linux-stable.git/arch/mips, branch v3.18.6

vm: add VM_FAULT_SIGSEGV handling support

2015-02-06T06:36:01+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 
Signed-off-by: Greg Kroah-Hartman

mips: bpf: Fix broken BPF_MOD

2014-12-16T17:39:05+00:00

[ Upstream commit 2e46477a12f6fd273e31a220b155d66e8352198c ]

Remove optimize_div() from BPF_MOD | BPF_K case
since we don't know the dividend and fix the
emit_mod() by reading the mod operation result from HI register

Signed-off-by: Denis Kirjanov 
Reviewed-by: Markos Chandras 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

MIPS: tlbex: Fix potential HTW race on TLBL/M/S handlers

2014-11-27T16:21:56+00:00

There is a potential race when probing the TLB in TLBL/M/S exception
handlers for a matching entry. Between the time we hit a TLBL/S/M
exception and the time we get to execute the TLBP instruction, the
HTW may have replaced the TLB entry we are interested in hence the TLB
probe may fail. However, in the existing handlers, we never checked the
status of the TLBP (ie check the result in the C0/Index register). We
fix this by adding such a check when the core implements the HTW. If
we couldn't find a matching entry, we return back and try again.

Signed-off-by: Leonid Yegoshin 
Signed-off-by: Markos Chandras 
Reviewed-by: James Hogan 
Cc:  # v3.17+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8599/
Signed-off-by: Ralf Baechle

MIPS: Fix address type used for early memory detection.

2014-11-24T06:44:07+00:00

In 'early_parse_mem' the data type used for the start
and size of a memory region specified on the command line
is incorrect. If 64-bit addressing is used, the value
gets truncated.

Signed-off-by: Steven J. Hill 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8456/
Signed-off-by: Ralf Baechle

MIPS: Kconfig: Don't allow both microMIPS and SmartMIPS to be selected.

2014-11-24T06:44:07+00:00

microMIPS and SmartMIPS can't be used together. This fixes the
following build problem:

Warning: the 32-bit microMIPS architecture does not support the `smartmips' extension
arch/mips/kernel/entry.S:90: Error: unrecognized opcode `mtlhx $24'
[...]
arch/mips/kernel/entry.S:109: Error: unrecognized opcode `mtlhx $24'

Signed-off-by: Markos Chandras 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7421/
Signed-off-by: Ralf Baechle

MIPS: kernel: cps-vec: Set ISA level to mips32r2 for the MIPS MT ASE

2014-11-24T06:44:06+00:00

Fixes the following build warnings:
arch/mips/kernel/cps-vec.S: Assembler messages:
arch/mips/kernel/cps-vec.S:228: Warning: the `mt' extension requires
MIPS32 revision 2 or greater
[...]
arch/mips/kernel/cps-vec.S: Assembler messages:
arch/mips/kernel/cps-vec.S:345: Warning: the `mt' extension requires
MIPS32 revision 2 or greater

Signed-off-by: Markos Chandras 
Cc: Paul Burton 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7355/
Signed-off-by: Ralf Baechle

MIPS: Netlogic: handle modular AHCI builds

2014-11-24T06:44:06+00:00

Commits a951440971d0 ("MIPS: Netlogic: Support for XLP3XX on-chip SATA")
and fedfcb1137d2 ("MIPS: Netlogic: XLP9XX on-chip SATA support") added
ahci-init and ahci-init-xlp2 as objects to build when CONFIG_SATA_AHCI
is enabled.

If CONFIG_SATA_AHCI is made modular, these two files will also get built
as modules (obj-m), which will result in the following linking failure:

ERROR: "nlm_set_pic_extra_ack" [arch/mips/netlogic/xlp/ahci-init.ko]
undefined!
ERROR: "nlm_io_base" [arch/mips/netlogic/xlp/ahci-init.ko] undefined!
ERROR: "nlm_nodes" [arch/mips/netlogic/xlp/ahci-init-xlp2.ko] undefined!
ERROR: "nlm_set_pic_extra_ack"
[arch/mips/netlogic/xlp/ahci-init-xlp2.ko] undefined!
ERROR: "xlp_socdev_to_node" [arch/mips/netlogic/xlp/ahci-init-xlp2.ko]
undefined!
ERROR: "nlm_io_base" [arch/mips/netlogic/xlp/ahci-init-xlp2.ko]
undefined!

Just check whether CONFIG_SATA_AHCI is defined for this build, and if
that is the case, add these objects to the list of built-in object
files.

Signed-off-by: Florian Fainelli 
Cc: linux-mips@linux-mips.org
Cc: ganesanr@broadcom.com
Cc: jchandra@broadcom.com
Patchwork: https://patchwork.linux-mips.org/patch/7855/
Signed-off-by: Ralf Baechle

MIPS: Netlogic: handle modular USB case

2014-11-24T06:44:06+00:00

Commit 1004165f346a ("MIPS: Netlogic: USB support for XLP") and then
commit 9eac3591e78b ("MIPS: Netlogic: Add support for USB on XLP2xx")
added usb-init and usb-init-xlp2 as objects to build when CONFIG_USB is
enabled.

If CONFIG_USB is made modular, these two files will also get built as
modules (obj-m), which will result in the following linking failure:

ERROR: "nlm_io_base" [arch/mips/netlogic/xlp/usb-init.ko] undefined!
ERROR: "nlm_nodes" [arch/mips/netlogic/xlp/usb-init-xlp2.ko] undefined!
ERROR: "nlm_set_pic_extra_ack" [arch/mips/netlogic/xlp/usb-init-xlp2.ko]
undefined!
ERROR: "xlp_socdev_to_node" [arch/mips/netlogic/xlp/usb-init-xlp2.ko]
undefined!
ERROR: "nlm_io_base" [arch/mips/netlogic/xlp/usb-init-xlp2.ko]
undefined!

Just check whether CONFIG_USB is defined for this build, and if that is
the case, add these objects to the list of built-in object files.

Signed-off-by: Florian Fainelli 
Cc: linux-mips@linux-mips.org
Cc: ganesanr@broadcom.com
Cc: jchandra@broadcom.com
Patchwork: https://patchwork.linux-mips.org/patch/7854/
Signed-off-by: Ralf Baechle

MIPS: Loongson: Make platform serial setup always built-in.

2014-11-24T06:44:06+00:00

If SERIAL_8250 is compiled as a module, the platform specific setup
for Loongson will be a module too, and it will not work very well.
At least on Loongson 3 it will trigger a build failure,
since loongson_sysconf is not exported to modules.

Fix by making the platform specific serial code always built-in.

Signed-off-by: Aaro Koskinen 
Reported-by: Ralf Baechle 
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: Huacai Chen 
Cc: Markos Chandras 
Patchwork: https://patchwork.linux-mips.org/patch/8533/
Signed-off-by: Ralf Baechle

MIPS: fix EVA & non-SMP non-FPU FP context signal handling

2014-11-24T06:44:06+00:00

The save_fp_context & restore_fp_context pointers were being assigned
to the wrong variables if either:

  - The kernel is configured for UP & runs on a system without an FPU,
    since b2ead5282885 "MIPS: Move & rename
    fpu_emulator_{save,restore}_context".

  - The kernel is configured for EVA, since ca750649e08c "MIPS: kernel:
    signal: Prevent save/restore FPU context in user memory".

This would lead to FP context being clobbered incorrectly when setting
up a sigcontext, then the garbage values being saved uselessly when
returning from the signal.

Fix by swapping the pointer assignments appropriately.

Signed-off-by: Paul Burton 
Cc: stable@vger.kernel.org # v3.15+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/8230/
Signed-off-by: Ralf Baechle