linux/tools
Jiri Olsa 943930e472 perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event
Synthesize bpf images (trampolines/dispatchers) on start, as ksymbol
events from /proc/kallsyms. Having this perf can recognize samples from
those images and perf report and top shows them correctly.

The rest of the ksymbol handling is already in place from for the bpf
programs monitoring, so only the initial state was needed.

perf report output:

  # Overhead  Command     Shared Object                  Symbol

    12.37%  test_progs  [kernel.vmlinux]                 [k] entry_SYSCALL_64
    11.80%  test_progs  [kernel.vmlinux]                 [k] syscall_return_via_sysret
     9.63%  test_progs  bpf_prog_bcf7977d3b93787c_prog2  [k] bpf_prog_bcf7977d3b93787c_prog2
     6.90%  test_progs  bpf_trampoline_24456             [k] bpf_trampoline_24456
     6.36%  test_progs  [kernel.vmlinux]                 [k] memcpy_erms

Committer notes:

Use scnprintf() instead of strncpy() to overcome this on fedora:32,
rawhide and OpenMandriva Cooker:

    CC       /tmp/build/perf/util/bpf-event.o
  In file included from /usr/include/string.h:495,
                   from /git/linux/tools/lib/bpf/libbpf_common.h:12,
                   from /git/linux/tools/lib/bpf/bpf.h:31,
                   from util/bpf-event.c:4:
  In function 'strncpy',
      inlined from 'process_bpf_image' at util/bpf-event.c:323:2,
      inlined from 'kallsyms_process_symbol' at util/bpf-event.c:358:9:
  /usr/include/bits/string_fortified.h:106:10: error: '__builtin_strncpy' specified bound 256 equals destination size [-Werror=stringop-truncation]
    106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
        |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@redhat.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200312195610.346362-14-jolsa@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-04-16 12:19:06 -03:00
..
accounting SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
arch tools arch x86: Sync asm/cpufeatures.h with the kernel sources 2020-04-14 09:08:23 -03:00
bootconfig New tracing features: 2020-04-05 10:36:18 -07:00
bpf SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
build perf updates all over the place: 2020-04-05 12:26:24 -07:00
cgroup .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
debugging
edid tools/edid: Move EDID data sets from Documentation/ 2020-02-19 04:10:32 -07:00
firewire
firmware
gpio This is the bulk of GPIO development for the v5.7 kernel cycle. 2020-04-04 10:27:00 -07:00
hv Tools: hv: Reopen the devices if read() or write() returns errors 2020-01-26 22:10:10 -05:00
iio .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
include tools headers: Synchronize linux/bits.h with the kernel sources 2020-04-14 11:40:05 -03:00
io_uring
kvm/kvm_stat tools/kvm_stat: add command line switch '-c' to log in csv format 2020-03-23 15:44:21 -04:00
laptop change email address for Pali Rohár 2020-04-10 15:36:22 -07:00
leds .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
lib lib/rbtree: fix coding style of assignments 2020-04-07 10:43:43 -07:00
memory-model .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
nfsd
objtool kbuild: support LLVM=1 to switch the default tools to Clang/LLVM 2020-04-09 03:18:21 +09:00
pci tools: PCI: Add 'e' to clear IRQ 2020-04-02 17:57:10 +01:00
pcmcia .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
perf perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event 2020-04-16 12:19:06 -03:00
power SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
scripts Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-25 18:58:11 -07:00
spi SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
testing selftests: kmod: test disabling module autoloading 2020-04-10 15:36:22 -07:00
thermal/tmon - Convert tsens configuration DT binding to yaml (Rajeshwari) 2020-04-07 20:00:16 -07:00
time
usb .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
virtio virtio: fixes, vdpa 2020-04-08 10:51:53 -07:00
vm .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
wmi
Makefile tools: bootconfig: Add bootconfig command 2020-01-13 13:19:39 -05:00