linux/tools
Quentin Monnet 6ae32b29c0 tools: bpftool: Restore message on failure to guess program type
In commit 4a3d6c6a6e ("libbpf: Reduce log level for custom section
names"), log level for messages for libbpf_attach_type_by_name() and
libbpf_prog_type_by_name() was downgraded from "info" to "debug". The
latter function, in particular, is used by bpftool when attempting to
load programs, and this change caused bpftool to exit with no hint or
error message when it fails to detect the type of the program to load
(unless "-d" option was provided).

To help users understand why bpftool fails to load the program, let's do
a second run of the function with log level in "debug" mode in case of
failure.

Before:

    # bpftool prog load sample_ret0.o /sys/fs/bpf/sample_ret0
    # echo $?
    255

Or really verbose with -d flag:

    # bpftool -d prog load sample_ret0.o /sys/fs/bpf/sample_ret0
    libbpf: loading sample_ret0.o
    libbpf: section(1) .strtab, size 134, link 0, flags 0, type=3
    libbpf: skip section(1) .strtab
    libbpf: section(2) .text, size 16, link 0, flags 6, type=1
    libbpf: found program .text
    libbpf: section(3) .debug_abbrev, size 55, link 0, flags 0, type=1
    libbpf: skip section(3) .debug_abbrev
    libbpf: section(4) .debug_info, size 75, link 0, flags 0, type=1
    libbpf: skip section(4) .debug_info
    libbpf: section(5) .rel.debug_info, size 32, link 14, flags 0, type=9
    libbpf: skip relo .rel.debug_info(5) for section(4)
    libbpf: section(6) .debug_str, size 150, link 0, flags 30, type=1
    libbpf: skip section(6) .debug_str
    libbpf: section(7) .BTF, size 155, link 0, flags 0, type=1
    libbpf: section(8) .BTF.ext, size 80, link 0, flags 0, type=1
    libbpf: section(9) .rel.BTF.ext, size 32, link 14, flags 0, type=9
    libbpf: skip relo .rel.BTF.ext(9) for section(8)
    libbpf: section(10) .debug_frame, size 40, link 0, flags 0, type=1
    libbpf: skip section(10) .debug_frame
    libbpf: section(11) .rel.debug_frame, size 16, link 14, flags 0, type=9
    libbpf: skip relo .rel.debug_frame(11) for section(10)
    libbpf: section(12) .debug_line, size 74, link 0, flags 0, type=1
    libbpf: skip section(12) .debug_line
    libbpf: section(13) .rel.debug_line, size 16, link 14, flags 0, type=9
    libbpf: skip relo .rel.debug_line(13) for section(12)
    libbpf: section(14) .symtab, size 96, link 1, flags 0, type=2
    libbpf: looking for externs among 4 symbols...
    libbpf: collected 0 externs total
    libbpf: failed to guess program type from ELF section '.text'
    libbpf: supported section(type) names are: socket sk_reuseport kprobe/ [...]

After:

    # bpftool prog load sample_ret0.o /sys/fs/bpf/sample_ret0
    libbpf: failed to guess program type from ELF section '.text'
    libbpf: supported section(type) names are: socket sk_reuseport kprobe/ [...]

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200311021205.9755-1-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2020-03-13 12:49:51 -07:00
..
accounting
arch tools headers kvm: Sync kvm headers with the kernel sources 2020-02-12 12:41:20 -03:00
bootconfig bootconfig: Add append value operator support 2020-02-21 09:59:39 -05:00
bpf tools: bpftool: Restore message on failure to guess program type 2020-03-13 12:49:51 -07:00
build bpftool: Only build bpftool-prog-profile if supported by clang 2020-03-13 00:08:33 +01:00
cgroup iocost: Fix iocost_monitor.py due to helper type mismatch 2020-01-17 11:54:35 -08:00
debugging
firewire
firmware
gpio tools: gpio: Correctly add make dependencies for gpio_utils 2019-11-13 13:46:04 +01:00
hv Tools: hv: Reopen the devices if read() or write() returns errors 2020-01-26 22:10:10 -05:00
iio tools: iio: Correctly add make dependency for iio_utils 2019-11-10 17:11:06 +00:00
include bpf: Add bpf_xdp_output() helper 2020-03-12 17:47:38 -07:00
io_uring
kvm/kvm_stat tools/kvm_stat: Fix kvm_exit filter name 2020-01-23 09:51:06 +01:00
laptop
leds
lib libbpf: Split BTF presence checks into libbpf- and kernel-specific parts 2020-03-13 00:15:16 +01:00
memory-model tools/memory-model/Documentation: Add plain accesses and data races to explanation.txt 2019-10-05 11:59:44 -07:00
nfsd
objtool objtool: Fix ARCH=x86_64 build error 2020-01-22 07:54:57 +01:00
pci tools: PCI: Fix fd leakage 2019-10-29 12:04:18 +00:00
pcmcia
perf perf llvm: Fix script used to obtain kernel make directives to work with new kbuild 2020-02-14 10:06:00 -03:00
power More power manadement updates for 5.6-rc1 2020-01-31 14:36:35 -08:00
scripts bpftool: Introduce "prog profile" command 2020-03-10 00:04:07 +01:00
spi
testing bpf: Add bpf_xdp_output() helper 2020-03-12 17:47:38 -07:00
thermal/tmon
time
usb usbip: Fix unsafe unaligned pointer usage 2020-01-09 16:44:26 +01:00
virtio tools/virtio: xen stub 2019-10-13 09:38:27 -04:00
vm tools/vm/slabinfo: fix sanity checks enabling 2020-01-31 10:30:38 -08:00
wmi
Makefile tools: bootconfig: Add bootconfig command 2020-01-13 13:19:39 -05:00