linux.git/include/linux/bpf_types.h, branch v6.1.168 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git bpf: Define new BPF_MAP_TYPE_USER_RINGBUF map type 2022-09-21T23:24:17+00:00 David Vernet void@manifault.com 2022-09-20T00:00:57+00:00 583c1f420173f7d84413a1a1fbf5109d798b4faa We want to support a ringbuf map type where samples are published from user-space, to be consumed by BPF programs. BPF currently supports a kernel -> user-space circular ring buffer via the BPF_MAP_TYPE_RINGBUF map type. We'll need to define a new map type for user-space -> kernel, as none of the helpers exported for BPF_MAP_TYPE_RINGBUF will apply to a user-space producer ring buffer, and we'll want to add one or more helper functions that would not apply for a kernel-producer ring buffer. This patch therefore adds a new BPF_MAP_TYPE_USER_RINGBUF map type definition. The map type is useless in its current form, as there is no way to access or use it for anything until we one or more BPF helpers. A follow-on patch will therefore add a new helper function that allows BPF programs to run callbacks on samples that are published to the ring buffer. Signed-off-by: David Vernet <void@manifault.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220920000100.477320-2-void@manifault.com 
We want to support a ringbuf map type where samples are published from
user-space, to be consumed by BPF programs. BPF currently supports a
kernel -> user-space circular ring buffer via the BPF_MAP_TYPE_RINGBUF
map type.  We'll need to define a new map type for user-space -> kernel,
as none of the helpers exported for BPF_MAP_TYPE_RINGBUF will apply
to a user-space producer ring buffer, and we'll want to add one or
more helper functions that would not apply for a kernel-producer
ring buffer.

This patch therefore adds a new BPF_MAP_TYPE_USER_RINGBUF map type
definition. The map type is useless in its current form, as there is no
way to access or use it for anything until we one or more BPF helpers. A
follow-on patch will therefore add a new helper function that allows BPF
programs to run callbacks on samples that are published to the ring
buffer.

Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220920000100.477320-2-void@manifault.com
bpf, x86: Generate trampolines from bpf_tramp_links 2022-05-11T00:50:40+00:00 Kui-Feng Lee kuifeng@fb.com 2022-05-10T20:59:19+00:00 f7e0beaf39d3868dc700d4954b26cf8443c5d423 Replace struct bpf_tramp_progs with struct bpf_tramp_links to collect struct bpf_tramp_link(s) for a trampoline. struct bpf_tramp_link extends bpf_link to act as a linked list node. arch_prepare_bpf_trampoline() accepts a struct bpf_tramp_links to collects all bpf_tramp_link(s) that a trampoline should call. Change BPF trampoline and bpf_struct_ops to pass bpf_tramp_links instead of bpf_tramp_progs. Signed-off-by: Kui-Feng Lee <kuifeng@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220510205923.3206889-2-kuifeng@fb.com 
Replace struct bpf_tramp_progs with struct bpf_tramp_links to collect
struct bpf_tramp_link(s) for a trampoline.  struct bpf_tramp_link
extends bpf_link to act as a linked list node.

arch_prepare_bpf_trampoline() accepts a struct bpf_tramp_links to
collects all bpf_tramp_link(s) that a trampoline should call.

Change BPF trampoline and bpf_struct_ops to pass bpf_tramp_links
instead of bpf_tramp_progs.

Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220510205923.3206889-2-kuifeng@fb.com
bpf: Add multi kprobe link 2022-03-18T03:17:18+00:00 Jiri Olsa jolsa@kernel.org 2022-03-16T12:24:09+00:00 0dcac272540613d41c05e89679e4ddb978b612f1 Adding new link type BPF_LINK_TYPE_KPROBE_MULTI that attaches kprobe program through fprobe API. The fprobe API allows to attach probe on multiple functions at once very fast, because it works on top of ftrace. On the other hand this limits the probe point to the function entry or return. The kprobe program gets the same pt_regs input ctx as when it's attached through the perf API. Adding new attach type BPF_TRACE_KPROBE_MULTI that allows attachment kprobe to multiple function with new link. User provides array of addresses or symbols with count to attach the kprobe program to. The new link_create uapi interface looks like: struct { __u32 flags; __u32 cnt; __aligned_u64 syms; __aligned_u64 addrs; } kprobe_multi; The flags field allows single BPF_TRACE_KPROBE_MULTI bit to create return multi kprobe. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220316122419.933957-4-jolsa@kernel.org 
Adding new link type BPF_LINK_TYPE_KPROBE_MULTI that attaches kprobe
program through fprobe API.

The fprobe API allows to attach probe on multiple functions at once
very fast, because it works on top of ftrace. On the other hand this
limits the probe point to the function entry or return.

The kprobe program gets the same pt_regs input ctx as when it's attached
through the perf API.

Adding new attach type BPF_TRACE_KPROBE_MULTI that allows attachment
kprobe to multiple function with new link.

User provides array of addresses or symbols with count to attach the
kprobe program to. The new link_create uapi interface looks like:

  struct {
          __u32           flags;
          __u32           cnt;
          __aligned_u64   syms;
          __aligned_u64   addrs;
  } kprobe_multi;

The flags field allows single BPF_TRACE_KPROBE_MULTI bit to create
return multi kprobe.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220316122419.933957-4-jolsa@kernel.org
Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-11-02T02:59:46+00:00 Jakub Kicinski kuba@kernel.org 2021-11-02T02:59:45+00:00 b7b98f868987cd3e86c9bd9a6db048614933d7a0 Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-11-01 We've added 181 non-merge commits during the last 28 day(s) which contain a total of 280 files changed, 11791 insertions(+), 5879 deletions(-). The main changes are: 1) Fix bpf verifier propagation of 64-bit bounds, from Alexei. 2) Parallelize bpf test_progs, from Yucong and Andrii. 3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus. 4) Improve bpf selftests on s390, from Ilya. 5) bloomfilter bpf map type, from Joanne. 6) Big improvements to JIT tests especially on Mips, from Johan. 7) Support kernel module function calls from bpf, from Kumar. 8) Support typeless and weak ksym in light skeleton, from Kumar. 9) Disallow unprivileged bpf by default, from Pawan. 10) BTF_KIND_DECL_TAG support, from Yonghong. 11) Various bpftool cleanups, from Quentin. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits) libbpf: Deprecate AF_XDP support kbuild: Unify options for BTF generation for vmlinux and modules selftests/bpf: Add a testcase for 64-bit bounds propagation issue. bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit. bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off. selftests/bpf: Fix also no-alu32 strobemeta selftest bpf: Add missing map_delete_elem method to bloom filter map selftests/bpf: Add bloom map success test for userspace calls bpf: Add alignment padding for "map_extra" + consolidate holes bpf: Bloom filter map naming fixups selftests/bpf: Add test cases for struct_ops prog bpf: Add dummy BPF STRUCT_OPS for test purpose bpf: Factor out helpers for ctx access checking bpf: Factor out a helper to prepare trampoline for struct_ops prog selftests, bpf: Fix broken riscv build riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h tools, build: Add RISC-V to HOSTARCH parsing riscv, bpf: Increase the maximum number of iterations selftests, bpf: Add one test for sockmap with strparser selftests, bpf: Fix test_txmsg_ingress_parser error ... ==================== Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-11-01

We've added 181 non-merge commits during the last 28 day(s) which contain
a total of 280 files changed, 11791 insertions(+), 5879 deletions(-).

The main changes are:

1) Fix bpf verifier propagation of 64-bit bounds, from Alexei.

2) Parallelize bpf test_progs, from Yucong and Andrii.

3) Deprecate various libbpf apis including af_xdp, from Andrii, Hengqi, Magnus.

4) Improve bpf selftests on s390, from Ilya.

5) bloomfilter bpf map type, from Joanne.

6) Big improvements to JIT tests especially on Mips, from Johan.

7) Support kernel module function calls from bpf, from Kumar.

8) Support typeless and weak ksym in light skeleton, from Kumar.

9) Disallow unprivileged bpf by default, from Pawan.

10) BTF_KIND_DECL_TAG support, from Yonghong.

11) Various bpftool cleanups, from Quentin.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (181 commits)
  libbpf: Deprecate AF_XDP support
  kbuild: Unify options for BTF generation for vmlinux and modules
  selftests/bpf: Add a testcase for 64-bit bounds propagation issue.
  bpf: Fix propagation of signed bounds from 64-bit min/max into 32-bit.
  bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.
  selftests/bpf: Fix also no-alu32 strobemeta selftest
  bpf: Add missing map_delete_elem method to bloom filter map
  selftests/bpf: Add bloom map success test for userspace calls
  bpf: Add alignment padding for "map_extra" + consolidate holes
  bpf: Bloom filter map naming fixups
  selftests/bpf: Add test cases for struct_ops prog
  bpf: Add dummy BPF STRUCT_OPS for test purpose
  bpf: Factor out helpers for ctx access checking
  bpf: Factor out a helper to prepare trampoline for struct_ops prog
  selftests, bpf: Fix broken riscv build
  riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
  tools, build: Add RISC-V to HOSTARCH parsing
  riscv, bpf: Increase the maximum number of iterations
  selftests, bpf: Add one test for sockmap with strparser
  selftests, bpf: Fix test_txmsg_ingress_parser error
  ...
====================

Link: https://lore.kernel.org/r/20211102013123.9005-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
bpf: Add bloom filter map implementation 2021-10-28T20:22:49+00:00 Joanne Koong joannekoong@fb.com 2021-10-27T23:45:00+00:00 9330986c03006ab1d33d243b7cfe598a7a3c1baa This patch adds the kernel-side changes for the implementation of a bpf bloom filter map. The bloom filter map supports peek (determining whether an element is present in the map) and push (adding an element to the map) operations.These operations are exposed to userspace applications through the already existing syscalls in the following way: BPF_MAP_LOOKUP_ELEM -> peek BPF_MAP_UPDATE_ELEM -> push The bloom filter map does not have keys, only values. In light of this, the bloom filter map's API matches that of queue stack maps: user applications use BPF_MAP_LOOKUP_ELEM/BPF_MAP_UPDATE_ELEM which correspond internally to bpf_map_peek_elem/bpf_map_push_elem, and bpf programs must use the bpf_map_peek_elem and bpf_map_push_elem APIs to query or add an element to the bloom filter map. When the bloom filter map is created, it must be created with a key_size of 0. For updates, the user will pass in the element to add to the map as the value, with a NULL key. For lookups, the user will pass in the element to query in the map as the value, with a NULL key. In the verifier layer, this requires us to modify the argument type of a bloom filter's BPF_FUNC_map_peek_elem call to ARG_PTR_TO_MAP_VALUE; as well, in the syscall layer, we need to copy over the user value so that in bpf_map_peek_elem, we know which specific value to query. A few things to please take note of: * If there are any concurrent lookups + updates, the user is responsible for synchronizing this to ensure no false negative lookups occur. * The number of hashes to use for the bloom filter is configurable from userspace. If no number is specified, the default used will be 5 hash functions. The benchmarks later in this patchset can help compare the performance of using different number of hashes on different entry sizes. In general, using more hashes decreases both the false positive rate and the speed of a lookup. * Deleting an element in the bloom filter map is not supported. * The bloom filter map may be used as an inner map. * The "max_entries" size that is specified at map creation time is used to approximate a reasonable bitmap size for the bloom filter, and is not otherwise strictly enforced. If the user wishes to insert more entries into the bloom filter than "max_entries", they may do so but they should be aware that this may lead to a higher false positive rate. Signed-off-by: Joanne Koong <joannekoong@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211027234504.30744-2-joannekoong@fb.com 
This patch adds the kernel-side changes for the implementation of
a bpf bloom filter map.

The bloom filter map supports peek (determining whether an element
is present in the map) and push (adding an element to the map)
operations.These operations are exposed to userspace applications
through the already existing syscalls in the following way:

BPF_MAP_LOOKUP_ELEM -> peek
BPF_MAP_UPDATE_ELEM -> push

The bloom filter map does not have keys, only values. In light of
this, the bloom filter map's API matches that of queue stack maps:
user applications use BPF_MAP_LOOKUP_ELEM/BPF_MAP_UPDATE_ELEM
which correspond internally to bpf_map_peek_elem/bpf_map_push_elem,
and bpf programs must use the bpf_map_peek_elem and bpf_map_push_elem
APIs to query or add an element to the bloom filter map. When the
bloom filter map is created, it must be created with a key_size of 0.

For updates, the user will pass in the element to add to the map
as the value, with a NULL key. For lookups, the user will pass in the
element to query in the map as the value, with a NULL key. In the
verifier layer, this requires us to modify the argument type of
a bloom filter's BPF_FUNC_map_peek_elem call to ARG_PTR_TO_MAP_VALUE;
as well, in the syscall layer, we need to copy over the user value
so that in bpf_map_peek_elem, we know which specific value to query.

A few things to please take note of:
 * If there are any concurrent lookups + updates, the user is
responsible for synchronizing this to ensure no false negative lookups
occur.
 * The number of hashes to use for the bloom filter is configurable from
userspace. If no number is specified, the default used will be 5 hash
functions. The benchmarks later in this patchset can help compare the
performance of using different number of hashes on different entry
sizes. In general, using more hashes decreases both the false positive
rate and the speed of a lookup.
 * Deleting an element in the bloom filter map is not supported.
 * The bloom filter map may be used as an inner map.
 * The "max_entries" size that is specified at map creation time is used
to approximate a reasonable bitmap size for the bloom filter, and is not
otherwise strictly enforced. If the user wishes to insert more entries
into the bloom filter than "max_entries", they may do so but they should
be aware that this may lead to a higher false positive rate.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-2-joannekoong@fb.com
bpf: Move BPF_MAP_TYPE for INODE_STORAGE and TASK_STORAGE outside of CONFIG_NET 2021-10-26T19:35:16+00:00 Tejun Heo tj@kernel.org 2021-10-21T18:46:10+00:00 99d0a3831e3500d945162cdb2310e3a5fce90b60 bpf_types.h has BPF_MAP_TYPE_INODE_STORAGE and BPF_MAP_TYPE_TASK_STORAGE declared inside #ifdef CONFIG_NET although they are built regardless of CONFIG_NET. So, when CONFIG_BPF_SYSCALL && !CONFIG_NET, they are built without the declarations leading to spurious build failures and not registered to bpf_map_types making them unavailable. Fix it by moving the BPF_MAP_TYPE for the two map types outside of CONFIG_NET. Reported-by: kernel test robot <lkp@intel.com> Fixes: a10787e6d58c ("bpf: Enable task local storage for tracing programs") Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/YXG1cuuSJDqHQfRY@slm.duckdns.org 
bpf_types.h has BPF_MAP_TYPE_INODE_STORAGE and BPF_MAP_TYPE_TASK_STORAGE
declared inside #ifdef CONFIG_NET although they are built regardless of
CONFIG_NET. So, when CONFIG_BPF_SYSCALL && !CONFIG_NET, they are built
without the declarations leading to spurious build failures and not
registered to bpf_map_types making them unavailable.

Fix it by moving the BPF_MAP_TYPE for the two map types outside of
CONFIG_NET.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: a10787e6d58c ("bpf: Enable task local storage for tracing programs")
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/YXG1cuuSJDqHQfRY@slm.duckdns.org
bpf: Implement minimal BPF perf link 2021-08-16T22:45:07+00:00 Andrii Nakryiko andrii@kernel.org 2021-08-15T07:05:57+00:00 b89fbfbb854c9afc3047e8273cc3a694650b802e Introduce a new type of BPF link - BPF perf link. This brings perf_event-based BPF program attachments (perf_event, tracepoints, kprobes, and uprobes) into the common BPF link infrastructure, allowing to list all active perf_event based attachments, auto-detaching BPF program from perf_event when link's FD is closed, get generic BPF link fdinfo/get_info functionality. BPF_LINK_CREATE command expects perf_event's FD as target_fd. No extra flags are currently supported. Force-detaching and atomic BPF program updates are not yet implemented, but with perf_event-based BPF links we now have common framework for this without the need to extend ioctl()-based perf_event interface. One interesting consideration is a new value for bpf_attach_type, which BPF_LINK_CREATE command expects. Generally, it's either 1-to-1 mapping from bpf_attach_type to bpf_prog_type, or many-to-1 mapping from a subset of bpf_attach_types to one bpf_prog_type (e.g., see BPF_PROG_TYPE_SK_SKB or BPF_PROG_TYPE_CGROUP_SOCK). In this case, though, we have three different program types (KPROBE, TRACEPOINT, PERF_EVENT) using the same perf_event-based mechanism, so it's many bpf_prog_types to one bpf_attach_type. I chose to define a single BPF_PERF_EVENT attach type for all of them and adjust link_create()'s logic for checking correspondence between attach type and program type. The alternative would be to define three new attach types (e.g., BPF_KPROBE, BPF_TRACEPOINT, and BPF_PERF_EVENT), but that seemed like unnecessary overkill and BPF_KPROBE will cause naming conflicts with BPF_KPROBE() macro, defined by libbpf. I chose to not do this to avoid unnecessary proliferation of bpf_attach_type enum values and not have to deal with naming conflicts. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/bpf/20210815070609.987780-5-andrii@kernel.org 
Introduce a new type of BPF link - BPF perf link. This brings perf_event-based
BPF program attachments (perf_event, tracepoints, kprobes, and uprobes) into
the common BPF link infrastructure, allowing to list all active perf_event
based attachments, auto-detaching BPF program from perf_event when link's FD
is closed, get generic BPF link fdinfo/get_info functionality.

BPF_LINK_CREATE command expects perf_event's FD as target_fd. No extra flags
are currently supported.

Force-detaching and atomic BPF program updates are not yet implemented, but
with perf_event-based BPF links we now have common framework for this without
the need to extend ioctl()-based perf_event interface.

One interesting consideration is a new value for bpf_attach_type, which
BPF_LINK_CREATE command expects. Generally, it's either 1-to-1 mapping from
bpf_attach_type to bpf_prog_type, or many-to-1 mapping from a subset of
bpf_attach_types to one bpf_prog_type (e.g., see BPF_PROG_TYPE_SK_SKB or
BPF_PROG_TYPE_CGROUP_SOCK). In this case, though, we have three different
program types (KPROBE, TRACEPOINT, PERF_EVENT) using the same perf_event-based
mechanism, so it's many bpf_prog_types to one bpf_attach_type. I chose to
define a single BPF_PERF_EVENT attach type for all of them and adjust
link_create()'s logic for checking correspondence between attach type and
program type.

The alternative would be to define three new attach types (e.g., BPF_KPROBE,
BPF_TRACEPOINT, and BPF_PERF_EVENT), but that seemed like unnecessary overkill
and BPF_KPROBE will cause naming conflicts with BPF_KPROBE() macro, defined by
libbpf. I chose to not do this to avoid unnecessary proliferation of
bpf_attach_type enum values and not have to deal with naming conflicts.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/bpf/20210815070609.987780-5-andrii@kernel.org
bpf: Fix OOB read when printing XDP link fdinfo 2021-07-19T22:14:40+00:00 Lorenz Bauer lmb@cloudflare.com 2021-07-19T08:51:34+00:00 d6371c76e20d7d3f61b05fd67b596af4d14a8886 We got the following UBSAN report on one of our testing machines: ================================================================================ UBSAN: array-index-out-of-bounds in kernel/bpf/syscall.c:2389:24 index 6 is out of range for type 'char *[6]' CPU: 43 PID: 930921 Comm: systemd-coredum Tainted: G O 5.10.48-cloudflare-kasan-2021.7.0 #1 Hardware name: <snip> Call Trace: dump_stack+0x7d/0xa3 ubsan_epilogue+0x5/0x40 __ubsan_handle_out_of_bounds.cold+0x43/0x48 ? seq_printf+0x17d/0x250 bpf_link_show_fdinfo+0x329/0x380 ? bpf_map_value_size+0xe0/0xe0 ? put_files_struct+0x20/0x2d0 ? __kasan_kmalloc.constprop.0+0xc2/0xd0 seq_show+0x3f7/0x540 seq_read_iter+0x3f8/0x1040 seq_read+0x329/0x500 ? seq_read_iter+0x1040/0x1040 ? __fsnotify_parent+0x80/0x820 ? __fsnotify_update_child_dentry_flags+0x380/0x380 vfs_read+0x123/0x460 ksys_read+0xed/0x1c0 ? __x64_sys_pwrite64+0x1f0/0x1f0 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 <snip> ================================================================================ ================================================================================ UBSAN: object-size-mismatch in kernel/bpf/syscall.c:2384:2 From the report, we can infer that some array access in bpf_link_show_fdinfo at index 6 is out of bounds. The obvious candidate is bpf_link_type_strs[BPF_LINK_TYPE_XDP] with BPF_LINK_TYPE_XDP == 6. It turns out that BPF_LINK_TYPE_XDP is missing from bpf_types.h and therefore doesn't have an entry in bpf_link_type_strs: pos: 0 flags: 02000000 mnt_id: 13 link_type: (null) link_id: 4 prog_tag: bcf7977d3b93787c prog_id: 4 ifindex: 1 Fixes: aa8d3a716b59 ("bpf, xdp: Add bpf_link-based XDP attachment API") Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210719085134.43325-2-lmb@cloudflare.com 
We got the following UBSAN report on one of our testing machines:

    ================================================================================
    UBSAN: array-index-out-of-bounds in kernel/bpf/syscall.c:2389:24
    index 6 is out of range for type 'char *[6]'
    CPU: 43 PID: 930921 Comm: systemd-coredum Tainted: G           O      5.10.48-cloudflare-kasan-2021.7.0 #1
    Hardware name: <snip>
    Call Trace:
     dump_stack+0x7d/0xa3
     ubsan_epilogue+0x5/0x40
     __ubsan_handle_out_of_bounds.cold+0x43/0x48
     ? seq_printf+0x17d/0x250
     bpf_link_show_fdinfo+0x329/0x380
     ? bpf_map_value_size+0xe0/0xe0
     ? put_files_struct+0x20/0x2d0
     ? __kasan_kmalloc.constprop.0+0xc2/0xd0
     seq_show+0x3f7/0x540
     seq_read_iter+0x3f8/0x1040
     seq_read+0x329/0x500
     ? seq_read_iter+0x1040/0x1040
     ? __fsnotify_parent+0x80/0x820
     ? __fsnotify_update_child_dentry_flags+0x380/0x380
     vfs_read+0x123/0x460
     ksys_read+0xed/0x1c0
     ? __x64_sys_pwrite64+0x1f0/0x1f0
     do_syscall_64+0x33/0x40
     entry_SYSCALL_64_after_hwframe+0x44/0xa9
    <snip>
    ================================================================================
    ================================================================================
    UBSAN: object-size-mismatch in kernel/bpf/syscall.c:2384:2

From the report, we can infer that some array access in bpf_link_show_fdinfo at index 6
is out of bounds. The obvious candidate is bpf_link_type_strs[BPF_LINK_TYPE_XDP] with
BPF_LINK_TYPE_XDP == 6. It turns out that BPF_LINK_TYPE_XDP is missing from bpf_types.h
and therefore doesn't have an entry in bpf_link_type_strs:

    pos:	0
    flags:	02000000
    mnt_id:	13
    link_type:	(null)
    link_id:	4
    prog_tag:	bcf7977d3b93787c
    prog_id:	4
    ifindex:	1

Fixes: aa8d3a716b59 ("bpf, xdp: Add bpf_link-based XDP attachment API")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210719085134.43325-2-lmb@cloudflare.com
bpf: Introduce bpf_sys_bpf() helper and program type. 2021-05-18T22:33:39+00:00 Alexei Starovoitov ast@kernel.org 2021-05-14T00:36:03+00:00 79a7f8bdb159d9914b58740f3d31d602a6e4aca8 Add placeholders for bpf_sys_bpf() helper and new program type. Make sure to check that expected_attach_type is zero for future extensibility. Allow tracing helper functions to be used in this program type, since they will only execute from user context via bpf_prog_test_run. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-2-alexei.starovoitov@gmail.com 
Add placeholders for bpf_sys_bpf() helper and new program type.
Make sure to check that expected_attach_type is zero for future extensibility.
Allow tracing helper functions to be used in this program type, since they will
only execute from user context via bpf_prog_test_run.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210514003623.28033-2-alexei.starovoitov@gmail.com
bpf: Clean up sockmap related Kconfigs 2021-02-26T20:28:03+00:00 Cong Wang cong.wang@bytedance.com 2021-02-23T18:49:26+00:00 887596095ec2a9ea39ffcf98f27bf2e77c5eb512 As suggested by John, clean up sockmap related Kconfigs: Reduce the scope of CONFIG_BPF_STREAM_PARSER down to TCP stream parser, to reflect its name. Make the rest sockmap code simply depend on CONFIG_BPF_SYSCALL and CONFIG_INET, the latter is still needed at this point because of TCP/UDP proto update. And leave CONFIG_NET_SOCK_MSG untouched, as it is used by non-sockmap cases. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Lorenz Bauer <lmb@cloudflare.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20210223184934.6054-2-xiyou.wangcong@gmail.com 
As suggested by John, clean up sockmap related Kconfigs:

Reduce the scope of CONFIG_BPF_STREAM_PARSER down to TCP stream
parser, to reflect its name.

Make the rest sockmap code simply depend on CONFIG_BPF_SYSCALL
and CONFIG_INET, the latter is still needed at this point because
of TCP/UDP proto update. And leave CONFIG_NET_SOCK_MSG untouched,
as it is used by non-sockmap cases.

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Lorenz Bauer <lmb@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20210223184934.6054-2-xiyou.wangcong@gmail.com