Hou Tao says:
====================
Now bpf uses RCU grace period chaining to wait for the completion of
access from both sleepable and non-sleepable bpf program: calling
call_rcu_tasks_trace() firstly to wait for a RCU-tasks-trace grace
period, then in its callback calls call_rcu() or kfree_rcu() to wait for
a normal RCU grace period.
According to the implementation of RCU Tasks Trace, it inovkes
->postscan_func() to wait for one RCU-tasks-trace grace period and
rcu_tasks_trace_postscan() inovkes synchronize_rcu() to wait for one
normal RCU grace period in turn, so one RCU-tasks-trace grace period
will imply one normal RCU grace period. To codify the implication,
introduces rcu_trace_implies_rcu_gp() in patch #1. And using it in patch
Other two uses of call_rcu_tasks_trace() are unchanged: for
__bpf_prog_put_rcu() there is no gp chain and for
__bpf_tramp_image_put_rcu_tasks() it chains RCU tasks trace GP and RCU
tasks GP.
An alternative way to remove these unnecessary RCU grace period
chainings is using the RCU polling API to check whether or not a normal
RCU grace period has passed (e.g. get_state_synchronize_rcu()). But it
needs an unsigned long space for each free element or each call, and
it is not affordable for local storage element, so as for now always
rcu_trace_implies_rcu_gp().
Comments are always welcome.
Change Log:
v2:
* codify the implication of RCU Tasks Trace grace period instead of
assuming for it
v1: https://lore.kernel.org/bpf/20221011071128.3470622-1-houtao@huaweicloud.com
Hou Tao (3):
bpf: Use rcu_trace_implies_rcu_gp() in bpf memory allocator
bpf: Use rcu_trace_implies_rcu_gp() in local storage map
bpf: Use rcu_trace_implies_rcu_gp() for program array freeing
====================
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
To support both sleepable and normal uprobe bpf program, the freeing of
trace program array chains a RCU-tasks-trace grace period and a normal
RCU grace period one after the other.
With the introduction of rcu_trace_implies_rcu_gp(),
__bpf_prog_array_free_sleepable_cb() can check whether or not a normal
RCU grace period has also passed after a RCU-tasks-trace grace period
has passed. If it is true, it is safe to invoke kfree() directly.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221014113946.965131-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Local storage map is accessible for both sleepable and non-sleepable bpf
program, and its memory is freed by using both call_rcu_tasks_trace() and
kfree_rcu() to wait for both RCU-tasks-trace grace period and RCU grace
period to pass.
With the introduction of rcu_trace_implies_rcu_gp(), both
bpf_selem_free_rcu() and bpf_local_storage_free_rcu() can check whether
or not a normal RCU grace period has also passed after a RCU-tasks-trace
grace period has passed. If it is true, it is safe to call kfree()
directly.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221014113946.965131-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The memory free logic in bpf memory allocator chains a RCU Tasks Trace
grace period and a normal RCU grace period one after the other, so it
can ensure that both sleepable and non-sleepable programs have finished.
With the introduction of rcu_trace_implies_rcu_gp(),
__free_rcu_tasks_trace() can check whether or not a normal RCU grace
period has also passed after a RCU Tasks Trace grace period has passed.
If it is true, freeing these elements directly, else freeing through
call_rcu().
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221014113946.965131-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
As an accident of implementation, an RCU Tasks Trace grace period also
acts as an RCU grace period. However, this could change at any time.
This commit therefore creates an rcu_trace_implies_rcu_gp() that currently
returns true to codify this accident. Code relying on this accident
must call this function to verify that this accident is still happening.
Reported-by: Hou Tao <houtao@huaweicloud.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Link: https://lore.kernel.org/r/20221014113946.965131-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
SYS_pidfd_open may be undefined for old glibc, so using sys_pidfd_open()
helper defined in task_local_storage_helpers.h instead to fix potential
build failure.
And according to commit 7615d9e178 ("arch: wire-up pidfd_open()"), the
syscall number of pidfd_open is always 434 except for alpha architure,
so update the definition of __NR_pidfd_open accordingly.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221011071249.3471760-1-houtao@huaweicloud.com
Shung-Hsi Yu says:
====================
Hi, this patch set fixes several fuzzer-reported issues of libbpf when
dealing with (malformed) BPF object file:
- patch #1 fix out-of-bound heap write reported by oss-fuzz (currently
incorrectly marked as fixed)
- patch #2 and #3 fix null-pointer dereference found by locally-run
fuzzer.
v2:
- Rebase to bpf-next
- Move elf_getshdrnum() closer to where it's result is used in patch #1, as
suggested by Andrii
- Touch up the comment in bpf_object__elf_collect(), replacing mention of
e_shnum with elf_getshdrnum()
- Minor wording change in commit message of patch #1 to for better readability
- Remove extra note that comes after commit message in patch #1
v1: https://lore.kernel.org/bpf/20221007174816.17536-1-shung-hsi.yu@suse.com/
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
When there are no program sections, obj->programs is left unallocated,
and find_prog_by_sec_insn()'s search lands on &obj->programs[0] == NULL,
and will cause null-pointer dereference in the following access to
prog->sec_idx.
Guard the search with obj->nr_programs similar to what's being done in
__bpf_program__iter() to prevent null-pointer access from happening.
Fixes: db2b8b0642 ("libbpf: Support CO-RE relocations for multi-prog sections")
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221012022353.7350-4-shung-hsi.yu@suse.com
This commit replace e_shnum with the elf_getshdrnum() helper to fix two
oss-fuzz-reported heap-buffer overflow in __bpf_object__open. Both
reports are incorrectly marked as fixed and while still being
reproducible in the latest libbpf.
# clusterfuzz-testcase-minimized-bpf-object-fuzzer-5747922482888704
libbpf: loading object 'fuzz-object' from buffer
libbpf: sec_cnt is 0
libbpf: elf: section(1) .data, size 0, link 538976288, flags 2020202020202020, type=2
libbpf: elf: section(2) .data, size 32, link 538976288, flags 202020202020ff20, type=1
=================================================================
==13==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x6020000000c0 at pc 0x0000005a7b46 bp 0x7ffd12214af0 sp 0x7ffd12214ae8
WRITE of size 4 at 0x6020000000c0 thread T0
SCARINESS: 46 (4-byte-write-heap-buffer-overflow-far-from-bounds)
#0 0x5a7b45 in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3414:24
#1 0x5733c0 in bpf_object_open /src/libbpf/src/libbpf.c:7223:16
#2 0x5739fd in bpf_object__open_mem /src/libbpf/src/libbpf.c:7263:20
...
The issue lie in libbpf's direct use of e_shnum field in ELF header as
the section header count. Where as libelf implemented an extra logic
that, when e_shnum == 0 && e_shoff != 0, will use sh_size member of the
initial section header as the real section header count (part of ELF
spec to accommodate situation where section header counter is larger
than SHN_LORESERVE).
The above inconsistency lead to libbpf writing into a zero-entry calloc
area. So intead of using e_shnum directly, use the elf_getshdrnum()
helper provided by libelf to retrieve the section header counter into
sec_cnt.
Fixes: 0d6988e16a ("libbpf: Fix section counting logic")
Fixes: 25bbbd7a44 ("libbpf: Remove assumptions about uniqueness of .rodata/.data/.bss maps")
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40868
Link: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40957
Link: https://lore.kernel.org/bpf/20221012022353.7350-2-shung-hsi.yu@suse.com
test_xdp_adjust_tail_grow failed with ipv6:
test_xdp_adjust_tail_grow:FAIL:ipv6 unexpected error: -28 (errno 28)
The reason is that this test case tests ipv4 before ipv6, and when ipv4
test finished, topts.data_size_out was set to 54, which is smaller than the
ipv6 output data size 114, so ipv6 test fails with NOSPC error.
Fix it by reset topts.data_size_out to sizeof(buf) before testing ipv6.
