History log of /openbmc/linux/kernel/trace/bpf_trace.c (Results 1526 – 1545 of 1545)
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# 98006636 06-Jul-2015 Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Merge tag 'v4.2-rc1' into patchwork

Linux 4.2-rc1

* tag 'v4.2-rc1': (12415 commits)
Linux 4.2-rc1
bluetooth: fix list handling
9p: cope with bogus responses from server in p9_client_{read,wri

Merge tag 'v4.2-rc1' into patchwork

Linux 4.2-rc1

* tag 'v4.2-rc1': (12415 commits)
Linux 4.2-rc1
bluetooth: fix list handling
9p: cope with bogus responses from server in p9_client_{read,write}
p9_client_write(): avoid double p9_free_req()
9p: forgetting to cancel request on interrupted zero-copy RPC
dax: bdev_direct_access() may sleep
block: Add support for DAX reads/writes to block devices
dax: Use copy_from_iter_nocache
dax: Add block size note to documentation
NTB: Add split BAR output for debugfs stats
NTB: Change WARN_ON_ONCE to pr_warn_once on unsafe
NTB: Print driver name and version in module init
NTB: Increase transport MTU to 64k from 16k
NTB: Rename Intel code names to platform names
NTB: Default to CPU memcpy for performance
NTB: Improve performance with write combining
NTB: Use NUMA memory in Intel driver
NTB: Use NUMA memory and DMA chan in transport
NTB: Rate limit ntb_qp_link_work
NTB: Add tool test client
...

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Revision tags: v4.2-rc1
# e0456717 24-Jun-2015 Linus Torvalds <torvalds@linux-foundation.org>

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:

1) Add TX fast path in mac80211, from Johannes Berg.

2) Add TSO/GRO support to ibmve

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

Pull networking updates from David Miller:

1) Add TX fast path in mac80211, from Johannes Berg.

2) Add TSO/GRO support to ibmveth, from Thomas Falcon

3) Move away from cached routes in ipv6, just like ipv4, from Martin
KaFai Lau.

4) Lots of new rhashtable tests, from Thomas Graf.

5) Run ingress qdisc lockless, from Alexei Starovoitov.

6) Allow servers to fetch TCP packet headers for SYN packets of new
connections, for fingerprinting. From Eric Dumazet.

7) Add mode parameter to pktgen, for testing receive. From Alexei
Starovoitov.

8) Cache access optimizations via simplifications of build_skb(), from
Alexander Duyck.

9) Move page frag allocator under mm/, also from Alexander.

10) Add xmit_more support to hv_netvsc, from KY Srinivasan.

11) Add a counter guard in case we try to perform endless reclassify
loops in the packet scheduler.

12) Extern flow dissector to be programmable and use it in new "Flower"
classifier. From Jiri Pirko.

13) AF_PACKET fanout rollover fixes, performance improvements, and new
statistics. From Willem de Bruijn.

14) Add netdev driver for GENEVE tunnels, from John W Linville.

15) Add ingress netfilter hooks and filtering, from Pablo Neira Ayuso.

16) Fix handling of epoll edge triggers in TCP, from Eric Dumazet.

17) Add an ECN retry fallback for the initial TCP handshake, from Daniel
Borkmann.

18) Add tail call support to BPF, from Alexei Starovoitov.

19) Add several pktgen helper scripts, from Jesper Dangaard Brouer.

20) Add zerocopy support to AF_UNIX, from Hannes Frederic Sowa.

21) Favor even port numbers for allocation to connect() requests, and
odd port numbers for bind(0), in an effort to help avoid
ip_local_port_range exhaustion. From Eric Dumazet.

22) Add Cavium ThunderX driver, from Sunil Goutham.

23) Allow bpf programs to access skb_iif and dev->ifindex SKB metadata,
from Alexei Starovoitov.

24) Add support for T6 chips in cxgb4vf driver, from Hariprasad Shenai.

25) Double TCP Small Queues default to 256K to accomodate situations
like the XEN driver and wireless aggregation. From Wei Liu.

26) Add more entropy inputs to flow dissector, from Tom Herbert.

27) Add CDG congestion control algorithm to TCP, from Kenneth Klette
Jonassen.

28) Convert ipset over to RCU locking, from Jozsef Kadlecsik.

29) Track and act upon link status of ipv4 route nexthops, from Andy
Gospodarek.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1670 commits)
bridge: vlan: flush the dynamically learned entries on port vlan delete
bridge: multicast: add a comment to br_port_state_selection about blocking state
net: inet_diag: export IPV6_V6ONLY sockopt
stmmac: troubleshoot unexpected bits in des0 & des1
net: ipv4 sysctl option to ignore routes when nexthop link is down
net: track link-status of ipv4 nexthops
net: switchdev: ignore unsupported bridge flags
net: Cavium: Fix MAC address setting in shutdown state
drivers: net: xgene: fix for ACPI support without ACPI
ip: report the original address of ICMP messages
net/mlx5e: Prefetch skb data on RX
net/mlx5e: Pop cq outside mlx5e_get_cqe
net/mlx5e: Remove mlx5e_cq.sqrq back-pointer
net/mlx5e: Remove extra spaces
net/mlx5e: Avoid TX CQE generation if more xmit packets expected
net/mlx5e: Avoid redundant dev_kfree_skb() upon NOP completion
net/mlx5e: Remove re-assignment of wq type in mlx5e_enable_rq()
net/mlx5e: Use skb_shinfo(skb)->gso_segs rather than counting them
net/mlx5e: Static mapping of netdev priv resources to/from netdev TX queues
net/mlx4_en: Use HW counters for rx/tx bytes/packets in PF device
...

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# ec3b34e1 22-Jun-2015 Jiri Kosina <jkosina@suse.cz>

Merge branches 'for-4.2/i2c-hid', 'for-4.2/lenovo', 'for-4.2/plantronics', 'for-4.2/rmi', 'for-4.2/sensor-hub', 'for-4.2/sjoy', 'for-4.2/sony' and 'for-4.2/wacom' into for-linus

Conflicts:
drivers/

Merge branches 'for-4.2/i2c-hid', 'for-4.2/lenovo', 'for-4.2/plantronics', 'for-4.2/rmi', 'for-4.2/sensor-hub', 'for-4.2/sjoy', 'for-4.2/sony' and 'for-4.2/wacom' into for-linus

Conflicts:
drivers/hid/wacom_wac.c

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Revision tags: v4.1
# 9f42c8b3 15-Jun-2015 David S. Miller <davem@davemloft.net>

Merge branch 'bpf-share-helpers'

Alexei Starovoitov says:

====================
v1->v2: switched to init_user_ns from current_user_ns as suggested by Andy

Introduce new helpers to access 'struct ta

Merge branch 'bpf-share-helpers'

Alexei Starovoitov says:

====================
v1->v2: switched to init_user_ns from current_user_ns as suggested by Andy

Introduce new helpers to access 'struct task_struct'->pid, tgid, uid, gid, comm
fields in tracing and networking.

Share bpf_trace_printk() and bpf_get_smp_processor_id() helpers between
tracing and networking.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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Revision tags: v4.1-rc8
# ab1973d3 12-Jun-2015 Alexei Starovoitov <ast@plumgrid.com>

bpf: let kprobe programs use bpf_get_smp_processor_id() helper

It's useful to do per-cpu histograms.

Suggested-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Alexei Starovoitov <ast@

bpf: let kprobe programs use bpf_get_smp_processor_id() helper

It's useful to do per-cpu histograms.

Suggested-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

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# 0756ea3e 12-Jun-2015 Alexei Starovoitov <ast@plumgrid.com>

bpf: allow networking programs to use bpf_trace_printk() for debugging

bpf_trace_printk() is a helper function used to debug eBPF programs.
Let socket and TC programs use it as well.
Note, it's DEBU

bpf: allow networking programs to use bpf_trace_printk() for debugging

bpf_trace_printk() is a helper function used to debug eBPF programs.
Let socket and TC programs use it as well.
Note, it's DEBUG ONLY helper. If it's used in the program,
the kernel will print warning banner to make sure users don't use
it in production.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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# ffeedafb 12-Jun-2015 Alexei Starovoitov <ast@plumgrid.com>

bpf: introduce current->pid, tgid, uid, gid, comm accessors

eBPF programs attached to kprobes need to filter based on
current->pid, uid and other fields, so introduce helper functions:

u64 bpf_get_

bpf: introduce current->pid, tgid, uid, gid, comm accessors

eBPF programs attached to kprobes need to filter based on
current->pid, uid and other fields, so introduce helper functions:

u64 bpf_get_current_pid_tgid(void)
Return: current->tgid << 32 | current->pid

u64 bpf_get_current_uid_gid(void)
Return: current_gid << 32 | current_uid

bpf_get_current_comm(char *buf, int size_of_buf)
stores current->comm into buf

They can be used from the programs attached to TC as well to classify packets
based on current task fields.

Update tracex2 example to print histogram of write syscalls for each process
instead of aggregated for all.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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# 206c59d1 10-Jun-2015 Johannes Berg <johannes.berg@intel.com>

Merge remote-tracking branch 'net-next/master' into mac80211-next

Merge back net-next to get wireless driver changes (from Kalle)
to be able to create the API change across all trees properly.

Sign

Merge remote-tracking branch 'net-next/master' into mac80211-next

Merge back net-next to get wireless driver changes (from Kalle)
to be able to create the API change across all trees properly.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

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# 6724af48 09-Jun-2015 Mark Brown <broonie@kernel.org>

Merge branch 'fix/fsl-dspi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-fsl-dspi


Revision tags: v4.1-rc7, v4.1-rc6
# 17ca8cbf 29-May-2015 Daniel Borkmann <daniel@iogearbox.net>

ebpf: allow bpf_ktime_get_ns_proto also for networking

As this is already exported from tracing side via commit d9847d310ab4
("tracing: Allow BPF programs to call bpf_ktime_get_ns()"), we might
as w

ebpf: allow bpf_ktime_get_ns_proto also for networking

As this is already exported from tracing side via commit d9847d310ab4
("tracing: Allow BPF programs to call bpf_ktime_get_ns()"), we might
as well want to move it to the core, so also networking users can make
use of it, e.g. to measure diffs for certain flows from ingress/egress.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Revision tags: v4.1-rc5
# 3f55b7ed 21-May-2015 David S. Miller <davem@davemloft.net>

Merge branch 'ebpf-tail-call'

Alexei Starovoitov says:

====================
bpf: introduce bpf_tail_call() helper

introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used

Merge branch 'ebpf-tail-call'

Alexei Starovoitov says:

====================
bpf: introduce bpf_tail_call() helper

introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used from BPF programs like:
int bpf_prog(struct pt_regs *ctx)
{
...
bpf_tail_call(ctx, &jmp_table, index);
...
}
that is roughly equivalent to:
int bpf_prog(struct pt_regs *ctx)
{
...
if (jmp_table[index])
return (*jmp_table[index])(ctx);
...
}
The important detail that it's not a normal call, but a tail call.
The kernel stack is precious, so this helper reuses the current
stack frame and jumps into another BPF program without adding
extra call frame.
It's trivially done in interpreter and a bit trickier in JITs.

Use cases:
- simplify complex programs
- dispatch into other programs
(for example: index in jump table can be syscall number or network protocol)
- build dynamic chains of programs

The chain of tail calls can form unpredictable dynamic loops therefore
tail_call_cnt is used to limit the number of calls and currently is set to 32.

patch 1 - support bpf_tail_call() in interpreter
patch 2 - support in x64 JIT
We've discussed what's neccessary to support it in arm64/s390 JITs
and it looks fine.
patch 3 - sample example for tracing
patch 4 - sample example for networking

More details in every patch.

This set went through several iterations of reviews/fixes and older
attempts can be seen:
https://git.kernel.org/cgit/linux/kernel/git/ast/bpf.git/log/?h=tail_call_v[123456]
- tail_call_v1 does it without touching JITs but introduces overhead
for all programs that don't use this helper function.
- tail_call_v2 still has some overhead and x64 JIT does full stack
unwind (prologue skipping optimization wasn't there)
- tail_call_v3 reuses 'call' instruction encoding and has interpreter
overhead for every normal call
- tail_call_v4 fixes above architectural shortcomings and v5,v6 fix few
more bugs

This last tail_call_v6 approach seems to be the best.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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# 04fd61ab 19-May-2015 Alexei Starovoitov <ast@plumgrid.com>

bpf: allow bpf programs to tail-call other bpf programs

introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used from BPF programs like:
int bpf_prog(struct pt_regs *ctx)
{

bpf: allow bpf programs to tail-call other bpf programs

introduce bpf_tail_call(ctx, &jmp_table, index) helper function
which can be used from BPF programs like:
int bpf_prog(struct pt_regs *ctx)
{
...
bpf_tail_call(ctx, &jmp_table, index);
...
}
that is roughly equivalent to:
int bpf_prog(struct pt_regs *ctx)
{
...
if (jmp_table[index])
return (*jmp_table[index])(ctx);
...
}
The important detail that it's not a normal call, but a tail call.
The kernel stack is precious, so this helper reuses the current
stack frame and jumps into another BPF program without adding
extra call frame.
It's trivially done in interpreter and a bit trickier in JITs.
In case of x64 JIT the bigger part of generated assembler prologue
is common for all programs, so it is simply skipped while jumping.
Other JITs can do similar prologue-skipping optimization or
do stack unwind before jumping into the next program.

bpf_tail_call() arguments:
ctx - context pointer
jmp_table - one of BPF_MAP_TYPE_PROG_ARRAY maps used as the jump table
index - index in the jump table

Since all BPF programs are idenitified by file descriptor, user space
need to populate the jmp_table with FDs of other BPF programs.
If jmp_table[index] is empty the bpf_tail_call() doesn't jump anywhere
and program execution continues as normal.

New BPF_MAP_TYPE_PROG_ARRAY map type is introduced so that user space can
populate this jmp_table array with FDs of other bpf programs.
Programs can share the same jmp_table array or use multiple jmp_tables.

The chain of tail calls can form unpredictable dynamic loops therefore
tail_call_cnt is used to limit the number of calls and currently is set to 32.

Use cases:
Acked-by: Daniel Borkmann <daniel@iogearbox.net>

==========
- simplify complex programs by splitting them into a sequence of small programs

- dispatch routine
For tracing and future seccomp the program may be triggered on all system
calls, but processing of syscall arguments will be different. It's more
efficient to implement them as:
int syscall_entry(struct seccomp_data *ctx)
{
bpf_tail_call(ctx, &syscall_jmp_table, ctx->nr /* syscall number */);
... default: process unknown syscall ...
}
int sys_write_event(struct seccomp_data *ctx) {...}
int sys_read_event(struct seccomp_data *ctx) {...}
syscall_jmp_table[__NR_write] = sys_write_event;
syscall_jmp_table[__NR_read] = sys_read_event;

For networking the program may call into different parsers depending on
packet format, like:
int packet_parser(struct __sk_buff *skb)
{
... parse L2, L3 here ...
__u8 ipproto = load_byte(skb, ... offsetof(struct iphdr, protocol));
bpf_tail_call(skb, &ipproto_jmp_table, ipproto);
... default: process unknown protocol ...
}
int parse_tcp(struct __sk_buff *skb) {...}
int parse_udp(struct __sk_buff *skb) {...}
ipproto_jmp_table[IPPROTO_TCP] = parse_tcp;
ipproto_jmp_table[IPPROTO_UDP] = parse_udp;

- for TC use case, bpf_tail_call() allows to implement reclassify-like logic

- bpf_map_update_elem/delete calls into BPF_MAP_TYPE_PROG_ARRAY jump table
are atomic, so user space can build chains of BPF programs on the fly

Implementation details:
=======================
- high performance of bpf_tail_call() is the goal.
It could have been implemented without JIT changes as a wrapper on top of
BPF_PROG_RUN() macro, but with two downsides:
. all programs would have to pay performance penalty for this feature and
tail call itself would be slower, since mandatory stack unwind, return,
stack allocate would be done for every tailcall.
. tailcall would be limited to programs running preempt_disabled, since
generic 'void *ctx' doesn't have room for 'tail_call_cnt' and it would
need to be either global per_cpu variable accessed by helper and by wrapper
or global variable protected by locks.

In this implementation x64 JIT bypasses stack unwind and jumps into the
callee program after prologue.

- bpf_prog_array_compatible() ensures that prog_type of callee and caller
are the same and JITed/non-JITed flag is the same, since calling JITed
program from non-JITed is invalid, since stack frames are different.
Similarly calling kprobe type program from socket type program is invalid.

- jump table is implemented as BPF_MAP_TYPE_PROG_ARRAY to reuse 'map'
abstraction, its user space API and all of verifier logic.
It's in the existing arraymap.c file, since several functions are
shared with regular array map.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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Revision tags: v4.1-rc4, v4.1-rc3
# 7ae383be 08-May-2015 Ingo Molnar <mingo@kernel.org>

Merge branch 'linus' into x86/asm, before applying dependent patch

Signed-off-by: Ingo Molnar <mingo@kernel.org>


Revision tags: v4.1-rc2
# b3e5ced6 27-Apr-2015 Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Merge tag 'v4.1-rc1' into patchwork

Linux 4.1-rc1

* tag 'v4.1-rc1': (11651 commits)
Linux 4.1-rc1
x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue
v4l: xilinx: fix for includ

Merge tag 'v4.1-rc1' into patchwork

Linux 4.1-rc1

* tag 'v4.1-rc1': (11651 commits)
Linux 4.1-rc1
x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue
v4l: xilinx: fix for include file movement
platform/chrome: chromeos_laptop - instantiate Atmel at primary address
RCU pathwalk breakage when running into a symlink overmounting something
fix I_DIO_WAKEUP definition
direct-io: only inc/dec inode->i_dio_count for file systems
fs/9p: fix readdir()
Btrfs: prevent list corruption during free space cache processing
toshiba_acpi: Do not register vendor backlight when acpi_video bl is available
x86: fix special __probe_kernel_write() tail zeroing case
crypto: img-hash - CRYPTO_DEV_IMGTEC_HASH should depend on HAS_DMA
crypto: x86/sha512_ssse3 - fixup for asm function prototype change
nios2: rework cache
nios2: Add types.h header required for __u32 type
ALSA: hda - fix headset mic detection problem for one more machine
eth: bf609 eth clock: add pclk clock for stmmac driver probe
blackfin: Wire up missing syscalls
Btrfs: fix inode cache writeout
ACPI / scan: Add a scan handler for PRP0001
...

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Revision tags: v4.1-rc1
# 64131a87 21-Apr-2015 Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Merge branch 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux into v4l_for_linus

* 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux: (9717 commits)
media-bus: Fixup

Merge branch 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux into v4l_for_linus

* 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux: (9717 commits)
media-bus: Fixup RGB444_1X12, RGB565_1X16, and YUV8_1X24 media bus format
hexdump: avoid warning in test function
fs: take i_mutex during prepare_binprm for set[ug]id executables
smp: Fix error case handling in smp_call_function_*()
iommu-common: Fix PARISC compile-time warnings
sparc: Make LDC use common iommu poll management functions
sparc: Make sparc64 use scalable lib/iommu-common.c functions
Break up monolithic iommu table/lock into finer graularity pools and lock
sparc: Revert generic IOMMU allocator.
tools/power turbostat: correct dumped pkg-cstate-limit value
tools/power turbostat: calculate TSC frequency from CPUID(0x15) on SKL
tools/power turbostat: correct DRAM RAPL units on recent Xeon processors
tools/power turbostat: Initial Skylake support
tools/power turbostat: Use $(CURDIR) instead of $(PWD) and add support for O= option in Makefile
tools/power turbostat: modprobe msr, if needed
tools/power turbostat: dump MSR_TURBO_RATIO_LIMIT2
tools/power turbostat: use new MSR_TURBO_RATIO_LIMIT names
Bluetooth: hidp: Fix regression with older userspace and flags validation
config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected
perf/x86/intel/pt: Fix and clean up error handling in pt_event_add()
...

That solves several merge conflicts:
Documentation/DocBook/media/v4l/subdev-formats.xml
Documentation/devicetree/bindings/vendor-prefixes.txt
drivers/staging/media/mn88473/mn88473.c
include/linux/kconfig.h
include/uapi/linux/media-bus-format.h

The ones at subdev-formats.xml and media-bus-format.h are not trivial.
That's why we opted to merge from DRM.

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# 2c33ce00 19-Apr-2015 Dave Airlie <airlied@redhat.com>

Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-o

Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

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# 6c8a53c9 14-Apr-2015 Linus Torvalds <torvalds@linux-foundation.org>

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

Pull perf changes from Ingo Molnar:
"Core kernel changes:

- One of the more interesting features in t

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

Pull perf changes from Ingo Molnar:
"Core kernel changes:

- One of the more interesting features in this cycle is the ability
to attach eBPF programs (user-defined, sandboxed bytecode executed
by the kernel) to kprobes.

This allows user-defined instrumentation on a live kernel image
that can never crash, hang or interfere with the kernel negatively.
(Right now it's limited to root-only, but in the future we might
allow unprivileged use as well.)

(Alexei Starovoitov)

- Another non-trivial feature is per event clockid support: this
allows, amongst other things, the selection of different clock
sources for event timestamps traced via perf.

This feature is sought by people who'd like to merge perf generated
events with external events that were measured with different
clocks:

- cluster wide profiling

- for system wide tracing with user-space events,

- JIT profiling events

etc. Matching perf tooling support is added as well, available via
the -k, --clockid <clockid> parameter to perf record et al.

(Peter Zijlstra)

Hardware enablement kernel changes:

- x86 Intel Processor Trace (PT) support: which is a hardware tracer
on steroids, available on Broadwell CPUs.

The hardware trace stream is directly output into the user-space
ring-buffer, using the 'AUX' data format extension that was added
to the perf core to support hardware constraints such as the
necessity to have the tracing buffer physically contiguous.

This patch-set was developed for two years and this is the result.
A simple way to make use of this is to use BTS tracing, the PT
driver emulates BTS output - available via the 'intel_bts' PMU.
More explicit PT specific tooling support is in the works as well -
will probably be ready by 4.2.

(Alexander Shishkin, Peter Zijlstra)

- x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
feature of Intel Xeon CPUs that allows the measurement and
allocation/partitioning of caches to individual workloads.

These kernel changes expose the measurement side as a new PMU
driver, which exposes various QoS related PMU events. (The
partitioning change is work in progress and is planned to be merged
as a cgroup extension.)

(Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
Waskiewicz Jr)

- x86 Intel Haswell LBR call stack support: this is a new Haswell
feature that allows the hardware recording of call chains, plus
tooling support. To activate this feature you have to enable it
via the new 'lbr' call-graph recording option:

perf record --call-graph lbr
perf report

or:

perf top --call-graph lbr

This hardware feature is a lot faster than stack walk or dwarf
based unwinding, but has some limitations:

- It reuses the current LBR facility, so LBR call stack and
branch record can not be enabled at the same time.

- It is only available for user-space callchains.

(Yan, Zheng)

- x86 Intel Broadwell CPU support and various event constraints and
event table fixes for earlier models.

(Andi Kleen)

- x86 Intel HT CPUs event scheduling workarounds. This is a complex
CPU bug affecting the SNB,IVB,HSW families that results in counter
value corruption. The mitigation code is automatically enabled and
is transparent.

(Maria Dimakopoulou, Stephane Eranian)

The perf tooling side had a ton of changes in this cycle as well, so
I'm only able to list the user visible changes here, in addition to
the tooling changes outlined above:

User visible changes affecting all tools:

- Improve support of compressed kernel modules (Jiri Olsa)
- Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
- Bash completion for subcommands (Yunlong Song)
- Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
- Support missing -f to override perf.data file ownership. (Yunlong Song)
- Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)

User visible changes in individual tools:

'perf data':

New tool for converting perf.data to other formats, initially
for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
Sebastian Siewior)

'perf diff':

Add --kallsyms option (David Ahern)

'perf list':

Allow listing events with 'tracepoint' prefix (Yunlong Song)

Sort the output of the command (Yunlong Song)

'perf kmem':

Respect -i option (Jiri Olsa)

Print big numbers using thousands' group (Namhyung Kim)

Allow -v option (Namhyung Kim)

Fix alignment of slab result table (Namhyung Kim)

'perf probe':

Support multiple probes on different binaries on the same command line (Masami Hiramatsu)

Support unnamed union/structure members data collection. (Masami Hiramatsu)

Check kprobes blacklist when adding new events. (Masami Hiramatsu)

'perf record':

Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)

Support recording running/enabled time (Andi Kleen)

'perf sched':

Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)

'perf report' and 'perf top':

Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)

Indicate which callchain entries are annotated in the
TUI hists browser (Arnaldo Carvalho de Melo)

Add pid/tid filtering to 'report' and 'script' commands (David Ahern)

Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
events (Arnaldo Carvalho de Melo)

'perf stat':

Report unsupported events properly (Suzuki K. Poulose)

Output running time and run/enabled ratio in CSV mode (Andi Kleen)

'perf trace':

Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)

Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)

Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)

Dump stack on segfaults (Arnaldo Carvalho de Melo)

No need to explicitely enable evsels for workload started from perf, let it
be enabled via perf_event_attr.enable_on_exec, removing some events that take
place in the 'perf trace' before a workload is really started by it.
(Arnaldo Carvalho de Melo)

Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)

There's also been a ton of infrastructure work done, such as the
split-out of perf's build system into tools/build/ and other changes -
see the shortlog and changelog for details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
perf evlist: Fix type for references to data_head/tail
perf probe: Check the orphaned -x option
perf probe: Support multiple probes on different binaries
perf buildid-list: Fix segfault when show DSOs with hits
perf tools: Fix cross-endian analysis
perf tools: Fix error path to do closedir() when synthesizing threads
perf tools: Fix synthesizing fork_event.ppid for non-main thread
perf tools: Add 'I' event modifier for exclude_idle bit
perf report: Don't call map__kmap if map is NULL.
perf tests: Fix attr tests
perf probe: Fix ARM 32 building error
perf tools: Merge all perf_event_attr print functions
perf record: Add clockid parameter
perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
perf sched replay: Support using -f to override perf.data file ownership
perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
...

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Revision tags: v4.0, v4.0-rc7, v4.0-rc6
# 9c959c86 25-Mar-2015 Alexei Starovoitov <ast@plumgrid.com>

tracing: Allow BPF programs to call bpf_trace_printk()

Debugging of BPF programs needs some form of printk from the
program, so let programs call limited trace_printk() with %d %u
%x %p modifiers on

tracing: Allow BPF programs to call bpf_trace_printk()

Debugging of BPF programs needs some form of printk from the
program, so let programs call limited trace_printk() with %d %u
%x %p modifiers only.

Similar to kernel modules, during program load verifier checks
whether program is calling bpf_trace_printk() and if so, kernel
allocates trace_printk buffers and emits big 'this is debug
only' banner.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-6-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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# d9847d31 25-Mar-2015 Alexei Starovoitov <ast@plumgrid.com>

tracing: Allow BPF programs to call bpf_ktime_get_ns()

bpf_ktime_get_ns() is used by programs to compute time delta
between events or as a timestamp

Signed-off-by: Alexei Starovoitov <ast@plumgrid.

tracing: Allow BPF programs to call bpf_ktime_get_ns()

bpf_ktime_get_ns() is used by programs to compute time delta
between events or as a timestamp

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-5-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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# 2541517c 25-Mar-2015 Alexei Starovoitov <ast@plumgrid.com>

tracing, perf: Implement BPF programs attached to kprobes

BPF programs, attached to kprobes, provide a safe way to execute
user-defined BPF byte-code programs without being able to crash or
hang the

tracing, perf: Implement BPF programs attached to kprobes

BPF programs, attached to kprobes, provide a safe way to execute
user-defined BPF byte-code programs without being able to crash or
hang the kernel in any way. The BPF engine makes sure that such
programs have a finite execution time and that they cannot break
out of their sandbox.

The user interface is to attach to a kprobe via the perf syscall:

struct perf_event_attr attr = {
.type = PERF_TYPE_TRACEPOINT,
.config = event_id,
...
};

event_fd = perf_event_open(&attr,...);
ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);

'prog_fd' is a file descriptor associated with BPF program
previously loaded.

'event_id' is an ID of the kprobe created.

Closing 'event_fd':

close(event_fd);

... automatically detaches BPF program from it.

BPF programs can call in-kernel helper functions to:

- lookup/update/delete elements in maps

- probe_read - wraper of probe_kernel_read() used to access any
kernel data structures

BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is
architecture dependent) and return 0 to ignore the event and 1 to store
kprobe event into the ring buffer.

Note, kprobes are a fundamentally _not_ a stable kernel ABI,
so BPF programs attached to kprobes must be recompiled for
every kernel version and user must supply correct LINUX_VERSION_CODE
in attr.kern_version during bpf_prog_load() call.

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

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