- Build the kernel without the fix
- Add some flag to the purgatories KBUILD_CFLAGS,I used
-fno-asynchronous-unwind-tables
- Re-build the kernel
When you look at makes output you see that sha256.o is not re-build in the
last step. Also readelf -S still shows the .eh_frame section for
sha256.o.
With the fix sha256.o is rebuilt in the last step.
Without FORCE make does not detect changes only made to the command line
options. So object files might not be re-built even when they should be.
Fix this by adding FORCE where it is missing.
Link: http://lkml.kernel.org/r/20180704110044.29279-2-prudo@linux.ibm.com
Fixes: df6f2801f5 ("kernel/kexec_file.c: move purgatories sha256 to common code")
Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org> [4.17+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The code to verify the new kernels sha digest is applicable for all
architectures. Move it to common code.
One problem is the string.c implementation on x86. Currently sha256
includes x86/boot/string.h which defines memcpy and memset to be gcc
builtins. By moving the sha256 implementation to common code and
changing the include to linux/string.h both functions are no longer
defined. Thus definitions have to be provided in x86/purgatory/string.c
Link: http://lkml.kernel.org/r/20180321112751.22196-12-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo <prudo@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel build system already takes care of generating the dependency
files. Having the additional -MD in KBUILD_CFLAGS leads to stray
.<pid>.d files in the build directory when we call the cc-option macro.
Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Link: http://lkml.kernel.org/r/alpine.LNX.2.21.1803242219380.30139@titan.int.lan.stealer.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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>
The purgatory code defines global variables which are referenced via a
symbol lookup in the kexec code (core and arch).
A recent commit addressing sparse warnings made these static and thereby
broke kexec_file.
Why did this happen? Simply because the whole machinery is undocumented and
lacks any form of forward declarations. The variable names are unspecific
and lack a prefix, so adding forward declarations creates shadow variables
in the core code. Aside of that the code relies on magic constants and
duplicate struct definitions with no way to ensure that these things stay
in sync. The section placement of the purgatory variables happened by
chance and not by design.
Unbreak kexec and cleanup the mess:
- Add proper forward declarations and document the usage
- Use common struct definition
- Use the proper common defines instead of magic constants
- Add a purgatory_ prefix to have a proper name space
- Use ARRAY_SIZE() instead of a homebrewn reimplementation
- Add proper sections to the purgatory variables [ From Mike ]
Fixes: 72042a8c7b ("x86/purgatory: Make functions and variables static")
Reported-by: Mike Galbraith <<efault@gmx.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Nicholas Mc Guire <der.herr@hofr.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: "Tobin C. Harding" <me@tobin.cc>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1703101315140.3681@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Sparse emits warning, 'symbol not declared' for a function that has
neither file scope nor a forward declaration. The functions only call
site is an ASM file.
Add a header file with the function declaration. Include the header file in
the C source file defining the function in order to fix the sparse
warning. Include the header file in ASM file containing the call site to
document the usage.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Link: http://lkml.kernel.org/r/1487545956-2547-3-git-send-email-me@tobin.cc
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Sparse emits several 'symbol not declared' warnings for various
functions and variables.
Add static keyword to functions and variables which have file scope
only.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Link: http://lkml.kernel.org/r/1487545956-2547-2-git-send-email-me@tobin.cc
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If the gcc is configured to do -fPIE by default then the build aborts
later with:
| Unsupported relocation type: unknown type rel type name (29)
Tagging it stable so it is possible to compile recent stable kernels as
well.
Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
The sancov gcc plugin inserts a __sanitizer_cov_trace_pc() call
at the start of basic blocks.
This plugin is a helper plugin for the kcov feature. It supports
all gcc versions with plugin support (from gcc-4.5 on).
It is based on the gcc commit "Add fuzzing coverage support" by Dmitry Vyukov
(https://gcc.gnu.org/viewcvs/gcc?limit_changes=0&view=revision&revision=231296).
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Michal Marek <mmarek@suse.com>
Since commit 2aedcd098a ('kbuild: suppress annoying "... is up to
date." message'), $(call if_changed,...) is evaluated to "@:"
when there is nothing to do.
We no longer need to add "@:" after $(call if_changed,...) to
suppress "... is up to date." message.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
Code which runs outside the kernel's normal mode of operation often does
unusual things which can cause a static analysis tool like objtool to
emit false positive warnings:
- boot image
- vdso image
- relocation
- realmode
- efi
- head
- purgatory
- modpost
Set OBJECT_FILES_NON_STANDARD for their related files and directories,
which will tell objtool to skip checking them. It's ok to skip them
because they don't affect runtime stack traces.
Also skip the following code which does the right thing with respect to
frame pointers, but is too "special" to be validated by a tool:
- entry
- mcount
Also skip the test_nx module because it modifies its exception handling
table at runtime, which objtool can't understand. Fortunately it's
just a test module so it doesn't matter much.
Currently objtool is the only user of OBJECT_FILES_NON_STANDARD, but it
might eventually be useful for other tools.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris J Arges <chris.j.arges@canonical.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: live-patching@vger.kernel.org
Link: http://lkml.kernel.org/r/366c080e3844e8a5b6a0327dc7e8c2b90ca3baeb.1456719558.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 build, cleanup and defconfig updates from Ingo Molnar:
"A single minor build change to suppress a repetitive build messages,
misc cleanups and a defconfig update"
* 'x86-build-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/purgatory, build: Suppress kexec-purgatory.c is up to date message
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, CPU, AMD: Move K8 TLB flush filter workaround to K8 code
x86, espfix: Remove stale ptemask
x86, msr: Use seek definitions instead of hard-coded values
x86, msr: Convert printk to pr_foo()
x86, msr: Use PTR_ERR_OR_ZERO
x86/simplefb: Use PTR_ERR_OR_ZERO
x86/sysfb: Use PTR_ERR_OR_ZERO
x86, cpuid: Use PTR_ERR_OR_ZERO
* 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kconfig/defconfig: Enable CONFIG_FHANDLE=y
Suppress this unnecessary message during kernel re-build
(CONFIG_KEXEC_FILE=y):
make[1]: `arch/x86/purgatory/kexec-purgatory.c' is up to date.
Signed-off-by: WANG Chao <chaowang@redhat.com>
Link: http://lkml.kernel.org/r/1413262019-3759-1-git-send-email-chaowang@redhat.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Make the Makefile of kexec purgatory be consistent with others in linux
src tree, and make it look generic and simple.
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Thomas reported that build of x86_64 kernel was failing for him. He is
using 32bit tool chain.
Problem is that while compiling purgatory, I have not specified -m64
flag. And 32bit tool chain must be assuming -m32 by default.
Following is error message.
(mini) [~/work/linux-2.6] make
scripts/kconfig/conf --silentoldconfig Kconfig
CHK include/config/kernel.release
UPD include/config/kernel.release
CHK include/generated/uapi/linux/version.h
CHK include/generated/utsrelease.h
UPD include/generated/utsrelease.h
CC arch/x86/purgatory/purgatory.o
arch/x86/purgatory/purgatory.c:1:0: error: code model 'large' not supported in
the 32 bit mode
Fix it by explicitly passing appropriate -m64/-m32 build flag for
purgatory.
Reported-by: Thomas Glanzmann <thomas@glanzmann.de>
Tested-by: Thomas Glanzmann <thomas@glanzmann.de>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently new system call kexec_file_load() and all the associated code
compiles if CONFIG_KEXEC=y. But new syscall also compiles purgatory
code which currently uses gcc option -mcmodel=large. This option seems
to be available only gcc 4.4 onwards.
Hiding new functionality behind a new config option will not break
existing users of old gcc. Those who wish to enable new functionality
will require new gcc. Having said that, I am trying to figure out how
can I move away from using -mcmodel=large but that can take a while.
I think there are other advantages of introducing this new config
option. As this option will be enabled only on x86_64, other arches
don't have to compile generic kexec code which will never be used. This
new code selects CRYPTO=y and CRYPTO_SHA256=y. And all other arches had
to do this for CONFIG_KEXEC. Now with introduction of new config
option, we can remove crypto dependency from other arches.
Now CONFIG_KEXEC_FILE is available only on x86_64. So whereever I had
CONFIG_X86_64 defined, I got rid of that.
For CONFIG_KEXEC_FILE, instead of doing select CRYPTO=y, I changed it to
"depends on CRYPTO=y". This should be safer as "select" is not
recursive.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds support for loading a kexec on panic (kdump) kernel usning
new system call.
It prepares ELF headers for memory areas to be dumped and for saved cpu
registers. Also prepares the memory map for second kernel and limits its
boot to reserved areas only.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Create a stand alone relocatable object purgatory which runs between two
kernels. This name, concept and some code has been taken from
kexec-tools. Idea is that this code runs after a crash and it runs in
minimal environment. So keep it separate from rest of the kernel and in
long term we will have to practically do no maintenance of this code.
This code also has the logic to do verify sha256 hashes of various
segments which have been loaded into memory. So first we verify that the
kernel we are jumping to is fine and has not been corrupted and make
progress only if checsums are verified.
This code also takes care of copying some memory contents to backup region.
[sfr@canb.auug.org.au: run host built programs from objtree]
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Next two patches provide code for purgatory. This is a code which does
not link against the kernel and runs stand alone. This code runs between
two kernels. One of the primary purpose of this code is to verify the
digest of newly loaded kernel and making sure it matches the digest
computed at kernel load time.
We use sha256 for calculating digest of kexec segmetns. Purgatory can't
use stanard crypto API as that API is not available in purgatory context.
Hence, I have copied code from crypto/sha256_generic.c and compiled it
with purgaotry code so that it could be used. I could not #include
sha256_generic.c file here as some of the function signature requiered
little tweaking. Original functions work with crypto API but these ones
don't
So instead of doing #include on sha256_generic.c I just copied relevant
portions of code into arch/x86/purgatory/sha256.c. Now we shouldn't have
to touch this code at all. Do let me know if there are better ways to
handle it.
This patch does not enable compiling of this code. That happens in next
patch. I wanted to highlight this change in a separate patch for easy
review.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Greg Kroah-Hartman <greg@kroah.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: WANG Chao <chaowang@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