Fixes: 04fcb5f9a1 ("selftests/bpf: Migrate from bpf_prog_test_run")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20221011120108.782373-6-xukuohai@huaweicloud.com
ASAN reports an use-after-free in btf_dump_name_dups:
ERROR: AddressSanitizer: heap-use-after-free on address 0xffff927006db at pc 0xaaaab5dfb618 bp 0xffffdd89b890 sp 0xffffdd89b928
READ of size 2 at 0xffff927006db thread T0
#0 0xaaaab5dfb614 in __interceptor_strcmp.part.0 (test_progs+0x21b614)
#1 0xaaaab635f144 in str_equal_fn tools/lib/bpf/btf_dump.c:127
#2 0xaaaab635e3e0 in hashmap_find_entry tools/lib/bpf/hashmap.c:143
#3 0xaaaab635e72c in hashmap__find tools/lib/bpf/hashmap.c:212
#4 0xaaaab6362258 in btf_dump_name_dups tools/lib/bpf/btf_dump.c:1525
#5 0xaaaab636240c in btf_dump_resolve_name tools/lib/bpf/btf_dump.c:1552
#6 0xaaaab6362598 in btf_dump_type_name tools/lib/bpf/btf_dump.c:1567
#7 0xaaaab6360b48 in btf_dump_emit_struct_def tools/lib/bpf/btf_dump.c:912
#8 0xaaaab6360630 in btf_dump_emit_type tools/lib/bpf/btf_dump.c:798
#9 0xaaaab635f720 in btf_dump__dump_type tools/lib/bpf/btf_dump.c:282
#10 0xaaaab608523c in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:236
#11 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
#12 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
#13 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
#14 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
#15 0xaaaab5d65990 (test_progs+0x185990)
0xffff927006db is located 11 bytes inside of 16-byte region [0xffff927006d0,0xffff927006e0)
freed by thread T0 here:
#0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4)
#1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191
#2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163
#3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106
#4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157
#5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519
#6 0xaaaab6353e10 in btf__add_field tools/lib/bpf/btf.c:2032
#7 0xaaaab6084fcc in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:232
#8 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
#9 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
#10 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
#11 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
#12 0xaaaab5d65990 (test_progs+0x185990)
previously allocated by thread T0 here:
#0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4)
#1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191
#2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163
#3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106
#4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157
#5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519
#6 0xaaaab6353ff0 in btf_add_enum_common tools/lib/bpf/btf.c:2070
#7 0xaaaab6354080 in btf__add_enum tools/lib/bpf/btf.c:2102
#8 0xaaaab6082f50 in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:162
#9 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875
#10 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062
#11 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697
#12 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308
#13 0xaaaab5d65990 (test_progs+0x185990)
The reason is that the key stored in hash table name_map is a string
address, and the string memory is allocated by realloc() function, when
the memory is resized by realloc() later, the old memory may be freed,
so the address stored in name_map references to a freed memory, causing
use-after-free.
Fix it by storing duplicated string address in name_map.
Fixes: 919d2b1dbb ("libbpf: Allow modification of BTF and add btf__add_str API")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20221011120108.782373-2-xukuohai@huaweicloud.com
The recent vm image in CI has reported error in selftests that use
the iptables command. Manu Bretelle has pointed out the difference
in the recent vm image that the iptables is sym-linked to the iptables-nft.
With this knowledge, I can also reproduce the CI error by manually running
with the 'iptables-nft'.
This patch is to replace the iptables command with iptables-legacy
to unblock the CI tests.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20221012221235.3529719-1-martin.lau@linux.dev
The DENYLIST and DENYLIST.s390x files are used to specify testcases
which should not be run on CI. Currently, testcases are appended to the
end of these files as needed. This can make it a pain to resolve merge
conflicts. This patch alphabetizes the DENYLIST files to ease this
burden.
Signed-off-by: David Vernet <void@manifault.com>
Acked-by: Daniel Müller <deso@posteo.net>
Link: https://lore.kernel.org/r/20221011165255.774014-1-void@manifault.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Roberto Sassu says:
====================
From: Roberto Sassu <roberto.sassu@huawei.com>
Add the _opts variant for bpf_*_get_fd_by_id() functions, to be able to
pass to the kernel more options, when requesting a fd of an eBPF object.
Pass the options through a newly introduced structure,
bpf_get_fd_by_id_opts, which currently contains open_flags (the other two
members are for compatibility and for padding).
open_flags allows the caller to request specific permissions to access a
map (e.g. read-only). This is useful for example in the situation where a
map is write-protected.
Besides patches 2-6, which introduce the new variants and the data
structure, patch 1 fixes the LIBBPF_1.0.0 declaration in libbpf.map.
Changelog
v1:
- Don't CC stable kernel mailing list for patch 1 (suggested by Andrii)
- Rename bpf_get_fd_opts struct to bpf_get_fd_by_id_opts (suggested by
Andrii)
- Move declaration of _opts variants after non-opts variants (suggested by
Andrii)
- Correctly initialize bpf_map_info, fix style issues, use map from
skeleton, check valid fd in the test (suggested by Andrii)
- Rename libbpf_get_fd_opts test to libbpf_get_fd_by_id_opts
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Introduce the data_input map, write-protected with a small eBPF program
implementing the lsm/bpf_map hook.
Then, ensure that bpf_map_get_fd_by_id() and bpf_map_get_fd_by_id_opts()
with NULL opts don't succeed due to requesting read-write access to the
write-protected map. Also, ensure that bpf_map_get_fd_by_id_opts() with
open_flags in opts set to BPF_F_RDONLY instead succeeds.
After obtaining a read-only fd, ensure that only map lookup succeeds and
not update. Ensure that update works only with the read-write fd obtained
at program loading time, when the write protection was not yet enabled.
Finally, ensure that the other _opts variants of bpf_*_get_fd_by_id() don't
work if the BPF_F_RDONLY flag is set in opts (due to the kernel not
handling the open_flags member of bpf_attr).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-7-roberto.sassu@huaweicloud.com
Introduce bpf_link_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_link_get_fd_by_id(), and call bpf_link_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.
Currently, the kernel does not support non-zero open_flags for
bpf_link_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-6-roberto.sassu@huaweicloud.com
Introduce bpf_btf_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_btf_get_fd_by_id(), and call bpf_btf_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.
Currently, the kernel does not support non-zero open_flags for
bpf_btf_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-5-roberto.sassu@huaweicloud.com
Introduce bpf_prog_get_fd_by_id_opts(), for symmetry with
bpf_map_get_fd_by_id_opts(), to let the caller pass the newly introduced
data structure bpf_get_fd_by_id_opts. Keep the existing
bpf_prog_get_fd_by_id(), and call bpf_prog_get_fd_by_id_opts() with NULL as
opts argument, to prevent setting open_flags.
Currently, the kernel does not support non-zero open_flags for
bpf_prog_get_fd_by_id_opts(), and a call with them will result in an error
returned by the bpf() system call. The caller should always pass zero
open_flags.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-4-roberto.sassu@huaweicloud.com
Define a new data structure called bpf_get_fd_by_id_opts, with the member
open_flags, to be used by callers of the _opts variants of
bpf_*_get_fd_by_id() to specify the permissions needed for the file
descriptor to be obtained.
Also, introduce bpf_map_get_fd_by_id_opts(), to let the caller pass a
bpf_get_fd_by_id_opts structure.
Finally, keep the existing bpf_map_get_fd_by_id(), and call
bpf_map_get_fd_by_id_opts() with NULL as opts argument, to request
read-write permissions (current behavior).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221006110736.84253-3-roberto.sassu@huaweicloud.com
SSE2 and hence lfence are architectural in x86-64 and no need to check
whether they're supported in CPU. SSE2's CPUID flag is still set to
maintain backward compatibility with older code or code shared with x86,
but bpf_jit_comp.c is compiled under x86-64 exclusively so the check is
redundant.
Signed-off-by: Jie Meng <jmeng@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/bpf/20221005170039.3936894-1-jmeng@fb.com
BPF CI reported that selftest deny_namespace failed with s390x.
test_unpriv_userns_create_no_bpf:PASS:no-bpf unpriv new user ns 0 nsec
test_deny_namespace:PASS:skel load 0 nsec
libbpf: prog 'test_userns_create': failed to attach: ERROR: strerror_r(-524)=22
libbpf: prog 'test_userns_create': failed to auto-attach: -524
test_deny_namespace:FAIL:attach unexpected error: -524 (errno 524)
#57/1 deny_namespace/unpriv_userns_create_no_bpf:FAIL
#57 deny_namespace:FAIL
BPF program test_userns_create is a BPF LSM type program which is
based on trampoline and s390x does not support s390x. Let add the
test to x390x deny list to avoid this failure in BPF CI.
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20221006053429.3549165-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Relax bpf_doc.py's expectation of all BPF_FUNC_xxx enumerators having
sequential values increasing by one. Instead, only make sure that
relative order of BPF helper descriptions in comments matches
enumerators definitions order.
Also additionally make sure that helper IDs are not duplicated.
And also make sure that for cases when we have multiple descriptions for
the same BPF helper (e.g., for bpf_get_socket_cookie()), all such
descriptions are grouped together.
Such checks should capture all the same (and more) issues in upstream
UAPI headers, but also handle backported kernels correctly.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20221006042452.2089843-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Historically enum bpf_func_id's BPF_FUNC_xxx enumerators relied on
implicit sequential values being assigned by compiler. This is
convenient, as new BPF helpers are always added at the very end, but it
also has its downsides, some of them being:
- with over 200 helpers now it's very hard to know what's each helper's ID,
which is often important to know when working with BPF assembly (e.g.,
by dumping raw bpf assembly instructions with llvm-objdump -d
command). it's possible to work around this by looking into vmlinux.h,
dumping /sys/btf/kernel/vmlinux, looking at libbpf-provided
bpf_helper_defs.h, etc. But it always feels like an unnecessary step
and one should be able to quickly figure this out from UAPI header.
- when backporting and cherry-picking only some BPF helpers onto older
kernels it's important to be able to skip some enum values for helpers
that weren't backported, but preserve absolute integer IDs to keep BPF
helper IDs stable so that BPF programs stay portable across upstream
and backported kernels.
While neither problem is insurmountable, they come up frequently enough
and are annoying enough to warrant improving the situation. And for the
backporting the problem can easily go unnoticed for a while, especially
if backport is done with people not very familiar with BPF subsystem overall.
Anyways, it's easy to fix this by making sure that __BPF_FUNC_MAPPER
macro provides explicit helper IDs. Unfortunately that would potentially
break existing users that use UAPI-exposed __BPF_FUNC_MAPPER and are
expected to pass macro that accepts only symbolic helper identifier
(e.g., map_lookup_elem for bpf_map_lookup_elem() helper).
As such, we need to introduce a new macro (___BPF_FUNC_MAPPER) which
would specify both identifier and integer ID, but in such a way as to
allow existing __BPF_FUNC_MAPPER be expressed in terms of new
___BPF_FUNC_MAPPER macro. And that's what this patch is doing. To avoid
duplication and allow __BPF_FUNC_MAPPER stay *exactly* the same,
___BPF_FUNC_MAPPER accepts arbitrary "context" arguments, which can be
used to pass any extra macros, arguments, and whatnot. In our case we
use this to pass original user-provided macro that expects single
argument and __BPF_FUNC_MAPPER is using it's own three-argument
__BPF_FUNC_MAPPER_APPLY intermediate macro to impedance-match new and
old "callback" macros.
Once we resolve this, we use new ___BPF_FUNC_MAPPER to define enum
bpf_func_id with explicit values. The other users of __BPF_FUNC_MAPPER
in kernel (namely in kernel/bpf/disasm.c) are kept exactly the same both
as demonstration that backwards compat works, but also to avoid
unnecessary code churn.
Note that new ___BPF_FUNC_MAPPER() doesn't forcefully insert comma
between values, as that might not be appropriate in all possible cases
where ___BPF_FUNC_MAPPER might be used by users. This doesn't reduce
usability, as it's trivial to insert that comma inside "callback" macro.
To validate all the manually specified IDs are exactly right, we used
BTF to compare before and after values:
$ bpftool btf dump file ~/linux-build/default/vmlinux | rg bpf_func_id -A 211 > after.txt
$ git stash # stach UAPI changes
$ make -j90
... re-building kernel without UAPI changes ...
$ bpftool btf dump file ~/linux-build/default/vmlinux | rg bpf_func_id -A 211 > before.txt
$ diff -u before.txt after.txt
--- before.txt 2022-10-05 10:48:18.119195916 -0700
+++ after.txt 2022-10-05 10:46:49.446615025 -0700
@@ -1,4 +1,4 @@
-[14576] ENUM 'bpf_func_id' encoding=UNSIGNED size=4 vlen=211
+[9560] ENUM 'bpf_func_id' encoding=UNSIGNED size=4 vlen=211
'BPF_FUNC_unspec' val=0
'BPF_FUNC_map_lookup_elem' val=1
'BPF_FUNC_map_update_elem' val=2
As can be seen from diff above, the only thing that changed was resulting BTF
type ID of ENUM bpf_func_id, not any of the enumerators, their names or integer
values.
The only other place that needed fixing was scripts/bpf_doc.py used to generate
man pages and bpf_helper_defs.h header for libbpf and selftests. That script is
tightly-coupled to exact shape of ___BPF_FUNC_MAPPER macro definition, so had
to be trivially adapted.
Cc: Quentin Monnet <quentin@isovalent.com>
Reported-by: Andrea Terzolo <andrea.terzolo@polito.it>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20221006042452.2089843-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a step to attempt to "fix up" BPF object file to make it possible to
successfully load it. E.g., set non-zero size for BPF maps that expect
max_entries set, but BPF object file itself doesn't have declarative
max_entries values specified.
Another issue was with automatic map pinning. Pinning has no effect on
BPF verification process itself but can interfere when validating
multiple related programs and object files, so veristat disabled all the
pinning explicitly.
In the future more such fix up heuristics could be added to accommodate
common patterns encountered in practice.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221005161450.1064469-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Log level 1 on successfully verified programs are basically equivalent
to log level 4 (stats-only), so it's useful to be able to request more
verbose logs at log level 2. Teach test_verifier to recognize -vv as
"very verbose" mode switch and use log level 2 in such mode.
Also force verifier stats regradless of -v or -vv, they are very minimal
and useful to be always emitted in verbose mode.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221005161450.1064469-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
btf_dump_emit_struct_def attempts to print empty structures at a
single line, e.g. `struct empty {}`. However, it has to account for a
case when there are no regular but some padding fields in the struct.
In such case `vlen` would be zero, but size would be non-zero.
E.g. here is struct bpf_timer from vmlinux.h before this patch:
struct bpf_timer {
long: 64;
long: 64;};
And after this patch:
struct bpf_dynptr {
long: 64;
long: 64;
};
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221001104425.415768-1-eddyz87@gmail.com
Pull networking updates from Jakub Kicinski:
"Core:
- Introduce and use a single page frag cache for allocating small skb
heads, clawing back the 10-20% performance regression in UDP flood
test from previous fixes.
- Run packets which already went thru HW coalescing thru SW GRO. This
significantly improves TCP segment coalescing and simplifies
deployments as different workloads benefit from HW or SW GRO.
- Shrink the size of the base zero-copy send structure.
- Move TCP init under a new slow / sleepable version of DO_ONCE().
BPF:
- Add BPF-specific, any-context-safe memory allocator.
- Add helpers/kfuncs for PKCS#7 signature verification from BPF
programs.
- Define a new map type and related helpers for user space -> kernel
communication over a ring buffer (BPF_MAP_TYPE_USER_RINGBUF).
