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  1. 29 3月, 2016 1 次提交
    • H
      x86/build: Build compressed x86 kernels as PIE · 6d92bc9d
      由 H.J. Lu 提交于 
      The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X
relocation to get the symbol address in PIC.  When the compressed x86
kernel isn't built as PIC, the linker optimizes R_386_GOT32X relocations
to their fixed symbol addresses.  However, when the compressed x86
kernel is loaded at a different address, it leads to the following
load failure:

  Failed to allocate space for phdrs

during the decompression stage.

If the compressed x86 kernel is relocatable at run-time, it should be
compiled with -fPIE, instead of -fPIC, if possible and should be built as
Position Independent Executable (PIE) so that linker won't optimize
R_386_GOT32X relocation to its fixed symbol address.

Older linkers generate R_386_32 relocations against locally defined
symbols, _bss, _ebss, _got and _egot, in PIE.  It isn't wrong, just less
optimal than R_386_RELATIVE.  But the x86 kernel fails to properly handle
R_386_32 relocations when relocating the kernel.  To generate
R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as
hidden in both 32-bit and 64-bit x86 kernels.

To build a 64-bit compressed x86 kernel as PIE, we need to disable the
relocation overflow check to avoid relocation overflow errors. We do
this with a new linker command-line option, -z noreloc-overflow, which
got added recently:

 commit 4c10bbaa0912742322f10d9d5bb630ba4e15dfa7
 Author: H.J. Lu <hjl.tools@gmail.com>
 Date:   Tue Mar 15 11:07:06 2016 -0700

    Add -z noreloc-overflow option to x86-64 ld

    Add -z noreloc-overflow command-line option to the x86-64 ELF linker to
    disable relocation overflow check.  This can be used to avoid relocation
    overflow check if there will be no dynamic relocation overflow at
    run-time.

The 64-bit compressed x86 kernel is built as PIE only if the linker supports
-z noreloc-overflow.  So far 64-bit relocatable compressed x86 kernel
boots fine even when it is built as a normal executable.
Signed-off-by: NH.J. Lu <hjl.tools@gmail.com>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
[ Edited the changelog and comments. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      6d92bc9d
  3. 23 3月, 2016 1 次提交
    • D
      kernel: add kcov code coverage · 5c9a8750
      由 Dmitry Vyukov 提交于 
      kcov provides code coverage collection for coverage-guided fuzzing
(randomized testing).  Coverage-guided fuzzing is a testing technique
that uses coverage feedback to determine new interesting inputs to a
system.  A notable user-space example is AFL
(http://lcamtuf.coredump.cx/afl/).  However, this technique is not
widely used for kernel testing due to missing compiler and kernel
support.

kcov does not aim to collect as much coverage as possible.  It aims to
collect more or less stable coverage that is function of syscall inputs.
To achieve this goal it does not collect coverage in soft/hard
interrupts and instrumentation of some inherently non-deterministic or
non-interesting parts of kernel is disbled (e.g.  scheduler, locking).

Currently there is a single coverage collection mode (tracing), but the
API anticipates additional collection modes.  Initially I also
implemented a second mode which exposes coverage in a fixed-size hash
table of counters (what Quentin used in his original patch).  I've
dropped the second mode for simplicity.

This patch adds the necessary support on kernel side.  The complimentary
compiler support was added in gcc revision 231296.

We've used this support to build syzkaller system call fuzzer, which has
found 90 kernel bugs in just 2 months:

  https://github.com/google/syzkaller/wiki/Found-Bugs

We've also found 30+ bugs in our internal systems with syzkaller.
Another (yet unexplored) direction where kcov coverage would greatly
help is more traditional "blob mutation".  For example, mounting a
random blob as a filesystem, or receiving a random blob over wire.

Why not gcov.  Typical fuzzing loop looks as follows: (1) reset
coverage, (2) execute a bit of code, (3) collect coverage, repeat.  A
typical coverage can be just a dozen of basic blocks (e.g.  an invalid
input).  In such context gcov becomes prohibitively expensive as
reset/collect coverage steps depend on total number of basic
blocks/edges in program (in case of kernel it is about 2M).  Cost of
kcov depends only on number of executed basic blocks/edges.  On top of
that, kernel requires per-thread coverage because there are always
background threads and unrelated processes that also produce coverage.
With inlined gcov instrumentation per-thread coverage is not possible.

kcov exposes kernel PCs and control flow to user-space which is
insecure.  But debugfs should not be mapped as user accessible.

Based on a patch by Quentin Casasnovas.

[akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode']
[akpm@linux-foundation.org: unbreak allmodconfig]
[akpm@linux-foundation.org: follow x86 Makefile layout standards]
Signed-off-by: NDmitry Vyukov <dvyukov@google.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: syzkaller <syzkaller@googlegroups.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Tavis Ormandy <taviso@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@google.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: David Drysdale <drysdale@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5c9a8750
  5. 29 2月, 2016 1 次提交
    • J
      objtool: Mark non-standard object files and directories · c0dd6716
      由 Josh Poimboeuf 提交于 
      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: NJosh 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.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      c0dd6716
  7. 21 1月, 2016 1 次提交
  9. 14 2月, 2015 1 次提交
    • A
      x86_64: add KASan support · ef7f0d6a
      由 Andrey Ryabinin 提交于 
      This patch adds arch specific code for kernel address sanitizer.

16TB of virtual addressed used for shadow memory.  It's located in range
[ffffec0000000000 - fffffc0000000000] between vmemmap and %esp fixup
stacks.

At early stage we map whole shadow region with zero page.  Latter, after
pages mapped to direct mapping address range we unmap zero pages from
corresponding shadow (see kasan_map_shadow()) and allocate and map a real
shadow memory reusing vmemmap_populate() function.

Also replace __pa with __pa_nodebug before shadow initialized.  __pa with
CONFIG_DEBUG_VIRTUAL=y make external function call (__phys_addr)
__phys_addr is instrumented, so __asan_load could be called before shadow
area initialized.
Signed-off-by: NAndrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: NAndrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jim Davis <jim.epost@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ef7f0d6a
  11. 13 2月, 2015 1 次提交
    • M
      x86/efi: Avoid triple faults during EFI mixed mode calls · 96738c69
      由 Matt Fleming 提交于 
      Andy pointed out that if an NMI or MCE is received while we're in the
middle of an EFI mixed mode call a triple fault will occur. This can
happen, for example, when issuing an EFI mixed mode call while running
perf.

The reason for the triple fault is that we execute the mixed mode call
in 32-bit mode with paging disabled but with 64-bit kernel IDT handlers
installed throughout the call.

At Andy's suggestion, stop playing the games we currently do at runtime,
such as disabling paging and installing a 32-bit GDT for __KERNEL_CS. We
can simply switch to the __KERNEL32_CS descriptor before invoking
firmware services, and run in compatibility mode. This way, if an
NMI/MCE does occur the kernel IDT handler will execute correctly, since
it'll jump to __KERNEL_CS automatically.

However, this change is only possible post-ExitBootServices(). Before
then the firmware "owns" the machine and expects for its 32-bit IDT
handlers to be left intact to service interrupts, etc.

So, we now need to distinguish between early boot and runtime
invocations of EFI services. During early boot, we need to restore the
GDT that the firmware expects to be present. We can only jump to the
__KERNEL32_CS code segment for mixed mode calls after ExitBootServices()
has been invoked.

A liberal sprinkling of comments in the thunking code should make the
differences in early and late environments more apparent.
Reported-by: NAndy Lutomirski <luto@amacapital.net>
Tested-by: NBorislav Petkov <bp@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      96738c69
  13. 27 1月, 2015 1 次提交
  15. 24 11月, 2014 1 次提交
  17. 12 11月, 2014 1 次提交
    • A
      efi/x86: Move x86 back to libstub · 243b6754
      由 Ard Biesheuvel 提交于 
      This reverts commit 84be8805, which itself reverted my original
attempt to move x86 from #include'ing .c files from across the tree
to using the EFI stub built as a static library.

The issue that affected the original approach was that splitting
the implementation into several .o files resulted in the variable
'efi_early' becoming a global with external linkage, which under
-fPIC implies that references to it must go through the GOT. However,
dealing with this additional GOT entry turned out to be troublesome
on some EFI implementations. (GCC's visibility=hidden attribute is
supposed to lift this requirement, but it turned out not to work on
the 32-bit build.)

Instead, use a pure getter function to get a reference to efi_early.
This approach results in no additional GOT entries being generated,
so there is no need for any changes in the early GOT handling.
Tested-by: NMaarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      243b6754
  19. 02 11月, 2014 2 次提交
  21. 24 9月, 2014 1 次提交
    • M
      Revert "efi/x86: efistub: Move shared dependencies to <asm/efi.h>" · 84be8805
      由 Matt Fleming 提交于 
      This reverts commit f23cf8bd ("efi/x86: efistub: Move shared
dependencies to <asm/efi.h>") as well as the x86 parts of commit
f4f75ad5 ("efi: efistub: Convert into static library").

The road leading to these two reverts is long and winding.

The above two commits were merged during the v3.17 merge window and
turned the common EFI boot stub code into a static library. This
necessitated making some symbols global in the x86 boot stub which
introduced new entries into the early boot GOT.

The problem was that we weren't fixing up the newly created GOT entries
before invoking the EFI boot stub, which sometimes resulted in hangs or
resets. This failure was reported by Maarten on his Macbook pro.

The proposed fix was commit 9cb0e394 ("x86/efi: Fixup GOT in all
boot code paths"). However, that caused issues for Linus when booting
his Sony Vaio Pro 11. It was subsequently reverted in commit
f3670394.

So that leaves us back with Maarten's Macbook pro not booting.

At this stage in the release cycle the least risky option is to revert
the x86 EFI boot stub to the pre-merge window code structure where we
explicitly #include efi-stub-helper.c instead of linking with the static
library. The arm64 code remains unaffected.

We can take another swing at the x86 parts for v3.18.

Conflicts:
	arch/x86/include/asm/efi.h
Tested-by: NJosh Boyer <jwboyer@fedoraproject.org>
Tested-by: NMaarten Lankhorst <maarten.lankhorst@canonical.com>
Tested-by: Leif Lindholm <leif.lindholm@linaro.org> [arm64]
Tested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      84be8805
  23. 18 8月, 2014 3 次提交
  25. 19 7月, 2014 1 次提交
    • A
      efi: efistub: Convert into static library · f4f75ad5
      由 Ard Biesheuvel 提交于 
      This patch changes both x86 and arm64 efistub implementations
from #including shared .c files under drivers/firmware/efi to
building shared code as a static library.

The x86 code uses a stub built into the boot executable which
uncompresses the kernel at boot time. In this case, the library is
linked into the decompressor.

In the arm64 case, the stub is part of the kernel proper so the library
is linked into the kernel proper as well.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      f4f75ad5
  27. 10 12月, 2013 1 次提交
    • H
      x86, build: Pass in additional -mno-mmx, -mno-sse options · 8b3b005d
      由 H. Peter Anvin 提交于 
      In checkin

    5551a34e x86-64, build: Always pass in -mno-sse

we unconditionally added -mno-sse to the main build, to keep newer
compilers from generating SSE instructions from autovectorization.
However, this did not extend to the special environments
(arch/x86/boot, arch/x86/boot/compressed, and arch/x86/realmode/rm).
Add -mno-sse to the compiler command line for these environments, and
add -mno-mmx to all the environments as well, as we don't want a
compiler to generate MMX code either.

This patch also removes a $(cc-option) call for -m32, since we have
long since stopped supporting compilers too old for the -m32 option,
and in fact hardcode it in other places in the Makefiles.
Reported-by: NKevin B. Smith <kevin.b.smith@intel.com>
Cc: Sunil K. Pandey <sunil.k.pandey@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: H. J. Lu <hjl.tools@gmail.com>
Link: http://lkml.kernel.org/n/tip-j21wzqv790q834n7yc6g80j1@git.kernel.org
Cc: <stable@vger.kernel.org> # build fix only
      8b3b005d
  29. 13 10月, 2013 2 次提交
  31. 10 7月, 2013 1 次提交
  33. 17 4月, 2013 2 次提交
  35. 06 4月, 2013 1 次提交
    • J
      x86: Fix rebuild with EFI_STUB enabled · 91870824
      由 Jan Beulich 提交于 
      eboot.o and efi_stub_$(BITS).o didn't get added to "targets", and hence
their .cmd files don't get included by the build machinery, leading to
the files always getting rebuilt.

Rather than adding the two files individually, take the opportunity and
add $(VMLINUX_OBJS) to "targets" instead, thus allowing the assignment
at the top of the file to be shrunk quite a bit.

At the same time, remove a pointless flags override line - the variable
assigned to was misspelled anyway, and the options added are
meaningless for assembly sources.

[ hpa: the patch is not minimal, but I am taking it for -urgent anyway
  since the excess impact of the patch seems to be small enough. ]
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/515C5D2502000078000CA6AD@nat28.tlf.novell.com
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      91870824
  37. 17 9月, 2012 1 次提交
  39. 19 5月, 2012 1 次提交
    • H
      x86, realmode: 16-bit real-mode code support for relocs tool · 6520fe55
      由 H. Peter Anvin 提交于 
      A new option is added to the relocs tool called '--realmode'.
This option causes the generation of 16-bit segment relocations
and 32-bit linear relocations for the real-mode code. When
the real-mode code is moved to the low-memory during kernel
initialization, these relocation entries can be used to
relocate the code properly.

In the assembly code 16-bit segment relocations must be relative
to the 'real_mode_seg' absolute symbol. Linear relocations must be
relative to a symbol prefixed with 'pa_'.

16-bit segment relocation is used to load cs:ip in 16-bit code.
Linear relocations are used in the 32-bit code for relocatable
data references. They are declared in the linker script of the
real-mode code.

The relocs tool is moved to arch/x86/tools/relocs.c, and added new
target archscripts that can be used to build scripts needed building
an architecture.  be compiled before building the arch/x86 tree.

[ hpa: accelerating this because it detects invalid absolute
  relocations, a serious bug in binutils 2.22.52.0.x which currently
  produces bad kernels. ]
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.comSigned-off-by: NJarkko Sakkinen <jarkko.sakkinen@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
      6520fe55
  41. 09 5月, 2012 2 次提交
  43. 29 2月, 2012 1 次提交
  45. 13 12月, 2011 1 次提交
    • M
      x86, efi: EFI boot stub support · 291f3632
      由 Matt Fleming 提交于 
      There is currently a large divide between kernel development and the
development of EFI boot loaders. The idea behind this patch is to give
the kernel developers full control over the EFI boot process. As
H. Peter Anvin put it,

"The 'kernel carries its own stub' approach been very successful in
dealing with BIOS, and would make a lot of sense to me for EFI as
well."

This patch introduces an EFI boot stub that allows an x86 bzImage to
be loaded and executed by EFI firmware. The bzImage appears to the
firmware as an EFI application. Luckily there are enough free bits
within the bzImage header so that it can masquerade as an EFI
application, thereby coercing the EFI firmware into loading it and
jumping to its entry point. The beauty of this masquerading approach
is that both BIOS and EFI boot loaders can still load and run the same
bzImage, thereby allowing a single kernel image to work in any boot
environment.

The EFI boot stub supports multiple initrds, but they must exist on
the same partition as the bzImage. Command-line arguments for the
kernel can be appended after the bzImage name when run from the EFI
shell, e.g.

Shell> bzImage console=ttyS0 root=/dev/sdb initrd=initrd.img

v7:
 - Fix checkpatch warnings.

v6:

 - Try to allocate initrd memory just below hdr->inird_addr_max.

v5:

 - load_options_size is UTF-16, which needs dividing by 2 to convert
   to the corresponding ASCII size.

v4:

 - Don't read more than image->load_options_size

v3:

 - Fix following warnings when compiling CONFIG_EFI_STUB=n

   arch/x86/boot/tools/build.c: In function ‘main’:
   arch/x86/boot/tools/build.c:138:24: warning: unused variable ‘pe_header’
   arch/x86/boot/tools/build.c:138:15: warning: unused variable ‘file_sz’

 - As reported by Matthew Garrett, some Apple machines have GOPs that
   don't have hardware attached. We need to weed these out by
   searching for ones that handle the PCIIO protocol.

 - Don't allocate memory if no initrds are on cmdline
 - Don't trust image->load_options_size

Maarten Lankhorst noted:
 - Don't strip first argument when booted from efibootmgr
 - Don't allocate too much memory for cmdline
 - Don't update cmdline_size, the kernel considers it read-only
 - Don't accept '\n' for initrd names

v2:

 - File alignment was too large, was 8192 should be 512. Reported by
   Maarten Lankhorst on LKML.
 - Added UGA support for graphics
 - Use VIDEO_TYPE_EFI instead of hard-coded number.
 - Move linelength assignment until after we've assigned depth
 - Dynamically fill out AddressOfEntryPoint in tools/build.c
 - Don't use magic number for GDT/TSS stuff. Requested by Andi Kleen
 - The bzImage may need to be relocated as it may have been loaded at
   a high address address by the firmware. This was required to get my
   macbook booting because the firmware loaded it at 0x7cxxxxxx, which
   triggers this error in decompress_kernel(),

	if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff))
		error("Destination address too large");

Cc: Mike Waychison <mikew@google.com>
Cc: Matthew Garrett <mjg@redhat.com>
Tested-by: NHenrik Rydberg <rydberg@euromail.se>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1321383097.2657.9.camel@mfleming-mobl1.ger.corp.intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      291f3632
  47. 14 1月, 2011 1 次提交
    • L
      x86: support XZ-compressed kernel · 30314804
      由 Lasse Collin 提交于 
      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: NLasse 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      30314804
  49. 03 8月, 2010 1 次提交
    • Y
      x86, setup: enable early console output from the decompressor · 8fee13a4
      由 Yinghai Lu 提交于 
      This enables the decompressor output to be seen on the serial console.
Most of the code is shared with the regular boot code.

We could add printf to the decompressor if needed, but currently there
is no sufficiently compelling user.

-v2: define BOOT_BOOT_H to avoid include boot.h
-v3: early_serial_base need to be static in misc.c ?
-v4: create seperate string.c printf.c cmdline.c early_serial_console.c
     after hpa's patch that allow global variables in compressed/misc stage
-v5: remove printf.c related
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      8fee13a4
  51. 12 1月, 2010 1 次提交
  53. 26 12月, 2009 1 次提交
    • H
      x86, compress: Force i386 instructions for the decompressor · 17a2a9b5
      由 H. Peter Anvin 提交于 
      Recently, some distros have started shipping versions of gcc which
default to -march=i686.  This breaks building kernels for pre-i686
machines, even if they have been selected in Kconfig, due to the
generation of CMOV instructions.

There isn't enough benefit to try to preserve the generation of these
instructions even when selected, so simply force -march=i386 for the
decompressor when building a 32-bit kernel.
Reported-and-tested-by: NChris Rankin <rankincj@yahoo.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
LKML-Reference: <219280.97558.qm@web52907.mail.re2.yahoo.com>
      17a2a9b5
  55. 21 8月, 2009 1 次提交
  57. 19 6月, 2009 1 次提交
    • P
      gcov: enable GCOV_PROFILE_ALL for x86_64 · 7bf99fb6
      由 Peter Oberparleiter 提交于 
      Enable gcov profiling of the entire kernel on x86_64. Required changes
include disabling profiling for:

* arch/kernel/acpi/realmode and arch/kernel/boot/compressed:
  not linked to main kernel
* arch/vdso, arch/kernel/vsyscall_64 and arch/kernel/hpet:
  profiling causes segfaults during boot (incompatible context)
Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Li Wei <W.Li@Sun.COM>
Cc: Michael Ellerman <michaele@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7bf99fb6
  59. 09 5月, 2009 3 次提交
  61. 27 4月, 2009 1 次提交
    • L
      x86: unify arch/x86/boot/compressed/vmlinux_*.lds · 51b26ada
      由 Linus Torvalds 提交于 
      Look at the:

	diff -u arch/x86/boot/compressed/vmlinux_*.lds

output and realize that they're basially exactly the same except for
trivial naming differences, and the fact that the 64-bit version has a
"pgtable" thing.

So unify them.

There's some trivial cleanup there (make the output format a Kconfig thing
rather than doing #ifdef's for it, and unify both 32-bit and 64-bit BSS
end to "_ebss", where 32-bit used to use the traditional "_end"), but
other than that it's really very mindless and straigt conversion.

For example, I think we should aim to remove "startup_32" vs "startup_64",
and just call it "startup", and get rid of one more difference. I didn't
do that.

Also, notice the comment in the unified vmlinux.lds.S talks about
"head_64" and "startup_32" which is an odd and incorrect mix, but that was
actually what the old 64-bit only lds file had, so the confusion isn't
new, and now that mixing is arguably more accurate thanks to the
vmlinux.lds.S file being shared between the two cases ;)

[ Impact: cleanup, unification ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Acked-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      51b26ada
  63. 03 4月, 2009 1 次提交