), \
|
|
ASM_CALL_CONSTRAINT \
|
|
: "0" (ptr), "i" (sizeof(*(ptr)))); \
|
|
(x) = (__force __typeof__(*(ptr))) __val_gu; \
|
|
__builtin_expect(__ret_gu, 0); \
|
|
})
|
|
|
|
#define __put_user_x(size, x, ptr, __ret_pu) \
|
|
asm volatile("call __put_user_" #size : "=a" (__ret_pu) \
|
|
: "0" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
|
|
|
|
|
|
|
|
#ifdef CONFIG_X86_32
|
|
#define __put_user_goto_u64(x, addr, label) \
|
|
asm_volatile_goto("\n" \
|
|
"1: movl %%eax,0(%1)\n" \
|
|
"2: movl %%edx,4(%1)\n" \
|
|
_ASM_EXTABLE_UA(1b, %l2) \
|
|
_ASM_EXTABLE_UA(2b, %l2) \
|
|
: : "A" (x), "r" (addr) \
|
|
: : label)
|
|
|
|
#define __put_user_asm_ex_u64(x, addr) \
|
|
asm volatile("\n" \
|
|
"1: movl %%eax,0(%1)\n" \
|
|
"2: movl %%edx,4(%1)\n" \
|
|
"3:" \
|
|
_ASM_EXTABLE_EX(1b, 2b) \
|
|
_ASM_EXTABLE_EX(2b, 3b) \
|
|
: : "A" (x), "r" (addr))
|
|
|
|
#define __put_user_x8(x, ptr, __ret_pu) \
|
|
asm volatile("call __put_user_8" : "=a" (__ret_pu) \
|
|
: "A" ((typeof(*(ptr)))(x)), "c" (ptr) : "ebx")
|
|
#else
|
|
#define __put_user_goto_u64(x, ptr, label) \
|
|
__put_user_goto(x, ptr, "q", "", "er", label)
|
|
#define __put_user_asm_ex_u64(x, addr) \
|
|
__put_user_asm_ex(x, addr, "q", "", "er")
|
|
#define __put_user_x8(x, ptr, __ret_pu) __put_user_x(8, x, ptr, __ret_pu)
|
|
#endif
|
|
|
|
extern void __put_user_bad(void);
|
|
|
|
/*
|
|
* Strange magic calling convention: pointer in %ecx,
|
|
* value in %eax(:%edx), return value in %eax. clobbers %rbx
|
|
*/
|
|
extern void __put_user_1(void);
|
|
extern void __put_user_2(void);
|
|
extern void __put_user_4(void);
|
|
extern void __put_user_8(void);
|
|
|
|
/**
|
|
* put_user - Write a simple value into user space.
|
|
* @x: Value to copy to user space.
|
|
* @ptr: Destination address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple value from kernel space to user
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
|
|
* to the result of dereferencing @ptr.
|
|
*
|
|
* Return: zero on success, or -EFAULT on error.
|
|
*/
|
|
#define put_user(x, ptr) \
|
|
({ \
|
|
int __ret_pu; \
|
|
__typeof__(*(ptr)) __pu_val; \
|
|
__chk_user_ptr(ptr); \
|
|
might_fault(); \
|
|
__pu_val = x; \
|
|
switch (sizeof(*(ptr))) { \
|
|
case 1: \
|
|
__put_user_x(1, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_x(2, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_x(4, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
case 8: \
|
|
__put_user_x8(__pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
default: \
|
|
__put_user_x(X, __pu_val, ptr, __ret_pu); \
|
|
break; \
|
|
} \
|
|
__builtin_expect(__ret_pu, 0); \
|
|
})
|
|
|
|
#define __put_user_size(x, ptr, size, label) \
|
|
do { \
|
|
__chk_user_ptr(ptr); \
|
|
switch (size) { \
|
|
case 1: \
|
|
__put_user_goto(x, ptr, "b", "b", "iq", label); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_goto(x, ptr, "w", "w", "ir", label); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_goto(x, ptr, "l", "k", "ir", label); \
|
|
break; \
|
|
case 8: \
|
|
__put_user_goto_u64(x, ptr, label); \
|
|
break; \
|
|
default: \
|
|
__put_user_bad(); \
|
|
} \
|
|
} while (0)
|
|
|
|
/*
|
|
* This doesn't do __uaccess_begin/end - the exception handling
|
|
* around it must do that.
