License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2006-06-23 17:04:16 +08:00
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#ifndef __LINUX_UACCESS_H__
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#define __LINUX_UACCESS_H__
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2020-10-16 11:13:50 +08:00
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#include <linux/fault-inject-usercopy.h>
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2020-01-22 00:05:12 +08:00
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#include <linux/instrumented.h>
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2020-10-16 11:10:21 +08:00
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#include <linux/minmax.h>
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2015-05-11 23:52:06 +08:00
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#include <linux/sched.h>
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2016-12-28 07:14:09 +08:00
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#include <linux/thread_info.h>
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2016-12-28 07:00:15 +08:00
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2006-06-23 17:04:16 +08:00
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#include <asm/uaccess.h>
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2017-03-21 09:56:06 +08:00
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/*
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* Architectures should provide two primitives (raw_copy_{to,from}_user())
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2017-04-06 07:15:53 +08:00
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* and get rid of their private instances of copy_{to,from}_user() and
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* __copy_{to,from}_user{,_inatomic}().
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2017-03-21 09:56:06 +08:00
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*
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* raw_copy_{to,from}_user(to, from, size) should copy up to size bytes and
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* return the amount left to copy. They should assume that access_ok() has
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* already been checked (and succeeded); they should *not* zero-pad anything.
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* No KASAN or object size checks either - those belong here.
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*
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* Both of these functions should attempt to copy size bytes starting at from
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* into the area starting at to. They must not fetch or store anything
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* outside of those areas. Return value must be between 0 (everything
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* copied successfully) and size (nothing copied).
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*
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* If raw_copy_{to,from}_user(to, from, size) returns N, size - N bytes starting
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* at to must become equal to the bytes fetched from the corresponding area
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* starting at from. All data past to + size - N must be left unmodified.
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*
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* If copying succeeds, the return value must be 0. If some data cannot be
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* fetched, it is permitted to copy less than had been fetched; the only
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* hard requirement is that not storing anything at all (i.e. returning size)
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* should happen only when nothing could be copied. In other words, you don't
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* have to squeeze as much as possible - it is allowed, but not necessary.
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*
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* For raw_copy_from_user() to always points to kernel memory and no faults
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* on store should happen. Interpretation of from is affected by set_fs().
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* For raw_copy_to_user() it's the other way round.
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*
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* Both can be inlined - it's up to architectures whether it wants to bother
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* with that. They should not be used directly; they are used to implement
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* the 6 functions (copy_{to,from}_user(), __copy_{to,from}_user_inatomic())
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* that are used instead. Out of those, __... ones are inlined. Plain
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* copy_{to,from}_user() might or might not be inlined. If you want them
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* inlined, have asm/uaccess.h define INLINE_COPY_{TO,FROM}_USER.
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*
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* NOTE: only copy_from_user() zero-pads the destination in case of short copy.
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* Neither __copy_from_user() nor __copy_from_user_inatomic() zero anything
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* at all; their callers absolutely must check the return value.
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*
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* Biarch ones should also provide raw_copy_in_user() - similar to the above,
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* but both source and destination are __user pointers (affected by set_fs()
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* as usual) and both source and destination can trigger faults.
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*/
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2019-09-26 07:47:39 +08:00
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static __always_inline __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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__copy_from_user_inatomic(void *to, const void __user *from, unsigned long n)
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{
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2022-09-15 23:03:37 +08:00
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unsigned long res;
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instrument_copy_from_user_before(to, from, n);
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2017-03-21 09:56:06 +08:00
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check_object_size(to, n, false);
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2022-09-15 23:03:37 +08:00
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res = raw_copy_from_user(to, from, n);
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instrument_copy_from_user_after(to, from, n, res);
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return res;
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2017-03-21 09:56:06 +08:00
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}
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2019-09-26 07:47:39 +08:00
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static __always_inline __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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__copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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2022-09-15 23:03:37 +08:00
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unsigned long res;
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2017-03-21 09:56:06 +08:00
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might_fault();
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2022-09-15 23:03:37 +08:00
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instrument_copy_from_user_before(to, from, n);
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2020-10-16 11:13:50 +08:00
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if (should_fail_usercopy())
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return n;
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2017-03-21 09:56:06 +08:00
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check_object_size(to, n, false);
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2022-09-15 23:03:37 +08:00
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res = raw_copy_from_user(to, from, n);
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instrument_copy_from_user_after(to, from, n, res);
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return res;
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2017-03-21 09:56:06 +08:00
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}
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/**
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* __copy_to_user_inatomic: - Copy a block of data into user space, with less checking.
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* @to: Destination address, in user space.
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* @from: Source address, in kernel space.
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* @n: Number of bytes to copy.
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*
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* Context: User context only.
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*
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* Copy data from kernel space to user space. Caller must check
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* the specified block with access_ok() before calling this function.
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* The caller should also make sure he pins the user space address
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* so that we don't result in page fault and sleep.
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*/
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2019-09-26 07:47:39 +08:00
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static __always_inline __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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__copy_to_user_inatomic(void __user *to, const void *from, unsigned long n)
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{
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2020-10-16 11:13:50 +08:00
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if (should_fail_usercopy())
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return n;
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2020-01-22 00:05:12 +08:00
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instrument_copy_to_user(to, from, n);
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2017-03-21 09:56:06 +08:00
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check_object_size(from, n, true);
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return raw_copy_to_user(to, from, n);
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}
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2019-09-26 07:47:39 +08:00
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static __always_inline __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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__copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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might_fault();
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2020-10-16 11:13:50 +08:00
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if (should_fail_usercopy())
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return n;
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2020-01-22 00:05:12 +08:00
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instrument_copy_to_user(to, from, n);
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2017-03-21 09:56:06 +08:00
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check_object_size(from, n, true);
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return raw_copy_to_user(to, from, n);
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}
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#ifdef INLINE_COPY_FROM_USER
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2019-09-26 07:47:39 +08:00
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static inline __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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_copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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unsigned long res = n;
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2017-06-30 09:39:54 +08:00
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might_fault();
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2020-10-16 11:13:50 +08:00
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if (!should_fail_usercopy() && likely(access_ok(from, n))) {
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2022-09-15 23:03:37 +08:00
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instrument_copy_from_user_before(to, from, n);
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2017-03-21 09:56:06 +08:00
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res = raw_copy_from_user(to, from, n);
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2022-09-15 23:03:37 +08:00
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instrument_copy_from_user_after(to, from, n, res);
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2017-06-30 09:39:54 +08:00
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}
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2017-03-21 09:56:06 +08:00
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if (unlikely(res))
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memset(to + (n - res), 0, res);
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return res;
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}
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#else
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2019-09-26 07:47:39 +08:00
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extern __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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_copy_from_user(void *, const void __user *, unsigned long);
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#endif
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#ifdef INLINE_COPY_TO_USER
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2019-09-26 07:47:39 +08:00
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static inline __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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_copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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2017-06-30 09:39:54 +08:00
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might_fault();
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2020-10-16 11:13:50 +08:00
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if (should_fail_usercopy())
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return n;
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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 10:57:57 +08:00
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if (access_ok(to, n)) {
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2020-01-22 00:05:12 +08:00
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instrument_copy_to_user(to, from, n);
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2017-03-21 09:56:06 +08:00
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n = raw_copy_to_user(to, from, n);
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2017-06-30 09:39:54 +08:00
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}
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2017-03-21 09:56:06 +08:00
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return n;
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}
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#else
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2019-09-26 07:47:39 +08:00
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extern __must_check unsigned long
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2017-03-21 09:56:06 +08:00
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_copy_to_user(void __user *, const void *, unsigned long);
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#endif
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static __always_inline unsigned long __must_check
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copy_from_user(void *to, const void __user *from, unsigned long n)
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{
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2022-06-07 06:42:59 +08:00
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if (check_copy_size(to, n, false))
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2017-03-21 09:56:06 +08:00
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n = _copy_from_user(to, from, n);
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return n;
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}
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static __always_inline unsigned long __must_check
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copy_to_user(void __user *to, const void *from, unsigned long n)
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{
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2022-06-07 06:42:59 +08:00
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if (check_copy_size(from, n, true))
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2017-03-21 09:56:06 +08:00
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n = _copy_to_user(to, from, n);
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return n;
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}
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x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()
In reaction to a proposal to introduce a memcpy_mcsafe_fast()
implementation Linus points out that memcpy_mcsafe() is poorly named
relative to communicating the scope of the interface. Specifically what
addresses are valid to pass as source, destination, and what faults /
exceptions are handled.
Of particular concern is that even though x86 might be able to handle
the semantics of copy_mc_to_user() with its common copy_user_generic()
implementation other archs likely need / want an explicit path for this
case:
On Fri, May 1, 2020 at 11:28 AM Linus Torvalds <torvalds@linux-foundation.org> wrote:
>
> On Thu, Apr 30, 2020 at 6:21 PM Dan Williams <dan.j.williams@intel.com> wrote:
> >
> > However now I see that copy_user_generic() works for the wrong reason.
