2020-02-03 09:25:40 +00:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2009-03-27 13:25:23 +00:00
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/*
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2009-05-26 14:30:23 +00:00
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* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2008-2009 PetaLogix
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2009-03-27 13:25:23 +00:00
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* Copyright (C) 2006 Atmark Techno, Inc.
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*/
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#ifndef _ASM_MICROBLAZE_UACCESS_H
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#define _ASM_MICROBLAZE_UACCESS_H
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#include <linux/kernel.h>
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#include <asm/mmu.h>
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#include <asm/page.h>
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2020-06-09 04:32:38 +00:00
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#include <linux/pgtable.h>
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2016-12-25 19:34:44 +00:00
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#include <asm/extable.h>
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2009-03-27 13:25:23 +00:00
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#include <linux/string.h>
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2010-03-05 14:34:12 +00:00
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/*
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* On Microblaze the fs value is actually the top of the corresponding
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* address space.
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*
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* The fs value determines whether argument validity checking should be
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* performed or not. If get_fs() == USER_DS, checking is performed, with
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* get_fs() == KERNEL_DS, checking is bypassed.
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*
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* For historical reasons, these macros are grossly misnamed.
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*
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* For non-MMU arch like Microblaze, KERNEL_DS and USER_DS is equal.
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*/
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# define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
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# define KERNEL_DS MAKE_MM_SEG(0xFFFFFFFF)
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# define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
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# define get_fs() (current_thread_info()->addr_limit)
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# define set_fs(val) (current_thread_info()->addr_limit = (val))
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2020-01-16 14:58:41 +00:00
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# define user_addr_max() get_fs().seg
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2010-03-05 14:34:12 +00:00
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2020-08-12 01:33:44 +00:00
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# define uaccess_kernel() (get_fs().seg == KERNEL_DS.seg)
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2010-03-05 14:34:12 +00:00
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uaccess: generalize access_ok()
There are many different ways that access_ok() is defined across
architectures, but in the end, they all just compare against the
user_addr_max() value or they accept anything.
Provide one definition that works for most architectures, checking
against TASK_SIZE_MAX for user processes or skipping the check inside
of uaccess_kernel() sections.
For architectures without CONFIG_SET_FS(), this should be the fastest
check, as it comes down to a single comparison of a pointer against a
compile-time constant, while the architecture specific versions tend to
do something more complex for historic reasons or get something wrong.
Type checking for __user annotations is handled inconsistently across
architectures, but this is easily simplified as well by using an inline
function that takes a 'const void __user *' argument. A handful of
callers need an extra __user annotation for this.
Some architectures had trick to use 33-bit or 65-bit arithmetic on the
addresses to calculate the overflow, however this simpler version uses
fewer registers, which means it can produce better object code in the
end despite needing a second (statically predicted) branch.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64, asm-generic]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Stafford Horne <shorne@gmail.com>
Acked-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-02-15 16:55:04 +00:00
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#include <asm-generic/access_ok.h>
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2010-03-05 15:50:01 +00:00
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# define __FIXUP_SECTION ".section .fixup,\"ax\"\n"
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# define __EX_TABLE_SECTION ".section __ex_table,\"a\"\n"
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2010-03-22 17:39:20 +00:00
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extern unsigned long __copy_tofrom_user(void __user *to,
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const void __user *from, unsigned long size);
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2010-03-22 15:02:59 +00:00
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/* Return: number of not copied bytes, i.e. 0 if OK or non-zero if fail. */
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static inline unsigned long __must_check __clear_user(void __user *to,
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unsigned long n)
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{
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/* normal memset with two words to __ex_table */
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__asm__ __volatile__ ( \
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2011-02-10 18:12:13 +00:00
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"1: sb r0, %1, r0;" \
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2010-03-22 15:02:59 +00:00
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" addik %0, %0, -1;" \
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" bneid %0, 1b;" \
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2011-02-10 18:12:13 +00:00
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" addik %1, %1, 1;" \
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2010-03-22 15:02:59 +00:00
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"2: " \
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__EX_TABLE_SECTION \
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".word 1b,2b;" \
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".previous;" \
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2011-02-10 18:12:13 +00:00
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: "=r"(n), "=r"(to) \
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: "0"(n), "1"(to)
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2010-03-22 15:02:59 +00:00
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);
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return n;
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}
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static inline unsigned long __must_check clear_user(void __user *to,
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unsigned long n)
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{
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2013-05-26 14:30:56 +00:00
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might_fault();
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Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 02:57:57 +00:00
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if (unlikely(!access_ok(to, n)))
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2010-03-22 15:02:59 +00:00
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return n;
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return __clear_user(to, n);
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}
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2010-03-22 17:23:45 +00:00
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/* put_user and get_user macros */
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2010-03-08 09:52:24 +00:00
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extern long __user_bad(void);
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#define __get_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
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({ \
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__asm__ __volatile__ ( \
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"1:" insn " %1, %2, r0;" \
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" addk %0, r0, r0;" \
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"2: " \
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__FIXUP_SECTION \
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"3: brid 2b;" \
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" addik %0, r0, %3;" \
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".previous;" \
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__EX_TABLE_SECTION \
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".word 1b,3b;" \
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".previous;" \
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: "=&r"(__gu_err), "=r"(__gu_val) \
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: "r"(__gu_ptr), "i"(-EFAULT) \
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); \
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})
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/**
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* get_user: - Get a simple variable from user space.
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* @x: Variable to store result.
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* @ptr: Source address, in user space.
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*
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2015-05-11 15:52:08 +00:00
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* Context: User context only. This function may sleep if pagefaults are
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* enabled.
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2010-03-08 09:52:24 +00:00
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*
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* This macro copies a single simple variable from user space to kernel
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and the result of
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* dereferencing @ptr must be assignable to @x without a cast.
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*
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* Returns zero on success, or -EFAULT on error.
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* On error, the variable @x is set to zero.
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*/
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2019-09-17 01:39:44 +00:00
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#define get_user(x, ptr) ({ \
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const typeof(*(ptr)) __user *__gu_ptr = (ptr); \
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access_ok(__gu_ptr, sizeof(*__gu_ptr)) ? \
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__get_user(x, __gu_ptr) : -EFAULT; \
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2010-05-06 21:38:33 +00:00
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})
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2009-05-01 13:36:13 +00:00
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2010-03-08 09:52:24 +00:00
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#define __get_user(x, ptr) \
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({ \
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long __gu_err; \
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switch (sizeof(*(ptr))) { \
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case 1: \
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2022-02-15 14:37:37 +00:00
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__get_user_asm("lbu", (ptr), x, __gu_err); \
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2010-03-08 09:52:24 +00:00
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break; \
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case 2: \
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2022-02-15 14:37:37 +00:00
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__get_user_asm("lhu", (ptr), x, __gu_err); \
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2010-03-08 09:52:24 +00:00
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break; \
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case 4: \
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2022-02-15 14:37:37 +00:00
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__get_user_asm("lw", (ptr), x, __gu_err); \
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2010-03-08 09:52:24 +00:00
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break; \
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2022-02-15 14:37:37 +00:00
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case 8: { \
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__u64 __x = 0; \
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__gu_err = raw_copy_from_user(&__x, ptr, 8) ? \
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-EFAULT : 0; \
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(x) = (typeof(x))(typeof((x) - (x)))__x; \
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2019-09-17 01:39:44 +00:00
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break; \
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2022-02-15 14:37:37 +00:00
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} \
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2010-03-08 09:52:24 +00:00
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default: \
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/* __gu_val = 0; __gu_err = -EINVAL;*/ __gu_err = __user_bad();\
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} \
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__gu_err; \
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2009-05-26 14:30:23 +00:00
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})
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2009-03-27 13:25:23 +00:00
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2010-03-08 09:52:24 +00:00
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2010-03-22 15:22:41 +00:00
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#define __put_user_asm(insn, __gu_ptr, __gu_val, __gu_err) \
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({ \
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__asm__ __volatile__ ( \
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"1:" insn " %1, %2, r0;" \
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" addk %0, r0, r0;" \
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"2: " \
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__FIXUP_SECTION \
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"3: brid 2b;" \
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" addik %0, r0, %3;" \
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".previous;" \
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__EX_TABLE_SECTION \
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".word 1b,3b;" \
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".previous;" \
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: "=&r"(__gu_err) \
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: "r"(__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \
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); \
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})
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2009-03-27 13:25:23 +00:00
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2010-03-22 15:22:41 +00:00
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#define __put_user_asm_8(__gu_ptr, __gu_val, __gu_err) \
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2009-05-26 14:30:23 +00:00
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({ \
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2010-03-22 15:22:41 +00:00
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__asm__ __volatile__ (" lwi %0, %1, 0;" \
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"1: swi %0, %2, 0;" \
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" lwi %0, %1, 4;" \
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"2: swi %0, %2, 4;" \
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" addk %0, r0, r0;" \
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"3: " \
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__FIXUP_SECTION \
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"4: brid 3b;" \
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" addik %0, r0, %3;" \
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".previous;" \
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__EX_TABLE_SECTION \
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".word 1b,4b,2b,4b;" \
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".previous;" \
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: "=&r"(__gu_err) \
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: "r"(&__gu_val), "r"(__gu_ptr), "i"(-EFAULT) \
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); \
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2009-05-26 14:30:23 +00:00
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})
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2009-03-27 13:25:23 +00:00
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2010-03-22 17:23:45 +00:00
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/**
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* put_user: - Write a simple value into user space.
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* @x: Value to copy to user space.
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* @ptr: Destination address, in user space.
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*
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2015-05-11 15:52:08 +00:00
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* Context: User context only. This function may sleep if pagefaults are
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* enabled.
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2010-03-22 17:23:45 +00:00
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*
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* This macro copies a single simple value from kernel space to user
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* space. It supports simple types like char and int, but not larger
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* data types like structures or arrays.
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*
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* @ptr must have pointer-to-simple-variable type, and @x must be assignable
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* to the result of dereferencing @ptr.
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*
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* Returns zero on success, or -EFAULT on error.
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*/
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2010-05-06 21:38:33 +00:00
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#define put_user(x, ptr) \
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__put_user_check((x), (ptr), sizeof(*(ptr)))
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#define __put_user_check(x, ptr, size) \
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({ \
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2015-01-06 15:45:03 +00:00
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typeof(*(ptr)) volatile __pu_val = x; \
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2010-05-06 21:38:33 +00:00
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typeof(*(ptr)) __user *__pu_addr = (ptr); \
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int __pu_err = 0; \
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\
|
Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 02:57:57 +00:00
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|
|
if (access_ok(__pu_addr, size)) { \
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2010-05-06 21:38:33 +00:00
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switch (size) { \
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case 1: \
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__put_user_asm("sb", __pu_addr, __pu_val, \
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__pu_err); \
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break; \
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case 2: \
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__put_user_asm("sh", __pu_addr, __pu_val, \
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__pu_err); \
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break; \
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case 4: \
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__put_user_asm("sw", __pu_addr, __pu_val, \
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__pu_err); \
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break; \
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case 8: \
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__put_user_asm_8(__pu_addr, __pu_val, __pu_err);\
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break; \
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default: \
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__pu_err = __user_bad(); \
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break; \
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} \
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} else { \
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__pu_err = -EFAULT; \
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} \
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__pu_err; \
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})
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2010-03-22 17:23:45 +00:00
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2010-03-22 15:22:41 +00:00
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|
#define __put_user(x, ptr) \
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({ \
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__typeof__(*(ptr)) volatile __gu_val = (x); \
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long __gu_err = 0; \
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switch (sizeof(__gu_val)) { \
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case 1: \
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__put_user_asm("sb", (ptr), __gu_val, __gu_err); \
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break; \
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case 2: \
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__put_user_asm("sh", (ptr), __gu_val, __gu_err); \
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break; \
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case 4: \
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__put_user_asm("sw", (ptr), __gu_val, __gu_err); \
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break; \
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case 8: \
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__put_user_asm_8((ptr), __gu_val, __gu_err); \
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break; \
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|
default: \
|
|
|
|
/*__gu_err = -EINVAL;*/ __gu_err = __user_bad(); \
|
|
|
|
} \
|
|
|
|
__gu_err; \
|
|
|
|
})
|
2009-03-27 13:25:23 +00:00
|
|
|
|
2017-03-21 16:10:12 +00:00
|
|
|
static inline unsigned long
|
|
|
|
raw_copy_from_user(void *to, const void __user *from, unsigned long n)
|
2010-03-22 14:56:32 +00:00
|
|
|
{
|
2017-03-21 16:10:12 +00:00
|
|
|
return __copy_tofrom_user((__force void __user *)to, from, n);
|
2010-03-22 14:56:32 +00:00
|
|
|
}
|
|
|
|
|
2017-03-21 16:10:12 +00:00
|
|
|
static inline unsigned long
|
|
|
|
raw_copy_to_user(void __user *to, const void *from, unsigned long n)
|
2010-03-22 14:52:53 +00:00
|
|
|
{
|
2017-03-21 16:10:12 +00:00
|
|
|
return __copy_tofrom_user(to, (__force const void __user *)from, n);
|
2010-03-22 17:49:45 +00:00
|
|
|
}
|
2017-03-21 16:10:12 +00:00
|
|
|
#define INLINE_COPY_FROM_USER
|
|
|
|
#define INLINE_COPY_TO_USER
|
2010-03-22 17:49:45 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Copy a null terminated string from userspace.
|
|
|
|
*/
|
2020-01-16 14:58:41 +00:00
|
|
|
__must_check long strncpy_from_user(char *dst, const char __user *src,
|
|
|
|
long count);
|
2010-03-22 17:49:45 +00:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Return the size of a string (including the ending 0)
|
|
|
|
*
|
|
|
|
* Return 0 on exception, a value greater than N if too long
|
|
|
|
*/
|
2020-01-16 14:58:41 +00:00
|
|
|
__must_check long strnlen_user(const char __user *sstr, long len);
|
2010-03-22 14:52:53 +00:00
|
|
|
|
2009-03-27 13:25:23 +00:00
|
|
|
#endif /* _ASM_MICROBLAZE_UACCESS_H */
|