linux-stable.git/arch/mips/kernel, branch v3.16.40

mips/panic: replace smp_send_stop() with kdump friendly version in panic path

2017-02-23T03:54:11+00:00

commit 54c721b857fd45f3ad3bda695ee4f472518db02a upstream.

Daniel Walker reported problems which happens when
crash_kexec_post_notifiers kernel option is enabled
(https://lkml.org/lkml/2015/6/24/44).

In that case, smp_send_stop() is called before entering kdump routines
which assume other CPUs are still online.  As the result, kdump
routines fail to save other CPUs' registers.  Additionally for MIPS
OCTEON, it misses to stop the watchdog timer.

To fix this problem, call a new kdump friendly function,
crash_smp_send_stop(), instead of the smp_send_stop() when
crash_kexec_post_notifiers is enabled.  crash_smp_send_stop() is a
weak function, and it just call smp_send_stop().  Architecture
codes should override it so that kdump can work appropriately.
This patch provides MIPS version.

Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option)
Link: http://lkml.kernel.org/r/20160810080950.11028.28000.stgit@sysi4-13.yrl.intra.hitachi.co.jp
Signed-off-by: Hidehiro Kawai 
Reported-by: Daniel Walker 
Cc: Dave Young 
Cc: Baoquan He 
Cc: Vivek Goyal 
Cc: Eric Biederman 
Cc: Masami Hiramatsu 
Cc: Daniel Walker 
Cc: Xunlei Pang 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Borislav Petkov 
Cc: David Vrabel 
Cc: Toshi Kani 
Cc: Ralf Baechle 
Cc: David Daney 
Cc: Aaro Koskinen 
Cc: "Steven J. Hill" 
Cc: Corey Minyard 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Ben Hutchings

KEYS: 64-bit MIPS needs to use compat_sys_keyctl for 32-bit userspace

2016-11-20T01:16:59+00:00

commit 20f06ed9f61a185c6dabd662c310bed6189470df upstream.

MIPS64 needs to use compat_sys_keyctl for 32-bit userspace rather than
calling sys_keyctl.  The latter will work in a lot of cases, thereby hiding
the issue.

Reported-by: Stephan Mueller 
Signed-off-by: David Howells 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Cc: keyrings@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13832/
Signed-off-by: Ralf Baechle 
Signed-off-by: Ben Hutchings

MIPS: Avoid using unwind_stack() with usermode

2016-08-22T21:37:55+00:00

commit 81a76d7119f63c359750e4adeff922a31ad1135f upstream.

When showing backtraces in response to traps, for example crashes and
address errors (usually unaligned accesses) when they are set in debugfs
to be reported, unwind_stack will be used if the PC was in the kernel
text address range. However since EVA it is possible for user and kernel
address ranges to overlap, and even without EVA userland can still
trigger an address error by jumping to a KSeg0 address.

Adjust the check to also ensure that it was running in kernel mode. I
don't believe any harm can come of this problem, since unwind_stack() is
sufficiently defensive, however it is only meant for unwinding kernel
code, so to be correct it should use the raw backtracing instead.

Signed-off-by: James Hogan 
Reviewed-by: Leonid Yegoshin 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11701/
Signed-off-by: Ralf Baechle 
(cherry picked from commit d2941a975ac745c607dfb590e92bb30bc352dad9)
Signed-off-by: Ben Hutchings

MIPS: Don't unwind to user mode with EVA

2016-08-22T21:37:55+00:00

commit a816b306c62195b7c43c92cb13330821a96bdc27 upstream.

When unwinding through IRQs and exceptions, the unwinding only continues
if the PC is a kernel text address, however since EVA it is possible for
user and kernel address ranges to overlap, potentially allowing
unwinding to continue to user mode if the user PC happens to be in the
kernel text address range.

Adjust the check to also ensure that the register state from before the
exception is actually running in kernel mode, i.e. !user_mode(regs).

I don't believe any harm can come of this problem, since the PC is only
output, the stack pointer is checked to ensure it resides within the
task's stack page before it is dereferenced in search of the return
address, and the return address register is similarly only output (if
the PC is in a leaf function or the beginning of a non-leaf function).

However unwind_stack() is only meant for unwinding kernel code, so to be
correct the unwind should stop there.

Signed-off-by: James Hogan 
Reviewed-by: Leonid Yegoshin 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11700/
Signed-off-by: Ralf Baechle 
Signed-off-by: Ben Hutchings

MIPS: BMIPS: Fix PRID_IMP_BMIPS5000 masking for BMIPS5200

2016-08-22T21:37:55+00:00

commit cbbda6e7c9c3e4532bd70a73ff9d5e6655c894dc upstream.

