bb4878b39d
commit 8926d88ced46700bf6117ceaf391480b943ea9f4 upstream.
The get_user()/put_user() functions are meant to check for
access_ok(), while the __get_user()/__put_user() functions
don't.
This broke in 4.19 for nds32, when it gained an extraneous
check in __get_user(), but lost the check it needs in
__put_user().
Fixes: 487913ab18 ("nds32: Extract the checking and getting pointer to a macro")
Cc: stable@vger.kernel.org @ v4.19+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
301 lines
8.2 KiB
C
301 lines
8.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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// Copyright (C) 2005-2017 Andes Technology Corporation
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#ifndef _ASMANDES_UACCESS_H
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#define _ASMANDES_UACCESS_H
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/*
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* User space memory access functions
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*/
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#include <linux/sched.h>
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#include <asm/errno.h>
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#include <asm/memory.h>
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#include <asm/types.h>
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#include <linux/mm.h>
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#define __asmeq(x, y) ".ifnc " x "," y " ; .err ; .endif\n\t"
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/*
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* The exception table consists of pairs of addresses: the first is the
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* address of an instruction that is allowed to fault, and the second is
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* the address at which the program should continue. No registers are
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* modified, so it is entirely up to the continuation code to figure out
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* what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry {
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unsigned long insn, fixup;
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};
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extern int fixup_exception(struct pt_regs *regs);
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#define KERNEL_DS ((mm_segment_t) { ~0UL })
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#define USER_DS ((mm_segment_t) {TASK_SIZE - 1})
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#define get_fs() (current_thread_info()->addr_limit)
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#define user_addr_max get_fs
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static inline void set_fs(mm_segment_t fs)
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{
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current_thread_info()->addr_limit = fs;
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}
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#define segment_eq(a, b) ((a) == (b))
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#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs() -size))
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#define access_ok(addr, size) \
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__range_ok((unsigned long)addr, (unsigned long)size)
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/*
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* Single-value transfer routines. They automatically use the right
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* size if we just have the right pointer type. Note that the functions
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* which read from user space (*get_*) need to take care not to leak
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* kernel data even if the calling code is buggy and fails to check
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* the return value. This means zeroing out the destination variable
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* or buffer on error. Normally this is done out of line by the
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* fixup code, but there are a few places where it intrudes on the
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* main code path. When we only write to user space, there is no
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* problem.
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*
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* The "__xxx" versions of the user access functions do not verify the
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* address space - it must have been done previously with a separate
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* "access_ok()" call.
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*
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* The "xxx_error" versions set the third argument to EFAULT if an
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* error occurs, and leave it unchanged on success. Note that these
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* versions are void (ie, don't return a value as such).
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*/
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#define get_user(x, ptr) \
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({ \
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long __gu_err = 0; \
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__get_user_check((x), (ptr), __gu_err); \
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__gu_err; \
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})
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#define __get_user_error(x, ptr, err) \
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({ \
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__get_user_check((x), (ptr), (err)); \
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(void)0; \
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})
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#define __get_user(x, ptr) \
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({ \
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long __gu_err = 0; \
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const __typeof__(*(ptr)) __user *__p = (ptr); \
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__get_user_err((x), __p, (__gu_err)); \
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__gu_err; \
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})
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#define __get_user_check(x, ptr, err) \
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({ \
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const __typeof__(*(ptr)) __user *__p = (ptr); \
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might_fault(); \
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if (access_ok(__p, sizeof(*__p))) { \
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__get_user_err((x), __p, (err)); \
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} else { \
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(x) = 0; (err) = -EFAULT; \
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} \
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})
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#define __get_user_err(x, ptr, err) \
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do { \
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unsigned long __gu_val; \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__get_user_asm("lbi", __gu_val, (ptr), (err)); \
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break; \
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case 2: \
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__get_user_asm("lhi", __gu_val, (ptr), (err)); \
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break; \
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case 4: \
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__get_user_asm("lwi", __gu_val, (ptr), (err)); \
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break; \
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case 8: \
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__get_user_asm_dword(__gu_val, (ptr), (err)); \
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break; \
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default: \
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BUILD_BUG(); \
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break; \
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} \
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(x) = (__force __typeof__(*(ptr)))__gu_val; \
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} while (0)
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#define __get_user_asm(inst, x, addr, err) \
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__asm__ __volatile__ ( \
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"1: "inst" %1,[%2]\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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" .align 2\n" \
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"3: move %0, %3\n" \
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" move %1, #0\n" \
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" b 2b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 3b\n" \
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" .previous" \
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: "+r" (err), "=&r" (x) \
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: "r" (addr), "i" (-EFAULT) \
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: "cc")
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#ifdef __NDS32_EB__
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#define __gu_reg_oper0 "%H1"
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#define __gu_reg_oper1 "%L1"
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#else
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#define __gu_reg_oper0 "%L1"
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#define __gu_reg_oper1 "%H1"
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#endif
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#define __get_user_asm_dword(x, addr, err) \
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__asm__ __volatile__ ( \
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"\n1:\tlwi " __gu_reg_oper0 ",[%2]\n" \
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"\n2:\tlwi " __gu_reg_oper1 ",[%2+4]\n" \
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"3:\n" \
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" .section .fixup,\"ax\"\n" \
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" .align 2\n" \
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"4: move %0, %3\n" \
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" b 3b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 4b\n" \
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" .long 2b, 4b\n" \
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" .previous" \
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: "+r"(err), "=&r"(x) \
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: "r"(addr), "i"(-EFAULT) \
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: "cc")
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#define put_user(x, ptr) \
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({ \
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long __pu_err = 0; \
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__put_user_check((x), (ptr), __pu_err); \
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__pu_err; \
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})
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#define __put_user(x, ptr) \
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({ \
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long __pu_err = 0; \
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__typeof__(*(ptr)) __user *__p = (ptr); \
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__put_user_err((x), __p, __pu_err); \
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__pu_err; \
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})
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#define __put_user_error(x, ptr, err) \
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({ \
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__put_user_err((x), (ptr), (err)); \
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(void)0; \
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})
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#define __put_user_check(x, ptr, err) \
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({ \
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__typeof__(*(ptr)) __user *__p = (ptr); \
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might_fault(); \
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if (access_ok(__p, sizeof(*__p))) { \
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__put_user_err((x), __p, (err)); \
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} else { \
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(err) = -EFAULT; \
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} \
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})
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#define __put_user_err(x, ptr, err) \
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do { \
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__typeof__(*(ptr)) __pu_val = (x); \
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__chk_user_ptr(ptr); \
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switch (sizeof(*(ptr))) { \
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case 1: \
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__put_user_asm("sbi", __pu_val, (ptr), (err)); \
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break; \
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case 2: \
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__put_user_asm("shi", __pu_val, (ptr), (err)); \
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break; \
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case 4: \
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__put_user_asm("swi", __pu_val, (ptr), (err)); \
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break; \
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case 8: \
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__put_user_asm_dword(__pu_val, (ptr), (err)); \
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break; \
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default: \
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BUILD_BUG(); \
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break; \
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} \
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} while (0)
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#define __put_user_asm(inst, x, addr, err) \
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__asm__ __volatile__ ( \
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"1: "inst" %1,[%2]\n" \
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"2:\n" \
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" .section .fixup,\"ax\"\n" \
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" .align 2\n" \
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"3: move %0, %3\n" \
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" b 2b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 3b\n" \
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" .previous" \
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: "+r" (err) \
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: "r" (x), "r" (addr), "i" (-EFAULT) \
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: "cc")
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#ifdef __NDS32_EB__
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#define __pu_reg_oper0 "%H2"
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#define __pu_reg_oper1 "%L2"
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#else
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#define __pu_reg_oper0 "%L2"
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#define __pu_reg_oper1 "%H2"
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#endif
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#define __put_user_asm_dword(x, addr, err) \
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__asm__ __volatile__ ( \
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"\n1:\tswi " __pu_reg_oper0 ",[%1]\n" \
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"\n2:\tswi " __pu_reg_oper1 ",[%1+4]\n" \
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"3:\n" \
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" .section .fixup,\"ax\"\n" \
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" .align 2\n" \
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"4: move %0, %3\n" \
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" b 3b\n" \
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" .previous\n" \
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" .section __ex_table,\"a\"\n" \
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" .align 3\n" \
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" .long 1b, 4b\n" \
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" .long 2b, 4b\n" \
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" .previous" \
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: "+r"(err) \
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: "r"(addr), "r"(x), "i"(-EFAULT) \
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: "cc")
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extern unsigned long __arch_clear_user(void __user * addr, unsigned long n);
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extern long strncpy_from_user(char *dest, const char __user * src, long count);
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extern __must_check long strlen_user(const char __user * str);
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extern __must_check long strnlen_user(const char __user * str, long n);
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extern unsigned long __arch_copy_from_user(void *to, const void __user * from,
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unsigned long n);
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extern unsigned long __arch_copy_to_user(void __user * to, const void *from,
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unsigned long n);
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#define raw_copy_from_user __arch_copy_from_user
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#define raw_copy_to_user __arch_copy_to_user
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#define INLINE_COPY_FROM_USER
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#define INLINE_COPY_TO_USER
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static inline unsigned long clear_user(void __user * to, unsigned long n)
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{
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if (access_ok(to, n))
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n = __arch_clear_user(to, n);
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return n;
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}
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static inline unsigned long __clear_user(void __user * to, unsigned long n)
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{
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return __arch_clear_user(to, n);
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}
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#endif /* _ASMNDS32_UACCESS_H */
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