document on perf security, more Italian translations, more
improvements to the memory-management docs, improvements to the
pathname lookup documentation, and the usual array of smaller
fixes.
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Merge tag 'docs-5.0' of git://git.lwn.net/linux
Pull documentation update from Jonathan Corbet:
"A fairly normal cycle for documentation stuff. We have a new document
on perf security, more Italian translations, more improvements to the
memory-management docs, improvements to the pathname lookup
documentation, and the usual array of smaller fixes.
As is often the case, there are a few reaches outside of
Documentation/ to adjust kerneldoc comments"
* tag 'docs-5.0' of git://git.lwn.net/linux: (38 commits)
docs: improve pathname-lookup document structure
configfs: fix wrong name of struct in documentation
docs/mm-api: link slab_common.c to "The Slab Cache" section
slab: make kmem_cache_create{_usercopy} description proper kernel-doc
doc:process: add links where missing
docs/core-api: make mm-api.rst more structured
x86, boot: documentation whitespace fixup
Documentation: devres: note checking needs when converting
doc🇮🇹 add some process/* translations
doc🇮🇹 fixes in process/1.Intro
Documentation: convert path-lookup from markdown to resturctured text
Documentation/admin-guide: update admin-guide index.rst
Documentation/admin-guide: introduce perf-security.rst file
scripts/kernel-doc: Fix struct and struct field attribute processing
Documentation: dev-tools: Fix typos in index.rst
Correct gen_init_cpio tool's documentation
Document /proc/pid PID reuse behavior
Documentation: update path-lookup.md for parallel lookups
Documentation: Use "while" instead of "whilst"
dmaengine: Add mailing list address to the documentation
...
Fix an extra space that sneaked in with commit 09c205afd "(x86, boot:
Define the 2.12 bzImage boot protocol").
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Peter Anvin pointed out that commit:
ae7e1238e6 ("x86/boot: Add ACPI RSDP address to setup_header")
should be reverted as setup_header should only contain items set by the
legacy BIOS.
So revert said commit. Instead of fully reverting the dependent commit
of:
e7b66d16fe ("x86/acpi, x86/boot: Take RSDP address for boot params if available")
just remove the setup_header reference in order to replace it by
a boot_params in a followup patch.
Suggested-by: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: bp@alien8.de
Cc: daniel.kiper@oracle.com
Cc: sstabellini@kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181120072529.5489-2-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Xen PVH guests receive the address of the RSDP table from Xen. In order
to support booting a Xen PVH guest via Grub2 using the standard x86
boot entry we need a way for Grub2 to pass the RSDP address to the
kernel.
For this purpose expand the struct setup_header to hold the physical
address of the RSDP address. Being zero means it isn't specified and
has to be located the legacy way (searching through low memory or
EBDA).
While documenting the new setup_header layout and protocol version
2.14 add the missing documentation of protocol version 2.13.
There are Grub2 versions in several distros with a downstream patch
violating the boot protocol by writing past the end of setup_header.
This requires another update of the boot protocol to enable the kernel
to distinguish between a specified RSDP address and one filled with
garbage by such a broken Grub2.
From protocol 2.14 on Grub2 will write the version it is supporting
(but never a higher value than found to be supported by the kernel)
ored with 0x8000 to the version field of setup_header. This enables
the kernel to know up to which field Grub2 has written information
to. All fields after that are supposed to be clobbered.
Signed-off-by: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boris.ostrovsky@oracle.com
Cc: bp@alien8.de
Cc: corbet@lwn.net
Cc: linux-doc@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/20181010061456.22238-3-jgross@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Documentation/x86/boot.txt labels the bit in
boot_params.hdr.loadflags as ALSR_FLAG while it should be
KASLR_FLAG.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1429011324-7170-1-git-send-email-mbenes@suse.cz
Link: http://lkml.kernel.org/r/1431332153-18566-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The cmdline_size field in setup_header is listed as read-only, and is
never read by the kernel. Therefore, there is no need for it to be set
by a boot loader implementing the EFI handover protocol, so remove it
from the list of fields required to be set by a boot loader.
Signed-off-by: Alex Smith <alex@alex-smith.me.uk>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Commit:
e2b32e6785 ("x86, kaslr: randomize module base load address")
made module base address randomization unconditional and didn't regard
disabled KKASLR due to CONFIG_HIBERNATION and command line option
"nokaslr". For more info see (now reverted) commit:
f47233c2d3 ("x86/mm/ASLR: Propagate base load address calculation")
In order to propagate KASLR status to kernel proper, we need a single bit
in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the
top-down allocated bits for bits supposed to be used by the bootloader.
Originally-From: Jiri Kosina <jkosina@suse.cz>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Old kexec-tools can not load new kernels. The reason is kexec-tools does
not fill efi_info in x86 setup header previously, thus EFI failed to
initialize. In new kexec-tools it will by default to fill efi_info and
pass other EFI required infomation to 2nd kernel so kexec kernel EFI
initialization can succeed finally.
To prevent from breaking userspace, add a new xloadflags bit so
kexec-tools can check the flag and switch to old logic.
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Pull x86 mm changes from Peter Anvin:
"This is a huge set of several partly interrelated (and concurrently
developed) changes, which is why the branch history is messier than
one would like.
The *really* big items are two humonguous patchsets mostly developed
by Yinghai Lu at my request, which completely revamps the way we
create initial page tables. In particular, rather than estimating how
much memory we will need for page tables and then build them into that
memory -- a calculation that has shown to be incredibly fragile -- we
now build them (on 64 bits) with the aid of a "pseudo-linear mode" --
a #PF handler which creates temporary page tables on demand.
This has several advantages:
1. It makes it much easier to support things that need access to data
very early (a followon patchset uses this to load microcode way
early in the kernel startup).
2. It allows the kernel and all the kernel data objects to be invoked
from above the 4 GB limit. This allows kdump to work on very large
systems.
3. It greatly reduces the difference between Xen and native (Xen's
equivalent of the #PF handler are the temporary page tables created
by the domain builder), eliminating a bunch of fragile hooks.
The patch series also gets us a bit closer to W^X.
Additional work in this pull is the 64-bit get_user() work which you
were also involved with, and a bunch of cleanups/speedups to
__phys_addr()/__pa()."
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (105 commits)
x86, mm: Move reserving low memory later in initialization
x86, doc: Clarify the use of asm("%edx") in uaccess.h
x86, mm: Redesign get_user with a __builtin_choose_expr hack
x86: Be consistent with data size in getuser.S
x86, mm: Use a bitfield to mask nuisance get_user() warnings
x86/kvm: Fix compile warning in kvm_register_steal_time()
x86-32: Add support for 64bit get_user()
x86-32, mm: Remove reference to alloc_remap()
x86-32, mm: Remove reference to resume_map_numa_kva()
x86-32, mm: Rip out x86_32 NUMA remapping code
x86/numa: Use __pa_nodebug() instead
x86: Don't panic if can not alloc buffer for swiotlb
mm: Add alloc_bootmem_low_pages_nopanic()
x86, 64bit, mm: hibernate use generic mapping_init
x86, 64bit, mm: Mark data/bss/brk to nx
x86: Merge early kernel reserve for 32bit and 64bit
x86: Add Crash kernel low reservation
x86, kdump: Remove crashkernel range find limit for 64bit
memblock: Add memblock_mem_size()
x86, boot: Not need to check setup_header version for setup_data
...
OVMF (an implementation of UEFI based on TianoCore used in virtual
environments) now has the ability to boot Linux natively; this is used
for "qemu -kernel" and similar things in a UEFI environment.
Accordingly, assign it a bootloader ID.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Now 64bit entry is fixed on 0x200, can not be changed anymore.
Update the comments to reflect that.
Also put info about it in boot.txt
-v2: fix some grammar error
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1359058816-7615-27-git-send-email-yinghai@kernel.org
Cc: Rob Landley <rob@landley.net>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Define the 2.12 bzImage boot protocol: add xloadflags and additional
fields to allow the command line, initramfs and struct boot_params to
live above the 4 GiB mark.
The xloadflags now communicates if this is a 64-bit kernel with the
legacy 64-bit entry point and which of the EFI handover entry points
are supported.
Avoid adding new read flags to loadflags because of claimed
bootloaders testing the whole byte for == 1 to determine bzImageness
at least until the issue can be researched further.
This is based on patches by Yinghai Lu and David Woodhouse.
Originally-by: Yinghai Lu <yinghai@kernel.org>
Originally-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: David Woodhouse <dwmw2@infradead.org>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1359058816-7615-26-git-send-email-yinghai@kernel.org
Cc: Rob Landley <rob@landley.net>
Cc: Gokul Caushik <caushik1@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Joe Millenbach <jmillenbach@gmail.com>
Pull small x86 fixes from Peter Anvin:
"A collection of very small fixes, mostly pure documentation."
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, doc: Document that bootloader ID 4 is used also by iPXE
x86, doc: Add a formal bootloader ID for kexec-tools
x86, 8042: Enable A20 using KBC to fix S3 resume on some MSI laptops
Add bootloader id D for kexec-tools (it is kexec-tools, not the kexec
system call, that builds the data structures, therefore it is
kexec-tools which is the "bootloader" for this purpose.)
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/50C95832.5030306@zytor.com
Fixes some minor issues in the x86 boot documentation.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Rob Landley <rob@landley.net>
Link: http://lkml.kernel.org/r/20121026031702.GA23828@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pul x86/efi changes from Ingo Molnar:
"This tree adds an EFI bootloader handover protocol, which, once
supported on the bootloader side, will make bootup faster and might
result in simpler bootloaders.