BMIPS5000 have a PrID value of 0x5A00 and BMIPS5200 have a PrID value of
0x5B00, which, masked with 0x5A00, returns 0x5A00. Update all conditionals on
the PrID to cover both variants since we are going to need this to enable
BMIPS5200 SMP. The existing check, masking with 0xFF00 would not cover
BMIPS5200 at all.

Fixes: 68e6a78373a6d ("MIPS: BMIPS: Add PRId for BMIPS5200 (Whirlwind)")
Fixes: 6465460c92a85 ("MIPS: BMIPS: change compile time checks to runtime checks")
Signed-off-by: Florian Fainelli 
Cc: john@phrozen.org
Cc: cernekee@gmail.com
Cc: jogo@openwrt.org
Cc: jaedon.shin@gmail.com
Cc: jfraser@broadcom.com
Cc: pgynther@google.com
Cc: dragan.stancevic@gmail.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12279/
Signed-off-by: Ralf Baechle 
Signed-off-by: Ben Hutchings

MIPS: traps: Fix SIGFPE information leak from `do_ov' and `do_trap_or_bp'

2016-03-24T10:01:04+00:00

commit e723e3f7f9591b79e8c56b3d7c5a204a9c571b55 upstream.

Avoid sending a partially initialised `siginfo_t' structure along SIGFPE
signals issued from `do_ov' and `do_trap_or_bp', leading to information
leaking from the kernel stack.

Signed-off-by: Maciej W. Rozycki 
Signed-off-by: Ralf Baechle 
Signed-off-by: Luis Henriques

MIPS: uaccess: Take EVA into account in [__]clear_user

2016-01-25T10:43:31+00:00

commit d6a428fb583738ad685c91a684748cdee7b2a05f upstream.

__clear_user() (and clear_user() which uses it), always access the user
mode address space, which results in EVA store instructions when EVA is
enabled even if the current user address limit is KERNEL_DS.

Fix this by adding a new symbol __bzero_kernel for the normal kernel
address space bzero in EVA mode, and call that from __clear_user() if
eva_kernel_access().

Signed-off-by: James Hogan 
Cc: Markos Chandras 
Cc: Paul Burton 
Cc: Leonid Yegoshin 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10844/
Signed-off-by: Ralf Baechle 
[james.hogan@imgtec.com: backport]
Signed-off-by: James Hogan 
Signed-off-by: Luis Henriques

MIPS: CPS: #ifdef on CONFIG_MIPS_MT_SMP rather than CONFIG_MIPS_MT

2015-10-28T10:33:06+00:00

commit 7a63076d9a31a6c2073da45021eeb4f89d2a8b56 upstream.

The CONFIG_MIPS_MT symbol can be selected by CONFIG_MIPS_VPE_LOADER in
addition to CONFIG_MIPS_MT_SMP. We only want MT code in the CPS SMP boot
vector if we're using MT for SMP. Thus switch the config symbol we ifdef
against to CONFIG_MIPS_MT_SMP.

Signed-off-by: Paul Burton 
Cc: Markos Chandras 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10867/
Signed-off-by: Ralf Baechle 
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques

MIPS: CPS: Don't include MT code in non-MT kernels.

2015-10-28T10:33:05+00:00

commit a5b0f6db0e6cf6224e50f6585e9c8f0c2d38a8f8 upstream.

The MT-specific code in mips_cps_boot_vpes can safely be omitted from
kernels which don't support MT, with the default VPE==0 case being used
as it would be after the has_mt (Config3.MT) check failed at runtime.
Discarding the code entirely will save us a few bytes & allow cleaner
handling of MT ASE instructions by later patches.

Signed-off-by: Paul Burton 
Cc: Markos Chandras 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10866/
Signed-off-by: Ralf Baechle 
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques

MIPS: CPS: Stop dangling delay slot from has_mt.

2015-10-28T10:33:05+00:00

commit 1e5fb282f8eda889776ee83f9214d5df9edaa26d upstream.

The has_mt macro ended with a branch, leaving its callers with a delay
slot that would be executed if Config3.MT is not set. However it would
not be executed if Config3 (or earlier Config registers) don't exist
which makes it somewhat inconsistent at best. Fill the delay slot in the
macro & fix the mips_cps_boot_vpes caller appropriately.

Signed-off-by: Paul Burton 
Cc: Markos Chandras 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10865/
Signed-off-by: Ralf Baechle 
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques