linux.git/arch/mips/kernel/branch.c, branch v4.12

MIPS: Fix bnezc/jialc return address calculation

2017-06-15T09:47:42+00:00

The code handling the pop76 opcode (ie. bnezc & jialc instructions) in
__compute_return_epc_for_insn() needs to set the value of $31 in the
jialc case, which is encoded with rs = 0. However its check to
differentiate bnezc (rs != 0) from jialc (rs = 0) was unfortunately
backwards, meaning that if we emulate a bnezc instruction we clobber $31
& if we emulate a jialc instruction it actually behaves like a jic
instruction.

Fix this by inverting the check of rs to match the way the instructions
are actually encoded.

Signed-off-by: Paul Burton 
Fixes: 28d6f93d201d ("MIPS: Emulate the new MIPS R6 BNEZC and JIALC instructions")
Cc: stable  # v4.0+
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16178/
Signed-off-by: Ralf Baechle

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:29+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Replace with globally

2016-12-24T19:46:01+00:00

This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*'
  sed -i -e "s!$PATT!#include !" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro 
Signed-off-by: Linus Torvalds

MIPS: tracing: disable uprobe/kprobe on compact branch instructions

2016-10-06T15:37:40+00:00

Current instruction decoder for uprobe/kprobe handler only handles
branches with delay slots. For compact branches the behaviour is rather
unpredictable - and depending on the encoding of a compact branch
instruction may result in one (or more) of:
- executing an instruction that follows a branch which wasn't in a delay
  slot and shouldn't have been executed
- incorrectly emulating a branch leading to a jump to a wrong location
- unexpected branching out of the single-stepped code and never reaching
  the breakpoint that should terminate the probe handler

Results of these actions are generally unpredictable, but can end up
with a probed application or kernel crash, so disable placing probes on
compact branches until they are handled properly.

Signed-off-by: Marcin Nowakowski 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14336/
Signed-off-by: Ralf Baechle

MIPS: kernel: Audit and remove any unnecessary uses of module.h

2016-10-04T23:31:20+00:00

Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends.  That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig.  The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.

In the case of the n32/o32 files, we have to get rid of a couple
no-op MODULE_ tags to facilitate the module.h removal.  They piggy
back off the fs/ elf binary support, which is also a bool Kconfig.

Signed-off-by: Paul Gortmaker 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14032/
Signed-off-by: Ralf Baechle

MIPS: inst.h: Rename cbcond{0,1}_op to pop{1,3}0_op

2016-07-05T14:09:07+00:00

The opcodes currently defined in inst.h as cbcond0_op & cbcond1_op are
actually defined in the MIPS base instruction set manuals as pop10 &
pop30 respectively. Rename them as such, for consistency with the
documentation.

Signed-off-by: Paul Burton 
Signed-off-by: James Hogan 
Acked-by: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini

MIPS: inst.h: Rename b{eq,ne}zcji[al]c_op to pop{6,7}6_op

2016-07-05T14:08:59+00:00

The opcodes currently defined in inst.h as beqzcjic_op & bnezcjialc_op
are actually defined in the MIPS base instruction set manuals as pop66 &
pop76 respectively. Rename them as such, for consistency with the
documentation.

Signed-off-by: Paul Burton 
Signed-off-by: James Hogan 
Acked-by: Ralf Baechle 
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini

MIPS: Spelling fix lets -> let's

2016-05-28T10:35:09+00:00

As noticed by Sergei in the discussion of Andrea Gelmini's patch series.

Signed-off-by: Ralf Baechle 
Reported-by: Sergei Shtylyov

MIPS: Fix BC1{EQ,NE}Z return offset calculation

2016-05-13T12:02:21+00:00

The conditions for branching when emulating the BC1EQZ & BC1NEZ
instructions were backwards, leading to each of those instructions being
treated as the other. Fix this by reversing the conditions, and clear up
the code a little for readability & checkpatch.

Fixes: c8a34581ec09 ("MIPS: Emulate the BC1{EQ,NE}Z FPU instructions")
Signed-off-by: Paul Burton 
Reviewed-by: James Hogan 
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13151/
Signed-off-by: Ralf Baechle

MIPS: Fix branch emulation for BLTC and BGEC instructions

2015-07-09T09:10:40+00:00

Commits f1b44067c19258b7614e3cd09dfe8d8e12ff5895 ("MIPS: Emulate the
new MIPS R6 B{L,G}T{Z,}{AL,}C instructions") and commit
a8ff66f52d3f17b5ae793955270675c197f73d6c ("MIPS: Emulate the new MIPS
R6 B{L,G}E{Z,}{AL,}C instructions") added support for emulating various
branch compact instructions. However, it missed the case for those which
use the old BLEZL and BGTZL opcodes leading to random crashes when the R6
emulator is disabled. We fix this by ensuring that the 'rt' field is not
zero which is always true for these branch compact instructions.

Fixes: f1b44067c192 ("MIPS: Emulate the new MIPS R6 B{L,G}T{Z,}{AL,}C instructions")
Fixes: a8ff66f52d3f ("MIPS: Emulate the new MIPS R6 B{L,G}E{Z,}{AL,}C instructions")
Cc:  # 4.0+
Signed-off-by: Markos Chandras 
Cc: linux-mips@linux-mips.org
Cc: Markos Chandras 
Patchwork: https://patchwork.linux-mips.org/patch/10582/
Signed-off-by: Ralf Baechle