|
|
*/
|
|
#define __put_user_size_ex(x, ptr, size) \
|
|
do { \
|
|
__chk_user_ptr(ptr); \
|
|
switch (size) { \
|
|
case 1: \
|
|
__put_user_asm_ex(x, ptr, "b", "b", "iq"); \
|
|
break; \
|
|
case 2: \
|
|
__put_user_asm_ex(x, ptr, "w", "w", "ir"); \
|
|
break; \
|
|
case 4: \
|
|
__put_user_asm_ex(x, ptr, "l", "k", "ir"); \
|
|
break; \
|
|
case 8: \
|
|
__put_user_asm_ex_u64((__typeof__(*ptr))(x), ptr); \
|
|
break; \
|
|
default: \
|
|
__put_user_bad(); \
|
|
} \
|
|
} while (0)
|
|
|
|
#ifdef CONFIG_X86_32
|
|
#define __get_user_asm_u64(x, ptr, retval, errret) \
|
|
({ \
|
|
__typeof__(ptr) __ptr = (ptr); \
|
|
asm volatile("\n" \
|
|
"1: movl %2,%%eax\n" \
|
|
"2: movl %3,%%edx\n" \
|
|
"3:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"4: mov %4,%0\n" \
|
|
" xorl %%eax,%%eax\n" \
|
|
" xorl %%edx,%%edx\n" \
|
|
" jmp 3b\n" \
|
|
".previous\n" \
|
|
_ASM_EXTABLE_UA(1b, 4b) \
|
|
_ASM_EXTABLE_UA(2b, 4b) \
|
|
: "=r" (retval), "=&A"(x) \
|
|
: "m" (__m(__ptr)), "m" __m(((u32 __user *)(__ptr)) + 1), \
|
|
"i" (errret), "0" (retval)); \
|
|
})
|
|
|
|
#define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad()
|
|
#else
|
|
#define __get_user_asm_u64(x, ptr, retval, errret) \
|
|
__get_user_asm(x, ptr, retval, "q", "", "=r", errret)
|
|
#define __get_user_asm_ex_u64(x, ptr) \
|
|
__get_user_asm_ex(x, ptr, "q", "", "=r")
|
|
#endif
|
|
|
|
#define __get_user_size(x, ptr, size, retval, errret) \
|
|
do { \
|
|
retval = 0; \
|
|
__chk_user_ptr(ptr); \
|
|
switch (size) { \
|
|
case 1: \
|
|
__get_user_asm(x, ptr, retval, "b", "b", "=q", errret); \
|
|
break; \
|
|
case 2: \
|
|
__get_user_asm(x, ptr, retval, "w", "w", "=r", errret); \
|
|
break; \
|
|
case 4: \
|
|
__get_user_asm(x, ptr, retval, "l", "k", "=r", errret); \
|
|
break; \
|
|
case 8: \
|
|
__get_user_asm_u64(x, ptr, retval, errret); \
|
|
break; \
|
|
default: \
|
|
(x) = __get_user_bad(); \
|
|
} \
|
|
} while (0)
|
|
|
|
#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \
|
|
asm volatile("\n" \
|
|
"1: mov"itype" %2,%"rtype"1\n" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3: mov %3,%0\n" \
|
|
" xor"itype" %"rtype"1,%"rtype"1\n" \
|
|
" jmp 2b\n" \
|
|
".previous\n" \
|
|
_ASM_EXTABLE_UA(1b, 3b) \
|
|
: "=r" (err), ltype(x) \
|
|
: "m" (__m(addr)), "i" (errret), "0" (err))
|
|
|
|
#define __get_user_asm_nozero(x, addr, err, itype, rtype, ltype, errret) \
|
|
asm volatile("\n" \
|
|
"1: mov"itype" %2,%"rtype"1\n" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3: mov %3,%0\n" \
|
|
" jmp 2b\n" \
|
|
".previous\n" \
|
|
_ASM_EXTABLE_UA(1b, 3b) \
|
|
: "=r" (err), ltype(x) \
|
|
: "m" (__m(addr)), "i" (errret), "0" (err))
|
|
|
|
/*
|
|
* This doesn't do __uaccess_begin/end - the exception handling
|
|
* around it must do that.
|
|
*/
|
|
#define __get_user_size_ex(x, ptr, size) \
|
|
do { \
|
|
__chk_user_ptr(ptr); \
|
|
switch (size) { \
|
|
case 1: \
|
|
__get_user_asm_ex(x, ptr, "b", "b", "=q"); \
|
|
break; \
|
|
case 2: \
|
|
__get_user_asm_ex(x, ptr, "w", "w", "=r"); \
|
|
break; \
|
|
case 4: \
|
|
__get_user_asm_ex(x, ptr, "l", "k", "=r"); \
|
|
break; \
|
|
case 8: \
|
|
__get_user_asm_ex_u64(x, ptr); \
|
|
break; \
|
|
default: \
|
|
(x) = __get_user_bad(); \
|
|
} \
|
|
} while (0)
|
|
|
|
#define __get_user_asm_ex(x, addr, itype, rtype, ltype) \
|
|
asm volatile("1: mov"itype" %1,%"rtype"0\n" \
|
|
"2:\n" \
|
|
".section .fixup,\"ax\"\n" \
|
|
"3:xor"itype" %"rtype"0,%"rtype"0\n" \
|
|
" jmp 2b\n" \
|
|
".previous\n" \
|
|
_ASM_EXTABLE_EX(1b, 3b) \
|
|
: ltype(x) : "m" (__m(addr)))
|
|
|
|
#define __put_user_nocheck(x, ptr, size) \
|
|
({ \
|
|
__label__ __pu_label; \
|
|
int __pu_err = -EFAULT; \
|
|
__typeof__(*(ptr)) __pu_val = (x); \
|
|
__typeof__(ptr) __pu_ptr = (ptr); \
|
|
__typeof__(size) __pu_size = (size); \
|
|
__uaccess_begin(); \
|
|
__put_user_size(__pu_val, __pu_ptr, __pu_size, __pu_label); \
|
|
__pu_err = 0; \
|
|
__pu_label: \
|
|
__uaccess_end(); \
|
|
__builtin_expect(__pu_err, 0); \
|
|
})
|
|
|
|
#define __get_user_nocheck(x, ptr, size) \
|
|
({ \
|
|
int __gu_err; \
|
|
__inttype(*(ptr)) __gu_val; \
|
|
__typeof__(ptr) __gu_ptr = (ptr); \
|
|
__typeof__(size) __gu_size = (size); \
|
|
__uaccess_begin_nospec(); \
|
|
__get_user_size(__gu_val, __gu_ptr, __gu_size, __gu_err, -EFAULT); \
|
|
__uaccess_end(); \
|
|
(x) = (__force __typeof__(*(ptr)))__gu_val; \
|
|
__builtin_expect(__gu_err, 0); \
|
|
})
|
|
|
|
/* FIXME: this hack is definitely wrong -AK */
|
|
struct __large_struct { unsigned long buf[100]; };
|
|
#define __m(x) (*(struct __large_struct __user *)(x))
|
|
|
|
/*
|
|
* Tell gcc we read from memory instead of writing: this is because
|
|
* we do not write to any memory gcc knows about, so there are no
|
|
* aliasing issues.
|
|
*/
|
|
#define __put_user_goto(x, addr, itype, rtype, ltype, label) \
|
|
asm_volatile_goto("\n" \
|
|
"1: mov"itype" %"rtype"0,%1\n" \
|
|
_ASM_EXTABLE_UA(1b, %l2) \
|
|
: : ltype(x), "m" (__m(addr)) \
|
|
: : label)
|
|
|
|
#define __put_user_failed(x, addr, itype, rtype, ltype, errret) \
|
|
({ __label__ __puflab; \
|
|
int __pufret = errret; \
|
|
__put_user_goto(x,addr,itype,rtype,ltype,__puflab); \
|
|
__pufret = 0; \
|
|
__puflab: __pufret; })
|
|
|
|
#define __put_user_asm(x, addr, retval, itype, rtype, ltype, errret) do { \
|
|
retval = __put_user_failed(x, addr, itype, rtype, ltype, errret); \
|
|
} while (0)
|
|
|
|
#define __put_user_asm_ex(x, addr, itype, rtype, ltype) \
|
|
asm volatile("1: mov"itype" %"rtype"0,%1\n" \
|
|
"2:\n" \
|
|
_ASM_EXTABLE_EX(1b, 2b) \
|
|
: : ltype(x), "m" (__m(addr)))
|
|
|
|
/*
|
|
* uaccess_try and catch
|
|
*/
|
|
#define uaccess_try do { \
|
|
current->thread.uaccess_err = 0; \
|
|
__uaccess_begin(); \
|
|
barrier();
|
|
|
|
#define uaccess_try_nospec do { \
|
|
current->thread.uaccess_err = 0; \
|
|
__uaccess_begin_nospec(); \
|
|
|
|
#define uaccess_catch(err) \
|
|
__uaccess_end(); \
|
|
(err) |= (current->thread.uaccess_err ? -EFAULT : 0); \
|
|
} while (0)
|
|
|
|
/**
|
|
* __get_user - Get a simple variable from user space, with less checking.
|
|
* @x: Variable to store result.
|
|
* @ptr: Source address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple variable from user space to kernel
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and the result of
|
|
* dereferencing @ptr must be assignable to @x without a cast.
|
|
*
|
|
* Caller must check the pointer with access_ok() before calling this
|
|
* function.
|
|
*
|
|
* Return: zero on success, or -EFAULT on error.
|
|
* On error, the variable @x is set to zero.
|
|
*/
|
|
|
|
#define __get_user(x, ptr) \
|
|
__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
|
|
|
|
/**
|
|
* __put_user - Write a simple value into user space, with less checking.
|
|
* @x: Value to copy to user space.
|
|
* @ptr: Destination address, in user space.
|
|
*
|
|
* Context: User context only. This function may sleep if pagefaults are
|
|
* enabled.
|
|
*
|
|
* This macro copies a single simple value from kernel space to user
|
|
* space. It supports simple types like char and int, but not larger
|
|
* data types like structures or arrays.
|
|
*
|
|
* @ptr must have pointer-to-simple-variable type, and @x must be assignable
|
|
* to the result of dereferencing @ptr.
|
|
*
|
|
* Caller must check the pointer with access_ok() before calling this
|
|
* function.
|
|
*
|
|
* Return: zero on success, or -EFAULT on error.
|
|
*/
|
|
|
|
#define __put_user(x, ptr) \
|
|
__put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
|
|
|
|
/*
|
|
* {get|put}_user_try and catch
|
|
*
|
|
* get_user_try {
|
|
* get_user_ex(...);
|
|
* } get_user_catch(err)
|
|
*/
|
|
#define get_user_try uaccess_try_nospec
|
|
#define get_user_catch(err) uaccess_catch(err)
|
|
|
|
#define get_user_ex(x, ptr) do { \
|
|
unsigned long __gue_val; \
|
|
__get_user_size_ex((__gue_val), (ptr), (sizeof(*(ptr)))); \
|
|
(x) = (__force __typeof__(*(ptr)))__gue_val; \
|
|
} while (0)
|
|
|
|
#define put_user_try uaccess_try
|
|
#define put_user_catch(err) uaccess_catch(err)
|
|
|
|
#define put_user_ex(x, ptr) \
|
|
__put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
|
|
|
|
extern unsigned long
|
|
copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
|
|
extern __must_check long
|
|
strncpy_from_user(char *dst, const char __user *src, long count);
|
|
|
|
extern __must_check long strnlen_user(const char __user *str, long n);
|
|
|
|
unsigned long __must_check clear_user(void __user *mem, unsigned long len);
|
|
unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
|
|
|
|
extern void __cmpxchg_wrong_size(void)
|
|
__compiletime_error("Bad argument size for cmpxchg");
|
|
|
|
#define __user_atomic_cmpxchg_inatomic(uval, ptr, old, new, size) \
|
|
({ \
|
|
int __ret = 0; \
|
|
__typeof__(*(ptr)) __old = (old); \
|
|
__typeof__(*(ptr)) __new = (new); \
|
|
__uaccess_begin_nospec(); \
|
|
switch (size) { \
|
|
case 1: \
|
|
{ \
|
|
asm volatile("\n" \
|
|
"1:\t" LOCK_PREFIX "cmpxchgb %4, %2\n" \
|
|
"2:\n" \
|
|
"\t.section .fixup, \"ax\"\n" \
|
|
"3:\tmov %3, %0\n" \
|
|
"\tjmp 2b\n" \
|
|
"\t.previous\n" \
|
|
_ASM_EXTABLE_UA(1b, 3b) \
|
|
: "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
|
|
: "i" (-EFAULT), "q" (__new), "1" (__old) \
|
|
: "memory" \
|
|
); \
|
|
break; \
|
|
} \
|
|
case 2: \
|
|
{ \
|
|
asm volatile("\n" \
|
|
"1:\t" LOCK_PREFIX "cmpxchgw %4, %2\n" \
|
|
"2:\n" \
|
|
"\t.section .fixup, \"ax\"\n" \
|
|
"3:\tmov %3, %0\n" \
|
|
"\tjmp 2b\n" \
|
|
"\t.previous\n" \
|
|
_ASM_EXTABLE_UA(1b, 3b) \
|
|
: "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
|
|
: "i" (-EFAULT), "r" (__new), "1" (__old) \
|
|
: "memory" \
|
|
); \
|
|
break; \
|
|
} \
|
|
case 4: \
|
|
{ \
|
|
asm volatile("\n" \
|
|
"1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n" \
|
|
"2:\n" \
|
|
"\t.section .fixup, \"ax\"\n" \
|
|
"3:\tmov %3, %0\n" \
|
|
"\tjmp 2b\n" \
|
|
"\t.previous\n" \
|
|
_ASM_EXTABLE_UA(1b, 3b) \
|
|
: "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
|
|
: "i" (-EFAULT), "r" (__new), "1" (__old) \
|
|
: "memory" \
|
|
); \
|
|
break; \
|
|
} \
|
|
case 8: \
|
|
{ \
|
|
if (!IS_ENABLED(CONFIG_X86_64)) \
|
|
__cmpxchg_wrong_size(); \
|
|
\
|
|
asm volatile("\n" \
|
|
"1:\t" LOCK_PREFIX "cmpxchgq %4, %2\n" \
|
|
"2:\n" \
|
|
"\t.section .fixup, \"ax\"\n" \
|
|
"3:\tmov %3, %0\n" \
|
|
"\tjmp 2b\n" \
|
|
"\t.previous\n" \
|
|
_ASM_EXTABLE_UA(1b, 3b) \
|
|
: "+r" (__ret), "=a" (__old), "+m" (*(ptr)) \
|
|
: "i" (-EFAULT), "r" (__new), "1" (__old) \
|
|
: "memory" \
|
|
); \
|
|
break; \
|
|
} \
|
|
default: \
|
|
__cmpxchg_wrong_size(); \
|
|
} \
|
|
__uaccess_end(); \
|
|
*(uval) = __old; \
|
|
__ret; \
|
|
})
|
|
|
|
#define user_atomic_cmpxchg_inatomic(uval, ptr, old, new) \
|
|
({ \
|
|
access_ok((ptr), sizeof(*(ptr))) ? \
|
|
__user_atomic_cmpxchg_inatomic((uval), (ptr), \
|
|
(old), (new), sizeof(*(ptr))) : \
|
|
-EFAULT; \
|
|
})
|
|
|
|
/*
|
|
* movsl can be slow when source and dest are not both 8-byte aligned
|
|
*/
|
|
#ifdef CONFIG_X86_INTEL_USERCOPY
|
|
extern struct movsl_mask {
|
|
int mask;
|
|
} ____cacheline_aligned_in_smp movsl_mask;
|
|
#endif
|
|
|
|
#define ARCH_HAS_NOCACHE_UACCESS 1
|
|
|
|
#ifdef CONFIG_X86_32
|
|
# include <asm/uaccess_32.h>
|
|
#else
|
|
# include <asm/uaccess_64.h>
|
|
#endif
|
|
|
|
/*
|
|
* We rely on the nested NMI work to allow atomic faults from the NMI path; the
|
|
* nested NMI paths are careful to preserve CR2.
|
|
*
|
|
* Caller must use pagefault_enable/disable, or run in interrupt context,
|
|
* and also do a uaccess_ok() check
|
|
*/
|
|
#define __copy_from_user_nmi __copy_from_user_inatomic
|
|
|
|
/*
|
|
* The "unsafe" user accesses aren't really "unsafe", but the naming
|
|
* is a big fat warning: you have to not only do the access_ok()
|
|
* checking before using them, but you have to surround them with the
|
|
* user_access_begin/end() pair.
|
|
*/
|
|
static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len)
|
|
{
|
|
if (unlikely(!access_ok(ptr,len)))
|
|
return 0;
|
|
__uaccess_begin_nospec();
|
|
return 1;
|
|
}
|
|
#define user_access_begin(a,b) user_access_begin(a,b)
|
|
#define user_access_end() __uaccess_end()
|
|
|
|
#define user_access_save() smap_save()
|
|
#define user_access_restore(x) smap_restore(x)
|
|
|
|
#define unsafe_put_user(x, ptr, label) \
|
|
__put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), label)
|
|
|
|
#define unsafe_get_user(x, ptr, err_label) \
|
|
do { \
|
|
int __gu_err; \
|
|
__inttype(*(ptr)) __gu_val; \
|
|
__get_user_size(__gu_val, (ptr), sizeof(*(ptr)), __gu_err, -EFAULT); \
|
|
(x) = (__force __typeof__(*(ptr)))__gu_val; \
|
|
if (unlikely(__gu_err)) goto err_label; \
|
|
} while (0)
|
|
|
|
/*
|
|
* We want the unsafe accessors to always be inlined and use
|
|
* the error labels - thus the macro games.
|
|
*/
|
|
#define unsafe_copy_loop(dst, src, len, type, label) \
|
|
while (len >= sizeof(type)) { \
|
|
unsafe_put_user(*(type *)src,(type __user *)dst,label); \
|
|
dst += sizeof(type); \
|
|
src += sizeof(type); \
|
|
len -= sizeof(type); \
|
|
}
|
|
|
|
#define unsafe_copy_to_user(_dst,_src,_len,label) \
|
|
do { \
|
|
char __user *__ucu_dst = (_dst); \
|
|
const char *__ucu_src = (_src); \
|
|
size_t __ucu_len = (_len); \
|
|
unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u64, label); \
|
|
unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u32, label); \
|
|
unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u16, label); \
|
|
unsafe_copy_loop(__ucu_dst, __ucu_src, __ucu_len, u8, label); \
|
|
} while (0)
|
|
|
|
#endif /* _ASM_X86_UACCESS_H */
|
|
|