x86: Prepare asm files for straight-line-speculation

Replace all ret/retq instructions with RET in preparation of making
RET a macro. Since AS is case insensitive it's a big no-op without
RET defined.

find arch/x86/ -name \*.S | while read file
do
sed -i 's/\<ret[q]*\>/RET/' $file
done

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211204134907.905503893@infradead.org

x86/asm/32: Change all ENTRY+ENDPROC to SYM_FUNC_*

These are all functions which are invoked from elsewhere, so annotate
them as global using the new SYM_FUNC_START and their ENDPROC's by
SYM_FUNC_END.

Now, ENTRY/ENDPROC can be forced to be undefined on X86, so do so.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Allison Randal <allison@lohutok.net>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andy Shevchenko <andy@infradead.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Bill Metzenthen <billm@melbpc.org.au>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Darren Hart <dvhart@infradead.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
Cc: linux-efi <linux-efi@vger.kernel.org>
Cc: linux-efi@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: platform-driver-x86@vger.kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191011115108.12392-28-jslaby@suse.cz

x86/asm/32: Add ENDs to some functions and relabel with SYM_CODE_*

All these are functions which are invoked from elsewhere but they are
not typical C functions. So annotate them using the new SYM_CODE_START.
All these were not balanced with any END, so mark their ends by
SYM_CODE_END, appropriately.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> [xen bits]
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [hibernate]
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Len Brown <len.brown@intel.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/20191011115108.12392-26-jslaby@suse.cz

x86-32, hibernate: Adjust in_suspend after resumed on 32bit system

Update the in_suspend variable to reflect the actual hibernation
status. Back-port from 64bit system.

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86-32, hibernate: Set up temporary text mapping for 32bit system

Set up the temporary text mapping for the final jump address
so that the system could jump to the right address after all
the pages have been copied back to their original address -
otherwise the final mapping for the jump address is invalid.

Analogous changes were made for 64-bit in commit 65c0554b73c9
(x86/power/64: Fix kernel text mapping corruption during image
restoration).

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86-32, hibernate: Switch to relocated restore code during resume on 32bit system

On 64bit system, code should be executed in a safe page
during page restoring, as the page where instruction is
running during resume might be scribbled and causes issues.

Although on 32 bit, we only suspend resuming by same kernel
that did the suspend, we'd like to remove that restriction
in the future.

Porting corresponding code from
64bit system: Allocate a safe page, and copy the restore
code to it, then jump to the safe page to run the code.

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86-32, hibernate: Switch to original page table after resumed

After all the pages are restored to previous address, the page
table switches back to current swapper_pg_dir. However the
swapper_pg_dir currently in used might not be consistent with
previous page table, which might cause issue after resume.

Fix this issue by switching to original page table after resume,
and the address of the original page table is saved in the hibernation
image header.

Move the manipulation of restore_cr3 into common code blocks.

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86-32, hibernate: Use the page size macro instead of constant value

Convert the hard code into PAGE_SIZE for better scalability.

No functional change.

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86-32, hibernate: Use temp_pgt as the temporary page table

This is to reuse the temp_pgt for both 32bit and 64bit
system.

No intentional behavior change.

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

x86-32/asm/power: Create stack frames in hibernate_asm_32.S

swsusp_arch_suspend() is callable non-leaf function which doesn't
honor CONFIG_FRAME_POINTER, which can result in bad stack traces.
Also it's not annotated as ELF callable function which can confuse tooling.

Create a stack frame for it when CONFIG_FRAME_POINTER is enabled and
give it proper ELF function annotation.

Also in this patch introduces the restore_registers() symbol and
gives it ELF function annotation, thus to prepare for later register
restore.

Analogous changes were made for 64bit before in commit ef0f3ed5a4ac
(x86/asm/power: Create stack frames in hibernate_asm_64.S) and
commit 4ce827b4cc58 (x86/power/64: Fix hibernation return address
corruption).

Signed-off-by: Zhimin Gu <kookoo.gu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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>

x86, gdt, hibernate: Store/load GDT for hibernate path.

The git commite7a5cd063c7b4c58417f674821d63f5eb6747e37
("x86-64, gdt: Store/load GDT for ACPI S3 or hibernate/resume path
is not needed.") assumes that for the hibernate path the booting
kernel and the resuming kernel MUST be the same. That is certainly
the case for a 32-bit kernel (see check_image_kernel and
CONFIG_ARCH_HIBERNATION_HEADER config option).

However for 64-bit kernels it is OK to have a different kernel
version (and size of the image) of the booting and resuming kernels.
Hence the above mentioned git commit introduces an regression.

This patch fixes it by introducing a 'struct desc_ptr gdt_desc'
back in the 'struct saved_context'. However instead of having in the
'save_processor_state' and 'restore_processor_state' the
store/load_gdt calls, we are only saving the GDT in the
save_processor_state.

For the restore path the lgdt operation is done in
hibernate_asm_[32|64].S in the 'restore_registers' path.

The apt reader of this description will recognize that only 64-bit
kernels need this treatment, not 32-bit. This patch adds the logic
in the 32-bit path to be more similar to 64-bit so that in the future
the unification process can take advantage of this.

[ hpa: this also reverts an inadvertent on-disk format change ]

Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1367459610-9656-2-git-send-email-konrad.wilk@oracle.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

x86-32, resume: do a global tlb flush in S4 resume

Colin King reported a strange oops in S4 resume code path (see below). The test
system has i5/i7 CPU. The kernel doesn't open PAE, so 4M page table is used.
The oops always happen a virtual address 0xc03ff000, which is mapped to the
last 4k of first 4M memory. Doing a global tlb flush fixes the issue.

EIP: 0060:[<c0493a01>] EFLAGS: 00010086 CPU: 0
EIP is at copy_loop+0xe/0x15
EAX: 36aeb000 EBX: 00000000 ECX: 00000400 EDX: f55ad46c
ESI: 0f800000 EDI: c03ff000 EBP: f67fbec4 ESP: f67fbea8
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
...
...
CR2: 00000000c03ff000

Tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
LKML-Reference: <20100305005932.GA22675@sli10-desk.sh.intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@kernel.org>

x86: use _types.h headers in asm where available

In general, the only definitions that assembly files can use
are in _types.S headers (where available), so convert them.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

x86, cleanup: use X86_CR4_PGE in x86/power/hibernate_asm_32.S

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86: fix i486 suspend to disk CR4 oops

arch/x86/power/cpu_32.c __save_processor_state calls read_cr4()
only a i486 CPU doesn't have the CR4 register. Trying to read it
produces an invalid opcode oops during suspend to disk.

Use the safe rc4 reading op instead. If the value to be written is
zero the write is skipped.

arch/x86/power/hibernate_asm_32.S
done: swapped the use of %eax and %ecx to use jecxz for
the zero test and jump over store to %cr4.
restore_image: s/%ecx/%eax/ to be consistent with done:

In addition to __save_processor_state, acpi_save_state_mem,
efi_call_phys_prelog, and efi_call_phys_epilog had checks added
(acpi restore was in assembly and already had a check for
non-zero). There were other reads and writes of CR4, but MCE and
virtualization shouldn't be executed on a i486 anyway.

Signed-off-by: David Fries <david@fries.net>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

x86 PM: rename 32-bit files in arch/x86/power

Rename cpu.c, suspend.c and swsusp.S in arch/x86/power to cpu_32.c,
hibernate_32.c and hibernate_asm_32.S, respectively, and update the
purpose and copyright information in these files.

Update the Makefile in arch/x86/power to reflect the above changes.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>