- Allow targeting BPF iterators to loop through resources of one
task/thread.
- Add ability to call selected destructive functions. Expose
crash_kexec() to allow BPF to trigger a kernel dump. Use
CAP_SYS_BOOT check on the loading process to judge permissions.
- Enable BPF to collect custom hierarchical cgroup stats efficiently
by integrating with the rstat framework.
- Support struct arguments for trampoline based programs. Only
structs with size <= 16B and x86 are supported.
- Invoke cgroup/connect{4,6} programs for unprivileged ICMP ping
sockets (instead of just TCP and UDP sockets).
- Add a helper for accessing CLOCK_TAI for time sensitive network
related programs.
- Support accessing network tunnel metadata's flags.
- Make TCP SYN ACK RTO tunable by BPF programs with TCP Fast Open.
- Add support for writing to Netfilter's nf_conn:mark.
Protocols:
- WiFi: more Extremely High Throughput (EHT) and Multi-Link Operation
(MLO) work (802.11be, WiFi 7).
- vsock: improve support for SO_RCVLOWAT.
- SMC: support SO_REUSEPORT.
- Netlink: define and document how to use netlink in a "modern" way.
Support reporting missing attributes via extended ACK.
- IPSec: support collect metadata mode for xfrm interfaces.
- TCPv6: send consistent autoflowlabel in SYN_RECV state and RST
packets.
- TCP: introduce optional per-netns connection hash table to allow
better isolation between namespaces (opt-in, at the cost of memory
and cache pressure).
- MPTCP: support TCP_FASTOPEN_CONNECT.
- Add NEXT-C-SID support in Segment Routing (SRv6) End behavior.
- Adjust IP_UNICAST_IF sockopt behavior for connected UDP sockets.
- Open vSwitch:
- Allow specifying ifindex of new interfaces.
- Allow conntrack and metering in non-initial user namespace.
- TLS: support the Korean ARIA-GCM crypto algorithm.
- Remove DECnet support.
Driver API:
- Allow selecting the conduit interface used by each port in DSA
switches, at runtime.
- Ethernet Power Sourcing Equipment and Power Device support.
- Add tc-taprio support for queueMaxSDU parameter, i.e. setting per
traffic class max frame size for time-based packet schedules.
- Support PHY rate matching - adapting between differing host-side
and link-side speeds.
- Introduce QUSGMII PHY mode and 1000BASE-KX interface mode.
- Validate OF (device tree) nodes for DSA shared ports; make
phylink-related properties mandatory on DSA and CPU ports.
Enforcing more uniformity should allow transitioning to phylink.
- Require that flash component name used during update matches one of
the components for which version is reported by info_get().
- Remove "weight" argument from driver-facing NAPI API as much as
possible. It's one of those magic knobs which seemed like a good
idea at the time but is too indirect to use in practice.
- Support offload of TLS connections with 256 bit keys.
New hardware / drivers:
- Ethernet:
- Microchip KSZ9896 6-port Gigabit Ethernet Switch
- Renesas Ethernet AVB (EtherAVB-IF) Gen4 SoCs
- Analog Devices ADIN1110 and ADIN2111 industrial single pair
Ethernet (10BASE-T1L) MAC+PHY.
- Rockchip RV1126 Gigabit Ethernet (a version of stmmac IP).
