linux-toradex.git/arch, branch v4.4.89

ARC: Re-enable MMU upon Machine Check exception

2017-09-27T09:00:16+00:00

commit 1ee55a8f7f6b7ca4c0c59e0b4b4e3584a085c2d3 upstream.

I recently came upon a scenario where I would get a double fault
machine check exception tiriggered by a kernel module.
However the ensuing crash stacktrace (ksym lookup) was not working
correctly.

Turns out that machine check auto-disables MMU while modules are allocated
in kernel vaddr spapce.

This patch re-enables the MMU before start printing the stacktrace
making stacktracing of modules work upon a fatal exception.

Signed-off-by: Jose Abreu 
Reviewed-by: Alexey Brodkin 
Signed-off-by: Vineet Gupta 
[vgupta: moved code into low level handler to avoid in 2 places]
Signed-off-by: Greg Kroah-Hartman

powerpc: Fix DAR reporting when alignment handler faults

2017-09-27T09:00:14+00:00

commit f9effe925039cf54489b5c04e0d40073bb3a123d upstream.

Anton noticed that if we fault part way through emulating an unaligned
instruction, we don't update the DAR to reflect that.

The DAR value is eventually reported back to userspace as the address
in the SEGV signal, and if userspace is using that value to demand
fault then it can be confused by us not setting the value correctly.

This patch is ugly as hell, but is intended to be the minimal fix and
back ports easily.

Signed-off-by: Michael Ellerman 
Reviewed-by: Paul Mackerras 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: MINA.: Fix some cases of infinity and zero inputs

2017-09-27T09:00:13+00:00

commit 304bfe473e70523e591fb1c9223289d355e0bdcb upstream.

Fix following special cases for MINA>.:

  - if one of the inputs is zero, and the other is subnormal, normal,
    or infinity, the  value of the former should be returned (that is,
    a zero).
  - if one of the inputs is infinity, and the other input is normal,
    or subnormal, the value of the latter should be returned.

The previous implementation's logic for such cases was incorrect - it
appears as if it implements MAXA, and not MINA instruction.

A relevant example:

MINA.S fd,fs,ft:
  If fs contains 100.0, and ft contains 0.0, fd is going to contain
  0.0 (without this patch, it used to contain 100.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16885/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of both infinite inputs

2017-09-27T09:00:13+00:00

commit 3444c4eb534c20e44f0d6670b34263efaf8b531f upstream.

Fix the value returned by . fd,fs,ft, if both inputs
are infinite. The previous implementation returned always the value
contained in ft in such cases. The correct behavior is specified
in Mips instruction set manual and is as follows:

    fs    ft        MAXA     MINA
  ---------------------------------
    inf   inf        inf      inf
    inf  -inf        inf     -inf
   -inf   inf        inf     -inf
   -inf  -inf       -inf     -inf

A relevant example:

MAXA.S fd,fs,ft:
  If fs contains +inf, and ft contains -inf, fd is going to contain
  +inf (without this patch, it used to contain -inf).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16884/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of input values with opposite signs

2017-09-27T09:00:13+00:00

commit 1a41b3b441508ae63b1a9ec699ec94065739eb60 upstream.

Fix the value returned by ., if the inputs are normal
fp numbers of the same absolute value, but opposite signs.

A relevant example:

MAXA.S fd,fs,ft:
  If fs contains -3.0, and ft contains +3.0, fd is going to contain
  +3.0 (without this patch, it used to contain -3.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16883/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of both inputs negative

2017-09-27T09:00:13+00:00

commit aabf5cf02e22ebc4e541adf835910f388b6c3e65 upstream.

Fix the value returned by ., if both inputs are negative
normal fp numbers. The previous logic did not take into account that
if both inputs have the same sign, there should be separate treatment
of the cases when both inputs are negative and when both inputs are
positive.

A relevant example:

MAX.S fd,fs,ft:
  If fs contains -5.0, and ft contains -7.0, fd is going to contain
  -5.0 (without this patch, it used to contain -7.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16882/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix cases of both inputs zero

2017-09-27T09:00:13+00:00

commit 15560a58bfd4ff82cdd16b2270d4ef9b06d2cc4d upstream.

Fix the value returned by ., if both inputs
are zeros. The right behavior in such cases is stated in instruction
reference manual and is as follows:

   fs  ft       MAX     MIN       MAXA    MINA
  ---------------------------------------------
    0   0        0       0         0       0
    0  -0        0      -0         0      -0
   -0   0        0      -0         0      -0
   -0  -0       -0      -0        -0      -0

Prior to this patch, some of the above cases were yielding correct
results. However, for the sake of code consistency, all such cases
are rewritten in this patch.

A relevant example:

MAX.S fd,fs,ft:
  If fs contains +0.0, and ft contains -0.0, fd is going to contain
  +0.0 (without this patch, it used to contain -0.0).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16881/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: .: Fix quiet NaN propagation

2017-09-27T09:00:13+00:00

commit e78bf0dc4789bdea1453595ae89e8db65918e22e upstream.

Fix the value returned by . fd,fs,ft, if both
inputs are quiet NaNs. The . specifications
state that the returned value in such cases should be the quiet NaN
contained in register fs.

A relevant example:

MAX.S fd,fs,ft:
  If fs contains qNaN1, and ft contains qNaN2, fd is going to contain
  qNaN1 (without this patch, it used to contain qNaN2).

Fixes: a79f5f9ba508 ("MIPS: math-emu: Add support for the MIPS R6 MAX{, A} FPU instruction")
Fixes: 4e9561b20e2f ("MIPS: math-emu: Add support for the MIPS R6 MIN{, A} FPU instruction")

Signed-off-by: Miodrag Dinic 
Signed-off-by: Goran Ferenc 
Signed-off-by: Aleksandar Markovic 
Reviewed-by: James Hogan 
Cc: Bo Hu 
Cc: Douglas Leung 
Cc: Jin Qian 
Cc: Paul Burton 
Cc: Petar Jovanovic 
Cc: Raghu Gandham 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16880/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

x86/fsgsbase/64: Report FSBASE and GSBASE correctly in core dumps

2017-09-27T09:00:12+00:00

commit 9584d98bed7a7a904d0702ad06bbcc94703cb5b4 upstream.

In ELF_COPY_CORE_REGS, we're copying from the current task, so
accessing thread.fsbase and thread.gsbase makes no sense.  Just read
the values from the CPU registers.

In practice, the old code would have been correct most of the time
simply because thread.fsbase and thread.gsbase usually matched the
CPU registers.

Signed-off-by: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Chang Seok 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

ARM: 8692/1: mm: abort uaccess retries upon fatal signal

2017-09-13T21:09:46+00:00

commit 746a272e44141af24a02f6c9b0f65f4c4598ed42 upstream.

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: Mark Rutland 
Reviewed-by: Steve Capper 
Signed-off-by: Russell King 
Signed-off-by: Greg Kroah-Hartman