linux_dsm_epyc7002/arch/x86/include/asm/segment.h

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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 21:07:57 +07:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_SEGMENT_H
#define _ASM_X86_SEGMENT_H
#include <linux/const.h>
#include <asm/alternative.h>
/*
* Constructor for a conventional segment GDT (or LDT) entry.
* This is a macro so it can be used in initializers.
*/
#define GDT_ENTRY(flags, base, limit) \
((((base) & _AC(0xff000000,ULL)) << (56-24)) | \
(((flags) & _AC(0x0000f0ff,ULL)) << 40) | \
(((limit) & _AC(0x000f0000,ULL)) << (48-16)) | \
(((base) & _AC(0x00ffffff,ULL)) << 16) | \
(((limit) & _AC(0x0000ffff,ULL))))
/* Simple and small GDT entries for booting only: */
#define GDT_ENTRY_BOOT_CS 2
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
#define GDT_ENTRY_BOOT_DS 3
#define GDT_ENTRY_BOOT_TSS 4
#define __BOOT_CS (GDT_ENTRY_BOOT_CS*8)
#define __BOOT_DS (GDT_ENTRY_BOOT_DS*8)
#define __BOOT_TSS (GDT_ENTRY_BOOT_TSS*8)
/*
* Bottom two bits of selector give the ring
* privilege level
*/
#define SEGMENT_RPL_MASK 0x3
/* User mode is privilege level 3: */
#define USER_RPL 0x3
/* Bit 2 is Table Indicator (TI): selects between LDT or GDT */
#define SEGMENT_TI_MASK 0x4
/* LDT segment has TI set ... */
#define SEGMENT_LDT 0x4
/* ... GDT has it cleared */
#define SEGMENT_GDT 0x0
#define GDT_ENTRY_INVALID_SEG 0
#ifdef CONFIG_X86_32
/*
* The layout of the per-CPU GDT under Linux:
*
* 0 - null <=== cacheline #1
* 1 - reserved
* 2 - reserved
* 3 - reserved
*
* 4 - unused <=== cacheline #2
* 5 - unused
*
* ------- start of TLS (Thread-Local Storage) segments:
*
* 6 - TLS segment #1 [ glibc's TLS segment ]
* 7 - TLS segment #2 [ Wine's %fs Win32 segment ]
* 8 - TLS segment #3 <=== cacheline #3
* 9 - reserved
* 10 - reserved
* 11 - reserved
*
* ------- start of kernel segments:
*
* 12 - kernel code segment <=== cacheline #4
* 13 - kernel data segment
* 14 - default user CS
* 15 - default user DS
* 16 - TSS <=== cacheline #5
* 17 - LDT
* 18 - PNPBIOS support (16->32 gate)
* 19 - PNPBIOS support
* 20 - PNPBIOS support <=== cacheline #6
* 21 - PNPBIOS support
* 22 - PNPBIOS support
* 23 - APM BIOS support
* 24 - APM BIOS support <=== cacheline #7
* 25 - APM BIOS support
*
* 26 - ESPFIX small SS
* 27 - per-cpu [ offset to per-cpu data area ]
* 28 - stack_canary-20 [ for stack protector ] <=== cacheline #8
* 29 - unused
* 30 - unused
* 31 - TSS for double fault handler
*/
#define GDT_ENTRY_TLS_MIN 6
#define GDT_ENTRY_TLS_MAX (GDT_ENTRY_TLS_MIN + GDT_ENTRY_TLS_ENTRIES - 1)
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
#define GDT_ENTRY_KERNEL_CS 12
#define GDT_ENTRY_KERNEL_DS 13
#define GDT_ENTRY_DEFAULT_USER_CS 14
#define GDT_ENTRY_DEFAULT_USER_DS 15
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
#define GDT_ENTRY_TSS 16
#define GDT_ENTRY_LDT 17
#define GDT_ENTRY_PNPBIOS_CS32 18
#define GDT_ENTRY_PNPBIOS_CS16 19
#define GDT_ENTRY_PNPBIOS_DS 20
#define GDT_ENTRY_PNPBIOS_TS1 21
#define GDT_ENTRY_PNPBIOS_TS2 22
#define GDT_ENTRY_APMBIOS_BASE 23
#define GDT_ENTRY_ESPFIX_SS 26
#define GDT_ENTRY_PERCPU 27
#define GDT_ENTRY_STACK_CANARY 28
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
#define GDT_ENTRY_DOUBLEFAULT_TSS 31
/*
* Number of entries in the GDT table:
*/
#define GDT_ENTRIES 32
/*
* Segment selector values corresponding to the above entries:
*/
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
#define __KERNEL_CS (GDT_ENTRY_KERNEL_CS*8)
#define __KERNEL_DS (GDT_ENTRY_KERNEL_DS*8)
#define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3)
#define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3)
#define __ESPFIX_SS (GDT_ENTRY_ESPFIX_SS*8)
/* segment for calling fn: */
#define PNP_CS32 (GDT_ENTRY_PNPBIOS_CS32*8)
/* code segment for BIOS: */
#define PNP_CS16 (GDT_ENTRY_PNPBIOS_CS16*8)
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
/* "Is this PNP code selector (PNP_CS32 or PNP_CS16)?" */
#define SEGMENT_IS_PNP_CODE(x) (((x) & 0xf4) == PNP_CS32)
/* data segment for BIOS: */
#define PNP_DS (GDT_ENTRY_PNPBIOS_DS*8)
/* transfer data segment: */
#define PNP_TS1 (GDT_ENTRY_PNPBIOS_TS1*8)
/* another data segment: */
#define PNP_TS2 (GDT_ENTRY_PNPBIOS_TS2*8)
#ifdef CONFIG_SMP
# define __KERNEL_PERCPU (GDT_ENTRY_PERCPU*8)
#else
# define __KERNEL_PERCPU 0
#endif
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>
2018-06-14 10:21:18 +07:00
#ifdef CONFIG_STACKPROTECTOR
# define __KERNEL_STACK_CANARY (GDT_ENTRY_STACK_CANARY*8)
#else
# define __KERNEL_STACK_CANARY 0
#endif
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
#else /* 64-bit: */
#include <asm/cache.h>
#define GDT_ENTRY_KERNEL32_CS 1
#define GDT_ENTRY_KERNEL_CS 2
#define GDT_ENTRY_KERNEL_DS 3
/*
* We cannot use the same code segment descriptor for user and kernel mode,
* not even in long flat mode, because of different DPL.
*
* GDT layout to get 64-bit SYSCALL/SYSRET support right. SYSRET hardcodes
* selectors:
*
* if returning to 32-bit userspace: cs = STAR.SYSRET_CS,
* if returning to 64-bit userspace: cs = STAR.SYSRET_CS+16,
*
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
* ss = STAR.SYSRET_CS+8 (in either case)
*
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
* thus USER_DS should be between 32-bit and 64-bit code selectors:
*/
#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
#define GDT_ENTRY_TLS_MIN 12
#define GDT_ENTRY_TLS_MAX 14
/* Abused to load per CPU data from limit */
#define GDT_ENTRY_PER_CPU 15
x86/asm: Deobfuscate segment.h This file just defines a number of constants, and a few macros and inline functions. It is particularly badly written. For example, it is not trivial to see how descriptors are numbered (you'd expect that should be easy, right?). This change deobfuscates it via the following changes: Group all GDT_ENTRY_foo together (move intervening stuff away). Number them explicitly: use a number, not PREV_DEFINE+1, +2, +3: I want to immediately see that GDT_ENTRY_PNPBIOS_CS32 is 18. Seeing (GDT_ENTRY_KERNEL_BASE+6) instead is not useful. The above change allows to remove GDT_ENTRY_KERNEL_BASE and GDT_ENTRY_PNPBIOS_BASE, which weren't used anywhere else. After a group of GDT_ENTRY_foo, define all selector values. Remove or improve some comments. In particular: Comment deleted as stating the obvious: /* * The GDT has 32 entries */ #define GDT_ENTRIES 32 "The segment offset needs to contain a RPL. Grr. -AK" changed to "Selectors need to also have a correct RPL (+3 thingy)" "GDT layout to get 64bit syscall right (sysret hardcodes gdt offsets)" expanded into a description *how exactly* sysret hardcodes them. Patch was tested to compile and not change vmlinux.o on 32-bit and 64-bit builds (verified with objdump). Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> Cc: Alexei Starovoitov <ast@plumgrid.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 04:01:12 +07:00
/*
* Number of entries in the GDT table:
*/
#define GDT_ENTRIES 16
/*
* 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)
#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU*8 + 3)
#endif
#ifndef CONFIG_PARAVIRT_XXL
# define get_kernel_rpl() 0
#endif
#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)
#ifdef __KERNEL__
x86/asm/irq: Stop relying on magic JMP behavior for early_idt_handlers The early_idt_handlers asm code generates an array of entry points spaced nine bytes apart. It's not really clear from that code or from the places that reference it what's going on, and the code only works in the first place because GAS never generates two-byte JMP instructions when jumping to global labels. Clean up the code to generate the correct array stride (member size) explicitly. This should be considerably more robust against screw-ups, as GAS will warn if a .fill directive has a negative count. Using '. =' to advance would have been even more robust (it would generate an actual error if it tried to move backwards), but it would pad with nulls, confusing anyone who tries to disassemble the code. The new scheme should be much clearer to future readers. While we're at it, improve the comments and rename the array and common code. Binutils may start relaxing jumps to non-weak labels. If so, this change will fix our build, and we may need to backport this change. Before, on x86_64: 0000000000000000 <early_idt_handlers>: 0: 6a 00 pushq $0x0 2: 6a 00 pushq $0x0 4: e9 00 00 00 00 jmpq 9 <early_idt_handlers+0x9> 5: R_X86_64_PC32 early_idt_handler-0x4 ... 48: 66 90 xchg %ax,%ax 4a: 6a 08 pushq $0x8 4c: e9 00 00 00 00 jmpq 51 <early_idt_handlers+0x51> 4d: R_X86_64_PC32 early_idt_handler-0x4 ... 117: 6a 00 pushq $0x0 119: 6a 1f pushq $0x1f 11b: e9 00 00 00 00 jmpq 120 <early_idt_handler> 11c: R_X86_64_PC32 early_idt_handler-0x4 After: 0000000000000000 <early_idt_handler_array>: 0: 6a 00 pushq $0x0 2: 6a 00 pushq $0x0 4: e9 14 01 00 00 jmpq 11d <early_idt_handler_common> ... 48: 6a 08 pushq $0x8 4a: e9 d1 00 00 00 jmpq 120 <early_idt_handler_common> 4f: cc int3 50: cc int3 ... 117: 6a 00 pushq $0x0 119: 6a 1f pushq $0x1f 11b: eb 03 jmp 120 <early_idt_handler_common> 11d: cc int3 11e: cc int3 11f: cc int3 Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Binutils <binutils@sourceware.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/ac027962af343b0c599cbfcf50b945ad2ef3d7a8.1432336324.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-23 06:15:47 +07:00
/*
* 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
/*
* 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
#ifndef __ASSEMBLY__
x86/asm/irq: Stop relying on magic JMP behavior for early_idt_handlers The early_idt_handlers asm code generates an array of entry points spaced nine bytes apart. It's not really clear from that code or from the places that reference it what's going on, and the code only works in the first place because GAS never generates two-byte JMP instructions when jumping to global labels. Clean up the code to generate the correct array stride (member size) explicitly. This should be considerably more robust against screw-ups, as GAS will warn if a .fill directive has a negative count. Using '. =' to advance would have been even more robust (it would generate an actual error if it tried to move backwards), but it would pad with nulls, confusing anyone who tries to disassemble the code. The new scheme should be much clearer to future readers. While we're at it, improve the comments and rename the array and common code. Binutils may start relaxing jumps to non-weak labels. If so, this change will fix our build, and we may need to backport this change. Before, on x86_64: 0000000000000000 <early_idt_handlers>: 0: 6a 00 pushq $0x0 2: 6a 00 pushq $0x0 4: e9 00 00 00 00 jmpq 9 <early_idt_handlers+0x9> 5: R_X86_64_PC32 early_idt_handler-0x4 ... 48: 66 90 xchg %ax,%ax 4a: 6a 08 pushq $0x8 4c: e9 00 00 00 00 jmpq 51 <early_idt_handlers+0x51> 4d: R_X86_64_PC32 early_idt_handler-0x4 ... 117: 6a 00 pushq $0x0 119: 6a 1f pushq $0x1f 11b: e9 00 00 00 00 jmpq 120 <early_idt_handler> 11c: R_X86_64_PC32 early_idt_handler-0x4 After: 0000000000000000 <early_idt_handler_array>: 0: 6a 00 pushq $0x0 2: 6a 00 pushq $0x0 4: e9 14 01 00 00 jmpq 11d <early_idt_handler_common> ... 48: 6a 08 pushq $0x8 4a: e9 d1 00 00 00 jmpq 120 <early_idt_handler_common> 4f: cc int3 50: cc int3 ... 117: 6a 00 pushq $0x0 119: 6a 1f pushq $0x1f 11b: eb 03 jmp 120 <early_idt_handler_common> 11d: cc int3 11e: cc int3 11f: cc int3 Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Binutils <binutils@sourceware.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H.J. Lu <hjl.tools@gmail.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/ac027962af343b0c599cbfcf50b945ad2ef3d7a8.1432336324.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-23 06:15:47 +07:00
extern const char early_idt_handler_array[NUM_EXCEPTION_VECTORS][EARLY_IDT_HANDLER_SIZE];
extern void early_ignore_irq(void);
#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
/*
* 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.
*/
#define __loadsegment_simple(seg, value) \
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)
#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)
/*
* Save a segment register away:
*/
#define savesegment(seg, value) \
asm("mov %%" #seg ",%0":"=r" (value) : : "memory")
/*
* x86-32 user GS accessors:
*/
#ifdef CONFIG_X86_32
# 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 */
#endif /* X86_32 */
#endif /* !__ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_X86_SEGMENT_H */