Release 4.8 arch/arm64/include/asm/uaccess.h
/*
* Based on arch/arm/include/asm/uaccess.h
*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_UACCESS_H
#define __ASM_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/kasan-checks.h>
#include <linux/string.h>
#include <linux/thread_info.h>
#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/ptrace.h>
#include <asm/sysreg.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/compiler.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/*
* The exception table consists of pairs of relative offsets: the first
* is the relative offset to an instruction that is allowed to fault,
* and the second is the relative offset at which the program should
* continue. No registers are modified, so it is entirely up to the
* continuation code to figure out what to do.
*
* All the routines below use bits of fixup code that are out of line
* with the main instruction path. This means when everything is well,
* we don't even have to jump over them. Further, they do not intrude
* on our cache or tlb entries.
*/
struct exception_table_entry
{
int insn, fixup;
};
#define ARCH_HAS_RELATIVE_EXTABLE
extern int fixup_exception(struct pt_regs *regs);
#define KERNEL_DS (-1UL)
#define get_ds() (KERNEL_DS)
#define USER_DS TASK_SIZE_64
#define get_fs() (current_thread_info()->addr_limit)
static inline void set_fs(mm_segment_t fs)
{
current_thread_info()->addr_limit = fs;
/*
* Enable/disable UAO so that copy_to_user() etc can access
* kernel memory with the unprivileged instructions.
*/
if (IS_ENABLED(CONFIG_ARM64_UAO) && fs == KERNEL_DS)
asm(ALTERNATIVE("nop", SET_PSTATE_UAO(1), ARM64_HAS_UAO));
else
asm(ALTERNATIVE("nop", SET_PSTATE_UAO(0), ARM64_HAS_UAO,
CONFIG_ARM64_UAO));
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| catalin marinas | catalin marinas | 17 | 53.12% | 1 | 50.00% |
| james morse | james morse | 15 | 46.88% | 1 | 50.00% |
| Total | 32 | 100.00% | 2 | 100.00% |
#define segment_eq(a, b) ((a) == (b))
/*
* Test whether a block of memory is a valid user space address.
* Returns 1 if the range is valid, 0 otherwise.
*
* This is equivalent to the following test:
* (u65)addr + (u65)size <= current->addr_limit
*
* This needs 65-bit arithmetic.
*/
#define __range_ok(addr, size) \
({ \
unsigned long flag, roksum; \
__chk_user_ptr(addr); \
asm("adds %1, %1, %3; ccmp %1, %4, #2, cc; cset %0, ls" \
: "=&r" (flag), "=&r" (roksum) \
: "1" (addr), "Ir" (size), \
"r" (current_thread_info()->addr_limit) \
: "cc"); \
flag; \
})
#define access_ok(type, addr, size) __range_ok(addr, size)
#define user_addr_max get_fs
#define _ASM_EXTABLE(from, to) \
" .pushsection __ex_table, \"a\"\n" \
" .align 3\n" \
" .long (" #from " - .), (" #to " - .)\n" \
" .popsection\n"
/*
* 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.
*/
#define __get_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
asm volatile( \
"1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
alt_instr " " reg "1, [%2]\n", feature) \
"2:\n" \
" .section .fixup, \"ax\"\n" \
" .align 2\n" \
"3: mov %w0, %3\n" \
" mov %1, #0\n" \
" b 2b\n" \
" .previous\n" \
_ASM_EXTABLE(1b, 3b) \
: "+r" (err), "=&r" (x) \
: "r" (addr), "i" (-EFAULT))
#define __get_user_err(x, ptr, err) \
do { \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\
CONFIG_ARM64_PAN)); \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
case 2: \
__get_user_asm("ldrh", "ldtrh", "%w", __gu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
case 4: \
__get_user_asm("ldr", "ldtr", "%w", __gu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
case 8: \
__get_user_asm("ldr", "ldtr", "%", __gu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
default: \
BUILD_BUG(); \
} \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\
CONFIG_ARM64_PAN)); \
} while (0)
#define __get_user(x, ptr) \
({ \
int __gu_err = 0; \
__get_user_err((x), (ptr), __gu_err); \
__gu_err; \
})
#define __get_user_error(x, ptr, err) \
({ \
__get_user_err((x), (ptr), (err)); \
(void)0; \
})
#define __get_user_unaligned __get_user
#define get_user(x, ptr) \
({ \
__typeof__(*(ptr)) __user *__p = (ptr); \
might_fault(); \
access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \
__get_user((x), __p) : \
((x) = 0, -EFAULT); \
})
#define __put_user_asm(instr, alt_instr, reg, x, addr, err, feature) \
asm volatile( \
"1:"ALTERNATIVE(instr " " reg "1, [%2]\n", \
alt_instr " " reg "1, [%2]\n", feature) \
"2:\n" \
" .section .fixup,\"ax\"\n" \
" .align 2\n" \
"3: mov %w0, %3\n" \
" b 2b\n" \
" .previous\n" \
_ASM_EXTABLE(1b, 3b) \
: "+r" (err) \
: "r" (x), "r" (addr), "i" (-EFAULT))
#define __put_user_err(x, ptr, err) \
do { \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\
CONFIG_ARM64_PAN)); \
switch (sizeof(*(ptr))) { \
case 1: \
__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
case 2: \
__put_user_asm("strh", "sttrh", "%w", __pu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
case 4: \
__put_user_asm("str", "sttr", "%w", __pu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
case 8: \
__put_user_asm("str", "sttr", "%", __pu_val, (ptr), \
(err), ARM64_HAS_UAO); \
break; \
default: \
BUILD_BUG(); \
} \
asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\
CONFIG_ARM64_PAN)); \
} while (0)
#define __put_user(x, ptr) \
({ \
int __pu_err = 0; \
__put_user_err((x), (ptr), __pu_err); \
__pu_err; \
})
#define __put_user_error(x, ptr, err) \
({ \
__put_user_err((x), (ptr), (err)); \
(void)0; \
})
#define __put_user_unaligned __put_user
#define put_user(x, ptr) \
({ \
__typeof__(*(ptr)) __user *__p = (ptr); \
might_fault(); \
access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \
__put_user((x), __p) : \
-EFAULT; \
})
extern unsigned long __must_check __arch_copy_from_user(void *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __arch_copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check __copy_in_user(void __user *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __clear_user(void __user *addr, unsigned long n);
static inline unsigned long __must_check __copy_from_user(void *to, const void __user *from, unsigned long n)
{
kasan_check_write(to, n);
check_object_size(to, n, false);
return __arch_copy_from_user(to, from, n);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| yang shi | yang shi | 40 | 81.63% | 1 | 50.00% |
| kees cook | kees cook | 9 | 18.37% | 1 | 50.00% |
| Total | 49 | 100.00% | 2 | 100.00% |
static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n)
{
kasan_check_read(from, n);
check_object_size(from, n, true);
return __arch_copy_to_user(to, from, n);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| yang shi | yang shi | 40 | 81.63% | 1 | 50.00% |
| kees cook | kees cook | 9 | 18.37% | 1 | 50.00% |
| Total | 49 | 100.00% | 2 | 100.00% |
static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
{
kasan_check_write(to, n);
if (access_ok(VERIFY_READ, from, n)) {
check_object_size(to, n, false);
n = __arch_copy_from_user(to, from, n);
} else /* security hole - plug it */
memset(to, 0, n);
return n;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| catalin marinas | catalin marinas | 58 | 75.32% | 1 | 33.33% |
| kees cook | kees cook | 11 | 14.29% | 1 | 33.33% |
| yang shi | yang shi | 8 | 10.39% | 1 | 33.33% |
| Total | 77 | 100.00% | 3 | 100.00% |
static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
{
kasan_check_read(from, n);
if (access_ok(VERIFY_WRITE, to, n)) {
check_object_size(from, n, true);
n = __arch_copy_to_user(to, from, n);
}
return n;
}
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| Person | Tokens | Prop | Commits | CommitProp |
| catalin marinas | catalin marinas | 47 | 71.21% | 1 | 33.33% |
| kees cook | kees cook | 11 | 16.67% | 1 | 33.33% |
| yang shi | yang shi | 8 | 12.12% | 1 | 33.33% |
| Total | 66 | 100.00% | 3 | 100.00% |
static inline unsigned long __must_check copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
if (access_ok(VERIFY_READ, from, n) && access_ok(VERIFY_WRITE, to, n))
n = __copy_in_user(to, from, n);
return n;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| catalin marinas | catalin marinas | 58 | 100.00% | 1 | 100.00% |
| Total | 58 | 100.00% | 1 | 100.00% |
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user
static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
{
if (access_ok(VERIFY_WRITE, to, n))
n = __clear_user(to, n);
return n;
}
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| Person | Tokens | Prop | Commits | CommitProp |
| catalin marinas | catalin marinas | 41 | 100.00% | 1 | 100.00% |
| Total | 41 | 100.00% | 1 | 100.00% |
extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);
#endif /* __ASM_UACCESS_H */
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| Person | Tokens | Prop | Commits | CommitProp |
| catalin marinas | catalin marinas | 563 | 72.37% | 1 | 10.00% |
| yang shi | yang shi | 101 | 12.98% | 1 | 10.00% |
| kees cook | kees cook | 40 | 5.14% | 1 | 10.00% |
| james morse | james morse | 34 | 4.37% | 3 | 30.00% |
| will deacon | will deacon | 19 | 2.44% | 1 | 10.00% |
| ard biesheuvel | ard biesheuvel | 17 | 2.19% | 1 | 10.00% |
| akashi takahiro | akashi takahiro | 2 | 0.26% | 1 | 10.00% |
| christopher covington | christopher covington | 2 | 0.26% | 1 | 10.00% |
| Total | 778 | 100.00% | 10 | 100.00% |
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