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Vasily Gorbik 2d6f74f797 s390/decompressor: correct EXCLUDE_FILE construct
The following linker construct is problematic with linkers of
binutils < 2.28:

EXCLUDE_FILE (*piggy.o) *(.rodata.*)

from 8f1732fc2a11dc of binutils:
"though the linker accepts this without complaint the
EXCLUDE_FILE part is silently ignored and has no effect."

Silent ignoring of EXCLUDE_FILE construct made .rodata.compressed be
part of .rodata, and in case of .rodata.compressed following some
unaligned data, input_len would also become unaligned.

from arch/s390/boot/compressed/vmlinux.map:
 .rodata.compressed
                0x0000000000012fea   0x4d57e7 arch/s390/boot/compressed/piggy.o
                0x0000000000012fea                input_len
                0x0000000000012fee                input_data

input_len is later used here:
arch/s390/boot/compressed/misc.c:113
	__decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error);

asm generated by gcc looks like:
	.loc 3 113 0
egfrl	%r11,input_len

from what assembler generates invalid (the second operand must be aligned
on a doubleword boundary):
   0x00000000000129b4 <+148>:   c4 bc 00 00 03 1b       lgfrl   %r11,0x12fea
hence specification exception is recognized.

To avoid an issue use EXCLUDE_FILE construct which is recognized by
older linkers (since at least binutils-2_11)
	*(EXCLUDE_FILE (*piggy.o) .rodata.compressed)

Also ensure that .rodata.compressed is at least doubleword aligned.

Fixes: 89b5202e81 ("s390/decompressor: support uncompressed kernel")
Reported-by: Halil Pasic <pasic@linux.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-07-02 11:25:01 +02:00
arch s390/decompressor: correct EXCLUDE_FILE construct 2018-07-02 11:25:01 +02:00
block for-linus-20180623 2018-06-24 06:33:54 +08:00
certs docs: Fix some broken references 2018-06-15 18:10:01 -03:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-06-24 06:31:54 +08:00
Documentation This contains a few fixes and a clean up. 2018-06-24 06:23:28 +08:00
drivers s390/zcrypt: add copy_from_user length plausibility checks 2018-07-02 11:24:55 +02:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs \n 2018-06-22 18:04:56 +09:00
include Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-24 20:18:19 +08:00
init init/Kconfig: add an option for uncompressed kernel 2018-06-25 10:14:40 +02:00
ipc ipc: use new return type vm_fault_t 2018-06-15 07:55:25 +09:00
kernel Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-24 20:29:15 +08:00
lib Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-24 19:36:16 +08:00
LICENSES LICENSES: Add Linux-OpenIB license text 2018-04-27 16:41:53 -06:00
mm for-linus-20180623 2018-06-24 06:33:54 +08:00
net NFS client bugfixes for Linux 4.18 2018-06-22 06:21:34 +09:00
samples VFIO updates for v4.18 2018-06-12 13:11:26 -07:00
scripts tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcount 2018-06-21 15:12:56 -04:00
security docs: Fix some broken references 2018-06-15 18:10:01 -03:00
sound docs: Fix some broken references 2018-06-15 18:10:01 -03:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-24 20:29:15 +08:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt KVM: arm64: Prevent KVM_COMPAT from being selected 2018-06-21 17:17:50 +01:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge branch 'asoc-4.17' into asoc-4.18 for compress dependencies 2018-04-26 12:24:28 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: add basic helper macros to scripts/Kconfig.include 2018-05-29 03:31:19 +09:00
MAINTAINERS Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-24 19:59:52 +08:00
Makefile Linux 4.18-rc2 2018-06-24 20:54:29 +08:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.