The other change activates the EFI wall clock time accessors on x86-64
as well, instead of the legacy RTC readout."
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, efi: Handover Protocol
x86-64/efi: Use EFI to deal with platform wall clock
Assign a bootloader ID for Sebastian Plotz' "Minimal Linux Bootloader"
(http://sebastian-plotz.blogspot.de). Sebastian has agreed to make
this the pilot for the use of extended boot loader IDs, so this is
assigned version ID 0x11 (avoid assigning 0x10 for now to catch bugs
with people putting E in the primary ID but leaving the extended ID as
zero.)
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Sebastian Plotz <sebastian-plotz@web.de>
Link: http://lkml.kernel.org/n/tip-nq318h0okuaem8x9dpv9854k@git.kernel.org
As things currently stand, traditional EFI boot loaders and the EFI
boot stub are carrying essentially the same initialisation code
required to setup an EFI machine for booting a kernel. There's really
no need to have this code in two places and the hope is that, with
this new protocol, initialisation and booting of the kernel can be
left solely to the kernel's EFI boot stub. The responsibilities of the
boot loader then become,
o Loading the kernel image from boot media
File system code still needs to be carried by boot loaders for the
scenario where the kernel and initrd files reside on a file system
that the EFI firmware doesn't natively understand, such as ext4, etc.
o Providing a user interface
Boot loaders still need to display any menus/interfaces, for example
to allow the user to select from a list of kernels.
Bump the boot protocol number because we added the 'handover_offset'
field to indicate the location of the handover protocol entry point.
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Acked-and-Tested-by: Matthew Garrett <mjg@redhat.com>
Link: http://lkml.kernel.org/r/1342689828-16815-1-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
The real-mode kernel header init_size field is located at 0x260 per the field
listing in th e"REAL-MODE KERNEL HEADER" section. It is listed as 0x25c in
the "DETAILS OF HEADER FIELDS" section, which overlaps with pref_address.
Correct the details listing to 0x260.
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Link: http://lkml.kernel.org/r/541cf88e2dfe5b8186d8b96b136d892e769a68c1.1310441260.git.dvhart@linux.intel.com
CC: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This integrates the XZ decompression code to the x86 pre-boot code.
mkpiggy.c is updated to reserve about 32 KiB more buffer safety margin for
kernel decompression. It is done unconditionally for all decompressors to
keep the code simpler.
The XZ decompressor needs around 30 KiB of heap, so the heap size is
increased to 32 KiB on both x86-32 and x86-64.
Documentation/x86/boot.txt is updated to list the XZ magic number.
With the x86 BCJ filter in XZ, XZ-compressed x86 kernel tends to be a few
percent smaller than the equivalent LZMA-compressed kernel.
Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86 bootprotocol 2.07 has introduced hardware_subarch ID in the boot
parameters provided by FW. We use it to identify Moorestown platforms.
[ tglx: Cleanup and paravirt fix ]
Signed-off-by: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
A long ago, in days of yore, it all began with a god named Thor.
There were vikings and boats and some plans for a Linux kernel
header. Unfortunately, a single 8-bit field was used for bootloader
type and version. This has generally worked without *too* much pain,
but we're getting close to flat running out of ID fields.
Add extension fields for both type and version. The type will be
extended if it the old field is 0xE; the version is a simple MSB
extension.
Keep /proc/sys/kernel/bootloader_type containing
(type << 4) + (ver & 0xf) for backwards compatiblity, but also add
/proc/sys/kernel/bootloader_version which contains the full version
number.
[ Impact: new feature to support more bootloaders ]
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Modify field names to the right ones:
- start_sys was changed to start_sys_seg
- iinitrd_addr_max was changed to ramdisk_max
- pad2 was changed to pad2 and pad3
- readmode_swtch was changed to realmode_swtch
Signed-off-by: Baodong Chen <[email]chenbdchenbd@gmail.com[email]>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: documentation
Update the boot protocol specification to include the currently
supported file formats and their magic numbers.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Impact: clarify documentation
Documentation/x86/boot.txt describes payload_offset as the offset
from the end of the real-mode code. In fact, it is more accurately
described as the offset from the beginning of the protected-mode
code, as (a) this is how it is actually calculated and (b) the padding
after the real-mode code is not included in the offset.
Signed-off-by: Philipp Kohlbecher <xt28@gmx.de>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: documentation fix
I met okuji-san (GRUB maintainer) yesterday.
He said GRuB isn't correct spelled and he want to fix it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The boot protocol, USB legacy support, and zero-page documentation is
common to the x86 platform, not i386-specific.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Linus Torvalds