linux-stable.git/tools/arch/s390/include, branch linux-5.0.y

tools headers: Sync the various kvm.h header copies

2018-10-31T12:57:53+00:00

For powerpc, s390, x86 and the main uapi linux/kvm.h header, none of
them entail changes in tooling.

Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-avn7iy8f4tcm2y40sbsdk31m@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tools, perf: add and use optimized ring_buffer_{read_head, write_tail} helpers

2018-10-19T20:43:08+00:00

Currently, on x86-64, perf uses LFENCE and MFENCE (rmb() and mb(),
respectively) when processing events from the perf ring buffer which
is unnecessarily expensive as we can do more lightweight in particular
given this is critical fast-path in perf.

According to Peter rmb()/mb() were added back then via a94d342b9cb0
("tools/perf: Add required memory barriers") at a time where kernel
still supported chips that needed it, but nowadays support for these
has been ditched completely, therefore we can fix them up as well.

While for x86-64, replacing rmb() and mb() with smp_*() variants would
result in just a compiler barrier for the former and LOCK + ADD for
the latter (__sync_synchronize() uses slower MFENCE by the way), Peter
suggested we can use smp_{load_acquire,store_release}() instead for
architectures where its implementation doesn't resolve in slower smp_mb().
Thus, e.g. in x86-64 we would be able to avoid CPU barrier entirely due
to TSO. For architectures where the latter needs to use smp_mb() e.g.
on arm, we stick to cheaper smp_rmb() variant for fetching the head.

This work adds helpers ring_buffer_read_head() and ring_buffer_write_tail()
for tools infrastructure that either switches to smp_load_acquire() for
architectures where it is cheaper or uses READ_ONCE() + smp_rmb() barrier
for those where it's not in order to fetch the data_head from the perf
control page, and it uses smp_store_release() to write the data_tail.
Latter is smp_mb() + WRITE_ONCE() combination or a cheaper variant if
architecture allows for it. Those that rely on smp_rmb() and smp_mb() can
further improve performance in a follow up step by implementing the two
under tools/arch/*/include/asm/barrier.h such that they don't have to
fallback to rmb() and mb() in tools/include/asm/barrier.h.

Switch perf to use ring_buffer_read_head() and ring_buffer_write_tail()
so it can make use of the optimizations. Later, we convert libbpf as
well to use the same helpers.

Side note [0]: the topic has been raised of whether one could simply use
the C11 gcc builtins [1] for the smp_load_acquire() and smp_store_release()
instead:

  __atomic_load_n(ptr, __ATOMIC_ACQUIRE);
  __atomic_store_n(ptr, val, __ATOMIC_RELEASE);

Kernel and (presumably) tooling shipped along with the kernel has a
minimum requirement of being able to build with gcc-4.6 and the latter
does not have C11 builtins. While generally the C11 memory models don't
align with the kernel's, the C11 load-acquire and store-release alone
/could/ suffice, however. Issue is that this is implementation dependent
on how the load-acquire and store-release is done by the compiler and
the mapping of supported compilers must align to be compatible with the
kernel's implementation, and thus needs to be verified/tracked on a
case by case basis whether they match (unless an architecture uses them
also from kernel side). The implementations for smp_load_acquire() and
smp_store_release() in this patch have been adapted from the kernel side
ones to have a concrete and compatible mapping in place.

  [0] http://patchwork.ozlabs.org/patch/985422/
  [1] https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html

Signed-off-by: Daniel Borkmann 
Acked-by: Peter Zijlstra (Intel) 
Cc: "Paul E. McKenney" 
Cc: Will Deacon 
Cc: Arnaldo Carvalho de Melo 
Signed-off-by: Alexei Starovoitov

tools headers uapi: Update tools's copies of kvm headers

2018-09-11T16:09:26+00:00

To get the changes in:

	a449938297e5 ("KVM: s390: Add huge page enablement control")
	8fcc4b5923af ("kvm: nVMX: Introduce KVM_CAP_NESTED_STATE")
	be26b3a73413 ("arm64: KVM: export the capability to set guest SError syndrome")
	b7b27facc7b5 ("arm/arm64: KVM: Add KVM_GET/SET_VCPU_EVENTS")
	b0960b9569db ("KVM: arm: Add 32bit get/set events support")
	a3da7b4a3be5 ("KVM: s390: add etoken support for guests")

This makes 'perf trace' automagically get aware of these new ioctls:

  $ cp include/uapi/linux/kvm.h tools/include/uapi/linux/kvm.h
  $ tools/perf/trace/beauty/kvm_ioctl.sh  > /tmp/after
  $ diff -u /tmp/before /tmp/after
  --- /tmp/before	2018-09-11 11:18:29.173207586 -0300
  +++ /tmp/after	2018-09-11 11:18:38.488200446 -0300
  @@ -84,6 +84,8 @@
        [0xbb] = "MEMORY_ENCRYPT_REG_REGION",
        [0xbc] = "MEMORY_ENCRYPT_UNREG_REGION",
        [0xbd] = "HYPERV_EVENTFD",
  +     [0xbe] = "GET_NESTED_STATE",
  +     [0xbf] = "SET_NESTED_STATE",
        [0xe0] = "CREATE_DEVICE",
        [0xe1] = "SET_DEVICE_ATTR",
        [0xe2] = "G

And cures the following warning during perf's build:

	Warning: Kernel ABI header at 'tools/include/uapi/linux/kvm.h' differs from latest version at 'include/uapi/linux/kvm.h'
	diff -u tools/include/uapi/linux/kvm.h include/uapi/linux/kvm.h

Cc: Adrian Hunter 
Cc: Christian Borntraeger 
Cc: Cornelia Huck 
Cc: David Ahern 
Cc: David Hildenbrand 
Cc: Dongjiu Geng 
Cc: Eduardo Habkost 
Cc: James Morse 
Cc: Janosch Frank 
Cc: Jim Mattson 
Cc: Jiri Olsa 
Cc: Marc Zyngier 
Cc: Namhyung Kim 
Cc: Paolo Bonzini 
Cc: Peter Zijlstra 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-2vvwh2o19orn56di0ksrtgzr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 

Signed-off-by: Arnaldo Carvalho de Melo

Revert "tools include s390: Grab a copy of arch/s390/include/uapi/asm/unistd.h"

2018-02-15T13:06:15+00:00

This reverts commit f120c7b187e6c418238710b48723ce141f467543 which is no
longer required with the introduction of a syscall.tbl on s390.

Signed-off-by: Hendrik Brueckner 
Cc: Jiri Olsa 
Cc: Michael Petlan 
Cc: Thomas Richter 
Cc: linux-s390@vger.kernel.org
LPU-Reference: 1518090470-2899-2-git-send-email-brueckner@linux.vnet.ibm.com
Link: https://lkml.kernel.org/n/tip-q1lg0nvhha1tk39ri9aqalcb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

tooling headers: Synchronize updated s390 kvm UAPI headers

2018-02-02T19:43:45+00:00

The 35b3fde6203b ("KVM: s390: wire up bpb feature") was noticed by the
perf build process:

  Warning: Kernel ABI header at 'tools/arch/s390/include/uapi/asm/kvm.h' differs from latest version at 'arch/s390/include/uapi/asm/kvm.h'

The changes in this cset don't cause or require changes in tools/perf/,
so just update the copy to silence the build warning.

Cc: Adrian Hunter 
Cc: Christian Borntraeger 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Radim Krčmář 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-kif2fdkcaewj8iqw6lwyil8s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'linus' into perf/core, to pick up fixes

2018-01-06T11:07:10+00:00

Signed-off-by: Ingo Molnar

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-12-31T19:47:24+00:00

Pull perf fixes from Thomas Gleixner:

 - plug a memory leak in the intel pmu init code

 - clang fixes

 - tooling fix to avoid including kernel headers

 - a fix for jvmti to generate correct debug information for inlined
   code

 - replace backtick with a regular shell function

 - fix the build in hardened environments

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Plug memory leak in intel_pmu_init()
  x86/asm: Allow again using asm.h when building for the 'bpf' clang target
  tools arch s390: Do not include header files from the kernel sources
  perf jvmti: Generate correct debug information for inlined code
  perf tools: Fix up build in hardened environments
  perf tools: Use shell function for perl cflags retrieval

tools include s390: Grab a copy of arch/s390/include/uapi/asm/unistd.h

2017-12-27T15:15:49+00:00

Will be used for generating the syscall id/string translation table.

Signed-off-by: Hendrik Brueckner 
Reviewed-by: Thomas Richter 
Cc: Jiri Olsa 
Cc: Michael Petlan 
Cc: linux-s390@vger.kernel.org
LPU-Reference: 1512635281-20733-2-git-send-email-brueckner@linux.vnet.ibm.com
Link: https://lkml.kernel.org/n/tip-vjfbfvgjrnqnbdluqd7leo98@git.kernel.org
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo

bpf: fix broken BPF selftest build on s390

2017-12-19T00:19:30+00:00

With 720f228e8d31 ("bpf: fix broken BPF selftest build") the
inclusion of arch-specific header files changed.  Including the
asm/bpf_perf_event.h on s390, correctly includes the s390 specific
header file.  This header file tries then to include the s390
asm/ptrace.h and the build fails with:

cc -Wall -O2 -I../../../include/uapi -I../../../lib -I../../../../include/generated  -I../../../include    test_verifier.c
+/root/git/linux/tools/testing/selftests/bpf/libbpf.a /root/git/linux/tools/testing/selftests/bpf/cgroup_helpers.c -lcap -lelf -o
+/root/git/linux/tools/testing/selftests/bpf/test_verifier
In file included from ../../../include/uapi/asm/bpf_perf_event.h:4:0,
                 from ../../../include/uapi/linux/bpf_perf_event.h:11,
                 from test_verifier.c:29:
../../../include/uapi/../../arch/s390/include/uapi/asm/bpf_perf_event.h:7:9: error: unknown type name 'user_pt_regs'
 typedef user_pt_regs bpf_user_pt_regs_t;
         ^~~~~~~~~~~~
make: *** [../lib.mk:109: /root/git/linux/tools/testing/selftests/bpf/test_verifier] Error 1

This is caused by a recent update to the s390 asm/ptrace.h file
that is not (yet) available in the local installation.  That means,
the s390 asm/ptrace.h must be included from the tools/arch/s390
directory.

Because there is no proper framework to deal with asm specific
includes in tools/, slightly modify the s390 asm/bpf_perf_event.h
to include the local ptrace.h header file.

See also discussion on
https://marc.info/?l=linux-s390&m=151359424420691&w=2

Please note that this needs to be preserved until tools/ is able to
correctly handle asm specific headers.

References: https://marc.info/?l=linux-s390&m=151359424420691&w=2
Fixes: 720f228e8d31 ("bpf: fix broken BPF selftest build")
Signed-off-by: Hendrik Brueckner 
Cc: Daniel Borkmann 
Cc: Hendrik Brueckner 
Cc: Arnaldo Carvalho de Melo 
Cc: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann

tools arch s390: Do not include header files from the kernel sources

2017-12-18T14:56:13+00:00

Long ago we decided to be verbotten including files in the kernel git
sources from tools/ living source code, to avoid disturbing kernel
development (and perf's and other tools/) when, say, a kernel hacker
adds something, tests everything but tools/ and have tools/ build
broken.

This got broken recently by s/390, fix it by copying
arch/s390/include/uapi/asm/perf_regs.h to tools/arch/s390/include/uapi/asm/,
making this one be used by means of  and updating
tools/perf/check_headers.sh to make sure we are notified when the
original changes, so that we can check if anything is needed on the
tooling side.

This would have been caught by the 'tarkpg' test entry in:

$ make -C tools/perf build-test

When run on a s/390 build system or container.

Acked-by: Heiko Carstens 
Cc: Hendrik Brueckner 
Cc: Thomas Richter 
Cc: Martin Schwidefsky 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Fixes: f704ef44602f ("s390/perf: add support for perf_regs and libdw")
Link: https://lkml.kernel.org/n/tip-n57139ic0v9uffx8wdqi3d8a@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo