linux-toradex.git/arch/um/kernel/trap.c, branch v3.17

um: segv: Save regs only in case of a kernel mode fault

2014-07-20T11:39:27+00:00

...otherwise me lose user mode regs and the resulting
stack trace is useless.

Signed-off-by: Richard Weinberger

um: Make stack trace reliable against kernel mode faults

2013-11-17T10:27:30+00:00

As UML uses an alternative signal stack we cannot use
the current stack pointer for stack dumping if UML itself
dies by SIGSEGV. To bypass this issue we save regs taken
from mcontext in our segv handler into thread_struct and
use these regs to obtain the stack pointer in show_stack().

Signed-off-by: Richard Weinberger

arch: mm: pass userspace fault flag to generic fault handler

2013-09-12T22:38:01+00:00

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 
Reviewed-by: Michal Hocko 
Cc: David Rientjes 
Cc: KAMEZAWA Hiroyuki 
Cc: azurIt 
Cc: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

arch: mm: do not invoke OOM killer on kernel fault OOM

2013-09-12T22:38:01+00:00

Kernel faults are expected to handle OOM conditions gracefully (gup,
uaccess etc.), so they should never invoke the OOM killer.  Reserve this
for faults triggered in user context when it is the only option.

Most architectures already do this, fix up the remaining few.

Signed-off-by: Johannes Weiner 
Reviewed-by: Michal Hocko 
Acked-by: KOSAKI Motohiro 
Cc: David Rientjes 
Cc: KAMEZAWA Hiroyuki 
Cc: azurIt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus-37rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2012-10-10T02:15:20+00:00

Pull UML changes from Richard Weinberger:
 "UML receives this time only cleanups.

  The most outstanding change is the 'include "foo.h"' do 'include
  ' conversion done by Al Viro.

  It touches many files, that's why the diffstat is rather big."

* 'for-linus-37rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  typo in UserModeLinux-HOWTO
  hppfs: fix the return value of get_inode()
  hostfs: drop vmtruncate
  um: get rid of pointless include "..." where include <...> will do
  um: move sysrq.h out of include/shared
  um/x86: merge 32 and 64 bit variants of ptrace.h
  um/x86: merge 32 and 64bit variants of checksum.h

um: get rid of pointless include "..." where include <...> will do

2012-10-09T20:28:45+00:00

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

readahead: fault retry breaks mmap file read random detection

2012-10-09T07:22:47+00:00

.fault now can retry.  The retry can break state machine of .fault.  In
filemap_fault, if page is miss, ra->mmap_miss is increased.  In the second
try, since the page is in page cache now, ra->mmap_miss is decreased.  And
these are done in one fault, so we can't detect random mmap file access.

Add a new flag to indicate .fault is tried once.  In the second try, skip
ra->mmap_miss decreasing.  The filemap_fault state machine is ok with it.

I only tested x86, didn't test other archs, but looks the change for other
archs is obvious, but who knows :)

Signed-off-by: Shaohua Li 
Cc: Rik van Riel 
Cc: Wu Fengguang 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

um: pass siginfo to guest process

2012-08-01T22:49:17+00:00

UML guest processes now get correct siginfo_t for SIGTRAP, SIGFPE,
SIGILL and SIGBUS. Specifically, si_addr and si_code are now correct
where previously they were si_addr = NULL and si_code = 128.

Signed-off-by: Martin Pärtel 
Signed-off-by: Richard Weinberger

um/kernel/trap.c: port OOM changes to handle_page_fault()

2012-06-01T00:49:26+00:00

Commit d065bd810b6d ("mm: retry page fault when blocking on disk
transfer") and commit 37b23e0525d3 ("x86,mm: make pagefault killable")
introduced changes into the x86 pagefault handler for making the page
fault handler retryable as well as killable.

These changes reduce the mmap_sem hold time, which is crucial during OOM
killer invocation.

Port these changes to um.

Signed-off-by: Kautuk Consul 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

um: distribute exports to where exported stuff is defined

2011-11-02T13:15:36+00:00

ksyms.c is down to the stuff defined in various USER_OBJS

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger