Pull perf tooling fixes from Thomas Gleixner:
"Another small set of perf tooling fixes and updates:
- Revert "perf pmu: Fix pmu events parsing rule", as it broke Intel
PT event description parsing (Arnaldo Carvalho de Melo)
- Sync x86's cpufeatures.h and kvm UAPI headers with the kernel
sources, suppressing the ABI drift warnings (Arnaldo Carvalho de
Melo)
- Remove duplicated entry for westmereep-dp in Intel's mapfile.csv
(William Cohen)
- Fix typo in 'perf bench numa' options description (Yisheng Xie)"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
Revert "perf pmu: Fix pmu events parsing rule"
tools headers kvm: Sync ARM UAPI headers with the kernel sources
tools headers kvm: Sync uapi/linux/kvm.h with the kernel sources
tools headers: Sync x86 cpufeatures.h with the kernel sources
perf vendor events intel: Remove duplicated entry for westmereep-dp in mapfile.csv
perf bench numa: Fix typo in options
The bpf syscall and selftests conflicts were trivial
overlapping changes.
The r8169 change involved moving the added mdelay from 'net' into a
different function.
A TLS close bug fix overlapped with the splitting of the TLS state
into separate TX and RX parts. I just expanded the tests in the bug
fix from "ctx->conf == X" into "ctx->tx_conf == X && ctx->rx_conf
== X".
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Verify lengths of keys provided by the user is AF_KEY, from Kevin
Easton.
2) Add device ID for BCM89610 PHY. Thanks to Bhadram Varka.
3) Add Spectre guards to some ATM code, courtesy of Gustavo A. R.
Silva.
4) Fix infinite loop in NSH protocol code. To Eric Dumazet we are most
grateful for this fix.
5) Line up /proc/net/netlink headers properly. This fix from YU Bo, we
do appreciate.
6) Use after free in TLS code. Once again we are blessed by the
honorable Eric Dumazet with this fix.
7) Fix regression in TLS code causing stalls on partial TLS records.
This fix is bestowed upon us by Andrew Tomt.
8) Deal with too small MTUs properly in LLC code, another great gift
from Eric Dumazet.
9) Handle cached route flushing properly wrt. MTU locking in ipv4, to
Hangbin Liu we give thanks for this.
10) Fix regression in SO_BINDTODEVIC handling wrt. UDP socket demux.
Paolo Abeni, he gave us this.
11) Range check coalescing parameters in mlx4 driver, thank you Moshe
Shemesh.
12) Some ipv6 ICMP error handling fixes in rxrpc, from our good brother
David Howells.
13) Fix kexec on mlx5 by freeing IRQs in shutdown path. Daniel Juergens,
you're the best!
14) Don't send bonding RLB updates to invalid MAC addresses. Debabrata
Benerjee saved us!
15) Uh oh, we were leaking in udp_sendmsg and ping_v4_sendmsg. The ship
is now water tight, thanks to Andrey Ignatov.
16) IPSEC memory leak in ixgbe from Colin Ian King, man we've got holes
everywhere!
17) Fix error path in tcf_proto_create, Jiri Pirko what would we do
without you!
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (92 commits)
net sched actions: fix refcnt leak in skbmod
net: sched: fix error path in tcf_proto_create() when modules are not configured
net sched actions: fix invalid pointer dereferencing if skbedit flags missing
ixgbe: fix memory leak on ipsec allocation
ixgbevf: fix ixgbevf_xmit_frame()'s return type
ixgbe: return error on unsupported SFP module when resetting
ice: Set rq_last_status when cleaning rq
ipv4: fix memory leaks in udp_sendmsg, ping_v4_sendmsg
mlxsw: core: Fix an error handling path in 'mlxsw_core_bus_device_register()'
bonding: send learning packets for vlans on slave
bonding: do not allow rlb updates to invalid mac
net/mlx5e: Err if asked to offload TC match on frag being first
net/mlx5: E-Switch, Include VF RDMA stats in vport statistics
net/mlx5: Free IRQs in shutdown path
rxrpc: Trace UDP transmission failure
rxrpc: Add a tracepoint to log ICMP/ICMP6 and error messages
rxrpc: Fix the min security level for kernel calls
rxrpc: Fix error reception on AF_INET6 sockets
rxrpc: Fix missing start of call timeout
qed: fix spelling mistake: "taskelt" -> "tasklet"
...
This is not specific to BPF but was found when parsing a .c BPF proggie
that while valid, had no events attached to tracepoints, kprobes, etc:
Very minimal file that perf's BPF code can compile:
# cat empty.c
char _license[] __attribute__((section("license"), used)) = "GPL";
int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
#
Before this patch:
# perf trace -e empty.c
WARNING: event parser found nothinginvalid or unsupported event: 'empty.c'
Run 'perf list' for a list of valid events
Usage: perf trace [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]
-e, --event <event> event/syscall selector. use 'perf list' to list available events
#
After:
# perf trace -e empty.c
WARNING: event parser found nothing
invalid or unsupported event: 'empty.c'
Run 'perf list' for a list of valid events
Usage: perf trace [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]
-e, --event <event> event/syscall selector. use 'perf list' to list available events
#
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: https://lkml.kernel.org/n/tip-8ysughiz00h6mjpcot04qyjj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
CoreSight doesn't allocate thread structure for unknown_thread in ETM
auxtrace, so unknown_thread is NULL pointer. If the perf data doesn't
contain valid tid and then cs_etm__mem_access() uses unknown_thread
instead as thread handler, this results in a segmentation fault when
thread__find_addr_map() accesses the thread handler.
This commit creates a new thread data which is used by unknown_thread, so
CoreSight tracing can roll back to use unknown_thread if perf data
doesn't include valid thread info. This commit also releases thread
data for initialization failure case and for normal auxtrace free flow.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1525924920-4381-1-git-send-email-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Right now, skipped tests are returning a failure exit code if /dev/kvm does
not exists. Consistently return a zero status code so that various scripts
over the interwebs do not complain. Also return a zero status code if
the KVM_CAP_SYNC_REGS capability is not present, and hardcode in the
test the register kinds that are covered (rather than just using whatever
value of KVM_SYNC_X86_VALID_FIELDS is provided by the kernel headers).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
BPF programs only have to specify the target kernel version for
tracing related hooks, in networking world that requirement does
not really apply. Loosen the checks in libbpf to reflect that.
bpf_object__open() users will continue to see the error for backward
compatibility (and because prog_type is not available there).
Error code for NULL file name is changed from ENOENT to EINVAL,
as it seems more appropriate, hopefully, that's an OK change.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
There are two copies of event reading loop - in bpftool and
trace_helpers "library". Consolidate them and move the code
to libbpf. Return codes from trace_helpers are kept, but
renamed to include LIBBPF prefix.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Ask the kernel to include sample time in each even instead of
reading the clock. This is also more accurate because our
clock reading was done when user space would dump the buffer,
not when sample was produced.
Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Sync the header from include/uapi/linux/bpf.h which was updated to add
fib lookup helper function. This fixes selftests/bpf build failure.
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
'|& ...' is a bash 4.0+ construct which is not guaranteed to be available
when using '$(shell ...)' in a Makefile. Fall back to the more portable
'2>&1 | ...'.
Fixes the following warning during compilation:
/bin/sh: 1: Syntax error: "&" unexpected
Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Simple example of fast-path forwarding. It has a serious flaw
in not verifying the egress device index supports XDP forwarding.
If the egress device does not packets are dropped.
Take this only as a simple example of fast-path forwarding.
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
- correct a typo in the value of 'matchPattern' of test 282d, potentially
causing false negative
- allow errors when 'teardown' executes '$TC action flush action bpf' in
test 282d, to fix false positive when it is run with act_bpf unloaded
- correct the value of 'matchPattern' in test e939, causing false positive
in case the BPF JIT is enabled
Fixes: 440ea4ae18 ("tc-testing: add selftests for 'bpf' action")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Lucas Bates <lucasb@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we perform the following command lines:
$ perf record -e "{cycles,branches}" ./div
$ perf annotate main --stdio
The output shows only the first event, "cycles" and the displaying
format is not correct.
Percent | Source code & Disassembly of div for cycles (44550 samples)
-----------------------------------------------------------------------------------
:
:
:
: Disassembly of section .text:
:
: 00000000004004b0 <main>:
: main():
:
: return i;
: }
:
: int main(void)
: {
0.00 : 4004b0: push %rbx
: int i;
: int flag;
: volatile double x = 1212121212, y = 121212;
:
: s_randseed = time(0);
0.00 : 4004b1: xor %edi,%edi
: srand(s_randseed);
0.00 : 4004b3: mov $0x77359400,%ebx
:
: return i;
: }
The issue is that the value of the 'nr_percent' variable is hardcoded to
1. This patch fixes it.
With this patch, the output is:
Percent | Source code & Disassembly of div for cycles (44550 samples)
-----------------------------------------------------------------------------------
:
:
:
: Disassembly of section .text:
:
: 00000000004004b0 <main>:
: main():
:
: return i;
: }
:
: int main(void)
: {
0.00 0.00 : 4004b0: push %rbx
: int i;
: int flag;
: volatile double x = 1212121212, y = 121212;
:
: s_randseed = time(0);
0.00 0.00 : 4004b1: xor %edi,%edi
: srand(s_randseed);
0.00 0.00 : 4004b3: mov $0x77359400,%ebx
:
: return i;
: }
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: f681d593d1 ("perf annotate: Remove disasm__calc_percent() from disasm_line__print()")
Link: http://lkml.kernel.org/r/1525881435-4092-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf test "probe libc's inet_pton & backtrace it with ping" fails on
4.17.0rc3 on s/390. It turned out that function __inet_pton is reported
as inline:
[root@s8360047 perf]# ./perf script -i /tmp/perf.data.111
ping 12457 [000] 1584.478959: probe_libc:inet_pton: (3ffb5a347e8)
1347e8 __inet_pton (inlined)
f19d7 gaih_inet.constprop.5 (/usr/lib64/libc-2.24.so)
f4c3f __GI_getaddrinfo (inlined)
410b main (/usr/bin/ping)
Allow __inet_pton listed as inline.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180503065837.71043-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Trivial fix to spelling mistake in dprintf message
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
The BPF selftests fail to build with missing headers
'asm/bitsperlong.h' and 'asm/errno.h'.
These already exist in 'tools/arch/[arch]/include';
add architecture-agnostic header files in 'tools/include/uapi'
to reference them.
Signed-off-by: Sirio Balmelli <sirio@b-ad.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch adds test for BPF_BTF_GET_FD_BY_ID and the new
btf_id/btf_key_id/btf_value_id in the "struct bpf_map_info".
It also modifies the existing BPF_OBJ_GET_INFO_BY_FD test
to reflect the new "struct bpf_btf_info".
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch sync the tools/include/uapi/linux/btf.h with
the newly introduced BTF ID support.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
This patch adds a CHECK() macro for condition checking
and error report purpose. Something similar to test_progs.c
It also counts the number of tests passed/skipped/failed and
print them at the end of the test run.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Alexei Starovoitov <ast@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Minor conflict, a CHECK was placed into an if() statement
in net-next, whilst a newline was added to that CHECK
call in 'net'. Thanks to Daniel for the merge resolution.
Signed-off-by: David S. Miller <davem@davemloft.net>
When a script file that isn't generated uses the variable
TEST_GEN_PROGS_EXTENDED and a 'make -C tools/testing/selftests clean' is
performed the script file gets removed and git shows the file as
deleted. For script files that isn't generated TEST_PROGS_EXTENDED
should be used.
Fixes: 9faedd643f ("selftests: net: add in_netns.sh TEST_GEN_PROGS_EXTENDED")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The generated files udpgso* shouldn't be part of TEST_PROGS, they are
used by udpgso.sh and udpgsp_bench.sh. They should be added to the
TEST_GEN_FILES to get installed without being added to the main
run_kselftest.sh script.
Fixes: 3a687bef14 ("selftests: udp gso benchmark")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This was used by the ide, scsi and networking code in the past to
determine if they should bounce payloads. Now that the dma mapping
always have to support dma to all physical memory (thanks to swiotlb
for non-iommu systems) there is no need to this crude hack any more.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Palmer Dabbelt <palmer@sifive.com> (for riscv)
Reviewed-by: Jens Axboe <axboe@kernel.dk>
If a seccomp user is not interested in Speculative Store Bypass mitigation
by default, it can set the new SECCOMP_FILTER_FLAG_SPEC_ALLOW flag when
adding filters.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Users of BPF sooner or later discover perf_event_output() helpers
and BPF_MAP_TYPE_PERF_EVENT_ARRAY. Dumping this array type is
not possible, however, we can add simple reading of perf events.
Create a new event_pipe subcommand for maps, this sub command
will only work with BPF_MAP_TYPE_PERF_EVENT_ARRAY maps.
Parts of the code from samples/bpf/trace_output_user.c.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Instead of spelling [hex] BYTES everywhere use DATA as keyword
for generalized value. This will help us keep the messages
concise when longer command are added in the future. It will
also be useful once BTF support comes. We will only have to
change the definition of DATA.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull ACPI fix from Rafael Wysocki:
"This fixes an ACPICA utilities (acpidump) build regression from the
4.16 cycle by setting LD in the CFLAGS passed to the linker to $(CC)
again (Jiri Slaby)"
* tag 'acpi-4.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
tools: power/acpi, revert to LD = gcc
Commit 7ed1c1901f (tools: fix cross-compile var clobbering) removed
setting of LD to $(CROSS_COMPILE)gcc. This broke build of acpica
(acpidump) in power/acpi:
ld: unrecognized option '-D_LINUX'
The tools pass CFLAGS to the linker (incl. -D_LINUX), so revert this
particular change and let LD be $(CC) again. Note that the old behaviour
was a bit different, it used $(CROSS_COMPILE)gcc which was eliminated by
the commit 7ed1c1901f. We use $(CC) for that reason.
Fixes: 7ed1c1901f (tools: fix cross-compile var clobbering)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: 4.16+ <stable@vger.kernel.org> # 4.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull kselftest fixes from Shuah Khan:
"This Kselftest update for 4.17-rc4 consists of a fix for a syntax
error in the script that runs selftests. Mathieu Desnoyers found this
bug in the script on systems running GNU Make 3.8 or older"
* tag 'linux-kselftest-4.17-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
selftests: Fix lib.mk run_tests target shell script
Pull networking fixes from David Miller:
1) Various sockmap fixes from John Fastabend (pinned map handling,
blocking in recvmsg, double page put, error handling during redirect
failures, etc.)
2) Fix dead code handling in x86-64 JIT, from Gianluca Borello.
3) Missing device put in RDS IB code, from Dag Moxnes.
4) Don't process fast open during repair mode in TCP< from Yuchung
Cheng.
5) Move address/port comparison fixes in SCTP, from Xin Long.
6) Handle add a bond slave's master into a bridge properly, from
Hangbin Liu.
7) IPv6 multipath code can operate on unitialized memory due to an
assumption that the icmp header is in the linear SKB area. Fix from
Eric Dumazet.
8) Don't invoke do_tcp_sendpages() recursively via TLS, from Dave
Watson.
9) Fix memory leaks in x86-64 JIT, from Daniel Borkmann.
10) RDS leaks kernel memory to userspace, from Eric Dumazet.
11) DCCP can invoke a tasklet on a freed socket, take a refcount. Also
from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (78 commits)
dccp: fix tasklet usage
smc: fix sendpage() call
net/smc: handle unregistered buffers
net/smc: call consolidation
qed: fix spelling mistake: "offloded" -> "offloaded"
net/mlx5e: fix spelling mistake: "loobpack" -> "loopback"
tcp: restore autocorking
rds: do not leak kernel memory to user land
qmi_wwan: do not steal interfaces from class drivers
ipv4: fix fnhe usage by non-cached routes
bpf: sockmap, fix error handling in redirect failures
bpf: sockmap, zero sg_size on error when buffer is released
bpf: sockmap, fix scatterlist update on error path in send with apply
net_sched: fq: take care of throttled flows before reuse
ipv6: Revert "ipv6: Allow non-gateway ECMP for IPv6"
bpf, x64: fix memleak when not converging on calls
bpf, x64: fix memleak when not converging after image
net/smc: restrict non-blocking connect finish
8139too: Use disable_irq_nosync() in rtl8139_poll_controller()
sctp: fix the issue that the cookie-ack with auth can't get processed
...
Only sync the header from include/uapi/linux/bpf.h.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Remove all eBPF tests involving LD_ABS/LD_IND from test_bpf.ko. Reason
is that the eBPF tests from test_bpf module do not go via BPF verifier
and therefore any instruction rewrites from verifier cannot take place.
Therefore, move them into test_verifier which runs out of user space,
so that verfier can rewrite LD_ABS/LD_IND internally in upcoming patches.
It will have the same effect since runtime tests are also performed from
there. This also allows to finally unexport bpf_skb_vlan_{push,pop}_proto
and keep it internal to core kernel.
Additionally, also add further cBPF LD_ABS/LD_IND test coverage into
test_bpf.ko suite.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The test fails to work if reverse-path filtering is in effect on the
mirrored-to host interface, or for all interfaces.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of hand-managing the sysctl set and restore, use the wrappers
sysctl_set() and sysctl_restore() to do the bookkeeping automatically.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add two helper functions: sysctl_set() to change the value of a given
sysctl setting, and sysctl_restore() to change it back to what it was.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
