Commit Graph

8 Commits

Author SHA1 Message Date
Linus Torvalds
206f18f2ca Merge branches 'x86-build-for-linus', 'x86-cleanups-for-linus' and 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
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
2014-12-10 12:35:46 -08:00
WANG Chao
3ea4b8ee24 x86/purgatory, build: Suppress kexec-purgatory.c is up to date message
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>
2014-10-15 08:31:21 -07:00
Baoquan He
887f4f8666 arch/x86/purgatory/Makefile: try to use automatic variable in kexec purgatory makefile
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>
2014-10-14 02:18:21 +02:00
Vivek Goyal
4df4185a59 x86/purgatory: use approprate -m64/-32 build flag for arch/x86/purgatory
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>
2014-08-29 16:28:16 -07:00
Vivek Goyal
74ca317c26 kexec: create a new config option CONFIG_KEXEC_FILE for new syscall
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>
2014-08-29 16:28:16 -07:00
Vivek Goyal
dd5f726076 kexec: support for kexec on panic using new system call
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>
2014-08-08 15:57:33 -07:00
Vivek Goyal
8fc5b4d412 purgatory: core purgatory functionality
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>
2014-08-08 15:57:32 -07:00
Vivek Goyal
daeba0641a purgatory/sha256: provide implementation of sha256 in purgaotory context
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>
2014-08-08 15:57:32 -07:00