linux.git/arch/arm/boot/compressed, branch v4.16

ARM: 8745/1: get rid of __memzero()

2018-01-21T15:37:56+00:00

The __memzero assembly code is almost identical to memset's except for
two orr instructions. The runtime performance of __memset(p, n) and
memset(p, 0, n) is accordingly almost identical.

However, the memset() macro used to guard against a zero length and to
call __memzero at compile time when the fill value is a constant zero
interferes with compiler optimizations.

Arnd found tha the test against a zero length brings up some new
warnings with gcc v8:

  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82103

And successively rremoving the test against a zero length and the call
to __memzero optimization produces the following kernel sizes for
defconfig with gcc 6:

    text     data     bss       dec       hex  filename
12248142  6278960  413588  18940690   1210312  vmlinux.orig
12244474  6278960  413588  18937022   120f4be  vmlinux.no_zero_test
12239160  6278960  413588  18931708   120dffc  vmlinux.no_memzero

So it is probably not worth keeping __memzero around given that the
compiler can do a better job at inlining trivial memset(p,0,n) on its
own. And the memset code already handles a zero length just fine.

Suggested-by: Arnd Bergmann 
Signed-off-by: Nicolas Pitre 
Acked-by: Ard Biesheuvel 
Acked-by: Arnd Bergmann 
Signed-off-by: Russell King

ARM: verify size of zImage

2017-12-17T22:14:05+00:00

The linker can sometimes add additional sections to the zImage ELF file
which results in the zImage binary being larger than expected.  This
causes appended DT blobs to fail.

Verify that the zImage binary is the expected size, and fail the build
if this is not the case.

We need to include the .data.rel.ro section in the image as the RiscPC
build includes font data that contains a small amount of data in this
section.

Tested-by: Ard Biesheuvel 
Tested-by: Gregory CLEMENT 
Signed-off-by: Russell King

Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

2017-11-16T20:50:35+00:00

Pull ARM updates from Russell King:

 - add support for ELF fdpic binaries on both MMU and noMMU platforms

 - linker script cleanups

 - support for compressed .data section for XIP images

 - discard memblock arrays when possible

 - various cleanups

 - atomic DMA pool updates

 - better diagnostics of missing/corrupt device tree

 - export information to allow userspace kexec tool to place images more
   inteligently, so that the device tree isn't overwritten by the
   booting kernel

 - make early_printk more efficient on semihosted systems

 - noMMU cleanups

 - SA1111 PCMCIA update in preparation for further cleanups

* 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: (38 commits)
  ARM: 8719/1: NOMMU: work around maybe-uninitialized warning
  ARM: 8717/2: debug printch/printascii: translate '\n' to "\r\n" not "\n\r"
  ARM: 8713/1: NOMMU: Support MPU in XIP configuration
  ARM: 8712/1: NOMMU: Use more MPU regions to cover memory
  ARM: 8711/1: V7M: Add support for MPU to M-class
  ARM: 8710/1: Kconfig: Kill CONFIG_VECTORS_BASE
  ARM: 8709/1: NOMMU: Disallow MPU for XIP
  ARM: 8708/1: NOMMU: Rework MPU to be mostly done in C
  ARM: 8707/1: NOMMU: Update MPU accessors to use cp15 helpers
  ARM: 8706/1: NOMMU: Move out MPU setup in separate module
  ARM: 8702/1: head-common.S: Clear lr before jumping to start_kernel()
  ARM: 8705/1: early_printk: use printascii() rather than printch()
  ARM: 8703/1: debug.S: move hexbuf to a writable section
  ARM: add additional table to compressed kernel
  ARM: decompressor: fix BSS size calculation
  pcmcia: sa1111: remove special sa1111 mmio accessors
  pcmcia: sa1111: use sa1111_get_irq() to obtain IRQ resources
  ARM: better diagnostics with missing/corrupt dtb
  ARM: 8699/1: dma-mapping: Remove init_dma_coherent_pool_size()
  ARM: 8698/1: dma-mapping: Mark atomic_pool as __ro_after_init
  ..

Merge branches 'fixes', 'misc' and 'sa1111-for-next' into for-next

2017-11-08T19:42:43+00:00

Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm

2017-11-04T21:26:30+00:00

Pull ARM fixes from Russell King:

 - omit EFI memory map sorting, which was recently introduced, but
   caused problems with the decompressor due to additional sections
   being emitted.

 - avoid unaligned load fault-generating instructions in the
   decompressor by switching to a private unaligned implementation.

 - add a symbol into the decompressor to further debug non-boot
   situations (ld's documentation is extremely poor for how "." works,
   ld doesn't seem to follow its own documentation!)

 - parse endian information to sparse

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: add debug ".edata_real" symbol
  ARM: 8716/1: pass endianness info to sparse
  efi/libstub: arm: omit sorting of the UEFI memory map
  ARM: 8715/1: add a private asm/unaligned.h

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

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 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

ARM: add debug ".edata_real" symbol

2017-11-02T00:10:28+00:00

Add an additional symbol to the decompressor image, which will allow
future debugging of non-bootable problems similar to the one encountered
with the EFI stub.

Signed-off-by: Russell King

ARM: 8704/1: semihosting: use proper instruction on v7m processors

2017-10-12T10:28:29+00:00

The svc instruction doesn't exist on v7m processors. Semihosting ops are
invoked with the bkpt instruction instead.

Signed-off-by: Nicolas Pitre 
Signed-off-by: Russell King

ARM: add additional table to compressed kernel

2017-10-03T12:27:07+00:00

Add an additional extendable table to the compressed kernel so that we
can provide further information to boot loaders regarding the properties
of the image contained within.

This is necessary for correct behaviour of kexec.

Tested-by: Tony Lindgren 
Tested-by: Keerthy 
Signed-off-by: Russell King

ARM: decompressor: fix BSS size calculation

2017-10-03T12:26:41+00:00

Assuming size(1) gives the size of the BSS is a mistake - it reports
the size of the .bss section in the ELF image, which may not be the
same as the region we mark with the __bss_start..__bss_stop symbols.

We use the size of the BSS in the decompressor to know whether the
kernel will overwrite the appended dtb, by adding the BSS size to the
size of the Image (stored at the end of the compressed data) and adding
the desired address of the decompressed image.

If the BSS size is smaller than it really is, the decompressor can
incorrectly assume that the BSS clearance will not overwrite the DTB.

Here is an illustration:

$ arm-linux-size vmlinux
   text    data      bss      dec     hex filename
8136972 3098076 10240348 21475396 147b044 vmlinux
$ arm-linux-nm vmlinux | grep __bss_
c0ac0e34 B __bss_start
c1484f9c B __bss_stop
$ stat -c %s arch/arm/boot/Image
11243060

In the above case, we are 12 bytes short.  This is caused by the BSS
section being aligned by one of its input sections:

Idx Name          Size      VMA       LMA       File off  Algn
 23 __bug_table   00005d3c  c0abb0f8  c0abb0f8  00acb0f8  2**2
                  CONTENTS, ALLOC, LOAD, DATA
 24 .bss          009c415c  c0ac0e40  c0ac0e40  00ad0e34  2**6
                  ALLOC

Note that there's an additional 12 bytes difference between the file
offset and LMA compared with the bug table - this occurs because one
of the input sections for the .bss section requires a 64 byte
alignment.

Fix this by using 'nm' and perl to obtain the address of the __bss_start
and __bss_stop symbols, using their difference for the size of the BSS.

Tested-by: Tony Lindgren 
Tested-by: Keerthy 
Signed-off-by: Russell King