Commit Graph

16 Commits

Author SHA1 Message Date
Nicolas Pitre 2f181e0ba8 ARM: linker script: factor out some common definitions between XIP and non-XIP
Lots of duplications between vmlinux.lds.S and vmlinux-xip.lds.S.
This may lead to one file being updated but not the other. For example,
SOFTIRQENTRY_TEXT and HYPERVISOR_TEXT were missing from the XIP version.

This creates vmlinux.lds.h where a bunch of common defines are moved.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>
2018-03-09 20:19:01 -05:00
Russell King c608906165 ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code
Avoid adding kprobes to any of the kernel entry/exit or startup
assembly code, or code in the identity-mapped region.  This code does
not conform to the standard C conventions, which means that the
expectations of the kprobes code is not forfilled.

Placing kprobes at some of these locations results in the kernel trying
to return to userspace addresses while retaining the CPU in kernel mode.

Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-12-17 22:14:21 +00:00
Linus Torvalds 441692aafc Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
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
  ..
2017-11-16 12:50:35 -08:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
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>
2017-11-02 11:10:55 +01:00
Vladimir Murzin 216218308c ARM: 8713/1: NOMMU: Support MPU in XIP configuration
Currently, there is assumption in early MPU setup code that kernel
image is located in RAM, which is obviously not true for XIP. To run
code from ROM we need to make sure that it is covered by MPU. However,
due to we allocate regions (semi-)dynamically we can run into issue of
trimming region we are running from in case ROM spawns several MPU
regions. To help deal with that we enforce minimum alignments for start
end end of XIP address space as 1MB and 128Kb correspondingly.

Tested-by: Alexandre TORGUE <alexandre.torgue@st.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2017-10-23 16:59:31 +01:00
Nicolas Pitre ca8b5d97d6 ARM: XIP kernel: store .data compressed in ROM
The .data segment stored in ROM is only copied to RAM once at boot time
and never referenced afterwards. This is arguably a suboptimal usage of
ROM resources.

This patch allows for compressing the .data segment before storing it
into ROM and decompressing it to RAM rather than simply copying it,
saving on precious ROM space.

Because global data is not available yet (obviously) we must allocate
decompressor workspace memory on the stack. The .bss area is used as a
stack area for that purpose before it is cleared. The required stack
frame is 9568 bytes for __inflate_kernel_data() alone, so make sure
the .bss is large enough to cope with that plus extra room for called
functions or fail the build.

Those numbers were picked arbitrarily based on the above 9568 byte
stack frame:

10240 (2.5 * PAGE_SIZE): used to override -Wframe-larger-than whose
default value is 1024.
12288 (3 * PAGE_SIZE): minimum .bss size to contain the stack.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>
2017-09-10 19:34:53 -04:00
Nicolas Pitre 0d302c710b ARM: vmlinux-xip.lds.S: fix multiple issues
The XIP linker script has several problems:

- PAGE_ALIGNED_DATA is missing and is likely to end up somewhere with
  the wrong LMA.

- BUG_TABLE definitely has the wrong LMA, it is not copied to RAM, and
  its VMA is unaccounted for and likely to clash with dynamic memory
  usage.

- TCM usage is similarly broken.

- PERCPU_SECTION is left in ROM despite being written to.

Let's use generic macros for those things and locate them appropriately.
Incidentally, those macros are usable with a LMA != VMA already by
properly defining LOAD_OFFSET.

TCM is not fixed here. It never worked in a XIP configuration anyway, so
that can wait until another round of cleanups.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>
2017-09-10 19:34:52 -04:00
Nicolas Pitre 88cac29f42 ARM: vmlinux*.lds.S: some decruftification
Remove stuff from vmlinux.lds.S that is relevant only to the XIP build,
and stuff from vmlinux-xip.lds.S related to self-modifying code that
makes no sense in the XIP case.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>
2017-09-10 19:34:52 -04:00
Nicolas Pitre 9520b1a1b5 ARM: head-common.S: speed up startup code
Let's use optimized routines such as memcpy to copy .data and memzero
to clear .bss in the startup code instead of doing it one word at a
time. Those routines don't use any global data so they're safe to use
even if .data and .bss segments are not initialized.

In the .data copy case a temporary stack is installed in the .bss area
as the actual kernel stack is located within the copied data area. The
XIP kernel linker script ensures a 8 byte alignment for that purpose.

Finally, make the .data copy and related pointers surrounded by
CONFIG_XIP_KERNEL to make it obvious what it is all about. This will
allow for further cleanups in the non-XIP linker script.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>
2017-09-10 19:34:52 -04:00
Peter Zijlstra b5effd3815 debug: Fix __bug_table[] in arch linker scripts
The kbuild test robot reported this build failure on a number
of architectures:

 >         make.cross ARCH=arm
 >    lib/lib.a(bug.o): In function `find_bug':
 > >> lib/bug.c:135: undefined reference to `__start___bug_table'
 > >> lib/bug.c:135: undefined reference to `__stop___bug_table'

Caused by:

  19d436268d ("debug: Add _ONCE() logic to report_bug()")

Which moved the BUG_TABLE from RO_DATA_SECTION() to RW_DATA_SECTION(),
but a number of architectures don't use RW_DATA_SECTION(), so they
ended up with no __bug_table[] ...

Ideally all those would use RW_DATA_SECTION() in their linker scripts,
but that's for another day.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: kbuild-all@01.org
Cc: tipbuild@zytor.com
Link: http://lkml.kernel.org/r/20170330154927.o6qmgfp4bdhrajbm@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-03 10:22:40 +02:00
Russell King 2a3811068f ARM: Fix XIP kernels
Commit 7619751f8c ("ARM: 8595/2: apply more __ro_after_init") caused
a regression with XIP kernels by moving the __ro_after_init data into
the read-only section.  With XIP kernels, the read-only section is
located in read-only memory from the very beginning.

Work around this by moving the __ro_after_init data back into the .data
section, which will be in RAM, and hence will be writable.

It should be noted that in doing so, this remains writable after init.

Fixes: 7619751f8c ("ARM: 8595/2: apply more __ro_after_init")
Reported-by: Andrea Merello <andrea.merello@gmail.com>
Tested-by: Andrea Merello <andrea.merello@gmail.com> [ XIP stm32 ]
Tested-by: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2016-11-16 23:51:19 +00:00
Chris Metcalf 6727ad9e20 nmi_backtrace: generate one-line reports for idle cpus
When doing an nmi backtrace of many cores, most of which are idle, the
output is a little overwhelming and very uninformative.  Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".

We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the interrupted
PC to see if it lies within that section.

This commit suitably tags x86 and tile idle routines, and only adds in
the minimal framework for other architectures.

Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org> [arm]
Tested-by: Petr Mladek <pmladek@suse.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-07 18:46:30 -07:00
Kees Cook 1475399207 ARM: 8537/1: drop unused DEBUG_RODATA from XIP_KERNEL
With CONFIG_DEBUG_RODATA not being sensible under XIP_KERNEL, remove it
from the XIP linker script.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-22 11:39:43 +00:00
Chris Brandt 02afa9a87b ARM: 8518/1: Use correct symbols for XIP_KERNEL
For an XIP build, _etext does not represent the end of the
binary image that needs to stay mapped into the MODULES_VADDR area.
Years ago, data came before text in the memory map. However,
now that the order is text/init/data, an XIP_KERNEL needs to map
up to the data location in order to keep from cutting off
parts of the kernel that are needed.
We only map up to the beginning of data because data has already been
copied, so there's no reason to keep it around anymore.
A new symbol is created to make it clear what it is we are referring
to.

This fixes the bug where you might lose the end of your kernel area
after page table setup is complete.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-11 15:43:14 +00:00
Ard Biesheuvel 31b96cae5c ARM: 8515/2: move .vectors and .stubs sections back into the kernel VMA
Commit b9b32bf70f ("ARM: use linker magic for vectors and vector stubs")
updated the linker script to emit the .vectors and .stubs sections into a
VMA range that is zero based and disjoint from the normal static kernel
region. The reason for that was that this way, the sections can be placed
exactly 4 KB apart, while the payload of the .vectors section is only 32
bytes.

Since the symbols that are part of the .stubs section are emitted into the
kallsyms table, they appear with zero based addresses as well, e.g.,

  00001004 t vector_rst
  00001020 t vector_irq
  000010a0 t vector_dabt
  00001120 t vector_pabt
  000011a0 t vector_und
  00001220 t vector_addrexcptn
  00001240 t vector_fiq
  00001240 T vector_fiq_offset

As this confuses perf when it accesses the kallsyms tables, commit
7122c3e915 ("scripts/link-vmlinux.sh: only filter kernel symbols for
arm") implemented a somewhat ugly special case for ARM, where the value
of CONFIG_PAGE_OFFSET is passed to scripts/kallsyms, and symbols whose
addresses are below it are filtered out. Note that this special case only
applies to CONFIG_XIP_KERNEL=n, not because the issue the patch addresses
exists only in that case, but because finding a limit below which to apply
the filtering is not entirely straightforward.

Since the .vectors and .stubs sections contain position independent code
that is never executed in place, we can emit it at its most likely runtime
VMA (for more recent CPUs), which is 0xffff0000 for the vector table and
0xffff1000 for the stubs. Not only does this fix the perf issue with
kallsyms, allowing us to drop the special case in scripts/kallsyms
entirely, it also gives debuggers a more realistic view of the address
space, and setting breakpoints or single stepping through code in the
vector table or the stubs is more likely to work as expected on CPUs that
use a high vector address. E.g.,

  00001240 A vector_fiq_offset
  ...
  c0c35000 T __init_begin
  c0c35000 T __vectors_start
  c0c35020 T __stubs_start
  c0c35020 T __vectors_end
  c0c352e0 T _sinittext
  c0c352e0 T __stubs_end
  ...
  ffff1004 t vector_rst
  ffff1020 t vector_irq
  ffff10a0 t vector_dabt
  ffff1120 t vector_pabt
  ffff11a0 t vector_und
  ffff1220 t vector_addrexcptn
  ffff1240 T vector_fiq

(Note that vector_fiq_offset is now an absolute symbol, which kallsyms
already ignores by default)

The LMA footprint is identical with or without this change, only the VMAs
are different:

  Before:
  Idx Name          Size      VMA       LMA       File off  Algn
   ...
   14 .notes        00000024  c0c34020  c0c34020  00a34020  2**2
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   15 .vectors      00000020  00000000  c0c35000  00a40000  2**1
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   16 .stubs        000002c0  00001000  c0c35020  00a41000  2**5
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   17 .init.text    0006b1b8  c0c352e0  c0c352e0  00a452e0  2**5
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   ...

  After:
  Idx Name          Size      VMA       LMA       File off  Algn
   ...
   14 .notes        00000024  c0c34020  c0c34020  00a34020  2**2
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   15 .vectors      00000020  ffff0000  c0c35000  00a40000  2**1
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   16 .stubs        000002c0  ffff1000  c0c35020  00a41000  2**5
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   17 .init.text    0006b1b8  c0c352e0  c0c352e0  00a452e0  2**5
                    CONTENTS, ALLOC, LOAD, READONLY, CODE
   ...

Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-11 15:33:39 +00:00
Chris Brandt 538bf46948 ARM: 8513/1: xip: Move XIP linking to a separate file
When building an XIP kernel, the linker script needs to be much different
than a conventional kernel's script. Over time, it's been difficult to
maintain both XIP and non-XIP layouts in one linker script. Therefore,
this patch separates the two procedures into two completely different
files.

The new linker script is essentially a straight copy of the current script
with all the non-CONFIG_XIP_KERNEL portions removed.

Additionally, all CONFIG_XIP_KERNEL portions have been removed from the
existing linker script...never to return again.

It should be noted that this does not fix any current XIP issues, but
rather is the first move in fixing them properly with subsequent patches.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-02-11 15:33:39 +00:00