linux.git/arch/s390/Kconfig.debug, branch v4.12

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2017-02-22T18:20:04+00:00

Pull s390 updates from Martin Schwidefsky:

 - New entropy generation for the pseudo random number generator.

 - Early boot printk output via sclp to help debug crashes on boot. This
   needs to be enabled with a kernel parameter.

 - Add proper no-execute support with a bit in the page table entry.

 - Bug fixes and cleanups.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (65 commits)
  s390/syscall: fix single stepped system calls
  s390/zcrypt: make ap_bus explicitly non-modular
  s390/zcrypt: Removed unneeded debug feature directory creation.
  s390: add missing "do {} while (0)" loop constructs to multiline macros
  s390/mm: add cond_resched call to kernel page table dumper
  s390: get rid of MACHINE_HAS_PFMF and MACHINE_HAS_HPAGE
  s390/mm: make memory_block_size_bytes available for !MEMORY_HOTPLUG
  s390: replace ACCESS_ONCE with READ_ONCE
  s390: Audit and remove any remaining unnecessary uses of module.h
  s390: mm: Audit and remove any unnecessary uses of module.h
  s390: kernel: Audit and remove any unnecessary uses of module.h
  s390/kdump: Use "LINUX" ELF note name instead of "CORE"
  s390: add no-execute support
  s390: report new vector facilities
  s390: use correct input data address for setup_randomness
  s390/sclp: get rid of common response code handling
  s390/sclp: don't add new lines to each printed string
  s390/sclp: make early sclp code readable
  s390/sclp: disable early sclp code as soon as the base sclp driver is active
  s390/sclp: move early printk code to drivers
  ...

arch: Move CONFIG_DEBUG_RODATA and CONFIG_SET_MODULE_RONX to be common

2017-02-07T20:32:52+00:00

There are multiple architectures that support CONFIG_DEBUG_RODATA and
CONFIG_SET_MODULE_RONX. These options also now have the ability to be
turned off at runtime. Move these to an architecture independent
location and make these options def_bool y for almost all of those
arches.

Signed-off-by: Laura Abbott 
Acked-by: Ingo Molnar 
Acked-by: Heiko Carstens 
Signed-off-by: Kees Cook

s390: provide sclp based boot console

2017-01-16T06:27:55+00:00

Use the early sclp code to provide a boot console. This boot console
is available if the kernel parameter "earlyprintk" has been specified,
just like it works for other architectures that also provide an early
boot console.

This makes debugging of early problems much easier, since now we
finally have working console output even before memory detection is
running.

The boot console will be automatically disabled as soon as another
console will be registered.

Reviewed-by: Peter Oberparleiter 
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug

2016-01-09T14:30:49+00:00

Let all the archs that implement devmem_is_allowed() opt-in to a common
definition of CONFIG_STRICT_DEVM in lib/Kconfig.debug.

Cc: Kees Cook 
Cc: Russell King 
Cc: Will Deacon 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Andrew Morton 
Cc: Greg Kroah-Hartman 
Cc: "David S. Miller" 
Acked-by: Catalin Marinas 
Acked-by: Heiko Carstens 
[heiko: drop 'default y' for s390]
Acked-by: Ingo Molnar 
Suggested-by: Arnd Bergmann 
Signed-off-by: Dan Williams

Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS

2013-05-01T00:04:09+00:00

The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files.  Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this
option isn't a problem when using pre 4.4 gcc.

To simplify the rewording, consolidate the text into lib/Kconfig.debug
and modify it there to be more explicit about when you should say N to
this config.

Also, make the text a bit more generic by stating that this option
enables compile time checks so we can cover architectures which emit
warnings vs.  ones which emit errors.  The details of how an
architecture decided to implement the checks isn't as important as the
concept of compile time checking of copy_from_user() calls.

While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.

Signed-off-by: Stephen Boyd 
Acked-by: Arnd Bergmann 
Acked-by: Ingo Molnar 
Acked-by: H. Peter Anvin 
Cc: Arjan van de Ven 
Acked-by: Helge Deller 
Cc: Heiko Carstens 
Cc: Stephen Rothwell 
Cc: Chris Metcalf 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390/mm: add page table dumper

2012-10-09T12:16:58+00:00

This is more or less the same as the x86 page table dumper which was
merged four years ago: 926e5392 "x86: add code to dump the (kernel)
page tables for visual inspection by kernel developers".

We add a file at /sys/kernel/debug/kernel_page_tables for debugging
purposes so it's quite easy to see the kernel page table layout and
possible odd mappings:

---[ Identity Mapping ]---
0x0000000000000000-0x0000000000100000        1M PTE RW
---[ Kernel Image Start ]---
0x0000000000100000-0x0000000000800000        7M PMD RO
0x0000000000800000-0x00000000008a9000      676K PTE RO
0x00000000008a9000-0x0000000000900000      348K PTE RW
0x0000000000900000-0x0000000001500000       12M PMD RW
---[ Kernel Image End ]---
0x0000000001500000-0x0000000280000000    10219M PMD RW
0x0000000280000000-0x000003d280000000     3904G PUD I
---[ vmemmap Area ]---
0x000003d280000000-0x000003d288c00000      140M PTE RW
0x000003d288c00000-0x000003d300000000     1908M PMD I
0x000003d300000000-0x000003e000000000       52G PUD I
---[ vmalloc Area ]---
0x000003e000000000-0x000003e000009000       36K PTE RW
0x000003e000009000-0x000003e0000ee000      916K PTE I
0x000003e0000ee000-0x000003e000146000      352K PTE RW
0x000003e000146000-0x000003e000200000      744K PTE I
0x000003e000200000-0x000003e080000000     2046M PMD I
0x000003e080000000-0x0000040000000000      126G PUD I

This usually makes only sense for kernel developers. The output
with CONFIG_DEBUG_PAGEALLOC is not very helpful, because of the
huge number of mapped out pages, however I decided for the time
being to not add a !DEBUG_PAGEALLOC dependency.
Maybe it's helpful for somebody even with that option.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

[S390] Write protect module text and RO data

2011-03-15T16:08:23+00:00

Implement write protection for kernel modules text and read-only
data sections by implementing set_memory_[ro|rw] on s390.
Since s390 has no execute bit in the pte's NX is not supported.

set_memory_[ro|rw] will only work on normal pages and not on
large pages, so in case a large page should be modified bail
out with a warning.

Signed-off-by: Jan Glauber 
Signed-off-by: Martin Schwidefsky

[S390] cleanup s390 Kconfig

2011-01-05T11:47:23+00:00

Make use of def_bool and def_tristate where possible and add sensible
defaults to the config symbols where applicable. This shortens the
defconfig file by another ~40 lines.

Signed-off-by: Martin Schwidefsky

[S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking

2010-11-10T09:05:54+00:00

Provide the devmem_is_allowed() routine to restrict access to
kernel memory from userspace.
Set the CONFIG_STRICT_DEVMEM config option to switch on checking.

Signed-off-by: Hendrik Brueckner 
Signed-off-by: Martin Schwidefsky

[S390] uaccess: implement strict user copy checks

2010-02-26T21:37:29+00:00

Same as on x86 and sparc, besides the fact that enabling the option
will just emit compile time warnings instead of errors.
Keeps allyesconfig kernels compiling.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky