提交 · 6bdf6abc56b53103324dfd270a86580306e1a232 · openeuler / Kernel

30 6月, 2017 1 次提交

bpf: prevent leaking pointer via xadd on unpriviledged · 6bdf6abc

由 Daniel Borkmann 提交于 6月 29, 2017

Leaking kernel addresses on unpriviledged is generally disallowed,
for example, verifier rejects the following:

  0: (b7) r0 = 0
  1: (18) r2 = 0xffff897e82304400
  3: (7b) *(u64 *)(r1 +48) = r2
  R2 leaks addr into ctx

Doing pointer arithmetic on them is also forbidden, so that they
don't turn into unknown value and then get leaked out. However,
there's xadd as a special case, where we don't check the src reg
for being a pointer register, e.g. the following will pass:

  0: (b7) r0 = 0
  1: (7b) *(u64 *)(r1 +48) = r0
  2: (18) r2 = 0xffff897e82304400 ; map
  4: (db) lock *(u64 *)(r1 +48) += r2
  5: (95) exit

We could store the pointer into skb->cb, loose the type context,
and then read it out from there again to leak it eventually out
of a map value. Or more easily in a different variant, too:

   0: (bf) r6 = r1
   1: (7a) *(u64 *)(r10 -8) = 0
   2: (bf) r2 = r10
   3: (07) r2 += -8
   4: (18) r1 = 0x0
   6: (85) call bpf_map_lookup_elem#1
   7: (15) if r0 == 0x0 goto pc+3
   R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R6=ctx R10=fp
   8: (b7) r3 = 0
   9: (7b) *(u64 *)(r0 +0) = r3
  10: (db) lock *(u64 *)(r0 +0) += r6
  11: (b7) r0 = 0
  12: (95) exit

  from 7 to 11: R0=inv,min_value=0,max_value=0 R6=ctx R10=fp
  11: (b7) r0 = 0
  12: (95) exit

Prevent this by checking xadd src reg for pointer types. Also
add a couple of test cases related to this.

Fixes: 1be7f75d ("bpf: enable non-root eBPF programs")
Fixes: 17a52670 ("bpf: verifier (add verifier core)")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Acked-by: NEdward Cree <ecree@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

6bdf6abc

20 6月, 2017 1 次提交

NTB: ntb_test: fix bug printing ntb_perf results · 07b0b22b

由 Logan Gunthorpe 提交于 6月 05, 2017

The code mistakenly prints the local perf results for the remote test
so the script reports identical results for both directions. Fix this
by ensuring we print the remote result.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Fixes: a9c59ef7 ("ntb_test: Add a selftest script for the NTB subsystem")
Acked-by: NAllen Hubbe <Allen.Hubbe@dell.com>
Signed-off-by: NJon Mason <jdmason@kudzu.us>

07b0b22b

17 6月, 2017 1 次提交

perf unwind: Report module before querying isactivation in dwfl unwind · 9126cbba

由 Milian Wolff 提交于 6月 02, 2017

The PC returned by dwfl_frame_pc() may map into a not-yet-reported
module. We have to report it before we continue unwinding. But when we
query for the isactivation flag in dwfl_frame_pc, libdw will actually do
one more unwinding step internally which can then break and lead to
missed frames or broken stacks.

