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 08:07:57 -06:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2008-10-22 23:26:29 -06:00
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#ifndef _ASM_X86_SEGMENT_H
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#define _ASM_X86_SEGMENT_H
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2008-01-30 05:31:09 -07:00
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2011-02-14 19:33:55 -07:00
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#include <linux/const.h>
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2016-04-26 13:23:26 -06:00
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#include <asm/alternative.h>
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2011-02-14 19:33:55 -07:00
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2015-03-24 13:45:42 -06:00
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/*
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* Constructor for a conventional segment GDT (or LDT) entry.
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* This is a macro so it can be used in initializers.
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*/
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2008-07-17 12:29:24 -06:00
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#define GDT_ENTRY(flags, base, limit) \
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2011-02-14 19:33:55 -07:00
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((((base) & _AC(0xff000000,ULL)) << (56-24)) | \
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(((flags) & _AC(0x0000f0ff,ULL)) << 40) | \
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(((limit) & _AC(0x000f0000,ULL)) << (48-16)) | \
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(((base) & _AC(0x00ffffff,ULL)) << 16) | \
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(((limit) & _AC(0x0000ffff,ULL))))
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2008-07-17 12:29:24 -06:00
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2015-03-24 13:45:42 -06:00
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/* Simple and small GDT entries for booting only: */
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2008-01-30 05:33:01 -07:00
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#define GDT_ENTRY_BOOT_CS 2
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2015-03-22 15:01:12 -06:00
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#define GDT_ENTRY_BOOT_DS 3
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#define GDT_ENTRY_BOOT_TSS 4
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2015-03-24 13:45:42 -06:00
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#define __BOOT_CS (GDT_ENTRY_BOOT_CS*8)
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#define __BOOT_DS (GDT_ENTRY_BOOT_DS*8)
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#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS*8)
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/*
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* Bottom two bits of selector give the ring
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* privilege level
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*/
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#define SEGMENT_RPL_MASK 0x3
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2019-11-18 08:21:12 -07:00
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/*
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* When running on Xen PV, the actual privilege level of the kernel is 1,
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* not 0. Testing the Requested Privilege Level in a segment selector to
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* determine whether the context is user mode or kernel mode with
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* SEGMENT_RPL_MASK is wrong because the PV kernel's privilege level
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* matches the 0x3 mask.
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*
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* Testing with USER_SEGMENT_RPL_MASK is valid for both native and Xen PV
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* kernels because privilege level 2 is never used.
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*/
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#define USER_SEGMENT_RPL_MASK 0x2
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2015-03-24 13:45:42 -06:00
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/* User mode is privilege level 3: */
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#define USER_RPL 0x3
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/* Bit 2 is Table Indicator (TI): selects between LDT or GDT */
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#define SEGMENT_TI_MASK 0x4
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/* LDT segment has TI set ... */
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#define SEGMENT_LDT 0x4
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/* ... GDT has it cleared */
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#define SEGMENT_GDT 0x0
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2014-12-09 05:25:59 -07:00
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2015-04-03 06:25:28 -06:00
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#define GDT_ENTRY_INVALID_SEG 0
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2007-10-11 03:20:03 -06:00
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#ifdef CONFIG_X86_32
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2008-01-30 05:31:09 -07:00
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/*
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* The layout of the per-CPU GDT under Linux:
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*
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2015-03-24 13:45:42 -06:00
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* 0 - null <=== cacheline #1
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2008-01-30 05:31:09 -07:00
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* 1 - reserved
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* 2 - reserved
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* 3 - reserved
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*
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2015-03-24 13:45:42 -06:00
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* 4 - unused <=== cacheline #2
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2008-01-30 05:31:09 -07:00
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* 5 - unused
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*
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* ------- start of TLS (Thread-Local Storage) segments:
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*
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* 6 - TLS segment #1 [ glibc's TLS segment ]
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* 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
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2015-03-24 13:45:42 -06:00
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* 8 - TLS segment #3 <=== cacheline #3
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2008-01-30 05:31:09 -07:00
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* 9 - reserved
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* 10 - reserved
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* 11 - reserved
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*
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* ------- start of kernel segments:
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*
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2015-03-24 13:45:42 -06:00
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* 12 - kernel code segment <=== cacheline #4
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2008-01-30 05:31:09 -07:00
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* 13 - kernel data segment
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* 14 - default user CS
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* 15 - default user DS
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2015-03-24 13:45:42 -06:00
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* 16 - TSS <=== cacheline #5
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2008-01-30 05:31:09 -07:00
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* 17 - LDT
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* 18 - PNPBIOS support (16->32 gate)
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* 19 - PNPBIOS support
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2015-03-24 13:45:42 -06:00
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* 20 - PNPBIOS support <=== cacheline #6
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2008-01-30 05:31:09 -07:00
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* 21 - PNPBIOS support
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* 22 - PNPBIOS support
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* 23 - APM BIOS support
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2015-03-24 13:45:42 -06:00
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* 24 - APM BIOS support <=== cacheline #7
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2008-01-30 05:31:09 -07:00
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* 25 - APM BIOS support
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*
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* 26 - ESPFIX small SS
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* 27 - per-cpu [ offset to per-cpu data area ]
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2015-03-24 13:45:42 -06:00
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* 28 - stack_canary-20 [ for stack protector ] <=== cacheline #8
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2008-01-30 05:31:09 -07:00
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* 29 - unused
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* 30 - unused
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* 31 - TSS for double fault handler
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*/
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2015-03-24 13:45:42 -06:00
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#define GDT_ENTRY_TLS_MIN 6
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#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
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2008-01-30 05:31:09 -07:00
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2015-03-22 15:01:12 -06:00
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#define GDT_ENTRY_KERNEL_CS 12
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#define GDT_ENTRY_KERNEL_DS 13
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2008-01-30 05:31:09 -07:00
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#define GDT_ENTRY_DEFAULT_USER_CS 14
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#define GDT_ENTRY_DEFAULT_USER_DS 15
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2015-03-22 15:01:12 -06:00
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#define GDT_ENTRY_TSS 16
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#define GDT_ENTRY_LDT 17
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#define GDT_ENTRY_PNPBIOS_CS32 18
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#define GDT_ENTRY_PNPBIOS_CS16 19
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#define GDT_ENTRY_PNPBIOS_DS 20
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#define GDT_ENTRY_PNPBIOS_TS1 21
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#define GDT_ENTRY_PNPBIOS_TS2 22
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#define GDT_ENTRY_APMBIOS_BASE 23
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#define GDT_ENTRY_ESPFIX_SS 26
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#define GDT_ENTRY_PERCPU 27
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#define GDT_ENTRY_STACK_CANARY 28
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2008-01-30 05:31:09 -07:00
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2015-03-22 15:01:12 -06:00
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#define GDT_ENTRY_DOUBLEFAULT_TSS 31
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2008-01-30 05:31:09 -07:00
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2015-03-24 13:45:42 -06:00
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/*
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* Number of entries in the GDT table:
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*/
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#define GDT_ENTRIES 32
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/*
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* Segment selector values corresponding to the above entries:
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*/
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2015-03-22 15:01:12 -06:00
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#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
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#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
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2015-03-24 13:45:42 -06:00
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#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
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#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
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2010-10-19 07:52:26 -06:00
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#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)
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2015-03-24 13:45:42 -06:00
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/* segment for calling fn: */
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#define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32*8)
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/* code segment for BIOS: */
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#define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16*8)
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2015-03-22 15:01:12 -06:00
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/* "Is this PNP code selector (PNP_CS32 or PNP_CS16)?" */
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2015-03-24 13:45:42 -06:00
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#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == PNP_CS32)
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/* data segment for BIOS: */
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#define PNP_DS (GDT_ENTRY_PNPBIOS_DS*8)
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/* transfer data segment: */
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#define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1*8)
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/* another data segment: */
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#define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2*8)
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2008-01-30 05:31:09 -07:00
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#ifdef CONFIG_SMP
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2015-03-24 13:45:42 -06:00
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# define __KERNEL_PERCPU (GDT_ENTRY_PERCPU*8)
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2008-01-30 05:31:09 -07:00
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#else
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2015-03-24 13:45:42 -06:00
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# define __KERNEL_PERCPU 0
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2008-01-30 05:31:09 -07:00
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#endif
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2015-03-24 13:45:42 -06:00
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Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.
That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.
HOWEVER.
It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like
CONFIG_HAVE_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_NONE is not set
# CONFIG_CC_STACKPROTECTOR_REGULAR is not set
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_STACKPROTECTOR_AUTO=y
and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:
CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_CC_STACKPROTECTOR=y
# CONFIG_CC_STACKPROTECTOR_STRONG is not set
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.
The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one. This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).
This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:
CONFIG_HAVE_CC_STACKPROTECTOR=y
CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
CONFIG_STACKPROTECTOR=y
CONFIG_STACKPROTECTOR_STRONG=y
CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-13 21:21:18 -06:00
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#ifdef CONFIG_STACKPROTECTOR
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2015-03-24 13:45:42 -06:00
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# define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
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2009-02-09 06:17:40 -07:00
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#else
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2015-03-24 13:45:42 -06:00
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# define __KERNEL_STACK_CANARY 0
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2009-02-09 06:17:40 -07:00
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#endif
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2015-03-22 15:01:12 -06:00
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#else /* 64-bit: */
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2008-01-30 05:31:09 -07:00
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#include <asm/cache.h>
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2015-03-24 13:45:42 -06:00
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#define GDT_ENTRY_KERNEL32_CS 1
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#define GDT_ENTRY_KERNEL_CS 2
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#define GDT_ENTRY_KERNEL_DS 3
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2008-01-30 05:31:09 -07:00
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/*
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2015-03-24 13:45:42 -06:00
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* We cannot use the same code segment descriptor for user and kernel mode,
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* not even in long flat mode, because of different DPL.
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*
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* GDT layout to get 64-bit SYSCALL/SYSRET support right. SYSRET hardcodes
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* selectors:
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*
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* if returning to 32-bit userspace: cs = STAR.SYSRET_CS,
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* if returning to 64-bit userspace: cs = STAR.SYSRET_CS+16,
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*
|
2015-03-22 15:01:12 -06:00
|
|
|
* ss = STAR.SYSRET_CS+8 (in either case)
|
2015-03-24 13:45:42 -06:00
|
|
|
*
|
2015-03-22 15:01:12 -06:00
|
|
|
* thus USER_DS should be between 32-bit and 64-bit code selectors:
|
2008-01-30 05:31:09 -07:00
|
|
|
*/
|
2015-03-24 13:45:42 -06:00
|
|
|
#define GDT_ENTRY_DEFAULT_USER32_CS 4
|
|
|
|
|
#define GDT_ENTRY_DEFAULT_USER_DS 5
|
|
|
|
|
#define GDT_ENTRY_DEFAULT_USER_CS 6
|
|
|
|
|
|
|
|
|
|
/* Needs two entries */
|
|
|
|
|
#define GDT_ENTRY_TSS 8
|
|
|
|
|
/* Needs two entries */
|
|
|
|
|
#define GDT_ENTRY_LDT 10
|
2008-01-30 05:31:09 -07:00
|
|
|
|
2015-03-24 13:45:42 -06:00
|
|
|
#define GDT_ENTRY_TLS_MIN 12
|
|
|
|
|
#define GDT_ENTRY_TLS_MAX 14
|
2008-01-30 05:31:09 -07:00
|
|
|
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
#define GDT_ENTRY_CPUNODE 15
|
2015-03-22 15:01:12 -06:00
|
|
|
|
2015-03-24 13:45:42 -06:00
|
|
|
/*
|
|
|
|
|
* Number of entries in the GDT table:
|
|
|
|
|
*/
|
|
|
|
|
#define GDT_ENTRIES 16
|
2008-01-30 05:31:09 -07:00
|
|
|
|
2015-03-24 13:45:42 -06:00
|
|
|
/*
|
|
|
|
|
* Segment selector values corresponding to the above entries:
|
|
|
|
|
*
|
|
|
|
|
* Note, selectors also need to have a correct RPL,
|
|
|
|
|
* expressed with the +3 value for user-space selectors:
|
|
|
|
|
*/
|
|
|
|
|
#define __KERNEL32_CS (GDT_ENTRY_KERNEL32_CS*8)
|
|
|
|
|
#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
|
|
|
|
|
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
|
|
|
|
|
#define __USER32_CS (GDT_ENTRY_DEFAULT_USER32_CS*8 + 3)
|
|
|
|
|
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
|
|
|
|
|
#define __USER32_DS __USER_DS
|
|
|
|
|
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
#define __CPUNODE_SEG (GDT_ENTRY_CPUNODE*8 + 3)
|
2008-01-30 05:31:09 -07:00
|
|
|
|
2007-10-11 03:20:03 -06:00
|
|
|
#endif
|
2008-01-30 05:31:09 -07:00
|
|
|
|
2018-08-28 01:40:22 -06:00
|
|
|
#ifndef CONFIG_PARAVIRT_XXL
|
2015-03-24 13:45:42 -06:00
|
|
|
# define get_kernel_rpl() 0
|
2008-01-30 05:31:09 -07:00
|
|
|
#endif
|
|
|
|
|
|
2015-03-24 13:45:42 -06:00
|
|
|
#define IDT_ENTRIES 256
|
|
|
|
|
#define NUM_EXCEPTION_VECTORS 32
|
|
|
|
|
|
|
|
|
|
/* Bitmask of exception vectors which push an error code on the stack: */
|
|
|
|
|
#define EXCEPTION_ERRCODE_MASK 0x00027d00
|
|
|
|
|
|
|
|
|
|
#define GDT_SIZE (GDT_ENTRIES*8)
|
|
|
|
|
#define GDT_ENTRY_TLS_ENTRIES 3
|
|
|
|
|
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES* 8)
|
2008-01-30 05:31:09 -07:00
|
|
|
|
2018-09-18 17:08:58 -06:00
|
|
|
#ifdef CONFIG_X86_64
|
|
|
|
|
|
|
|
|
|
/* Bit size and mask of CPU number stored in the per CPU data (and TSC_AUX) */
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
#define VDSO_CPUNODE_BITS 12
|
|
|
|
|
#define VDSO_CPUNODE_MASK 0xfff
|
2018-09-18 17:08:58 -06:00
|
|
|
|
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
|
|
|
|
|
|
/* Helper functions to store/load CPU and node numbers */
|
|
|
|
|
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
static inline unsigned long vdso_encode_cpunode(int cpu, unsigned long node)
|
2018-09-18 17:08:58 -06:00
|
|
|
{
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
return (node << VDSO_CPUNODE_BITS) | cpu;
|
2018-09-18 17:08:58 -06:00
|
|
|
}
|
|
|
|
|
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
static inline void vdso_read_cpunode(unsigned *cpu, unsigned *node)
|
2018-09-18 17:08:58 -06:00
|
|
|
{
|
|
|
|
|
unsigned int p;
|
|
|
|
|
|
|
|
|
|
/*
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
* Load CPU and node number from the GDT. LSL is faster than RDTSCP
|
2018-09-18 17:08:58 -06:00
|
|
|
* and works on all CPUs. This is volatile so that it orders
|
|
|
|
|
* correctly with respect to barrier() and to keep GCC from cleverly
|
|
|
|
|
* hoisting it out of the calling function.
|
|
|
|
|
*
|
|
|
|
|
* If RDPID is available, use it.
|
|
|
|
|
*/
|
|
|
|
|
alternative_io ("lsl %[seg],%[p]",
|
|
|
|
|
".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */
|
|
|
|
|
X86_FEATURE_RDPID,
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
[p] "=a" (p), [seg] "r" (__CPUNODE_SEG));
|
2018-09-18 17:08:58 -06:00
|
|
|
|
|
|
|
|
if (cpu)
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
*cpu = (p & VDSO_CPUNODE_MASK);
|
2018-09-18 17:08:58 -06:00
|
|
|
if (node)
|
x86/segments: Introduce the 'CPUNODE' naming to better document the segment limit CPU/node NR trick
We have a special segment descriptor entry in the GDT, whose sole purpose is to
encode the CPU and node numbers in its limit (size) field. There are user-space
instructions that allow the reading of the limit field, which gives us a really
fast way to read the CPU and node IDs from the vDSO for example.
But the naming of related functionality does not make this clear, at all:
VDSO_CPU_SIZE
VDSO_CPU_MASK
__CPU_NUMBER_SEG
GDT_ENTRY_CPU_NUMBER
vdso_encode_cpu_node
vdso_read_cpu_node
There's a number of problems:
- The 'VDSO_CPU_SIZE' doesn't really make it clear that these are number
of bits, nor does it make it clear which 'CPU' this refers to, i.e.
that this is about a GDT entry whose limit encodes the CPU and node number.
- Furthermore, the 'CPU_NUMBER' naming is actively misleading as well,
because the segment limit encodes not just the CPU number but the
node ID as well ...
So use a better nomenclature all around: name everything related to this trick
as 'CPUNODE', to make it clear that this is something special, and add
_BITS to make it clear that these are number of bits, and propagate this to
every affected name:
VDSO_CPU_SIZE => VDSO_CPUNODE_BITS
VDSO_CPU_MASK => VDSO_CPUNODE_MASK
__CPU_NUMBER_SEG => __CPUNODE_SEG
GDT_ENTRY_CPU_NUMBER => GDT_ENTRY_CPUNODE
vdso_encode_cpu_node => vdso_encode_cpunode
vdso_read_cpu_node => vdso_read_cpunode
This, beyond being less confusing, also makes it easier to grep for all related
functionality:
$ git grep -i cpunode arch/x86
Also, while at it, fix "return is not a function" style sloppiness in vdso_encode_cpunode().
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang S. Bae <chang.seok.bae@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1537312139-5580-2-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-10-08 02:41:59 -06:00
|
|
|
*node = (p >> VDSO_CPUNODE_BITS);
|
2018-09-18 17:08:58 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
|
#endif /* CONFIG_X86_64 */
|
|
|
|
|
|
2008-01-30 05:33:06 -07:00
|
|
|
#ifdef __KERNEL__
|
2015-05-22 17:15:47 -06:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* early_idt_handler_array is an array of entry points referenced in the
|
|
|
|
|
* early IDT. For simplicity, it's a real array with one entry point
|
|
|
|
|
* every nine bytes. That leaves room for an optional 'push $0' if the
|
|
|
|
|
* vector has no error code (two bytes), a 'push $vector_number' (two
|
|
|
|
|
* bytes), and a jump to the common entry code (up to five bytes).
|
|
|
|
|
*/
|
|
|
|
|
#define EARLY_IDT_HANDLER_SIZE 9
|
|
|
|
|
|
2017-11-24 01:42:21 -07:00
|
|
|
/*
|
|
|
|
|
* xen_early_idt_handler_array is for Xen pv guests: for each entry in
|
|
|
|
|
* early_idt_handler_array it contains a prequel in the form of
|
|
|
|
|
* pop %rcx; pop %r11; jmp early_idt_handler_array[i]; summing up to
|
|
|
|
|
* max 8 bytes.
|
|
|
|
|
*/
|
|
|
|
|
#define XEN_EARLY_IDT_HANDLER_SIZE 8
|
|
|
|
|
|
2008-01-30 05:33:06 -07:00
|
|
|
#ifndef __ASSEMBLY__
|
2015-03-24 13:45:42 -06:00
|
|
|
|
2015-05-22 17:15:47 -06:00
|
|
|
extern const char early_idt_handler_array[NUM_EXCEPTION_VECTORS][EARLY_IDT_HANDLER_SIZE];
|
2017-08-28 00:47:48 -06:00
|
|
|
extern void early_ignore_irq(void);
|
2012-03-28 11:11:12 -06:00
|
|
|
|
2017-11-24 01:42:21 -07:00
|
|
|
#if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
|
|
|
|
|
extern const char xen_early_idt_handler_array[NUM_EXCEPTION_VECTORS][XEN_EARLY_IDT_HANDLER_SIZE];
|
|
|
|
|
#endif
|
|
|
|
|
|
2012-03-28 11:11:12 -06:00
|
|
|
/*
|
2016-04-26 13:23:26 -06:00
|
|
|
* Load a segment. Fall back on loading the zero segment if something goes
|
|
|
|
|
* wrong. This variant assumes that loading zero fully clears the segment.
|
|
|
|
|
* This is always the case on Intel CPUs and, even on 64-bit AMD CPUs, any
|
|
|
|
|
* failure to fully clear the cached descriptor is only observable for
|
|
|
|
|
* FS and GS.
|
2012-03-28 11:11:12 -06:00
|
|
|
*/
|
2016-04-26 13:23:26 -06:00
|
|
|
#define __loadsegment_simple(seg, value) \
|
2012-03-28 11:11:12 -06:00
|
|
|
do { \
|
|
|
|
|
unsigned short __val = (value); \
|
|
|
|
|
\
|
|
|
|
|
asm volatile(" \n" \
|
|
|
|
|
"1: movl %k0,%%" #seg " \n" \
|
|
|
|
|
\
|
|
|
|
|
".section .fixup,\"ax\" \n" \
|
|
|
|
|
"2: xorl %k0,%k0 \n" \
|
|
|
|
|
" jmp 1b \n" \
|
|
|
|
|
".previous \n" \
|
|
|
|
|
\
|
|
|
|
|
_ASM_EXTABLE(1b, 2b) \
|
|
|
|
|
\
|
|
|
|
|
: "+r" (__val) : : "memory"); \
|
|
|
|
|
} while (0)
|
|
|
|
|
|
2016-04-26 13:23:26 -06:00
|
|
|
#define __loadsegment_ss(value) __loadsegment_simple(ss, (value))
|
|
|
|
|
#define __loadsegment_ds(value) __loadsegment_simple(ds, (value))
|
|
|
|
|
#define __loadsegment_es(value) __loadsegment_simple(es, (value))
|
|
|
|
|
|
|
|
|
|
#ifdef CONFIG_X86_32
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* On 32-bit systems, the hidden parts of FS and GS are unobservable if
|
|
|
|
|
* the selector is NULL, so there's no funny business here.
|
|
|
|
|
*/
|
|
|
|
|
#define __loadsegment_fs(value) __loadsegment_simple(fs, (value))
|
|
|
|
|
#define __loadsegment_gs(value) __loadsegment_simple(gs, (value))
|
|
|
|
|
|
|
|
|
|
#else
|
|
|
|
|
|
|
|
|
|
static inline void __loadsegment_fs(unsigned short value)
|
|
|
|
|
{
|
|
|
|
|
asm volatile(" \n"
|
|
|
|
|
"1: movw %0, %%fs \n"
|
|
|
|
|
"2: \n"
|
|
|
|
|
|
|
|
|
|
_ASM_EXTABLE_HANDLE(1b, 2b, ex_handler_clear_fs)
|
|
|
|
|
|
|
|
|
|
: : "rm" (value) : "memory");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* __loadsegment_gs is intentionally undefined. Use load_gs_index instead. */
|
|
|
|
|
|
|
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
#define loadsegment(seg, value) __loadsegment_ ## seg (value)
|
|
|
|
|
|
2012-03-28 11:11:12 -06:00
|
|
|
/*
|
2015-03-24 13:45:42 -06:00
|
|
|
* Save a segment register away:
|
2012-03-28 11:11:12 -06:00
|
|
|
*/
|
|
|
|
|
#define savesegment(seg, value) \
|
|
|
|
|
asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
|
|
|
|
|
|
|
|
|
|
/*
|
2015-03-24 13:45:42 -06:00
|
|
|
* x86-32 user GS accessors:
|
2012-03-28 11:11:12 -06:00
|
|
|
*/
|
|
|
|
|
#ifdef CONFIG_X86_32
|
2015-03-24 13:45:42 -06:00
|
|
|
# ifdef CONFIG_X86_32_LAZY_GS
|
|
|
|
|
# define get_user_gs(regs) (u16)({ unsigned long v; savesegment(gs, v); v; })
|
|
|
|
|
# define set_user_gs(regs, v) loadsegment(gs, (unsigned long)(v))
|
|
|
|
|
# define task_user_gs(tsk) ((tsk)->thread.gs)
|
|
|
|
|
# define lazy_save_gs(v) savesegment(gs, (v))
|
|
|
|
|
# define lazy_load_gs(v) loadsegment(gs, (v))
|
|
|
|
|
# else /* X86_32_LAZY_GS */
|
|
|
|
|
# define get_user_gs(regs) (u16)((regs)->gs)
|
|
|
|
|
# define set_user_gs(regs, v) do { (regs)->gs = (v); } while (0)
|
|
|
|
|
# define task_user_gs(tsk) (task_pt_regs(tsk)->gs)
|
|
|
|
|
# define lazy_save_gs(v) do { } while (0)
|
|
|
|
|
# define lazy_load_gs(v) do { } while (0)
|
|
|
|
|
# endif /* X86_32_LAZY_GS */
|
2012-03-28 11:11:12 -06:00
|
|
|
#endif /* X86_32 */
|
|
|
|
|
|
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
|
#endif /* __KERNEL__ */
|
2008-01-30 05:33:06 -07:00
|
|
|
|
2008-10-22 23:26:29 -06:00
|
|
|
#endif /* _ASM_X86_SEGMENT_H */
|