linux-stable.git/arch/microblaze, branch v3.10.78 Linux kernel stable tree vm: add VM_FAULT_SIGSEGV handling support 2015-04-29T08:34:00+00:00 Linus Torvalds torvalds@linux-foundation.org 2015-01-29T18:51:32+00:00 0c42d1fbb33f7e3fc97a4854e1f9804951ebdd0d commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream. The core VM already knows about VM_FAULT_SIGBUS, but cannot return a "you should SIGSEGV" error, because the SIGSEGV case was generally handled by the caller - usually the architecture fault handler. That results in lots of duplication - all the architecture fault handlers end up doing very similar "look up vma, check permissions, do retries etc" - but it generally works. However, there are cases where the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV. In particular, when accessing the stack guard page, libsigsegv expects a SIGSEGV. And it usually got one, because the stack growth is handled by that duplicated architecture fault handler. However, when the generic VM layer started propagating the error return from the stack expansion in commit fee7e49d4514 ("mm: propagate error from stack expansion even for guard page"), that now exposed the existing VM_FAULT_SIGBUS result to user space. And user space really expected SIGSEGV, not SIGBUS. To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those duplicate architecture fault handlers about it. They all already have the code to handle SIGSEGV, so it's about just tying that new return value to the existing code, but it's all a bit annoying. This is the mindless minimal patch to do this. A more extensive patch would be to try to gather up the mostly shared fault handling logic into one generic helper routine, and long-term we really should do that cleanup. Just from this patch, you can generally see that most architectures just copied (directly or indirectly) the old x86 way of doing things, but in the meantime that original x86 model has been improved to hold the VM semaphore for shorter times etc and to handle VM_FAULT_RETRY and other "newer" things, so it would be a good idea to bring all those improvements to the generic case and teach other architectures about them too. Reported-and-tested-by: Takashi Iwai <tiwai@suse.de> Tested-by: Jan Engelhardt <jengelh@inai.de> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots" Cc: linux-arch@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [shengyong: Backport to 3.10 - adjust context - ignore modification for arch nios2, because 3.10 does not support it - ignore modification for driver lustre, because 3.10 does not support it - ignore VM_FAULT_FALLBACK in VM_FAULT_ERROR, becase 3.10 does not support this flag - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.10 does not separate it to copro_fault.c - add SIGSEGV handling in mm/memory.c, because 3.10 does not separate it to gup.c ] Signed-off-by: Sheng Yong <shengyong1@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 33692f27597fcab536d7cbbcc8f52905133e4aa7 upstream.

The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.

That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works.  However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.

In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV.  And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.

However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d4514 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space.  And user space really
expected SIGSEGV, not SIGBUS.

To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it.  They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.

This is the mindless minimal patch to do this.  A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.

Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.

Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[shengyong: Backport to 3.10
 - adjust context
 - ignore modification for arch nios2, because 3.10 does not support it
 - ignore modification for driver lustre, because 3.10 does not support it
 - ignore VM_FAULT_FALLBACK in VM_FAULT_ERROR, becase 3.10 does not support
   this flag
 - add SIGSEGV handling to powerpc/cell spu_fault.c, because 3.10 does not
   separate it to copro_fault.c
 - add SIGSEGV handling in mm/memory.c, because 3.10 does not separate it
   to gup.c
]
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch: mm: pass userspace fault flag to generic fault handler 2014-11-21T17:22:56+00:00 Johannes Weiner hannes@cmpxchg.org 2013-09-12T22:13:39+00:00 e2ec2c2b96808afa2f57ec7d7949691146fca341 commit 759496ba6407c6994d6a5ce3a5e74937d7816208 upstream. Unlike global OOM handling, memory cgroup code will invoke the OOM killer in any OOM situation because it has no way of telling faults occuring in kernel context - which could be handled more gracefully - from user-triggered faults. Pass a flag that identifies faults originating in user space from the architecture-specific fault handlers to generic code so that memcg OOM handling can be improved. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: azurIt <azurit@pobox.sk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 759496ba6407c6994d6a5ce3a5e74937d7816208 upstream.

Unlike global OOM handling, memory cgroup code will invoke the OOM killer
in any OOM situation because it has no way of telling faults occuring in
kernel context - which could be handled more gracefully - from
user-triggered faults.

Pass a flag that identifies faults originating in user space from the
architecture-specific fault handlers to generic code so that memcg OOM
handling can be improved.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
microblaze: fix clone syscall 2013-08-20T15:43:02+00:00 Michal Simek michal.simek@xilinx.com 2013-08-13T23:00:53+00:00 4f01c72ef36d3305d6273fe7f1f6670c52745c3d commit dfa9771a7c4784bafd0673bc7abcee3813088b77 upstream. Fix inadvertent breakage in the clone syscall ABI for Microblaze that was introduced in commit f3268edbe6fe ("microblaze: switch to generic fork/vfork/clone"). The Microblaze syscall ABI for clone takes the parent tid address in the 4th argument; the third argument slot is used for the stack size. The incorrectly-used CLONE_BACKWARDS type assigned parent tid to the 3rd slot. This commit restores the original ABI so that existing userspace libc code will work correctly. All kernel versions from v3.8-rc1 were affected. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dfa9771a7c4784bafd0673bc7abcee3813088b77 upstream.

Fix inadvertent breakage in the clone syscall ABI for Microblaze that
was introduced in commit f3268edbe6fe ("microblaze: switch to generic
fork/vfork/clone").

The Microblaze syscall ABI for clone takes the parent tid address in the
4th argument; the third argument slot is used for the stack size.  The
incorrectly-used CLONE_BACKWARDS type assigned parent tid to the 3rd
slot.

This commit restores the original ABI so that existing userspace libc
code will work correctly.

All kernel versions from v3.8-rc1 were affected.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
microblaze: Use static inline functions in cacheflush.h 2013-06-03T09:33:23+00:00 Michal Simek michal.simek@xilinx.com 2013-06-03T09:30:04+00:00 62bc82a82bb1e2b5ee5048c088af7260ddb2b7b5 Using static inline functions ensure proper type checking which also remove compilation warning for no MMU Compilation warning: arch/microblaze/include/asm/cacheflush.h: warning: 'addr' may be used uninitialized in this function [-Wmaybe-uninitialized] Signed-off-by: Michal Simek <michal.simek@xilinx.com> 
Using static inline functions ensure proper type checking
which also remove compilation warning for no MMU

Compilation warning:
arch/microblaze/include/asm/cacheflush.h: warning: 'addr'
 may be used uninitialized in this function [-Wmaybe-uninitialized]

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
microblaze: Fix sparse warnings 2013-06-03T08:49:07+00:00 Michal Simek michal.simek@xilinx.com 2013-05-30T13:10:52+00:00 8706a6b6303dd75c7ee2baf2161de0f5a2fbdd8b arch/microblaze/include/asm/uaccess.h:101:3: warning: cast removes address space of expression arch/microblaze/include/asm/uaccess.h:107:2: warning: cast removes address space of expression Signed-off-by: Michal Simek <michal.simek@xilinx.com> 
arch/microblaze/include/asm/uaccess.h:101:3:
 warning: cast removes address space of expression
arch/microblaze/include/asm/uaccess.h:107:2:
 warning: cast removes address space of expression

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
microblaze: Reversed logic in futex cmpxchg 2013-05-27T10:29:35+00:00 Meyer, Kirk Kirk.Meyer@sencore.com 2013-05-23T17:06:57+00:00 f6a12a7d0b1a70e969ae4f6d7c5201cdaf6edde0 futex_atomic_cmpxchg_inatomic exchanged if the values were unequal rather than equal. This caused incorrect behavior of robust futexes. Signed-off-by: Kirk Meyer <kirk.meyer@sencore.com> Signed-off-by: Michal Simek <michal.simek@xilinx.com> 
futex_atomic_cmpxchg_inatomic exchanged if the values were
unequal rather than equal. This caused incorrect behavior
of robust futexes.

Signed-off-by: Kirk Meyer <kirk.meyer@sencore.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
microblaze: Use proper casting for inb/inw/inl in io.h 2013-05-23T06:49:33+00:00 Michal Simek michal.simek@xilinx.com 2013-05-23T06:04:09+00:00 b5dd0bb43e209455fb83161d4c8774ce2c23f6e2 We are going to move to asm-generic/io.h but let's fix compilation warnings first for 3.10. Warning message: arch/microblaze/include/asm/io.h:126:26: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] #define inb(port) readb((u8 *)((port))) ... Signed-off-by: Michal Simek <michal.simek@xilinx.com> 
We are going to move to asm-generic/io.h but
let's fix compilation warnings first for 3.10.

Warning message:
arch/microblaze/include/asm/io.h:126:26: warning: cast to
 pointer from integer of different size [-Wint-to-pointer-cast]
 #define inb(port)  readb((u8 *)((port)))
...

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
microblaze: Initialize temp variable to remove compilation warning 2013-05-14T07:09:08+00:00 Michal Simek michal.simek@xilinx.com 2013-05-14T07:06:17+00:00 972be324fe0adaa67717407510aa067a4ae53d2d Compilation warning: arch/microblaze/kernel/cpu/cache.c:148:2: warning: 'temp' is used uninitialized in this function [-Wuninitialized] Signed-off-by: Michal Simek <michal.simek@xilinx.com> 
Compilation warning:
arch/microblaze/kernel/cpu/cache.c:148:2: warning:
 'temp' is used uninitialized in this function [-Wuninitialized]

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Merge branch 'next' of git://git.monstr.eu/linux-2.6-microblaze 2013-05-10T14:19:52+00:00 Linus Torvalds torvalds@linux-foundation.org 2013-05-10T14:19:52+00:00 a1f0bcccffe508b36f8eb0bd39771d4bedc683a8 Pull microblaze updates from Michal Simek. * 'next' of git://git.monstr.eu/linux-2.6-microblaze: microblaze: Enable IRQ in arch_cpu_idle microblaze: Fix uaccess_ok macro microblaze: Add support for new cpu versions and target architecture microblaze: Do not select OPT_LIB_ASM by default microblaze: Fix initrd support microblaze: Do not use r6 in head.S microblaze: pci: Remove duplicated header microblaze: Set the default irq_domain microblaze: pci: Remove duplicated include from pci-common.c 
Pull microblaze updates from Michal Simek.

* 'next' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Enable IRQ in arch_cpu_idle
  microblaze: Fix uaccess_ok macro
  microblaze: Add support for new cpu versions and target architecture
  microblaze: Do not select OPT_LIB_ASM by default
  microblaze: Fix initrd support
  microblaze: Do not use r6 in head.S
  microblaze: pci: Remove duplicated header
  microblaze: Set the default irq_domain
  microblaze: pci: Remove duplicated include from pci-common.c
Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux 2013-05-09T16:59:16+00:00 Linus Torvalds torvalds@linux-foundation.org 2013-05-09T16:59:16+00:00 5647ac0ad4f355817b788372a01cb293ed63bde4 Pull removal of GENERIC_GPIO from Grant Likely: "GENERIC_GPIO now synonymous with GPIOLIB. There are no longer any valid cases for enableing GENERIC_GPIO without GPIOLIB, even though it is possible to do so which has been causing confusion and breakage. This branch does the work to completely eliminate GENERIC_GPIO." * tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux: gpio: update gpio Chinese documentation Remove GENERIC_GPIO config option Convert selectors of GENERIC_GPIO to GPIOLIB blackfin: force use of gpiolib m68k: coldfire: use gpiolib mips: pnx833x: remove requirement for GENERIC_GPIO openrisc: default GENERIC_GPIO to false avr32: default GENERIC_GPIO to false xtensa: remove explicit selection of GENERIC_GPIO sh: replace CONFIG_GENERIC_GPIO by CONFIG_GPIOLIB powerpc: remove redundant GENERIC_GPIO selection unicore32: default GENERIC_GPIO to false unicore32: remove unneeded select GENERIC_GPIO arm: plat-orion: use GPIO driver on CONFIG_GPIOLIB arm: remove redundant GENERIC_GPIO selection mips: alchemy: require gpiolib mips: txx9: change GENERIC_GPIO to GPIOLIB mips: loongson: use GPIO driver on CONFIG_GPIOLIB mips: remove redundant GENERIC_GPIO select 
Pull removal of GENERIC_GPIO from Grant Likely:
 "GENERIC_GPIO now synonymous with GPIOLIB.  There are no longer any
  valid cases for enableing GENERIC_GPIO without GPIOLIB, even though it
  is possible to do so which has been causing confusion and breakage.
  This branch does the work to completely eliminate GENERIC_GPIO."

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux:
  gpio: update gpio Chinese documentation
  Remove GENERIC_GPIO config option
  Convert selectors of GENERIC_GPIO to GPIOLIB
  blackfin: force use of gpiolib
  m68k: coldfire: use gpiolib
  mips: pnx833x: remove requirement for GENERIC_GPIO
  openrisc: default GENERIC_GPIO to false
  avr32: default GENERIC_GPIO to false
  xtensa: remove explicit selection of GENERIC_GPIO
  sh: replace CONFIG_GENERIC_GPIO by CONFIG_GPIOLIB
  powerpc: remove redundant GENERIC_GPIO selection
  unicore32: default GENERIC_GPIO to false
  unicore32: remove unneeded select GENERIC_GPIO
  arm: plat-orion: use GPIO driver on CONFIG_GPIOLIB
  arm: remove redundant GENERIC_GPIO selection
  mips: alchemy: require gpiolib
  mips: txx9: change GENERIC_GPIO to GPIOLIB
  mips: loongson: use GPIO driver on CONFIG_GPIOLIB
  mips: remove redundant GENERIC_GPIO select