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  1. Oct 10, 2017
  3. Oct 07, 2017
  5. Sep 26, 2017
  7. Sep 09, 2017
    • Dustin Brown's avatar
      ARM: 8691/1: Export save_stack_trace_tsk() · 9a3dc318
      Dustin Brown authored 
      

The kernel watchdog is a great debugging tool for finding tasks that
consume a disproportionate amount of CPU time in contiguous chunks. One
can imagine building a similar watchdog for arbitrary driver threads
using save_stack_trace_tsk() and print_stack_trace(). However, this is
not viable for dynamically loaded driver modules on ARM platforms
because save_stack_trace_tsk() is not exported for those architectures.
Export save_stack_trace_tsk() for the ARM architecture to align with
x86 and support various debugging use cases such as arbitrary driver
thread watchdog timers.

Signed-off-by: default avatarDustin Brown <dustinb@codeaurora.org>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      9a3dc318
    • Matthew Wilcox's avatar
      ARM: implement memset32 & memset64 · fd1d3626
      Matthew Wilcox authored 
      

Reuse the existing optimised memset implementation to implement an
optimised memset32 and memset64.

Link: http://lkml.kernel.org/r/20170720184539.31609-5-willy@infradead.org
Signed-off-by: default avatarMatthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "James E.J. Bottomley" <jejb@linux.vnet.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      fd1d3626
  9. Sep 05, 2017
  11. Sep 04, 2017
  13. Sep 02, 2017
  15. Sep 01, 2017
  17. Aug 31, 2017
  19. Aug 29, 2017
    • Mark Rutland's avatar
      ARM: 8692/1: mm: abort uaccess retries upon fatal signal · 746a272e
      Mark Rutland authored 
      

When there's a fatal signal pending, arm's do_page_fault()
implementation returns 0. The intent is that we'll return to the
faulting userspace instruction, delivering the signal on the way.

However, if we take a fatal signal during fixing up a uaccess, this
results in a return to the faulting kernel instruction, which will be
instantly retried, resulting in the same fault being taken forever. As
the task never reaches userspace, the signal is not delivered, and the
task is left unkillable. While the task is stuck in this state, it can
inhibit the forward progress of the system.

To avoid this, we must ensure that when a fatal signal is pending, we
apply any necessary fixup for a faulting kernel instruction. Thus we
will return to an error path, and it is up to that code to make forward
progress towards delivering the fatal signal.

Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
Reviewed-by: default avatarSteve Capper <steve.capper@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      746a272e
    • Hoeun Ryu's avatar
      ARM: 8690/1: lpae: build TTB control register value from scratch in v7_ttb_setup · f26fee5f
      Hoeun Ryu authored 
      

Reading TTBCR in early boot stage might return the value of the previous
kernel's configuration, especially in case of kexec. For example, if
normal kernel (first kernel) had run on a configuration of PHYS_OFFSET <=
PAGE_OFFSET and crash kernel (second kernel) is running on a configuration
PHYS_OFFSET > PAGE_OFFSET, which can happen because it depends on the
reserved area for crash kernel, reading TTBCR and using the value to OR
other bit fields might be risky because it doesn't have a reset value for TTBCR.

Suggested-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarHoeun Ryu <hoeun.ryu@gmail.com>
Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
      f26fee5f
  21. Aug 28, 2017
  23. Aug 27, 2017
  25. Aug 26, 2017
    • Jiri Slaby's avatar
      futex: Remove duplicated code and fix undefined behaviour · 30d6e0a4
      Jiri Slaby authored 
      There is code duplicated over all architecture's headers for
futex_atomic_op_inuser. Namely op decoding, access_ok check for uaddr,
and comparison of the result.

Remove this duplication and leave up to the arches only the needed
assembly which is now in arch_futex_atomic_op_inuser.

This effectively distributes the Will Deacon's arm64 fix for undefined
behaviour reported by UBSAN to all architectures. The fix was done in
commit 5f16a046 (arm64: futex: Fix undefined behaviour with
FUTEX_OP_OPARG_SHIFT usage). Look there for an example dump.

And as suggested by Thomas, check for negative oparg too, because it was
also reported to cause undefined behaviour report.

Note that s390 removed access_ok check in d12a2970

 ("s390/uaccess:
remove pointless access_ok() checks") as access_ok there returns true.
We introduce it back to the helper for the sake of simplicity (it gets
optimized away anyway).

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> [s390]
Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Reviewed-by: default avatarDarren Hart (VMware) <dvhart@infradead.org>
Reviewed-by: Will Deacon <will.deacon@arm.com> [core/arm64]
Cc: linux-mips@linux-mips.org
Cc: Rich Felker <dalias@libc.org>
Cc: linux-ia64@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: peterz@infradead.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: sparclinux@vger.kernel.org
Cc: Jonas Bonn <jonas@southpole.se>
Cc: linux-s390@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: linux-hexagon@vger.kernel.org
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: linux-snps-arc@lists.infradead.org
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-xtensa@linux-xtensa.org
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: openrisc@lists.librecores.org
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Stafford Horne <shorne@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Richard Henderson <rth@twiddle.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-parisc@vger.kernel.org
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-alpha@vger.kernel.org
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: "David S. Miller" <davem@davemloft.net>
Link: http://lkml.kernel.org/r/20170824073105.3901-1-jslaby@suse.cz
      30d6e0a4
  27. Aug 25, 2017
  29. Aug 24, 2017
  31. Aug 23, 2017