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Martin KaFai Lau d2836dddc9 libbpf: Ignore non function pointer member in struct_ops
When libbpf initializes the kernel's struct_ops in
"bpf_map__init_kern_struct_ops()", it enforces all
pointer types must be a function pointer and rejects
others.  It turns out to be too strict.  For example,
when directly using "struct tcp_congestion_ops" from vmlinux.h,
it has a "struct module *owner" member and it is set to NULL
in a bpf_tcp_cc.o.

Instead, it only needs to ensure the member is a function
pointer if it has been set (relocated) to a bpf-prog.
This patch moves the "btf_is_func_proto(kern_mtype)" check
after the existing "if (!prog) { continue; }".  The original debug
message in "if (!prog) { continue; }" is also removed since it is
no longer valid.  Beside, there is a later debug message to tell
which function pointer is set.

The "btf_is_func_proto(mtype)" has already been guaranteed
in "bpf_object__collect_st_ops_relos()" which has been run
before "bpf_map__init_kern_struct_ops()".  Thus, this check
is removed.

v2:
- Remove outdated debug message (Andrii)
  Remove because there is a later debug message to tell
  which function pointer is set.
- Following mtype->type is no longer needed. Remove:
  "skip_mods_and_typedefs(btf, mtype->type, &mtype_id)"
- Do "if (!prog)" test before skip_mods_and_typedefs.

Fixes: 590a008882 ("bpf: libbpf: Add STRUCT_OPS support")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210212021030.266932-1-kafai@fb.com
2021-02-12 11:49:36 -08:00
arch bpf: Add per-program recursion prevention mechanism 2021-02-11 16:19:13 +01:00
block block-5.11-2021-01-10 2021-01-10 12:53:08 -08:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto X.509: Fix crash caused by NULL pointer 2021-01-20 11:33:51 -08:00
Documentation docs: bpf: Clarify BPF_CMPXCHG wording 2021-02-11 22:01:13 -08:00
drivers net, veth: Alloc skb in bulk for ndo_xdp_xmit 2021-02-04 01:00:07 +01:00
fs cachefiles: Drop superfluous readpages aops NULL check 2021-01-20 11:33:51 -08:00
include bpf: Expose bpf_get_socket_cookie to tracing programs 2021-02-11 17:44:41 -08:00
init Revert "init/console: Use ttynull as a fallback when there is no console" 2021-01-08 11:02:18 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2020-12-15 12:53:37 -08:00
kernel bpf: Fix subreg optimization for BPF_FETCH 2021-02-11 22:03:19 -08:00
lib test_bpf: Remove EXPECTED_FAIL flag from bpf_fill_maxinsns11 2021-01-20 14:13:48 -08:00
LICENSES LICENSES: Add the CC-BY-4.0 license 2020-12-08 10:33:27 -07:00
mm mm: don't put pinned pages into the swap cache 2021-01-17 12:08:04 -08:00
net bpf: Expose bpf_get_socket_cookie to tracing programs 2021-02-11 17:44:41 -08:00
samples samples: bpf: Remove unneeded semicolon 2021-02-02 21:37:59 -08:00
scripts Kbuild fixes for v5.11 2021-01-10 13:24:55 -08:00
security dump_common_audit_data(): fix racy accesses to ->d_name 2021-01-16 15:11:35 -05:00
sound ALSA: hda/hdmi - enable runtime pm for CI AMD display audio 2021-01-12 16:06:01 +01:00
tools libbpf: Ignore non function pointer member in struct_ops 2021-02-12 11:49:36 -08:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt x86: 2021-01-08 15:06:02 -08:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.mailmap MAINTAINERS: Update my email address 2021-01-15 23:55:16 +01:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: dccp: move Gerrit Renker to CREDITS 2021-01-14 10:53:49 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-01-20 12:16:11 -08:00
Makefile kbuild: Do not clean resolve_btfids if the output does not exist 2021-02-11 11:27:58 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.