mainline inclusion
from mainline-5.11-rc1
commit 22dc4a0f
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=22dc4a0f5ed11b6dc8fd73a0892fa0ea1a4c3cdf

-------------------------------------------------

Remove a permeating assumption thoughout BPF verifier of vmlinux BTF. Instead,
wherever BTF type IDs are involved, also track the instance of struct btf that
goes along with the type ID. This allows to gradually add support for kernel
module BTFs and using/tracking module types across BPF helper calls and
registers.

This patch also renames btf_id() function to btf_obj_id() to minimize naming
clash with using btf_id to denote BTF *type* ID, rather than BTF *object*'s ID.

Also, altough btf_vmlinux can't get destructed and thus doesn't need
refcounting, module BTFs need that, so apply BTF refcounting universally when
BPF program is using BTF-powered attachment (tp_btf, fentry/fexit, etc). This
makes for simpler clean up code.

Now that BTF type ID is not enough to uniquely identify a BTF type, extend BPF
trampoline key to include BTF object ID. To differentiate that from target
program BPF ID, set 31st bit of type ID. BTF type IDs (at least currently) are
not allowed to take full 32 bits, so there is no danger of confusing that bit
with a valid BTF type ID.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-10-andrii@kernel.org
(cherry picked from commit 22dc4a0f)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

Conflicts:
	kernel/bpf/syscall.c
	kernel/bpf/verifier.c
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 6bcd39d3
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6bcd39d366b64318562785d5b47c2837e3a53ae5

-------------------------------------------------

Add a self-tests validating libbpf is able to perform CO-RE relocations
against the type defined in kernel module BTF. if bpf_testmod.o is not
supported by the kernel (e.g., due to version mismatch), skip tests, instead
of failing.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-9-andrii@kernel.org
(cherry picked from commit 6bcd39d3)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 5ed31472
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5ed31472b9ad6373a0a24bc21186b5eac999213d

-------------------------------------------------

Previously skipped sub-tests would be counted as passing with ":OK" appened
in the log. Change that to be accounted as ":SKIP".
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-8-andrii@kernel.org
(cherry picked from commit 5ed31472)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 9f7fa225
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9f7fa225894c7fcb014f3699a402fcc4d896cb1c

-------------------------------------------------

Add bpf_testmod module, which is conceptually out-of-tree module and provides
ways for selftests/bpf to test various kernel module-related functionality:
raw tracepoint, fentry/fexit/fmod_ret, etc. This module will be auto-loaded by
test_progs test runner and expected by some of selftests to be present and
loaded.

Pahole currently isn't able to generate BTF for static functions in kernel
modules, so make sure traced function is global.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-7-andrii@kernel.org
(cherry picked from commit 9f7fa225)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

Conflicts:
	tools/testing/selftests/bpf/Makefile
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 4f33a53d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4f33a53d56000cfa67e2e4e8a5dac08f084a979b

-------------------------------------------------

Teach libbpf to search for candidate types for CO-RE relocations across kernel
modules BTFs, in addition to vmlinux BTF. If at least one candidate type is
found in vmlinux BTF, kernel module BTFs are not iterated. If vmlinux BTF has
no matching candidates, then find all kernel module BTFs and search for all
matching candidates across all of them.

Kernel's support for module BTFs are inferred from the support for BTF name
pointer in BPF UAPI.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-6-andrii@kernel.org
(cherry picked from commit 4f33a53d)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 0f7515ca
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0f7515ca7cddadabe04e28e20a257b1bbb6cb98a

-------------------------------------------------

Refactor CO-RE relocation candidate search to not expect a single BTF, rather
return all candidate types with their corresponding BTF objects. This will
allow to extend CO-RE relocations to accommodate kernel module BTFs.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-5-andrii@kernel.org
(cherry picked from commit 0f7515ca)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit a19f93cf
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a19f93cfafdf85851c69bc9f677aa4f40c53610f

-------------------------------------------------

Add a btf_get_from_fd() helper, which constructs struct btf from in-kernel BTF
data by FD. This is used for loading module BTFs.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-4-andrii@kernel.org
(cherry picked from commit a19f93cf)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 2fe88908
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2fe8890848c799515a881502339a0a7b2b555988

-------------------------------------------------

Having real btf_data_size stored in struct module is benefitial to quickly
determine which kernel modules have associated BTF object and which don't.
There is no harm in keeping this info, as opposed to keeping invalid pointer.

Fixes: 607c543f ("bpf: Sanitize BTF data pointer after module is loaded")
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-3-andrii@kernel.org
(cherry picked from commit 2fe88908)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 58c185b8
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=58c185b85d0c1753b0b6a9390294bd883faf4d77

-------------------------------------------------

This object lives inside the trunner output dir,
i.e. tools/testing/selftests/bpf/no_alu32/btf_data.o

At some point it gets copied into the parent directory during another
part of the build, but that doesn't happen when building
test_progs-no_alu32 from clean.
Signed-off-by: NBrendan Jackman <jackmanb@google.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/bpf/20201203120850.859170-1-jackmanb@google.com
(cherry picked from commit 58c185b8)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit d6d418bd
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d6d418bd8f92aaa4c7c26d606188147c2ee0dae9

-------------------------------------------------

I've seen a situation, where a process that's under pprof constantly
generates SIGPROF which prevents program loading indefinitely.
The right thing to do probably is to disable signals in the upper
layers while loading, but it still would be nice to get some error from
libbpf instead of an endless loop.

Let's add some small retry limit to the program loading:
try loading the program 5 (arbitrary) times and give up.

v2:
* 10 -> 5 retires (Andrii Nakryiko)
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201202231332.3923644-1-sdf@google.com
(cherry picked from commit d6d418bd)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 80b2b5c3
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=80b2b5c3a701d56de98d00d99bc9cc384fb316d9

-------------------------------------------------

Before this patch, a program with unspecified type
(BPF_PROG_TYPE_UNSPEC) would be passed to the BPF syscall, only to have
the kernel reject it with an opaque invalid argument error. This patch
makes libbpf reject such programs with a nicer error message - in
particular libbpf now tries to diagnose bad ELF section names at both
open time and load time.
Signed-off-by: NAndrei Matei <andreimatei1@gmail.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201203043410.59699-1-andreimatei1@gmail.com
(cherry picked from commit 80b2b5c3)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 22e8ebe3
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=22e8ebe35a2e30ee19e02c41cacc99c2f896bc4b

-------------------------------------------------

Add missing newlines and fix polarity of strerror argument.
Signed-off-by: NBrendan Jackman <jackmanb@google.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/bpf/20201203102234.648540-1-jackmanb@google.com
(cherry picked from commit 22e8ebe3)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit fa452837
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa4528379a51ff8d5271e1bcfa0d5ef71657869f

-------------------------------------------------

In case of working with module's split BTF from /sys/kernel/btf/*,
auto-substitute /sys/kernel/btf/vmlinux as the base BTF. This makes using
bpftool with module BTFs faster and simpler.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201202065244.530571-4-andrii@kernel.org
(cherry picked from commit fa452837)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 0cfdcd63
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0cfdcd6378071f383c900e3d8862347e2af1d1ca

-------------------------------------------------

Add ability to get base BTF. It can be also used to check if BTF is split BTF.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201202065244.530571-3-andrii@kernel.org
(cherry picked from commit 0cfdcd63)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 71ccb500
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=71ccb50074f31a50a1da4c1d8306d54da0907b00

-------------------------------------------------

For consistency of output, emit "name <anon>" for BTFs without the name. This
keeps output more consistent and obvious.
Suggested-by: NSong Liu <songliubraving@fb.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201202065244.530571-2-andrii@kernel.org
(cherry picked from commit 71ccb500)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 607c543f
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=607c543f939d8ca6fed7afe90b3a8d6f6684dd17

-------------------------------------------------

Given .BTF section is not allocatable, it will get trimmed after module is
loaded. BPF system handles that properly by creating an independent copy of
data. But prevent any accidental misused by resetting the pointer to BTF data.

Fixes: 36e68442 ("bpf: Load and verify kernel module BTFs")
Suggested-by: NJessica Yu <jeyu@kernel.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NJessica Yu <jeyu@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/bpf/20201121070829.2612884-2-andrii@kernel.org
(cherry picked from commit 607c543f)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit de91e631
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=de91e631bdc7e6411989e1a9ab65501a31527e0b

-------------------------------------------------

When operating on split BTF, btf__find_by_name[_kind] will not
iterate over all types since they use btf->nr_types to show
the number of types to iterate over. For split BTF this is
the number of types _on top of base BTF_, so it will
underestimate the number of types to iterate over, especially
for vmlinux + module BTF, where the latter is much smaller.

Use btf__get_nr_types() instead.

Fixes: ba451366 ("libbpf: Implement basic split BTF support")
Signed-off-by: NAlan Maguire <alan.maguire@oracle.com>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/1605437195-2175-1-git-send-email-alan.maguire@oracle.com
(cherry picked from commit de91e631)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 0639e5e9
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0639e5e97ad9c58dd15dcf6f6ccf677cfba39f98

-------------------------------------------------

Commit ba2fd563 ("tools/bpftool: Support passing BPFTOOL_VERSION to
make") changed BPFTOOL_VERSION to a recursively expanded variable,
forcing it to be recomputed on every expansion of CFLAGS and
dramatically slowing down the bpftool build. Restore BPFTOOL_VERSION as
a simply expanded variable, guarded by an ifeq().

Fixes: ba2fd563 ("tools/bpftool: Support passing BPFTOOL_VERSION to make")
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201110164310.2600671-8-jean-philippe@linaro.org
(cherry picked from commit 0639e5e9)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 2d9393fe
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2d9393fefb506fb8c8a483e5dc9bbd7774657b89

-------------------------------------------------

When cross building runqslower for an other architecture, the
intermediate bpftool used to generate a skeleton must be built using the
host toolchain. Pass HOSTCC and HOSTLD, defined in Makefile.include, to
the bpftool Makefile.
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201110164310.2600671-7-jean-philippe@linaro.org
(cherry picked from commit 2d9393fe)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 85e59344
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=85e59344d0790379e063bf3cd3dd0fe91ce3b505

-------------------------------------------------

Enable out-of-tree build for runqslower. Only set OUTPUT=.output if it
wasn't already set by the user.
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201110164310.2600671-6-jean-philippe@linaro.org
(cherry picked from commit 85e59344)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 3290996e
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3290996e713315dfc9589e2c340a4c4997d90be8

-------------------------------------------------

Makefile.include defines variables such as OUTPUT and CC for out-of-tree
build and cross-build. Include it into the runqslower Makefile and use
its $(QUIET*) helpers.
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201110164310.2600671-5-jean-philippe@linaro.org
(cherry picked from commit 3290996e)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit c8a950d0
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c8a950d0d3b926a02c7b2e713850d38217cec3d1

-------------------------------------------------

Several Makefiles in tools/ need to define the host toolchain variables.
Move their definition to tools/scripts/Makefile.include
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Acked-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/bpf/20201110164310.2600671-2-jean-philippe@linaro.org
(cherry picked from commit c8a950d0)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 7112d127
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7112d127984bd7b0c8ded7973b358829f16735f5

-------------------------------------------------

Make sure btf_parse_module() is compiled out if module BTFs are not enabled.

Fixes: 36e68442 ("bpf: Load and verify kernel module BTFs")
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201111040645.903494-1-andrii@kernel.org
(cherry picked from commit 7112d127)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit cecaf4a0
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cecaf4a0f2dcbd7e76156f6d63748b84c176b95b

-------------------------------------------------

Display vmlinux BTF name and kernel module names when listing available BTFs
on the system.

In human-readable output mode, module BTFs are reported with "name
[module-name]", while vmlinux BTF will be reported as "name [vmlinux]".
Square brackets are added by bpftool and follow kernel convention when
displaying modules in human-readable text outputs.

[vmuser@archvm bpf]$ sudo ../../../bpf/bpftool/bpftool btf s
1: name [vmlinux]  size 4082281B
6: size 2365B  prog_ids 8,6  map_ids 3
7: name [button]  size 46895B
8: name [pcspkr]  size 42328B
9: name [serio_raw]  size 39375B
10: name [floppy]  size 57185B
11: name [i2c_core]  size 76186B
12: name [crc32c_intel]  size 16036B
13: name [i2c_piix4]  size 50497B
14: name [irqbypass]  size 14124B
15: name [kvm]  size 197985B
16: name [kvm_intel]  size 123564B
17: name [cryptd]  size 42466B
18: name [crypto_simd]  size 17187B
19: name [glue_helper]  size 39205B
20: name [aesni_intel]  size 41034B
25: size 36150B
        pids bpftool(2519)

In JSON mode, two fields (boolean "kernel" and string "name") are reported for
each BTF object. vmlinux BTF is reported with name "vmlinux" (kernel itself
returns and empty name for vmlinux BTF).

[vmuser@archvm bpf]$ sudo ../../../bpf/bpftool/bpftool btf s -jp
[{
        "id": 1,
        "size": 4082281,
        "prog_ids": [],
        "map_ids": [],
        "kernel": true,
        "name": "vmlinux"
    },{
        "id": 6,
        "size": 2365,
        "prog_ids": [8,6
        ],
        "map_ids": [3
        ],
        "kernel": false
    },{
        "id": 7,
        "size": 46895,
        "prog_ids": [],
        "map_ids": [],
        "kernel": true,
        "name": "button"
    },{

...
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Tested-by: NAlan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-6-andrii@kernel.org
(cherry picked from commit cecaf4a0)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 36e68442
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=36e68442d1afd4f720704ee1ea8486331507e834

-------------------------------------------------

Add kernel module listener that will load/validate and unload module BTF.
Module BTFs gets ID generated for them, which makes it possible to iterate
them with existing BTF iteration API. They are given their respective module's
names, which will get reported through GET_OBJ_INFO API. They are also marked
as in-kernel BTFs for tooling to distinguish them from user-provided BTFs.

Also, similarly to vmlinux BTF, kernel module BTFs are exposed through
sysfs as /sys/kernel/btf/<module-name>. This is convenient for user-space
tools to inspect module BTF contents and dump their types with existing tools:

[vmuser@archvm bpf]$ ls -la /sys/kernel/btf
total 0
drwxr-xr-x  2 root root       0 Nov  4 19:46 .
drwxr-xr-x 13 root root       0 Nov  4 19:46 ..

...

-r--r--r--  1 root root     888 Nov  4 19:46 irqbypass
-r--r--r--  1 root root  100225 Nov  4 19:46 kvm
-r--r--r--  1 root root   35401 Nov  4 19:46 kvm_intel
-r--r--r--  1 root root     120 Nov  4 19:46 pcspkr
-r--r--r--  1 root root     399 Nov  4 19:46 serio_raw
-r--r--r--  1 root root 4094095 Nov  4 19:46 vmlinux
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-5-andrii@kernel.org
(cherry picked from commit 36e68442)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 5f9ae91f
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5f9ae91f7c0dbbc4195e2a6c8eedcaeb5b9e4cbb

-------------------------------------------------

Detect if pahole supports split BTF generation, and generate BTF for each
selected kernel module, if it does. This is exposed to Makefiles and C code as
CONFIG_DEBUG_INFO_BTF_MODULES flag.

Kernel module BTF has to be re-generated if either vmlinux's BTF changes or
module's .ko changes. To achieve that, I needed a helper similar to
if_changed, but that would allow to filter out vmlinux from the list of
updated dependencies for .ko building. I've put it next to the only place that
uses and needs it, but it might be a better idea to just add it along the
other if_changed variants into scripts/Kbuild.include.

Each kernel module's BTF deduplication is pretty fast, as it does only
incremental BTF deduplication on top of already deduplicated vmlinux BTF. To
show the added build time, I've first ran make only just built kernel (to
establish the baseline) and then forced only BTF re-generation, without
regenerating .ko files. The build was performed with -j60 parallelization on
56-core machine. The final time also includes bzImage building, so it's not
a pure BTF overhead.

$ time make -j60
...
make -j60  27.65s user 10.96s system 782% cpu 4.933 total
$ touch ~/linux-build/default/vmlinux && time make -j60
...
make -j60  123.69s user 27.85s system 1566% cpu 9.675 total

So 4.6 seconds real time, with noticeable part spent in compressed vmlinux and
bzImage building.

To show size savings, I've built my kernel configuration with about 700 kernel
modules with full BTF per each kernel module (without deduplicating against
vmlinux) and with split BTF against deduplicated vmlinux (approach in this
patch). Below are top 10 modules with biggest BTF sizes. And total size of BTF
data across all kernel modules.

It shows that split BTF "compresses" 115MB down to 5MB total. And the biggest
kernel modules get a downsize from 500-570KB down to 200-300KB.

FULL BTF

========

$ for f in $(find . -name '*.ko'); do size -A -d $f | grep BTF | awk '{print $2}'; done | awk '{ s += $1 } END { print s }'
115710691

$ for f in $(find . -name '*.ko'); do printf "%s %d\n" $f $(size -A -d $f | grep BTF | awk '{print $2}'); done | sort -nr -k2 | head -n10
./drivers/gpu/drm/i915/i915.ko 570570
./drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.ko 520240
./drivers/gpu/drm/radeon/radeon.ko 503849
./drivers/infiniband/hw/mlx5/mlx5_ib.ko 491777
./fs/xfs/xfs.ko 411544
./drivers/net/ethernet/intel/i40e/i40e.ko 403904
./drivers/net/ethernet/broadcom/bnx2x/bnx2x.ko 398754
./drivers/infiniband/core/ib_core.ko 397224
./fs/cifs/cifs.ko 386249
./fs/nfsd/nfsd.ko 379738

SPLIT BTF
=========

$ for f in $(find . -name '*.ko'); do size -A -d $f | grep BTF | awk '{print $2}'; done | awk '{ s += $1 } END { print s }'
5194047

$ for f in $(find . -name '*.ko'); do printf "%s %d\n" $f $(size -A -d $f | grep BTF | awk '{print $2}'); done | sort -nr -k2 | head -n10
./drivers/gpu/drm/i915/i915.ko 293206
./drivers/gpu/drm/radeon/radeon.ko 282103
./fs/xfs/xfs.ko 222150
./drivers/net/ethernet/mellanox/mlx5/core/mlx5_core.ko 198503
./drivers/infiniband/hw/mlx5/mlx5_ib.ko 198356
./drivers/net/ethernet/broadcom/bnx2x/bnx2x.ko 113444
./fs/cifs/cifs.ko 109379
./arch/x86/kvm/kvm.ko 100225
./drivers/gpu/drm/drm.ko 94827
./drivers/infiniband/core/ib_core.ko 91188
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-4-andrii@kernel.org
(cherry picked from commit 5f9ae91f)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 53297220
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5329722057d41aebc31e391907a501feaa42f7d9

-------------------------------------------------

Allocate ID for vmlinux BTF. This makes it visible when iterating over all BTF
objects in the system. To allow distinguishing vmlinux BTF (and later kernel
module BTF) from user-provided BTFs, expose extra kernel_btf flag, as well as
BTF name ("vmlinux" for vmlinux BTF, will equal to module's name for module
BTF).  We might want to later allow specifying BTF name for user-provided BTFs
as well, if that makes sense. But currently this is reserved only for
in-kernel BTFs.

Having in-kernel BTFs exposed IDs will allow to extend BPF APIs that require
in-kernel BTF type with ability to specify BTF types from kernel modules, not
just vmlinux BTF. This will be implemented in a follow up patch set for
fentry/fexit/fmod_ret/lsm/etc.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-3-andrii@kernel.org
(cherry picked from commit 53297220)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 951bb646
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=951bb64621b8139c0cd99dcadc13e6510c08aa73

-------------------------------------------------

Adjust in-kernel BTF implementation to support a split BTF mode of operation.
Changes are mostly mirroring libbpf split BTF changes, with the exception of
start_id being 0 for in-kernel implementation due to simpler read-only mode.

Otherwise, for split BTF logic, most of the logic of jumping to base BTF,
where necessary, is encapsulated in few helper functions. Type numbering and
string offset in a split BTF are logically continuing where base BTF ends, so
most of the high-level logic is kept without changes.

Type verification and size resolution is only doing an added resolution of new
split BTF types and relies on already cached size and type resolution results
in the base BTF.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-2-andrii@kernel.org
(cherry picked from commit 951bb646)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 666475cc
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=666475ccbf1dc99c1e61e47975d5fbf86d6236aa

-------------------------------------------------

Remove duplicate btf_ids.h header which is included twice.
Signed-off-by: NWang Qing <wangqing@vivo.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/1604736650-11197-1-git-send-email-wangqing@vivo.com
(cherry picked from commit 666475cc)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 75fa1777
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=75fa1777694c245c1e59ac774cb1d58a15ecefeb

-------------------------------------------------

Add ability to work with split BTF by providing extra -B flag, which allows to
specify the path to the base BTF file.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-12-andrii@kernel.org
(cherry picked from commit 75fa1777)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 232338fa
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=232338fa2fb47726ab7c459419115a6ab6bfb3e3

-------------------------------------------------

Add selftests validating BTF deduplication for split BTF case. Add a helper
macro that allows to validate entire BTF with raw BTF dump, not just
type-by-type. This saves tons of code and complexity.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-11-andrii@kernel.org
(cherry picked from commit 232338fa)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 6b6e6b1d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6b6e6b1d09aa20c351a1fce0ea6402da436624a4

-------------------------------------------------

In some cases compiler seems to generate distinct DWARF types for identical
arrays within the same CU. That seems like a bug, but it's already out there
and breaks type graph equivalence checks, so accommodate it anyway by checking
for identical arrays, regardless of their type ID.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-10-andrii@kernel.org
(cherry picked from commit 6b6e6b1d)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit f86524ef
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f86524efcf9e3f3a7cf75ebcd82cf8f58ec716cc

-------------------------------------------------

Add support for deduplication split BTFs. When deduplicating split BTF, base
BTF is considered to be immutable and can't be modified or adjusted. 99% of
BTF deduplication logic is left intact (module some type numbering adjustments).
There are only two differences.

First, each type in base BTF gets hashed (expect VAR and DATASEC, of course,
those are always considered to be self-canonical instances) and added into
a table of canonical table candidates. Hashing is a shallow, fast operation,
so mostly eliminates the overhead of having entire base BTF to be a part of
BTF dedup.

Second difference is very critical and subtle. While deduplicating split BTF
types, it is possible to discover that one of immutable base BTF BTF_KIND_FWD
types can and should be resolved to a full STRUCT/UNION type from the split
BTF part.  This is, obviously, can't happen because we can't modify the base
BTF types anymore. So because of that, any type in split BTF that directly or
indirectly references that newly-to-be-resolved FWD type can't be considered
to be equivalent to the corresponding canonical types in base BTF, because
that would result in a loss of type resolution information. So in such case,
split BTF types will be deduplicated separately and will cause some
duplication of type information, which is unavoidable.

With those two changes, the rest of the algorithm manages to deduplicate split
BTF correctly, pointing all the duplicates to their canonical counter-parts in
base BTF, but also is deduplicating whatever unique types are present in split
BTF on their own.

Also, theoretically, split BTF after deduplication could end up with either
empty type section or empty string section. This is handled by libbpf
correctly in one of previous patches in the series.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-9-andrii@kernel.org
(cherry picked from commit f86524ef)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 1306c980
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1306c980cf892bc17e7296d3e9ab8e9082f893a1

-------------------------------------------------

Add re-usable btf_helpers.{c,h} to provide BTF-related testing routines. Start
with adding a raw BTF dumping helpers.

Raw BTF dump is the most succinct and at the same time a very human-friendly
way to validate exact contents of BTF types. Cross-validate raw BTF dump and
writable BTF in a single selftest. Raw type dump checks also serve as a good
self-documentation.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-7-andrii@kernel.org
(cherry picked from commit 1306c980)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 197389da
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=197389da2fbfbc3cefb229268c32d858d9575c96

-------------------------------------------------

Add selftest validating ability to programmatically generate and then dump
split BTF.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-6-andrii@kernel.org
(cherry picked from commit 197389da)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit ba451366
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ba451366bf44498f22dd16c31a792083bd6f2ae1

-------------------------------------------------

Support split BTF operation, in which one BTF (base BTF) provides basic set of
types and strings, while another one (split BTF) builds on top of base's types
and strings and adds its own new types and strings. From API standpoint, the
fact that the split BTF is built on top of the base BTF is transparent.

Type numeration is transparent. If the base BTF had last type ID #N, then all
types in the split BTF start at type ID N+1. Any type in split BTF can
reference base BTF types, but not vice versa. Programmatically construction of
a split BTF on top of a base BTF is supported: one can create an empty split
BTF with btf__new_empty_split() and pass base BTF as an input, or pass raw
binary data to btf__new_split(), or use btf__parse_xxx_split() variants to get
initial set of split types/strings from the ELF file with .BTF section.

String offsets are similarly transparent and are a logical continuation of
base BTF's strings. When building BTF programmatically and adding a new string
(explicitly with btf__add_str() or implicitly through appending new
types/members), string-to-be-added would first be looked up from the base
BTF's string section and re-used if it's there. If not, it will be looked up
and/or added to the split BTF string section. Similarly to type IDs, types in
split BTF can refer to strings from base BTF absolutely transparently (but not
vice versa, of course, because base BTF doesn't "know" about existence of
split BTF).

Internal type index is slightly adjusted to be zero-indexed, ignoring a fake
[0] VOID type. This allows to handle split/base BTF type lookups transparently
by using btf->start_id type ID offset, which is always 1 for base/non-split
BTF and equals btf__get_nr_types(base_btf) + 1 for the split BTF.

BTF deduplication is not yet supported for split BTF and support for it will
be added in separate patch.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-5-andrii@kernel.org
(cherry picked from commit ba451366)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit 88a82c2a
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=88a82c2a9ab5b2ce533c3de3f4517853c2f67f53

-------------------------------------------------

Revamp BTF dedup's string deduplication to match the approach of writable BTF
string management. This allows to transfer deduplicated strings index back to
BTF object after deduplication without expensive extra memory copying and hash
map re-construction. It also simplifies the code and speeds it up, because
hashmap-based string deduplication is faster than sort + unique approach.
Signed-off-by: NAndrii Nakryiko <andriin@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-4-andrii@kernel.org
(cherry picked from commit 88a82c2a)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit d9448f94
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d9448f94962bd28554df7d9a342d37c7f13d6232

-------------------------------------------------

Remove the requirement of a strictly exact string section contents. This used
to be true when string deduplication was done through sorting, but with string
dedup done through hash table, it's no longer true. So relax test harness to
relax strings checks and, consequently, type checks, which now don't have to
have exactly the same string offsets.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-3-andrii@kernel.org
(cherry picked from commit d9448f94)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.11-rc1
commit c81ed6d8
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c81ed6d81e0560713ceb94917ff1981848d0614e

-------------------------------------------------

Factor out commiting of appended type data. Also extract fetching the very
last type in the BTF (to append members to). These two operations are common
across many APIs and will be easier to refactor with split BTF, if they are
extracted into a single place.
Signed-off-by: NAndrii Nakryiko <andrii@kernel.org>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Acked-by: NSong Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201105043402.2530976-2-andrii@kernel.org
(cherry picked from commit c81ed6d8)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

mainline inclusion
from mainline-5.13-rc1
commit 7c32e8f8
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c32e8f8bc33a5f4b113a630857e46634e3e143b

-------------------------------------------------

Allow to pass sk_lookup programs to PROG_TEST_RUN. User space
provides the full bpf_sk_lookup struct as context. Since the
context includes a socket pointer that can't be exposed
to user space we define that PROG_TEST_RUN returns the cookie
of the selected socket or zero in place of the socket pointer.

We don't support testing programs that select a reuseport socket,
since this would mean running another (unrelated) BPF program
from the sk_lookup test handler.
Signed-off-by: NLorenz Bauer <lmb@cloudflare.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210303101816.36774-3-lmb@cloudflare.com
(cherry picked from commit 7c32e8f8)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>