With libunwind we get e.g.:

~~~~~
heaptrack_gui 2228 135073.400474: 613969 cycles:
108c8e [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1093bc [unknown] (/usr/lib/libQt5Core.so.5.8.0)
109e7b QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1470ff [unknown] (/usr/lib/libQt5Core.so.5.8.0)
147f67 QSystemLocale::query (/usr/lib/libQt5Core.so.5.8.0)
109fbf QLocalePrivate::updateSystemPrivate (/usr/lib/libQt5Core.so.5.8.0)
10aa27 QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1e02c3 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
2113bb [unknown] (/usr/lib/libQt5Core.so.5.8.0)
211505 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1b5df0 QFileInfo::exists (/usr/lib/libQt5Core.so.5.8.0)
92eb2 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93423 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93d2a QLibraryInfo::location (/usr/lib/libQt5Core.so.5.8.0)
2170af [unknown] (/usr/lib/libQt5Core.so.5.8.0)
297c53 QCoreApplicationPrivate::init (/usr/lib/libQt5Core.so.5.8.0)
f7cde QGuiApplicationPrivate::init (/usr/lib/libQt5Gui.so.5.8.0)
1589e8 QApplicationPrivate::init (/usr/lib/libQt5Widgets.so.5.8.0)
78622 main (/home/milian/projects/compiled/other/bin/heaptrack_gui)
20439 __libc_start_main (/usr/lib/libc-2.25.so)
78299 _start (/home/milian/projects/compiled/other/bin/heaptrack_gui)

heaptrack_gui 2228 135073.401156: 569521 cycles:
131633 QString::endsWith (/usr/lib/libQt5Core.so.5.8.0)
1a0701 QDir::cleanPath (/usr/lib/libQt5Core.so.5.8.0)
21b82d [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1b3727 QFileInfo::canonicalFilePath (/usr/lib/libQt5Core.so.5.8.0)
2780c7 QFactoryLoader::update (/usr/lib/libQt5Core.so.5.8.0)
279525 QFactoryLoader::QFactoryLoader (/usr/lib/libQt5Core.so.5.8.0)
e5bd0 QPlatformIntegrationFactory::create (/usr/lib/libQt5Gui.so.5.8.0)
f5a1c QGuiApplicationPrivate::createPlatformIntegration (/usr/lib/libQt5Gui.so.5.8.0)
f650c QGuiApplicationPrivate::createEventDispatcher (/usr/lib/libQt5Gui.so.5.8.0)
298524 QCoreApplicationPrivate::init (/usr/lib/libQt5Core.so.5.8.0)
f7cde QGuiApplicationPrivate::init (/usr/lib/libQt5Gui.so.5.8.0)
1589e8 QApplicationPrivate::init (/usr/lib/libQt5Widgets.so.5.8.0)
78622 main (/home/milian/projects/compiled/other/bin/heaptrack_gui)
20439 __libc_start_main (/usr/lib/libc-2.25.so)
78299 _start (/home/milian/projects/compiled/other/bin/heaptrack_gui)
~~~~~

Note the two frames 1589e8 and 78622 in the first sample. These are
missing when unwinding with libdw. The second sample's breakage is
more obvious:

~~~~~
heaptrack_gui 2228 135073.400474: 613969 cycles:
108c8e [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1093bc [unknown] (/usr/lib/libQt5Core.so.5.8.0)
109e7b QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1470ff [unknown] (/usr/lib/libQt5Core.so.5.8.0)
147f67 QSystemLocale::query (/usr/lib/libQt5Core.so.5.8.0)
109fbf QLocalePrivate::updateSystemPrivate (/usr/lib/libQt5Core.so.5.8.0)
10aa27 QLocale::QLocale (/usr/lib/libQt5Core.so.5.8.0)
1e02c3 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
2113bb [unknown] (/usr/lib/libQt5Core.so.5.8.0)
211505 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
1b5df0 QFileInfo::exists (/usr/lib/libQt5Core.so.5.8.0)
92eb2 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93423 [unknown] (/usr/lib/libQt5Core.so.5.8.0)
93d2a QLibraryInfo::location (/usr/lib/libQt5Core.so.5.8.0)
2170af [unknown] (/usr/lib/libQt5Core.so.5.8.0)
297c53 QCoreApplicationPrivate::init (/usr/lib/libQt5Core.so.5.8.0)
f7cde QGuiApplicationPrivate::init (/usr/lib/libQt5Gui.so.5.8.0)
20439 __libc_start_main (/usr/lib/libc-2.25.so)
78299 _start (/home/milian/projects/compiled/other/bin/heaptrack_gui)

This patch fixes this issue and the libdw unwinder mimicks the libunwind
behavior more closely.
Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
Acked-by: NJan Kratochvil <jan.kratochvil@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20170602143753.16907-2-milian.wolff@kdab.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

9126cbba

16 6月, 2017 1 次提交

objtool: Add fortify_panic as __noreturn function · 92b0a141

由 Kees Cook 提交于 6月 15, 2017

CONFIG_FORTIFY_SOURCE=y implements fortify_panic() as a __noreturn function,
so objtool needs to know about it too.
Suggested-by: NDaniel Micay <danielmicay@gmail.com>
Tested-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJosh Poimboeuf <jpoimboe@redhat.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/1497532835-32704-1-git-send-email-jpoimboe@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

92b0a141

15 6月, 2017 2 次提交

perf tools: Fix build with ARCH=x86_64 · 7a759cd8

由 Jiada Wang 提交于 4月 09, 2017

With commit: 0a943cb1 (tools build: Add HOSTARCH Makefile variable)
when building for ARCH=x86_64, ARCH=x86_64 is passed to perf instead of
ARCH=x86, so the perf build process searchs header files from
tools/arch/x86_64/include, which doesn't exist.

The following build failure is seen:

  In file included from util/event.c:2:0:
    tools/include/uapi/linux/mman.h:4:27: fatal error: uapi/asm/mman.h: No such file or directory
    compilation terminated.

Fix this issue by using SRCARCH instead of ARCH in perf, just like the
main kernel Makefile and tools/objtool's.
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Eugeniu Rosca <erosca@de.adit-jv.com>
Cc: Jan Stancek <jstancek@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Rui Teng <rui.teng@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 0a943cb1 ("tools build: Add HOSTARCH Makefile variable")
Link: http://lkml.kernel.org/r/1491793357-14977-2-git-send-email-jiada_wang@mentor.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

7a759cd8

perf evsel: Fix probing of precise_ip level for default cycles event · 7a1ac110

由 Arnaldo Carvalho de Melo 提交于 6月 09, 2017

Since commit 18e7a45a ("perf/x86: Reject non sampling events with
precise_ip") returns -EINVAL for sys_perf_event_open() with an attribute
with (attr.precise_ip > 0 && attr.sample_period == 0), just like is done
in the routine used to probe the max precise level when no events were
passed to 'perf record' or 'perf top', i.e.:

	perf_evsel__new_cycles()
		perf_event_attr__set_max_precise_ip()

The x86 code, in x86_pmu_hw_config(), which is called all the way from
sys_perf_event_open() did, starting with the aforementioned commit:

                /* There's no sense in having PEBS for non sampling events: */
                if (!is_sampling_event(event))
                        return -EINVAL;

Which makes it fail for cycles:ppp, cycles:pp and cycles:p, always using
just the non precise cycles variant.

To make sure that this is the case, I tested it, before this patch,
with:

  # perf probe -L x86_pmu_hw_config
  <x86_pmu_hw_config@/home/acme/git/linux/arch/x86/events/core.c:0>
        0  int x86_pmu_hw_config(struct perf_event *event)
        1  {
        2         if (event->attr.precise_ip) {
<SNIP>
       17                 if (event->attr.precise_ip > precise)
       18                         return -EOPNOTSUPP;

                          /* There's no sense in having PEBS for non sampling events: */
       21                 if (!is_sampling_event(event))
       22                         return -EINVAL;
                  }
<SNIP>
  # perf probe x86_pmu_hw_config:22
  Added new events:
    probe:x86_pmu_hw_config (on x86_pmu_hw_config:22)
    probe:x86_pmu_hw_config_1 (on x86_pmu_hw_config:22)

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

        perf record -e probe:x86_pmu_hw_config_1 -aR sleep 1

  # perf trace -e perf_event_open,probe:x86_pmu_hwconfig*/max-stack=16/ perf record usleep 1
     0.000 ( 0.015 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1      ) ...
     0.015 (         ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
                                       x86_pmu_hw_config ([kernel.kallsyms])
                                       hsw_hw_config ([kernel.kallsyms])
                                       x86_pmu_event_init ([kernel.kallsyms])
                                       perf_try_init_event ([kernel.kallsyms])
                                       perf_event_alloc ([kernel.kallsyms])
                                       SYSC_perf_event_open ([kernel.kallsyms])
                                       sys_perf_event_open ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
                                       perf_evsel__new_cycles (/home/acme/bin/perf)
                                       perf_evlist__add_default (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
                                       handle_internal_command (/home/acme/bin/perf)
     0.000 ( 0.021 ms): perf/4150  ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
     0.023 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1      ) ...
     0.025 (         ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
                                       x86_pmu_hw_config ([kernel.kallsyms])
                                       hsw_hw_config ([kernel.kallsyms])
                                       x86_pmu_event_init ([kernel.kallsyms])
                                       perf_try_init_event ([kernel.kallsyms])
                                       perf_event_alloc ([kernel.kallsyms])
                                       SYSC_perf_event_open ([kernel.kallsyms])
                                       sys_perf_event_open ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
                                       perf_evsel__new_cycles (/home/acme/bin/perf)
                                       perf_evlist__add_default (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
                                       handle_internal_command (/home/acme/bin/perf)
     0.023 ( 0.004 ms): perf/4150  ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
     0.028 ( 0.002 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8ba110, cpu: -1, group_fd: -1      ) ...
     0.030 (         ): probe:x86_pmu_hw_config:(ffffffff9c0065e1))
                                       x86_pmu_hw_config ([kernel.kallsyms])
                                       hsw_hw_config ([kernel.kallsyms])
                                       x86_pmu_event_init ([kernel.kallsyms])
                                       perf_try_init_event ([kernel.kallsyms])
                                       perf_event_alloc ([kernel.kallsyms])
                                       SYSC_perf_event_open ([kernel.kallsyms])
                                       sys_perf_event_open ([kernel.kallsyms])
                                       do_syscall_64 ([kernel.kallsyms])
                                       return_from_SYSCALL_64 ([kernel.kallsyms])
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
                                       perf_evsel__new_cycles (/home/acme/bin/perf)
                                       perf_evlist__add_default (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
                                       handle_internal_command (/home/acme/bin/perf)
     0.028 ( 0.004 ms): perf/4150  ... [continued]: perf_event_open()) = -1 EINVAL Invalid argument
    41.018 ( 0.012 ms): perf/4150 perf_event_open(attr_uptr: 0x7ffebc8b5dd0, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
    41.065 ( 0.011 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
    41.080 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c7db78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
    41.103 ( 0.010 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4
    41.115 ( 0.006 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5
    41.122 ( 0.004 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6
    41.128 ( 0.008 ms): perf/4150 perf_event_open(attr_uptr: 0x3c4e748, pid: 4151 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ]
  #

I.e. that return -EINVAL in x86_pmu_hw_config() is hit three times.

So fix it by just setting attr.sample_period

Now, after this patch:

  # perf trace --max-stack=2 -e perf_event_open,probe:x86_pmu_hw_config* perf record usleep 1
  [ perf record: Woken up 1 times to write data ]
     0.000 ( 0.017 ms): perf/8469 perf_event_open(attr_uptr: 0x7ffe36c27d10, pid: -1, cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_open_cloexec_flag (/home/acme/bin/perf)
     0.050 ( 0.031 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evlist__config (/home/acme/bin/perf)
     0.092 ( 0.040 ms): perf/8469 perf_event_open(attr_uptr: 0x24ebb78, pid: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evlist__config (/home/acme/bin/perf)
     0.143 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, cpu: -1, group_fd: -1           ) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_event_attr__set_max_precise_ip (/home/acme/bin/perf)
     0.161 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), group_fd: -1, flags: FD_CLOEXEC) = 4
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
     0.171 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 1, group_fd: -1, flags: FD_CLOEXEC) = 5
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
     0.180 ( 0.007 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 2, group_fd: -1, flags: FD_CLOEXEC) = 6
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
     0.190 ( 0.005 ms): perf/8469 perf_event_open(attr_uptr: 0x24bc748, pid: 8470 (perf), cpu: 3, group_fd: -1, flags: FD_CLOEXEC) = 8
                                       syscall (/usr/lib64/libc-2.24.so)
                                       perf_evsel__open (/home/acme/bin/perf)
  [ perf record: Captured and wrote 0.017 MB perf.data (7 samples) ]
  #

The probe one called from perf_event_attr__set_max_precise_ip() works
the first time, with attr.precise_ip = 3, wit hthe next ones being the
per cpu ones for the cycles:ppp event.

And here is the text from a report and alternative proposed patch by
Thomas-Mich Richter:

 ---

On s390 the counter and sampling facility do not support a precise IP
skid level and sometimes returns EOPNOTSUPP when structure member
precise_ip in struct perf_event_attr is not set to zero.

On s390 commnd 'perf record -- true' fails with error EOPNOTSUPP.  This
happens only when no events are specified on command line.

The functions called are
...
  --> perf_evlist__add_default
      --> perf_evsel__new_cycles
          --> perf_event_attr__set_max_precise_ip

The last function determines the value of structure member precise_ip by
invoking the perf_event_open() system call and checking the return code.
The first successful open is the value for precise_ip.

However the value is determined without setting member sample_period and
indicates no sampling.

On s390 the counter facility and sampling facility are different.  The
above procedure determines a precise_ip value of 3 using the counter
facility. Later it uses the sampling facility with a value of 3 and
fails with EOPNOTSUPP.

 ---

v2: Older compilers (e.g. gcc 4.4.7) don't support referencing members
    of unnamed union members in the container struct initialization, so
    move from:

	struct perf_event_attr attr = {
		...
		.sample_period = 1,
	};

to right after it as:

	struct perf_event_attr attr = {
		...
	};

	attr.sample_period = 1;

v3: We need to reset .sample_period to 0 to let the users of
perf_evsel__new_cycles() to properly setup attr.sample_period or
attr.sample_freq. Reported by Ingo Molnar.
Reported-and-Acked-by: NThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Acked-by: NHendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 18e7a45a ("perf/x86: Reject non sampling events with precise_ip")
Link: http://lkml.kernel.org/n/tip-yv6nnkl7tzqocrm0hl3x7vf1@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

7a1ac110

09 6月, 2017 10 次提交

bpf, tests: fix endianness selection · 78a5a93c

由 Daniel Borkmann 提交于 6月 08, 2017

I noticed that test_l4lb was failing in selftests:

  # ./test_progs
  test_pkt_access:PASS:ipv4 77 nsec
  test_pkt_access:PASS:ipv6 44 nsec
  test_xdp:PASS:ipv4 2933 nsec
  test_xdp:PASS:ipv6 1500 nsec
  test_l4lb:PASS:ipv4 377 nsec
  test_l4lb:PASS:ipv6 544 nsec
  test_l4lb:FAIL:stats 6297600000 200000
  test_tcp_estats:PASS: 0 nsec
  Summary: 7 PASSED, 1 FAILED

Tracking down the issue actually revealed that endianness selection
in bpf_endian.h is broken when compiled with clang with bpf target.
test_pkt_access.c, test_l4lb.c is compiled with __BYTE_ORDER as
__BIG_ENDIAN, test_xdp.c as __LITTLE_ENDIAN! test_l4lb noticeably
fails, because the test accounts bytes via bpf_ntohs(ip6h->payload_len)
and bpf_ntohs(iph->tot_len), and compares them against a defined
value and given a wrong endianness, the test outcome is different,
of course.

Turns out that there are actually two bugs: i) when we do __BYTE_ORDER
comparison with __LITTLE_ENDIAN/__BIG_ENDIAN, then depending on the
include order we see different outcomes. Reason is that __BYTE_ORDER
is undefined due to missing endian.h include. Before we include the
asm/byteorder.h (e.g. through linux/in.h), then __BYTE_ORDER equals
__LITTLE_ENDIAN since both are undefined, after the include which
correctly pulls in linux/byteorder/little_endian.h, __LITTLE_ENDIAN
is defined, but given __BYTE_ORDER is still undefined, we match on
__BYTE_ORDER equals to __BIG_ENDIAN since __BIG_ENDIAN is also
undefined at that point, sigh. ii) But even that would be wrong,
since when compiling the test cases with clang, one can select between
bpfeb and bpfel targets for cross compilation. Hence, we can also not
rely on what the system's endian.h provides, but we need to look at
the compiler's defined endianness. The compiler defines __BYTE_ORDER__,
and we can match __ORDER_LITTLE_ENDIAN__ and __ORDER_BIG_ENDIAN__,
which also reflects targets bpf (native), bpfel, bpfeb correctly,
thus really only rely on that. After patch:

  # ./test_progs
  test_pkt_access:PASS:ipv4 74 nsec
  test_pkt_access:PASS:ipv6 42 nsec
  test_xdp:PASS:ipv4 2340 nsec
  test_xdp:PASS:ipv6 1461 nsec
  test_l4lb:PASS:ipv4 400 nsec
  test_l4lb:PASS:ipv6 530 nsec
  test_tcp_estats:PASS: 0 nsec
  Summary: 7 PASSED, 0 FAILED

Fixes: 43bcf707 ("bpf: fix _htons occurences in test_progs")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

78a5a93c

perf symbols: Kill dso__build_id_is_kmod() · b89fe63f