linux-toradex.git/arch/score, branch v3.2.73

vm: add VM_FAULT_SIGSEGV handling support

2015-02-20T00:49:40+00:00

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 
Tested-by: Jan Engelhardt 
Acked-by: Heiko Carstens  # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Signed-off-by: Linus Torvalds 
[bwh: Backported to 3.2:
 - Adjust filenames, context
 - Drop arc, metag, nios2 and lustre changes
 - For sh, patch both 32-bit and 64-bit implementations to use goto bad_area
 - For s390, pass int_code and trans_exc_code as arguments to do_no_context()
   and do_sigsegv()]
Signed-off-by: Ben Hutchings

score: normalize global variables exported by vmlinux.lds

2014-08-06T17:07:41+00:00

commit ae49b83dcacfb69e22092cab688c415c2f2d870c upstream.

Generate mandatory global variables _sdata in file vmlinux.lds.

Signed-off-by: Jiang Liu 
Cc: Chen Liqin 
Cc: Lennox Wu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

score: Add missing #include

2014-08-06T17:07:41+00:00

There is no upstream commit for this, as arch/score/kernel/init_task.c
has been replaced by generic code and  is included
indirectly by arch/score/mm/init.c.

Signed-off-by: Ben Hutchings

Score: The commit is for compiling successfully. The modifications include: 1. Kconfig of Score: we don't support ioremap 2. Missed headfile including 3. There are some errors in other people's commit not checked by us, we fix it now 3.1 arch/score/kernel/entry.S: wrong instructions 3.2 arch/score/kernel/process.c : just some typos

2014-08-06T17:07:40+00:00

commit 5fbbf8a1a93452b26e7791cf32cefce62b0a480b upstream.

	Signed-off-by: Lennox Wu 
[bwh: Backported to 3.2:
 - Drop addition of 'select HAVE_GENERIC_HARDIRQS' which was not removed here
 - Drop inapplicale change to copy_thread()]
Signed-off-by: Ben Hutchings

score: fix off-by-one index into syscall table

2012-01-26T00:13:56+00:00

commit c25a785d6647984505fa165b5cd84cfc9a95970b upstream.

If the provided system call number is equal to __NR_syscalls, the
current check will pass and a function pointer just after the system
call table may be called, since sys_call_table is an array with total
size __NR_syscalls.

Whether or not this is a security bug depends on what the compiler puts
immediately after the system call table.  It's likely that this won't do
anything bad because there is an additional NULL check on the syscall
entry, but if there happens to be a non-NULL value immediately after the
system call table, this may result in local privilege escalation.

Signed-off-by: Dan Rosenberg 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Eugene Teo 
Cc: Arnd Bergmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

score: drop unused Kconfig symbols

2011-10-31T22:39:51+00:00

Signed-off-by: Paul Bolle 
Signed-off-by: Michal Marek

modules: make arch's use default loader hooks

2011-07-24T12:36:04+00:00

This patch removes all the module loader hook implementations in the
architecture specific code where the functionality is the same as that
now provided by the recently added default hooks.

Signed-off-by: Jonas Bonn 
Acked-by: Mike Frysinger 
Acked-by: Geert Uytterhoeven 
Tested-by: Michal Simek 
Signed-off-by: Rusty Russell

arch: remove CONFIG_GENERIC_FIND_{NEXT_BIT,BIT_LE,LAST_BIT}

2011-05-27T00:12:38+00:00

By the previous style change, CONFIG_GENERIC_FIND_NEXT_BIT,
CONFIG_GENERIC_FIND_BIT_LE, and CONFIG_GENERIC_FIND_LAST_BIT are not used
to test for existence of find bitops anymore.

Signed-off-by: Akinobu Mita 
Acked-by: Greg Ungerer 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib: consolidate DEBUG_STACK_USAGE option

2011-05-25T15:39:54+00:00

Most arches define CONFIG_DEBUG_STACK_USAGE exactly the same way.  Move it
to lib/Kconfig.debug so each arch doesn't have to define it.  This
obviously makes the option generic, but that's fine because the config is
already used in generic code.

It's not obvious to me that sysrq-P actually does anything caution by
keeping the most inclusive wording.

Signed-off-by: Stephen Boyd 
Cc: Chris Metcalf 
Acked-by: David S. Miller 
Acked-by: Richard Weinberger 
Acked-by: Mike Frysinger 
Cc: Russell King 
Cc: Hirokazu Takata 
Acked-by: Ralf Baechle 
Cc: Paul Mackerras 
Acked-by: Benjamin Herrenschmidt 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: now that all old mmu_gather code is gone, remove the storage

2011-05-25T15:39:16+00:00

Fold all the mmu_gather rework patches into one for submission

Signed-off-by: Peter Zijlstra 
Reported-by: Hugh Dickins 
Cc: Benjamin Herrenschmidt 
Cc: David Miller 
Cc: Martin Schwidefsky 
Cc: Russell King 
Cc: Paul Mundt 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Tony Luck 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Cc: KOSAKI Motohiro 
Cc: Nick Piggin 
Cc: Namhyung Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds