linux-toradex.git/arch/x86/platform/uv, branch v3.15

x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured

2014-01-25T07:55:11+00:00

Fix UV call into kgdb to depend only on whether KGDB is defined
and not both KGDB and KDB.  This allows the power nmi command to
use the gdb remote connection if enabled.  Note new action of
'kgdb' needs to be set as well to indicate user wants to wait
for gdb to be connected.  If it's set to 'kdb' then an error
message is displayed if KDB is not configured.

Also note that if both KGDB and KDB are enabled, then the action
of 'kgdb' or 'kdb' has no affect on which is used.  See the KGDB
documentation for further information.

Signed-off-by: Mike Travis 
Reviewed-by: Hedi Berriche 
Cc: Russ Anderson 
Cc: Jason Wessel 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Link: http://lkml.kernel.org/r/20140114162551.635540667@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar

x86/uv/nmi: Fix Sparse warnings

2014-01-25T07:55:10+00:00

Make uv_register_nmi_notifier() and uv_handle_nmi_ping() static
to address sparse warnings.

Fix problem where uv_nmi_kexec_failed is unused when
CONFIG_KEXEC is not defined.

Signed-off-by: Mike Travis 
Reviewed-by: Hedi Berriche 
Cc: Russ Anderson 
Cc: Jason Wessel 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Link: http://lkml.kernel.org/r/20140114162551.480872353@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar

kgdb/kdb: Fix no KDB config problem

2014-01-25T07:55:09+00:00

Some code added to the debug_core module had KDB dependencies
that it shouldn't have.  Move the KDB dependent REASON back to
the caller to remove the dependency in the debug core code.

Update the call from the UV NMI handler to conform to the new
interface.

Signed-off-by: Mike Travis 
Reviewed-by: Hedi Berriche 
Cc: Russ Anderson 
Cc: Jason Wessel 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Link: http://lkml.kernel.org/r/20140114162551.318251993@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar

sched/clock, x86: Rewrite cyc2ns() to avoid the need to disable IRQs

2014-01-13T14:13:06+00:00

Use a ring-buffer like multi-version object structure which allows
always having a coherent object; we use this to avoid having to
disable IRQs while reading sched_clock() and avoids a problem when
getting an NMI while changing the cyc2ns data.

                        MAINLINE   PRE        POST

    sched_clock_stable: 1          1          1
    (cold) sched_clock: 329841     331312     257223
    (cold) local_clock: 301773     310296     309889
    (warm) sched_clock: 38375      38247      25280
    (warm) local_clock: 100371     102713     85268
    (warm) rdtsc:       27340      27289      24247
    sched_clock_stable: 0          0          0
    (cold) sched_clock: 382634     372706     301224
    (cold) local_clock: 396890     399275     399870
    (warm) sched_clock: 38194      38124      25630
    (warm) local_clock: 143452     148698     129629
    (warm) rdtsc:       27345      27365      24307

Signed-off-by: Peter Zijlstra 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Link: http://lkml.kernel.org/n/tip-s567in1e5ekq2nlyhn8f987r@git.kernel.org
Signed-off-by: Ingo Molnar

x86/UV: Fix NULL pointer dereference in uv_flush_tlb_others() if the 'nobau' boot option is used

2013-12-10T09:06:00+00:00

The SGI UV tlb shootdown code panics the system with a NULL
pointer deference if 'nobau' is specified on the boot
commandline.

uv_flush_tlb_other() gets called for every flush, whether the
BAU is disabled or not.  It should not be keeping the s_enters
statistic while the BAU is disabled.

The panic occurs because during initialization
init_per_cpu_tunables() does not set the bcp->statp pointer if
'nobau' was specified.

Signed-off-by: Cliff Wickman 
Cc:  # 3.12.x
Link: http://lkml.kernel.org/r/E1VnzBi-0005yF-MU@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar

x86/dumpstack: Fix printk_address for direct addresses

2013-11-12T20:06:06+00:00

Consider a kernel crash in a module, simulated the following way:

 static int my_init(void)
 {
         char *map = (void *)0x5;
         *map = 3;
         return 0;
 }
 module_init(my_init);

When we turn off FRAME_POINTERs, the very first instruction in
that function causes a BUG. The problem is that we print IP in
the BUG report using %pB (from printk_address). And %pB
decrements the pointer by one to fix printing addresses of
functions with tail calls.

This was added in commit 71f9e59800e5ad4 ("x86, dumpstack: Use
%pB format specifier for stack trace") to fix the call stack
printouts.

So instead of correct output:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
  IP: [] my_init+0x0/0x10 [pb173]

We get:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
  IP: [] 0xffffffffa0151fff

To fix that, we use %pS only for stack addresses printouts (via
newly added printk_stack_address) and %pB for regs->ip (via
printk_address). I.e. we revert to the old behaviour for all
except call stacks. And since from all those reliable is 1, we
remove that parameter from printk_address.

Signed-off-by: Jiri Slaby 
Cc: Namhyung Kim 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: joe@perches.com
Cc: jirislaby@gmail.com
Link: http://lkml.kernel.org/r/1382706418-8435-1-git-send-email-jslaby@suse.cz
Signed-off-by: Ingo Molnar

Revert "x86/UV: Add uvtrace support"

2013-11-11T18:53:42+00:00

This reverts commit 8eba18428ac926f436064ac281e76d36d51bd631.

uv_trace() is not used by anything, nor is uv_trace_nmi_func, nor
uv_trace_func.

That's not how we do instrumentation code in the kernel: we add
tracepoints, printk()s, etc. so that everyone not just those with
magic kernel modules can debug a system.

So remove this unused (and misguied) piece of code.

Signed-off-by: Ingo Molnar 
Cc: Mike Travis 
Cc: Dimitri Sivanich 
Cc: Hedi Berriche 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Cc: Jason Wessel 
Link: http://lkml.kernel.org/n/tip-tumfBffmr4jmnt8Gyxanoblg@git.kernel.org

x86/UV: Add call to KGDB/KDB from NMI handler

2013-10-03T16:48:09+00:00

This patch restores the capability to enter KDB (and KGDB) from
the UV NMI handler.  This is needed because the UV system
console is not capable of sending the 'break' signal to the
serial console port.  It is also useful when the kernel is hung
in such a way that it isn't responding to normal external I/O,
so sending 'g' to sysreq-trigger does not work either.

Another benefit of the external NMI command is that all the cpus
receive the NMI signal at roughly the same time so they are more
closely aligned timewise.

It utilizes the newly added kgdb_nmicallin function to gain
entry to KGDB/KDB by the master.  The slaves still enter via the
standard kgdb_nmicallback function.  It also uses the new
'send_ready' pointer to tell KGDB/KDB to signal the slaves when
to proceed into the KGDB slave loop.

It is enabled when the nmi action is set to "kdb" and the kernel
is built with CONFIG_KDB enabled.  Note that if kgdb is
connected that interface will be used instead.

Signed-off-by: Mike Travis 
Reviewed-by: Dimitri Sivanich 
Reviewed-by: Hedi Berriche 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Cc: Jason Wessel 
Link: http://lkml.kernel.org/r/20131002151418.089692683@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar

x86/UV: Check for alloc_cpumask_var() failures properly in uv_nmi_setup()

2013-09-24T07:52:40+00:00

GCC warned about:

   arch/x86/platform/uv/uv_nmi.c: In function ‘uv_nmi_setup’:
   arch/x86/platform/uv/uv_nmi.c:664:2: warning: the address of ‘uv_nmi_cpu_mask’ will always evaluate as ‘true’

The reason is this code:

        alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL);
        BUG_ON(!uv_nmi_cpu_mask);

which is not the way to check for alloc_cpumask_var() failures - its
return code should be checked instead.

Cc: Mike Travis 
Link: http://lkml.kernel.org/n/tip-2pXRemsjupmvonbpmmnzleo1@git.kernel.org
Signed-off-by: Ingo Molnar

x86/UV: Add uvtrace support

2013-09-24T07:02:04+00:00

This patch adds support for the uvtrace module by providing a
skeleton call to the registered trace function.  It also
provides another separate 'NMI' tracer that is triggered by the
system wide 'power nmi' command.

Signed-off-by: Mike Travis 
Reviewed-by: Dimitri Sivanich 
Reviewed-by: Hedi Berriche 
Cc: Peter Zijlstra 
Cc: Paul Mackerras 
Cc: Arnaldo Carvalho de Melo 
Cc: Jason Wessel 
Link: http://lkml.kernel.org/r/20130923212501.185052551@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar