linux-stable.git/arch/metag/kernel/traps.c, branch master

metag: Remove arch/metag/

2018-02-22T11:07:21+00:00

The earliest Meta architecture port of Linux I have a record of was an
import of a Meta port of Linux v2.4.1 in February 2004, which was worked
on significantly over the next few years by Graham Whaley, Will Newton,
Matt Fleming, myself and others.

Eventually the port was merged into mainline in v3.9 in March 2013, not
long after Imagination Technologies bought MIPS Technologies and shifted
its CPU focus over to the MIPS architecture.

As a result, though the port was maintained for a while, kept on life
support for a while longer, and useful for testing a few specific
drivers for which I don't have ready access to the equivalent MIPS
hardware, it is now essentially dead with no users.

It is also stuck using an out-of-tree toolchain based on GCC 4.2.4 which
is no longer maintained, now struggles to build modern kernels due to
toolchain bugs, and doesn't itself build with a modern GCC. The latest
buildroot port is still using an old uClibc snapshot which is no longer
served, and the latest uClibc doesn't build with GCC 4.2.4.

So lets call it a day and drop the Meta architecture port from the
kernel. RIP Meta.

Signed-off-by: James Hogan 
Link: https://lkml.kernel.org/r/95906b76-6ce1-3f84-eaba-c29b4ae952eb@roeck-us.net
Reviewed-by: Guenter Roeck 
Acked-by: Peter Zijlstra (Intel) 
Acked-by: Graham Whaley 
Cc: linux-metag@vger.kernel.org

signal/metag: Document a conflict with SI_USER with SIGFPE

2018-01-12T20:21:03+00:00

Setting si_code to 0 results in a userspace seeing an si_code of 0.
This is the same si_code as SI_USER.  Posix and common sense requires
that SI_USER not be a signal specific si_code.  As such this use of 0
for the si_code is a pretty horribly broken ABI.

Further use of si_code == 0 guaranteed that copy_siginfo_to_user saw a
value of __SI_KILL and now sees a value of SIL_KILL with the result
hat uid and pid fields are copied and which might copying the si_addr
field by accident but certainly not by design.  Making this a very
flakey implementation.

Utilizing FPE_FIXME siginfo_layout will now return SIL_FAULT and the
appropriate fields will reliably be copied.

Possible ABI fixes includee:
  - Send the signal without siginfo
  - Don't generate a signal
  - Possibly assign and use an appropriate si_code
  - Don't handle cases which can't happen

Cc: James Hogan 
Cc: linux-metag@vger.kernel.org
Ref: ac919f0883e5 ("metag: Traps")
Signed-off-by: "Eric W. Biederman"

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

2017-03-02T07:42:36+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

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

2017-03-02T07:42:35+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

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

2017-03-02T07:42:34+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

metag: handle low level kicks directly

2013-11-06T10:40:02+00:00

Kick interrupts trigger the LWK (low level kick) signal, usually handled
by the __TBIDoStdLWK() function which is the only handler inherited from
the bootloader. The LWK signal is converted either to a SWK (plain
software kick) or a SWS (software kick with an attached message).

Linux has kick_handler() to handle SWK and call registered kick handlers
(IPIs and inter-thread comms), but SWS is as far as I'm aware unused
with Linux.

Therefore remove that abstraction and have Linux handle LWK directly.
This will reduce kick latency slightly, and reduce our dependence on the
bootloader, which makes it easier to directly boot a kernel in QEMU
(particularly for SMP).

Signed-off-by: James Hogan

metag: delete __cpuinit usage from all metag files

2013-07-14T23:36:54+00:00

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/metag uses of the __cpuinit macros from
all C files.  Currently metag does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: James Hogan 
Acked-by: James Hogan 
Signed-off-by: Paul Gortmaker

metag/traps: include setup.h for the per_cpu_trap_init declaration

2013-06-13T11:55:30+00:00

Signed-off-by: Markos Chandras 
Signed-off-by: James Hogan

metag/traps: Mark die() as __noreturn to match the declaration.

2013-06-13T11:55:29+00:00

Signed-off-by: Markos Chandras 
Signed-off-by: James Hogan

dump_stack: consolidate dump_stack() implementations and unify their behaviors

2013-05-01T00:04:02+00:00

Both dump_stack() and show_stack() are currently implemented by each
architecture.  show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack().  On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().

There's no reason to require archs to implement two separate but mostly
identical functions.  It leads to unnecessary subtle information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin.  Blackfin's
dump_stack() does something wonky that I don't understand.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information.  This is used
in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
  printed.  This is because the top frame was determined in
  dump_stack() on those archs while generic dump_stack() can't do that
  reliably.  It can be compensated by inlining dump_stack() but not
  sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack().  They do
  now.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Hardware name: empty
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [] dump_stack+0x19/0x1b
  [] warn_slowpath_common+0x7f/0xc0
  [] warn_slowpath_null+0x1a/0x20
  [] init_workqueues+0x35/0x505
  ...

v2: CPU number added to the generic debug info as requested by s390
    folks and dropped the s390 specific dump_stack().  This loses %ksp
    from the debug message which the maintainers think isn't important
    enough to keep the s390-specific dump_stack() implementation.

    dump_stack_print_info() is moved to kernel/printk.c from
    lib/dump_stack.c.  Because linkage is per objecct file,
    dump_stack_print_info() living in the same lib file as generic
    dump_stack() means that archs which implement custom dump_stack()
    - at this point, only blackfin - can't use dump_stack_print_info()
    as that will bring in the generic version of dump_stack() too.  v1
    The v1 patch broke build on blackfin due to this issue.  The build
    breakage was reported by Fengguang Wu.

Signed-off-by: Tejun Heo 
Acked-by: David S. Miller 
Acked-by: Vineet Gupta 
Acked-by: Jesper Nilsson 
Acked-by: Vineet Gupta 
Acked-by: Martin Schwidefsky 	[s390 bits]
Cc: Heiko Carstens 
Cc: Mike Frysinger 
Cc: Fengguang Wu 
Cc: Bjorn Helgaas 
Cc: Sam Ravnborg 
Acked-by: Richard Kuo 		[hexagon bits]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds