Fix a bug with --add, where the title of the column
is un-initialized if not specified by the user.

The initial implementation of --show and --hide
neglected to handle the pc8/pc9/pc10 counters.

Fix a bug where "--show Core" only worked with --debug
Reported-by: NWendy Wang <wendy.wang@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

The CPU ticks at a rate in the "bus clock" domain.
eg. 100 MHz * bus_ratio.

On newer processors, the TSC has been moved out of this BCLK
domain and into a separate crystal-clock domain.

While the TSC ticks "close to" the base frequency, those that look
closely at the numbers will notice small errors in calculations that
mix units of TSC clocks and bus clocks.

"tsc_tweak" was introduced to address the most visible
mixing -- the %Busy and the the Busy_MHz calculations.
(A simplification as since removed TSC from the BusyMHz calculation)

Here we apply the tsc_tweak to everyplace where BCLK
and TSC units are mixed.  The results is that
on a system which is 100% idle, the sum of the C-states
are now much more likely to be closer to 100%.
Reported-by: NTravis Downs <travis.downs@gmail.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

Some users want turbostat to tell them everything, by default.
Some users want turbostat to be quiet, by default.

I find that I'm in the 1st camp, and so I've never liked
needing to type the --debug parameter to decode the system
configuration.

So here we change the default and print the system configuration,
by default.  (The --debug option is now un-documented, though
it does still exist for debugging turbostat internals)

When you do not want to see the system configuration
header, use the new "--quiet" option.
Signed-off-by: NLen Brown <len.brown@intel.com>

Some time ago, turbostat overflowed 80 columns.

So on the assumption that a "casual" user would always
want topology and frequency columns, we hid the rest
of the columns and the system configuration decoding
behind the --debug option.

Not everybody liked that change -- including me.
I use --debug 99% of the time...

Well, now we have "-o file" to put turbostat output into a file,
so unless you are watching real-time in a small window,
column count is less frequently a factor.

And more recently, we got the "--hide columnA,columnB" option
to specify columns to skip.

So now we "un-hide" the rest of the columns from behind --debug,
and show them all, by default.
Signed-off-by: NLen Brown <len.brown@intel.com>

useful for observing if the BIOS disabled prefetch
Not architectural, but docuemented as present on NHM, SNB
and is present on others.
Signed-off-by: NLen Brown <len.brown@intel.com>

show the CPUID feature for turbo to clarify the case
when it may not be shown in MISC_ENABLE

CPUID(6): APERF, TURBO, DTS, PTM, No-HWP, No-HWPnotify, No-HWPwindow, No-HWPepp, No-HWPpkg, EPB
cpu4: MSR_IA32_MISC_ENABLE: 0x00850089 (TCC EIST MWAIT TURBO)
Signed-off-by: NLen Brown <len.brown@intel.com>

Turbostat dumps MSR_TURBO_RATIO_LIMIT on Core Architecture.
But Atom Architecture uses MSR_ATOM_CORE_RATIOS and
MSR_ATOM_CORE_TURBO_RATIOS.
Signed-off-by: NLen Brown <len.brown@intel.com>

Decode MISC_ENABLE.NO_TURBO,
also use the #defines in msr-index.h for decoding this register

cpu0: MSR_IA32_MISC_ENABLE: 0x00850089 (TCC EIST MWAIT TURBO)

Although it is not architectural, decode also
MSR_IA32_MISC_ENABLE.prefetch-disable (bit-9).
documented to be present on: Core, P4, Intel-Xeon
reserved on: Atom, Silvermont, Nehalem, SNB, PHI ec.
Signed-off-by: NLen Brown <len.brown@intel.com>

Add a digit of precision to the --debug output for frequency range.
This is useful when BCLK is not an integer.

old:
6 * 83 = 500 MHz max efficiency frequency
26 * 83 = 2166 MHz base frequency

new:
6 * 83.3 = 499.8 MHz max efficiency frequency
26 * 83.3 = 2165.8 MHz base frequency
Signed-off-by: NLen Brown <len.brown@intel.com>

The Baytrail SOC, with its Silvermont core, has some unique properties:

1. a hardware CC1 residency counter
2. a module-c6 residency counter
3. a package-c6 counter at traditional package-c7 counter address.

The SOC does not support c3, pc3, c7 or pc7 counters.
Signed-off-by: NLen Brown <len.brown@intel.com>

Previously called MSR_NHM_SNB_PKG_CST_CFG_CTL
Signed-off-by: NLen Brown <len.brown@intel.com>

AMT value 0 is unlimited, not PC0
Signed-off-by: NLen Brown <len.brown@intel.com>

Without --debug, a debug line was printed on Baytrail:

SLM BCLK: 83.3 Mhz
Signed-off-by: NLen Brown <len.brown@intel.com>

with --debug, see:

cpu0: MSR_CC6_DEMOTION_POLICY_CONFIG: 0x00000000 (DISable-CC6-Demotion)
cpu0: MSR_MC6_DEMOTION_POLICY_CONFIG: 0x00000000 (DISable-MC6-Demotion)

Note that the hardware default is to enable demotion,
and Linux started clearing these registers in 3.17.
Signed-off-by: NLen Brown <len.brown@intel.com>

and so --debug fails with:

turbostat: msr 1 offset 0x1aa read failed: Input/output error

It seems that baytrail, and airmont do not have this MSR.
It is included in subsequent Goldmont Atom.
Signed-off-by: NLen Brown <len.brown@intel.com>

Add the "--show" and "--hide" cmdline parameters.

By default, turbostat shows all columns.

turbostat --hide counter_list
will continue showing all columns, except for those listed.

turbostat --show counter_list
will show _only_ the listed columns

These features work for built-in counters, and have no effect
on columns added with the --add parameter.
Signed-off-by: NLen Brown <len.brown@intel.com>

When --add was used more than once, overflowed buffers
caused some counters to be stored on top of others,
corrupting the results.  Simplify the code by simply
reserving space for up to 16 added counters per each
cpu, core, package.

Per-cpu added counters were being printed only per-core.
Signed-off-by: NLen Brown <len.brown@intel.com>

Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If BPF_F_ALLOW_OVERRIDE flag is used in BPF_PROG_ATTACH command
to the given cgroup the descendent cgroup will be able to override
effective bpf program that was inherited from this cgroup.
By default it's not passed, therefore override is disallowed.

Examples:
1.
prog X attached to /A with default
prog Y fails to attach to /A/B and /A/B/C
Everything under /A runs prog X

2.
prog X attached to /A with allow_override.
prog Y fails to attach to /A/B with default (non-override)
prog M attached to /A/B with allow_override.
Everything under /A/B runs prog M only.

3.
prog X attached to /A with allow_override.
prog Y fails to attach to /A with default.
The user has to detach first to switch the mode.

In the future this behavior may be extended with a chain of
non-overridable programs.

Also fix the bug where detach from cgroup where nothing is attached
was not throwing error. Return ENOENT in such case.

Add several testcases and adjust libbpf.

Fixes: 30070984 ("cgroup: add support for eBPF programs")
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NTejun Heo <tj@kernel.org>
Acked-by: NDaniel Mack <daniel@zonque.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If dso__load_kcore frees all of the existing maps, but one has already
been attached to a callchain cursor node, then we can get a SIGSEGV in
any function that happens to try to use this invalid cursor.  Use the
existing map refcount mechanism to forestall cleanup of a map until the
cursor iterates past the node.
Signed-off-by: NKrister Johansen <kjlx@templeofstupid.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: stable@kernel.org
Fixes: 84c2cafa ("perf tools: Reference count struct map")
Link: http://lkml.kernel.org/r/20170106062331.GB2707@templeofstupid.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Commit 21e6d842 ("perf diff: Use perf_hpp__register_sort_field
interface") changed list_add() to perf_hpp__register_sort_field().

This resulted in a behavior change since the field was added to the tail
instead of the head.  So the -o option is mostly ignored due to its
order in the list.

This patch fixes it by adding perf_hpp__prepend_sort_field().
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: 21e6d842 ("perf diff: Use perf_hpp__register_sort_field interface")
Link: http://lkml.kernel.org/r/20170118051457.30946-2-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The -o/--order option is to select column number to sort a diff result.

It does the job by adding a hpp field at the beginning of the sort list.
But it should not be added to the output field list as it has no
callbacks required by a output field.

During the setup_sorting(), the perf_hpp__setup_output_field() appends
the given sort keys to the output field if it's not there already.

Originally it was checked by fmt->list being non-empty.  But commit
3f931f2c ("perf hists: Make hpp setup function generic") changed it
to check the ->equal callback.

Anyways, we don't need to add the pseudo hpp field to the output field
list since it won't be used for output.  So just skip fields if they
have no ->color or ->entry callbacks.
Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: 3f931f2c ("perf hists: Make hpp setup function generic")
Link: http://lkml.kernel.org/r/20170118051457.30946-1-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Make ringtest work on s390 too.
Signed-off-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: NSascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>

Since ef1b144d ("tools/virtio/ringtest: fix run-on-all.sh to work
without /dev/cpu") run-on-all.sh uses seq 0 $HOST_AFFINITY as the list
of ids of the CPUs to run the command on (assuming ids of online CPUs
are consecutive and start from 0), where $HOST_AFFINITY is the highest
CPU id in the system previously determined using lscpu.  This can fail
on systems with offline CPUs.

Instead let's use lscpu to determine the list of online CPUs.
Signed-off-by: NHalil Pasic <pasic@linux.vnet.ibm.com>
Fixes: ef1b144d ("tools/virtio/ringtest: fix run-on-all.sh to work without
/dev/cpu")
Reviewed-by: NSascha Silbe <silbe@linux.vnet.ibm.com>
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>

The IRET opcode is 0xcf according to the Intel manual and also to objdump of my
vmlinux:

    1ea8:       48 cf                   iretq

Fix the opcode in arch_decode_instruction().

The previous value (0xc5) seems to correspond to LDS.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Acked-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170118132921.19319-1-jslaby@suse.czSigned-off-by: NIngo Molnar <mingo@kernel.org>

Test uses PMC2 to count the event. But PMC1 is being initialized.
Patch to fix it.

Fixes: 3752e453 ('selftests/powerpc: Add tests of PMU EBBs')
Signed-off-by: NMadhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

test_lru_sanity5() fails when the number of online cpus
is fewer than the number of possible cpus.  It can be
reproduced with qemu by using cmd args "--smp cpus=2,maxcpus=8".

The problem is the loop in test_lru_sanity5() is testing
'i' which is incorrect.

This patch:
1. Make sched_next_online() always return -1 if it cannot
   find a next cpu to schedule the process.
2. In test_lru_sanity5(), the parent process does
   sched_setaffinity() first (through sched_next_online())
   and the forked process will inherit it according to
   the 'man sched_setaffinity'.

Fixes: 5db58faf ("bpf: Add tests for the LRU bpf_htab")
Reported-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix to probe on gcc generated functions on modules. Since
probing on a module is based on its symbol name, it should
be adjusted on actual symbols.

E.g. without this fix, perf probe shows probe definition
on non-exist symbol as below.

  $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -F in_range*
  in_range.isra.12
  $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
  p:probe/in_range nf_nat:in_range+0

With this fix, perf probe correctly shows a probe on
gcc-generated symbol.

  $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range
  p:probe/in_range nf_nat:in_range.isra.12+0

This also fixes same problem on online module as below.

  $ perf probe -m i915 -D assert_plane
  p:probe/assert_plane i915:assert_plane.constprop.134+0
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148411450673.9978.14905987549651656075.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add error check codes on post processing and improve it for offline
probe events as:

 - post processing fails if no matched symbol found in map(-ENOENT)
   or strdup() failed(-ENOMEM).

 - Even if the symbol name is the same, it updates symbol address
   and offset.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148411443738.9978.4617979132625405545.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix to show correct locations for events on modules by relocating given
address instead of retrying after failure.

This happens when the module text size is big enough, bigger than
sh_addr, because the original code retries with given address + sh_addr
if it failed to find CU DIE at the given address.

Any address smaller than sh_addr always fails and it retries with the
correct address, but addresses bigger than sh_addr will get a CU DIE
which is on the given address (not adjusted by sh_addr).

In my environment(x86-64), the sh_addr of ".text" section is 0x10030.
Since i915 is a huge kernel module, we can see this issue as below.

  $ grep "[Tt] .*\[i915\]" /proc/kallsyms | sort | head -n1
  ffffffffc0270000 t i915_switcheroo_can_switch	[i915]

ffffffffc0270000 + 0x10030 = ffffffffc0280030, so we'll check
symbols cross this boundary.

  $ grep "[Tt] .*\[i915\]" /proc/kallsyms | grep -B1 ^ffffffffc028\
  | head -n 2
  ffffffffc027ff80 t haswell_init_clock_gating	[i915]
  ffffffffc0280110 t valleyview_init_clock_gating	[i915]

So setup probes on both function and see what happen.

  $ sudo ./perf probe -m i915 -a haswell_init_clock_gating \
        -a valleyview_init_clock_gating
  Added new events:
    probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
    probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)

  You can now use it in all perf tools, such as:

  	perf record -e probe:valleyview_init_clock_gating -aR sleep 1

  $ sudo ./perf probe -l
    probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
    probe:valleyview_init_clock_gating (on i915_vga_set_decode:4@gpu/drm/i915/i915_drv.c in i915)

As you can see, haswell_init_clock_gating is correctly shown,
but valleyview_init_clock_gating is not.

With this patch, both events are shown correctly.

  $ sudo ./perf probe -l
    probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
    probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)

Committer notes:

In my case:

  # perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating
  Added new events:
    probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
    probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)

  You can now use it in all perf tools, such as:

	  perf record -e probe:valleyview_init_clock_gating -aR sleep 1

  # perf probe -l
    probe:haswell_init_clock_gating (on i915_getparam+432@gpu/drm/i915/i915_drv.c in i915)
    probe:valleyview_init_clock_gating (on __i915_printk+240@gpu/drm/i915/i915_drv.c in i915)
  #

  # readelf -SW /lib/modules/4.9.0+/build/vmlinux | egrep -w '.text|Name'
   [Nr] Name   Type      Address          Off    Size   ES Flg Lk Inf Al
   [ 1] .text  PROGBITS  ffffffff81000000 200000 822fd3 00  AX  0   0 4096
  #

  So both are b0rked, now with the fix:

  # perf probe -m i915 -a haswell_init_clock_gating -a valleyview_init_clock_gating
  Added new events:
    probe:haswell_init_clock_gating (on haswell_init_clock_gating in i915)
    probe:valleyview_init_clock_gating (on valleyview_init_clock_gating in i915)

  You can now use it in all perf tools, such as:

	perf record -e probe:valleyview_init_clock_gating -aR sleep 1

  # perf probe -l
    probe:haswell_init_clock_gating (on haswell_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
    probe:valleyview_init_clock_gating (on valleyview_init_clock_gating@gpu/drm/i915/intel_pm.c in i915)
  #

Both looks correct.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148411436777.9978.1440275861947194930.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The flag was introduced by commit 78afd561 ("mm: add
__GFP_OTHER_NODE flag") to allow proper accounting of remote node
allocations done by kernel daemons on behalf of a process - e.g.
khugepaged.

After "mm: fix remote numa hits statistics" we do not need and actually
use the flag so we can safely remove it because all allocations which
are satisfied from their "home" node are accounted properly.

[mhocko@suse.com: fix build]
Link: http://lkml.kernel.org/r/20170106122225.GK5556@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20170102153057.9451-3-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix spelling mistake in print test pass message.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

Nothing in this minimal script seems to require bash. We often run these
tests on embedded devices where the only shell available is the busybox
ash. Use sh instead.
Signed-off-by: NRolf Eike Beer <eb@emlix.com>
Cc: stable@vger.kernel.org
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

Nothing in this minimal script seems to require bash. We often run these
tests on embedded devices where the only shell available is the busybox
ash. Use sh instead.
Signed-off-by: NRolf Eike Beer <eb@emlix.com>
Cc: stable@vger.kernel.org
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

Nothing in this minimal script seems to require bash. We often run these
tests on embedded devices where the only shell available is the busybox
ash. Use sh instead.
Signed-off-by: NRolf Eike Beer <eb@emlix.com>
Cc: stable@vger.kernel.org
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

Fix perf-probe to show probe definition on gcc generated symbols for
offline kernel (including cross-arch kernel image).

gcc sometimes optimizes functions and generate new symbols with suffixes
such as ".constprop.N" or ".isra.N" etc. Since those symbol names are
not recorded in DWARF, we have to find correct generated symbols from
offline ELF binary to probe on it (kallsyms doesn't correct it).  For
online kernel or uprobes we don't need it because those are rebased on
_text, or a section relative address.

E.g. Without this:

  $ perf probe -k build-arm/vmlinux -F __slab_alloc*
  __slab_alloc.constprop.9
  $ perf probe -k build-arm/vmlinux -D __slab_alloc
  p:probe/__slab_alloc __slab_alloc+0

If you put above definition on target machine, it should fail
because there is no __slab_alloc in kallsyms.

With this fix, perf probe shows correct probe definition on
__slab_alloc.constprop.9:

  $ perf probe -k build-arm/vmlinux -D __slab_alloc
  p:probe/__slab_alloc __slab_alloc.constprop.9+0
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148350060434.19001.11864836288580083501.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix --funcs (-F) option to show correct symbols for offline module.
Since previous perf-probe uses machine__findnew_module_map() for offline
module, even if user passes a module file (with full path) which is for
other architecture, perf-probe always tries to load symbol map for
current kernel module.

This fix uses dso__new_map() to load the map from given binary as same
as a map for user applications.
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/148350053478.19001.15435255244512631545.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Markus reported that perf segfaults when reading /sys/kernel/notes from
a kernel linked with GNU gold, due to what looks like a gold bug, so do
some bounds checking to avoid crashing in that case.
Reported-by: NMarkus Trippelsdorf <markus@trippelsdorf.de>
Report-Link: http://lkml.kernel.org/r/20161219161821.GA294@x4
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ryhgs6a6jxvz207j2636w31c@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Those are binaries as well, so should be installed by:

  make -C tools/perf install-bin'

too.

Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/n/tip-3841b37u05evxrs1igkyu6ks@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Currently, the sched:sched_switch tracepoint reports deadline tasks with
priority -1. But when reading the trace via perf script I've got the
following output:

  # ./d & # (d is a deadline task, see [1])
  # perf record -e sched:sched_switch -a sleep 1
  # perf script
      ...
         swapper     0 [000]  2146.962441: sched:sched_switch: swapper/0:0 [120] R ==> d:2593 [4294967295]
               d  2593 [000]  2146.972472: sched:sched_switch: d:2593 [4294967295] R ==> g:2590 [4294967295]

The task d reports the wrong priority [4294967295]. This happens because
the "int prio" is stored in an unsigned long long val. Although it is
set as a %lld, as int is shorter than unsigned long long,
trace_seq_printf prints it as a positive number.

The fix is just to cast the val as an int, and print it as a %d,
as in the sched:sched_switch tracepoint's "format".

The output with the fix is:

  # ./d &
  # perf record -e sched:sched_switch -a sleep 1
  # perf script
      ...
         swapper     0 [000]  4306.374037: sched:sched_switch: swapper/0:0 [120] R ==> d:10941 [-1]
               d 10941 [000]  4306.383823: sched:sched_switch: d:10941 [-1] R ==> swapper/0:0 [120]

[1] d.c

 ---
  #include <stdio.h>
  #include <unistd.h>
  #include <sys/syscall.h>
  #include <linux/types.h>
  #include <linux/sched.h>

  struct sched_attr {
	__u32 size, sched_policy;
	__u64 sched_flags;
	__s32 sched_nice;
	__u32 sched_priority;
	__u64 sched_runtime, sched_deadline, sched_period;
  };

  int sched_setattr(pid_t pid, const struct sched_attr *attr, unsigned int flags)
  {
	return syscall(__NR_sched_setattr, pid, attr, flags);
  }

  int main(void)
  {
	struct sched_attr attr = {
		.size		= sizeof(attr),
		.sched_policy	= SCHED_DEADLINE, /* This creates a 10ms/30ms reservation */
		.sched_runtime	= 10 * 1000 * 1000,
		.sched_period	= attr.sched_deadline = 30 * 1000 * 1000,
	};

	if (sched_setattr(0, &attr, 0) < 0) {
		perror("sched_setattr");
		return -1;
	}

	for(;;);
  }
 ---

Committer notes:

Got the program from the provided URL, http://bristot.me/lkml/d.c,
trimmed it and included in the cset log above, so that we have
everything needed to test it in one place.
Signed-off-by: NDaniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/866ef75bcebf670ae91c6a96daa63597ba981f0d.1483443552.git.bristot@redhat.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>