linux.git/arch/s390/Kconfig.debug, branch v3.18.74

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

generic debug pagealloc: build fix

2009-04-03T02:04:48+00:00

This fixes a build failure with generic debug pagealloc:

  mm/debug-pagealloc.c: In function 'set_page_poison':
  mm/debug-pagealloc.c:8: error: 'struct page' has no member named 'debug_flags'
  mm/debug-pagealloc.c: In function 'clear_page_poison':
  mm/debug-pagealloc.c:13: error: 'struct page' has no member named 'debug_flags'
  mm/debug-pagealloc.c: In function 'page_poison':
  mm/debug-pagealloc.c:18: error: 'struct page' has no member named 'debug_flags'
  mm/debug-pagealloc.c: At top level:
  mm/debug-pagealloc.c:120: error: redefinition of 'kernel_map_pages'
  include/linux/mm.h:1278: error: previous definition of 'kernel_map_pages' was here
  mm/debug-pagealloc.c: In function 'kernel_map_pages':
  mm/debug-pagealloc.c:122: error: 'debug_pagealloc_enabled' undeclared (first use in this function)

by fixing

 - debug_flags should be in struct page
 - define DEBUG_PAGEALLOC config option for all architectures

Signed-off-by: Akinobu Mita 
Reported-by: Alexander Beregalov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

generic debug pagealloc

2009-04-01T15:59:13+00:00

CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390.  This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().

This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.

Signed-off-by: Akinobu Mita 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[S390] DEBUG_PAGEALLOC support for s390.

2008-02-05T15:50:54+00:00

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

[PATCH] lockdep: irqtrace subsystem, s390 support

2006-07-03T22:27:03+00:00

irqtrace support for s390.

Signed-off-by: Heiko Carstens 
Signed-off-by: Ingo Molnar 
Cc: Martin Schwidefsky 
Cc: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds