linux.git/arch/mips/kernel, branch v4.14.124

MIPS: KGDB: fix kgdb support for SMP platforms.

2019-05-10T15:53:09+00:00

[ Upstream commit ab8a6d821179ab9bea1a9179f535ccba6330c1ed ]

KGDB_call_nmi_hook is called by other cpu through smp call.
MIPS smp call is processed in ipi irq handler and regs is saved in
 handle_int.
So kgdb_call_nmi_hook get regs by get_irq_regs and regs will be passed
 to kgdb_cpu_enter.

Signed-off-by: Chong Qiao 
Reviewed-by: Douglas Anderson 
Acked-by: Daniel Thompson 
Signed-off-by: Paul Burton 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: Will Deacon 
Cc: Christophe Leroy 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: QiaoChong 
Signed-off-by: Sasha Levin

MIPS: scall64-o32: Fix indirect syscall number load

2019-05-02T07:40:28+00:00

commit 79b4a9cf0e2ea8203ce777c8d5cfa86c71eae86e upstream.

Commit 4c21b8fd8f14 (MIPS: seccomp: Handle indirect system calls (o32))
added indirect syscall detection for O32 processes running on MIPS64,
but it did not work correctly for big endian kernel/processes. The
reason is that the syscall number is loaded from ARG1 using the lw
instruction while this is a 64-bit value, so zero is loaded instead of
the syscall number.

Fix the code by using the ld instruction instead. When running a 32-bit
processes on a 64 bit CPU, the values are properly sign-extended, so it
ensures the value passed to syscall_trace_enter is correct.

Recent systemd versions with seccomp enabled whitelist the getpid
syscall for their internal  processes (e.g. systemd-journald), but call
it through syscall(SYS_getpid). This fix therefore allows O32 big endian
systems with a 64-bit kernel to run recent systemd versions.

Signed-off-by: Aurelien Jarno 
Cc:  # v3.15+
Reviewed-by: Philippe Mathieu-Daudé 
Signed-off-by: Paul Burton 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

MIPS: Ensure ELF appended dtb is relocated

2019-03-27T05:13:52+00:00

commit 3f0a53bc6482fb09770982a8447981260ea258dc upstream.

This fixes booting with the combination of CONFIG_RELOCATABLE=y
and CONFIG_MIPS_ELF_APPENDED_DTB=y.

Sections that appear after the relocation table are not relocated
on system boot (except .bss, which has special handling).

With CONFIG_MIPS_ELF_APPENDED_DTB, the dtb is part of the
vmlinux ELF, so it must be relocated together with everything else.

Fixes: 069fd766271d ("MIPS: Reserve space for relocation table")
Signed-off-by: Yasha Cherikovsky 
Signed-off-by: Paul Burton 
Cc: Ralf Baechle 
Cc: Paul Burton 
Cc: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v4.7+
Signed-off-by: Greg Kroah-Hartman

MIPS: Remove function size check in get_frame_info()

2019-03-13T21:03:22+00:00

[ Upstream commit 2b424cfc69728224fcb5fad138ea7260728e0901 ]

Patch (b6c7a324df37b "MIPS: Fix get_frame_info() handling of
microMIPS function size.") introduces additional function size
check for microMIPS by only checking insn between ip and ip + func_size.
However, func_size in get_frame_info() is always 0 if KALLSYMS is not
enabled. This causes get_frame_info() to return immediately without
calculating correct frame_size, which in turn causes "Can't analyze
schedule() prologue" warning messages at boot time.

This patch removes func_size check, and let the frame_size check run
up to 128 insns for both MIPS and microMIPS.

Signed-off-by: Jun-Ru Chang 
Signed-off-by: Tony Wu 
Signed-off-by: Paul Burton 
Fixes: b6c7a324df37b ("MIPS: Fix get_frame_info() handling of microMIPS function size.")
Cc: 
Cc: 
Cc: 
Cc: 
Cc: 
Cc: 
Cc: 
Cc: 
Signed-off-by: Sasha Levin

MIPS: irq: Allocate accurate order pages for irq stack

2019-03-13T21:03:10+00:00

commit 72faa7a773ca59336f3c889e878de81445c5a85c upstream.

The irq_pages is the number of pages for irq stack, but not the
order which is needed by __get_free_pages().
We can use get_order() to calculate the accurate order.

Signed-off-by: Liu Xiang 
Signed-off-by: Paul Burton 
Fixes: fe8bd18ffea5 ("MIPS: Introduce irq_stack")
Cc: linux-mips@vger.kernel.org
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Greg Kroah-Hartman

MIPS: fix truncation in __cmpxchg_small for short values

2019-03-05T16:58:03+00:00

commit 94ee12b507db8b5876e31c9d6c9d84f556a4b49f upstream.

__cmpxchg_small erroneously uses u8 for load comparison which can
be either char or short. This patch changes the local variable to
u32 which is sufficiently sized, as the loaded value is already
masked and shifted appropriately. Using an integer size avoids
any unnecessary canonicalization from use of non native widths.

This patch is part of a series that adapts the MIPS small word
atomics code for xchg and cmpxchg on short and char to RISC-V.

Cc: RISC-V Patches 
Cc: Linux RISC-V 
Cc: Linux MIPS 
Signed-off-by: Michael Clark 
[paul.burton@mips.com:
  - Fix varialble typo per Jonas Gorski.
  - Consolidate load variable with other declarations.]
Signed-off-by: Paul Burton 
Fixes: 3ba7f44d2b19 ("MIPS: cmpxchg: Implement 1 byte & 2 byte cmpxchg()")
Cc: stable@vger.kernel.org # v4.13+
Signed-off-by: Greg Kroah-Hartman

mips: cm: reprime error cause

2019-02-15T07:09:12+00:00

commit 05dc6001af0630e200ad5ea08707187fe5537e6d upstream.

Accordingly to the documentation
---cut---
The GCR_ERROR_CAUSE.ERR_TYPE field and the GCR_ERROR_MULT.ERR_TYPE
fields can be cleared by either a reset or by writing the current
value of GCR_ERROR_CAUSE.ERR_TYPE to the
GCR_ERROR_CAUSE.ERR_TYPE register.
---cut---
Do exactly this. Original value of cm_error may be safely written back;
it clears error cause and keeps other bits untouched.

Fixes: 3885c2b463f6 ("MIPS: CM: Add support for reporting CM cache errors")
Signed-off-by: Vladimir Kondratiev 
Signed-off-by: Paul Burton 
Cc: Ralf Baechle 
Cc: James Hogan 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v4.3+
Signed-off-by: Greg Kroah-Hartman

MIPS: math-emu: Write-protect delay slot emulation pages

2019-01-09T16:14:51+00:00

commit adcc81f148d733b7e8e641300c5590a2cdc13bf3 upstream.

Mapping the delay slot emulation page as both writeable & executable
presents a security risk, in that if an exploit can write to & jump into
the page then it can be used as an easy way to execute arbitrary code.

Prevent this by mapping the page read-only for userland, and using
access_process_vm() with the FOLL_FORCE flag to write to it from
mips_dsemul().

This will likely be less efficient due to copy_to_user_page() performing
cache maintenance on a whole page, rather than a single line as in the
previous use of flush_cache_sigtramp(). However this delay slot
emulation code ought not to be running in any performance critical paths
anyway so this isn't really a problem, and we can probably do better in
copy_to_user_page() anyway in future.

A major advantage of this approach is that the fix is small & simple to
backport to stable kernels.

Reported-by: Andy Lutomirski 
Signed-off-by: Paul Burton 
Fixes: 432c6bacbd0c ("MIPS: Use per-mm page to execute branch delay slot instructions")
Cc: stable@vger.kernel.org # v4.8+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Rich Felker 
Cc: David Daney 
Signed-off-by: Greg Kroah-Hartman

MIPS: kexec: Mark CPU offline before disabling local IRQ

2018-11-21T08:24:03+00:00

[ Upstream commit dc57aaf95a516f70e2d527d8287a0332c481a226 ]

After changing CPU online status, it will not be sent any IPIs such as in
__flush_cache_all() on software coherency systems. Do this before disabling
local IRQ.

Signed-off-by: Dengcheng Zhu 
Signed-off-by: Paul Burton 
Patchwork: https://patchwork.linux-mips.org/patch/20571/
Cc: pburton@wavecomp.com
Cc: ralf@linux-mips.org
Cc: linux-mips@linux-mips.org
Cc: rachel.mozes@intel.com
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: VDSO: Always map near top of user memory

2018-10-18T07:16:23+00:00

commit ea7e0480a4b695d0aa6b3fa99bd658a003122113 upstream.

When using the legacy mmap layout, for example triggered using ulimit -s
unlimited, get_unmapped_area() fills memory from bottom to top starting
from a fairly low address near TASK_UNMAPPED_BASE.

This placement is suboptimal if the user application wishes to allocate
large amounts of heap memory using the brk syscall. With the VDSO being
located low in the user's virtual address space, the amount of space
available for access using brk is limited much more than it was prior to
the introduction of the VDSO.

For example:

  # ulimit -s unlimited; cat /proc/self/maps
  00400000-004ec000 r-xp 00000000 08:00 71436      /usr/bin/coreutils
  004fc000-004fd000 rwxp 000ec000 08:00 71436      /usr/bin/coreutils
  004fd000-0050f000 rwxp 00000000 00:00 0
  00cc3000-00ce4000 rwxp 00000000 00:00 0          [heap]
  2ab96000-2ab98000 r--p 00000000 00:00 0          [vvar]
  2ab98000-2ab99000 r-xp 00000000 00:00 0          [vdso]
  2ab99000-2ab9d000 rwxp 00000000 00:00 0
  ...

Resolve this by adjusting STACK_TOP to reserve space for the VDSO &
providing an address hint to get_unmapped_area() causing it to use this
space even when using the legacy mmap layout.

We reserve enough space for the VDSO, plus 1MB or 256MB for 32 bit & 64
bit systems respectively within which we randomize the VDSO base
address. Previously this randomization was taken care of by the mmap
base address randomization performed by arch_mmap_rnd(). The 1MB & 256MB
sizes are somewhat arbitrary but chosen such that we have some
randomization without taking up too much of the user's virtual address
space, which is often in short supply for 32 bit systems.

With this the VDSO is always mapped at a high address, leaving lots of
space for statically linked programs to make use of brk:

  # ulimit -s unlimited; cat /proc/self/maps
  00400000-004ec000 r-xp 00000000 08:00 71436      /usr/bin/coreutils
  004fc000-004fd000 rwxp 000ec000 08:00 71436      /usr/bin/coreutils
  004fd000-0050f000 rwxp 00000000 00:00 0
  00c28000-00c49000 rwxp 00000000 00:00 0          [heap]
  ...
  7f67c000-7f69d000 rwxp 00000000 00:00 0          [stack]
  7f7fc000-7f7fd000 rwxp 00000000 00:00 0
  7fcf1000-7fcf3000 r--p 00000000 00:00 0          [vvar]
  7fcf3000-7fcf4000 r-xp 00000000 00:00 0          [vdso]

Signed-off-by: Paul Burton 
Reported-by: Huacai Chen 
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Cc: Huacai Chen 
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Greg Kroah-Hartman