> > It works because the exception on the source address due to poison
> > looks no different than a write fault on the user address to the
> > caller, it's still just a short copy. So it makes copy_to_user() work
> > for the wrong reason relative to the name.
>
> Right.
>
> And it won't work that way on other architectures. On x86, we have a
> generic function that can take faults on either side, and we use it
> for both cases (and for the "in_user" case too), but that's an
> artifact of the architecture oddity.
>
> In fact, it's probably wrong even on x86 - because it can hide bugs -
> but writing those things is painful enough that everybody prefers
> having just one function.
Replace a single top-level memcpy_mcsafe() with either
copy_mc_to_user(), or copy_mc_to_kernel().
Introduce an x86 copy_mc_fragile() name as the rename for the
low-level x86 implementation formerly named memcpy_mcsafe(). It is used
as the slow / careful backend that is supplanted by a fast
copy_mc_generic() in a follow-on patch.
One side-effect of this reorganization is that separating copy_mc_64.S
to its own file means that perf no longer needs to track dependencies
for its memcpy_64.S benchmarks.
[ bp: Massage a bit. ]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: <stable@vger.kernel.org>
Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com
Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com
2020-10-06 11:40:16 +08:00
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#ifndef copy_mc_to_kernel
|
|
|
|
/*
|
|
|
|
* Without arch opt-in this generic copy_mc_to_kernel() will not handle
|
|
|
|
* #MC (or arch equivalent) during source read.
|
|
|
|
*/
|
|
|
|
static inline unsigned long __must_check
|
|
|
|
copy_mc_to_kernel(void *dst, const void *src, size_t cnt)
|
|
|
|
{
|
|
|
|
memcpy(dst, src, cnt);
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
2015-05-11 23:52:06 +08:00
|
|
|
static __always_inline void pagefault_disabled_inc(void)
|
|
|
|
{
|
|
|
|
current->pagefault_disabled++;
|
|
|
|
}
|
|
|
|
|
|
|
|
static __always_inline void pagefault_disabled_dec(void)
|
|
|
|
{
|
|
|
|
current->pagefault_disabled--;
|
|
|
|
}
|
|
|
|
|
2006-12-07 12:32:20 +08:00
|
|
|
/*
|
2015-05-11 23:52:06 +08:00
|
|
|
* These routines enable/disable the pagefault handler. If disabled, it will
|
|
|
|
* not take any locks and go straight to the fixup table.
|
|
|
|
*
|
2015-05-11 23:52:20 +08:00
|
|
|
* User access methods will not sleep when called from a pagefault_disabled()
|
|
|
|
* environment.
|
2006-12-07 12:32:20 +08:00
|
|
|
*/
|
|
|
|
static inline void pagefault_disable(void)
|
|
|
|
{
|
2015-05-11 23:52:06 +08:00
|
|
|
pagefault_disabled_inc();
|
2006-12-07 12:32:20 +08:00
|
|
|
/*
|
|
|
|
* make sure to have issued the store before a pagefault
|
|
|
|
* can hit.
|
|
|
|
*/
|
|
|
|
barrier();
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void pagefault_enable(void)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* make sure to issue those last loads/stores before enabling
|
|
|
|
* the pagefault handler again.
|
|
|
|
*/
|
|
|
|
barrier();
|
2015-05-11 23:52:06 +08:00
|
|
|
pagefault_disabled_dec();
|
2006-12-07 12:32:20 +08:00
|
|
|
}
|
|
|
|
|
2015-05-11 23:52:06 +08:00
|
|
|
/*
|
|
|
|
* Is the pagefault handler disabled? If so, user access methods will not sleep.
|
|
|
|
*/
|
2019-05-15 13:38:06 +08:00
|
|
|
static inline bool pagefault_disabled(void)
|
|
|
|
{
|
|
|
|
return current->pagefault_disabled != 0;
|
|
|
|
}
|
2015-05-11 23:52:06 +08:00
|
|
|
|
2015-05-11 23:52:11 +08:00
|
|
|
/*
|
|
|
|
* The pagefault handler is in general disabled by pagefault_disable() or
|
|
|
|
* when in irq context (via in_atomic()).
|
|
|
|
*
|
|
|
|
* This function should only be used by the fault handlers. Other users should
|
|
|
|
* stick to pagefault_disabled().
|
|
|
|
* Please NEVER use preempt_disable() to disable the fault handler. With
|
|
|
|
* !CONFIG_PREEMPT_COUNT, this is like a NOP. So the handler won't be disabled.
|
|
|
|
* in_atomic() will report different values based on !CONFIG_PREEMPT_COUNT.
|
|
|
|
*/
|
|
|
|
#define faulthandler_disabled() (pagefault_disabled() || in_atomic())
|
|
|
|
|
2022-04-23 18:07:49 +08:00
|
|
|
#ifndef CONFIG_ARCH_HAS_SUBPAGE_FAULTS
|
|
|
|
|
|
|
|
/**
|
|
|
|
* probe_subpage_writeable: probe the user range for write faults at sub-page
|
|
|
|
* granularity (e.g. arm64 MTE)
|
|
|
|
* @uaddr: start of address range
|
|
|
|
* @size: size of address range
|
|
|
|
*
|
|
|
|
* Returns 0 on success, the number of bytes not probed on fault.
|
|
|
|
*
|
|
|
|
* It is expected that the caller checked for the write permission of each
|
|
|
|
* page in the range either by put_user() or GUP. The architecture port can
|
|
|
|
* implement a more efficient get_user() probing if the same sub-page faults
|
|
|
|
* are triggered by either a read or a write.
|
|
|
|
*/
|
|
|
|
static inline size_t probe_subpage_writeable(char __user *uaddr, size_t size)
|
|
|
|
{
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif /* CONFIG_ARCH_HAS_SUBPAGE_FAULTS */
|
|
|
|
|
2006-06-23 17:04:16 +08:00
|
|
|
#ifndef ARCH_HAS_NOCACHE_UACCESS
|
|
|
|
|
2019-09-26 07:47:39 +08:00
|
|
|
static inline __must_check unsigned long
|
|
|
|
__copy_from_user_inatomic_nocache(void *to, const void __user *from,
|
|
|
|
unsigned long n)
|
2006-06-23 17:04:16 +08:00
|
|
|
{
|
|
|
|
return __copy_from_user_inatomic(to, from, n);
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif /* ARCH_HAS_NOCACHE_UACCESS */
|
|
|
|
|
2019-10-01 09:10:52 +08:00
|
|
|
extern __must_check int check_zeroed_user(const void __user *from, size_t size);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* copy_struct_from_user: copy a struct from userspace
|
|
|
|
* @dst: Destination address, in kernel space. This buffer must be @ksize
|
|
|
|
* bytes long.
|
|
|
|
* @ksize: Size of @dst struct.
|
|
|
|
* @src: Source address, in userspace.
|
|
|
|
* @usize: (Alleged) size of @src struct.
|
|
|
|
*
|
|
|
|
* Copies a struct from userspace to kernel space, in a way that guarantees
|
|
|
|
* backwards-compatibility for struct syscall arguments (as long as future
|
|
|
|
* struct extensions are made such that all new fields are *appended* to the
|
|
|
|
* old struct, and zeroed-out new fields have the same meaning as the old
|
|
|
|
* struct).
|
|
|
|
*
|
|
|
|
* @ksize is just sizeof(*dst), and @usize should've been passed by userspace.
|
|
|
|
* The recommended usage is something like the following:
|
|
|
|
*
|
|
|
|
* SYSCALL_DEFINE2(foobar, const struct foo __user *, uarg, size_t, usize)
|
|
|
|
* {
|
|
|
|
* int err;
|
|
|
|
* struct foo karg = {};
|
|
|
|
*
|
|
|
|
* if (usize > PAGE_SIZE)
|
|
|
|
* return -E2BIG;
|
|
|
|
* if (usize < FOO_SIZE_VER0)
|
|
|
|
* return -EINVAL;
|
|
|
|
*
|
|
|
|
* err = copy_struct_from_user(&karg, sizeof(karg), uarg, usize);
|
|
|
|
* if (err)
|
|
|
|
* return err;
|
|
|
|
*
|
|
|
|
* // ...
|
|
|
|
* }
|
|
|
|
*
|
|
|
|
* There are three cases to consider:
|
|
|
|
* * If @usize == @ksize, then it's copied verbatim.
|
|
|
|
* * If @usize < @ksize, then the userspace has passed an old struct to a
|
|
|
|
* newer kernel. The rest of the trailing bytes in @dst (@ksize - @usize)
|
|
|
|
* are to be zero-filled.
|
|
|
|
* * If @usize > @ksize, then the userspace has passed a new struct to an
|
|
|
|
* older kernel. The trailing bytes unknown to the kernel (@usize - @ksize)
|
|
|
|
* are checked to ensure they are zeroed, otherwise -E2BIG is returned.
|
|
|
|
*
|
|
|
|
* Returns (in all cases, some data may have been copied):
|
|
|
|
* * -E2BIG: (@usize > @ksize) and there are non-zero trailing bytes in @src.
|
|
|
|
* * -EFAULT: access to userspace failed.
|
|
|
|
*/
|
|
|
|
static __always_inline __must_check int
|
|
|
|
copy_struct_from_user(void *dst, size_t ksize, const void __user *src,
|
|
|
|
size_t usize)
|
|
|
|
{
|
|
|
|
size_t size = min(ksize, usize);
|
|
|
|
size_t rest = max(ksize, usize) - size;
|
|
|
|
|
|
|
|
/* Deal with trailing bytes. */
|
|
|
|
if (usize < ksize) {
|
|
|
|
memset(dst + size, 0, rest);
|
|
|
|
} else if (usize > ksize) {
|
|
|
|
int ret = check_zeroed_user(src + size, rest);
|
|
|
|
if (ret <= 0)
|
|
|
|
return ret ?: -E2BIG;
|
|
|
|
}
|
|
|
|
/* Copy the interoperable parts of the struct. */
|
|
|
|
if (copy_from_user(dst, src, size))
|
|
|
|
return -EFAULT;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2020-06-17 15:37:53 +08:00
|
|
|
bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size);
|
2020-06-09 12:34:27 +08:00
|
|
|
|
2020-06-17 15:37:53 +08:00
|
|
|
long copy_from_kernel_nofault(void *dst, const void *src, size_t size);
|
|
|
|
long notrace copy_to_kernel_nofault(void *dst, const void *src, size_t size);
|
2019-05-15 13:38:18 +08:00
|
|
|
|
2020-06-17 15:37:54 +08:00
|
|
|
long copy_from_user_nofault(void *dst, const void __user *src, size_t size);
|
|
|
|
long notrace copy_to_user_nofault(void __user *dst, const void *src,
|
2020-06-17 15:37:53 +08:00
|
|
|
size_t size);
|
2019-11-02 07:17:56 +08:00
|
|
|
|
2020-06-09 12:34:17 +08:00
|
|
|
long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr,
|
|
|
|
long count);
|
2020-06-09 12:34:27 +08:00
|
|
|
|
2020-06-09 12:34:14 +08:00
|
|
|
long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
|
|
|
|
long count);
|
2020-06-09 12:34:20 +08:00
|
|
|
long strnlen_user_nofault(const void __user *unsafe_addr, long count);
|
2015-08-29 06:56:22 +08:00
|
|
|
|
uaccess: add generic __{get,put}_kernel_nofault
Nine architectures are still missing __{get,put}_kernel_nofault:
alpha, ia64, microblaze, nds32, nios2, openrisc, sh, sparc32, xtensa.
Add a generic version that lets everything use the normal
copy_{from,to}_kernel_nofault() code based on these, removing the last
use of get_fs()/set_fs() from architecture-independent code.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-02-11 15:50:00 +08:00
|
|
|
#ifndef __get_kernel_nofault
|
|
|
|
#define __get_kernel_nofault(dst, src, type, label) \
|
|
|
|
do { \
|
|
|
|
type __user *p = (type __force __user *)(src); \
|
|
|
|
type data; \
|
|
|
|
if (__get_user(data, p)) \
|
|
|
|
goto label; \
|
|
|
|
*(type *)dst = data; \
|
|
|
|
} while (0)
|
|
|
|
|
|
|
|
#define __put_kernel_nofault(dst, src, type, label) \
|
|
|
|
do { \
|
|
|
|
type __user *p = (type __force __user *)(dst); \
|
|
|
|
type data = *(type *)src; \
|
|
|
|
if (__put_user(data, p)) \
|
|
|
|
goto label; \
|
|
|
|
} while (0)
|
|
|
|
#endif
|
|
|
|
|
2015-11-06 10:46:03 +08:00
|
|
|
/**
|
2020-06-17 15:37:55 +08:00
|
|
|
* get_kernel_nofault(): safely attempt to read from a location
|
|
|
|
* @val: read into this variable
|
|
|
|
* @ptr: address to read from
|
2015-11-06 10:46:03 +08:00
|
|
|
*
|
|
|
|
* Returns 0 on success, or -EFAULT.
|
|
|
|
*/
|
maccess: make get_kernel_nofault() check for minimal type compatibility
Now that we've renamed probe_kernel_address() to get_kernel_nofault()
and made it look and behave more in line with get_user(), some of the
subtle type behavior differences end up being more obvious and possibly
dangerous.
When you do
get_user(val, user_ptr);
the type of the access comes from the "user_ptr" part, and the above
basically acts as
val = *user_ptr;
by design (except, of course, for the fact that the actual dereference
is done with a user access).
Note how in the above case, the type of the end result comes from the
pointer argument, and then the value is cast to the type of 'val' as
part of the assignment.
So the type of the pointer is ultimately the more important type both
for the access itself.
But 'get_kernel_nofault()' may now _look_ similar, but it behaves very
differently. When you do
get_kernel_nofault(val, kernel_ptr);
it behaves like
val = *(typeof(val) *)kernel_ptr;
except, of course, for the fact that the actual dereference is done with
exception handling so that a faulting access is suppressed and returned
as the error code.
But note how different the casting behavior of the two superficially
similar accesses are: one does the actual access in the size of the type
the pointer points to, while the other does the access in the size of
the target, and ignores the pointer type entirely.
Actually changing get_kernel_nofault() to act like get_user() is almost
certainly the right thing to do eventually, but in the meantime this
patch adds logit to at least verify that the pointer type is compatible
with the type of the result.
In many cases, this involves just casting the pointer to 'void *' to
make it obvious that the type of the pointer is not the important part.
It's not how 'get_user()' acts, but at least the behavioral difference
is now obvious and explicit.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-19 03:10:37 +08:00
|
|
|
#define get_kernel_nofault(val, ptr) ({ \
|
|
|
|
const typeof(val) *__gk_ptr = (ptr); \
|
|
|
|
copy_from_kernel_nofault(&(val), __gk_ptr, sizeof(val));\
|
|
|
|
})
|
2015-11-06 10:46:03 +08:00
|
|
|
|
2015-12-18 01:57:27 +08:00
|
|
|
#ifndef user_access_begin
|
2019-01-05 04:56:09 +08:00
|
|
|
#define user_access_begin(ptr,len) access_ok(ptr, len)
|
2015-12-18 01:57:27 +08:00
|
|
|
#define user_access_end() do { } while (0)
|
uaccess: implement a proper unsafe_copy_to_user() and switch filldir over to it
In commit 9f79b78ef744 ("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: 9f79b78ef744 ("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>
2019-10-08 03:56:48 +08:00
|
|
|
#define unsafe_op_wrap(op, err) do { if (unlikely(op)) goto err; } while (0)
|
|
|
|
#define unsafe_get_user(x,p,e) unsafe_op_wrap(__get_user(x,p),e)
|
|
|
|
#define unsafe_put_user(x,p,e) unsafe_op_wrap(__put_user(x,p),e)
|
|
|
|
#define unsafe_copy_to_user(d,s,l,e) unsafe_op_wrap(__copy_to_user(d,s,l),e)
|
2021-03-19 19:06:50 +08:00
|
|
|
#define unsafe_copy_from_user(d,s,l,e) unsafe_op_wrap(__copy_from_user(d,s,l),e)
|
2019-04-03 15:39:48 +08:00
|
|
|
static inline unsigned long user_access_save(void) { return 0UL; }
|
|
|
|
static inline void user_access_restore(unsigned long flags) { }
|
2015-12-18 01:57:27 +08:00
|
|
|
#endif
|
2020-04-03 15:20:50 +08:00
|
|
|
#ifndef user_write_access_begin
|
|
|
|
#define user_write_access_begin user_access_begin
|
|
|
|
#define user_write_access_end user_access_end
|
|
|
|
#endif
|
|
|
|
#ifndef user_read_access_begin
|
|
|
|
#define user_read_access_begin user_access_begin
|
|
|
|
#define user_read_access_end user_access_end
|
|
|
|
#endif
|
2015-12-18 01:57:27 +08:00
|
|
|
|
2018-01-11 06:22:38 +08:00
|
|
|
#ifdef CONFIG_HARDENED_USERCOPY
|
|
|
|
void __noreturn usercopy_abort(const char *name, const char *detail,
|
|
|
|
bool to_user, unsigned long offset,
|
|
|
|
unsigned long len);
|
|
|
|
#endif
|
|
|
|
|
2006-06-23 17:04:16 +08:00
|
|
|
#endif /* __LINUX_UACCESS_H__ */
|