- Ethernet SFPs / modules:
- RollBall / Hilink / Turris 10G copper SFPs
- HALNy GPON module
- WiFi:
- CYW43439 SDIO chipset (brcmfmac)
- CYW89459 PCIe chipset (brcmfmac)
- BCM4378 on Apple platforms (brcmfmac)
Drivers:
- CAN:
- gs_usb: HW timestamp support
- Ethernet PHYs:
- lan8814: cable diagnostics
- Ethernet NICs:
- Intel (100G):
- implement control of FCS/CRC stripping
- port splitting via devlink
- L2TPv3 filtering offload
- nVidia/Mellanox:
- tunnel offload for sub-functions
- MACSec offload, w/ Extended packet number and replay window
offload
- significantly restructure, and optimize the AF_XDP support,
align the behavior with other vendors
- Huawei:
- configuring DSCP map for traffic class selection
- querying standard FEC statistics
- querying SerDes lane number via ethtool
- Marvell/Cavium:
- egress priority flow control
- MACSec offload
- AMD/SolarFlare:
- PTP over IPv6 and raw Ethernet
- small / embedded:
- ax88772: convert to phylink (to support SFP cages)
- altera: tse: convert to phylink
- ftgmac100: support fixed link
- enetc: standard Ethtool counters
- macb: ZynqMP SGMII dynamic configuration support
- tsnep: support multi-queue and use page pool
- lan743x: Rx IP & TCP checksum offload
- igc: add xdp frags support to ndo_xdp_xmit
- Ethernet high-speed switches:
- Marvell (prestera):
- support SPAN port features (traffic mirroring)
- nexthop object offloading
- Microchip (sparx5):
- multicast forwarding offload
- QoS queuing offload (tc-mqprio, tc-tbf, tc-ets)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- support RGMII cmode
- NXP (felix):
- standardized ethtool counters
- Microchip (lan966x):
- QoS queuing offload (tc-mqprio, tc-tbf, tc-cbs, tc-ets)
- traffic policing and mirroring
- link aggregation / bonding offload
- QUSGMII PHY mode support
- Qualcomm 802.11ax WiFi (ath11k):
- cold boot calibration support on WCN6750
- support to connect to a non-transmit MBSSID AP profile
- enable remain-on-channel support on WCN6750
- Wake-on-WLAN support for WCN6750
- support to provide transmit power from firmware via nl80211
- support to get power save duration for each client
- spectral scan support for 160 MHz
- MediaTek WiFi (mt76):
- WiFi-to-Ethernet bridging offload for MT7986 chips
- RealTek WiFi (rtw89):
- P2P support"
* tag 'net-next-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1864 commits)
eth: pse: add missing static inlines
once: rename _SLOW to _SLEEPABLE
net: pse-pd: add regulator based PSE driver
dt-bindings: net: pse-dt: add bindings for regulator based PoDL PSE controller
ethtool: add interface to interact with Ethernet Power Equipment
net: mdiobus: search for PSE nodes by parsing PHY nodes.
net: mdiobus: fwnode_mdiobus_register_phy() rework error handling
net: add framework to support Ethernet PSE and PDs devices
dt-bindings: net: phy: add PoDL PSE property
net: marvell: prestera: Propagate nh state from hw to kernel
net: marvell: prestera: Add neighbour cache accounting
net: marvell: prestera: add stub handler neighbour events
net: marvell: prestera: Add heplers to interact with fib_notifier_info
net: marvell: prestera: Add length macros for prestera_ip_addr
net: marvell: prestera: add delayed wq and flush wq on deinit
net: marvell: prestera: Add strict cleanup of fib arbiter
net: marvell: prestera: Add cleanup of allocated fib_nodes
net: marvell: prestera: Add router nexthops ABI
eth: octeon: fix build after netif_napi_add() changes
net/mlx5: E-Switch, Return EBUSY if can't get mode lock
...
Pull landlock updates from Mickaël Salaün:
"Improve user help for Landlock (documentation and sample)"
* tag 'landlock-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
landlock: Fix documentation style
landlock: Slightly improve documentation and fix spelling
samples/landlock: Print hints about ABI versions
Pull audit updates from Paul Moore:
"Six audit patches for v6.1, most are pretty trivial, but a quick list
of the highlights are below:
- Only free the audit proctitle information on task exit. This allows
us to cache the information and improve performance slightly.
- Use the time_after() macro to do time comparisons instead of doing
it directly and potentially causing ourselves problems when the
timer wraps.
- Convert an audit_context state comparison from a relative enum
comparison, e.g. (x < y), to a not-equal comparison to ensure that
we are not caught out at some unknown point in the future by an
enum shuffle.
- A handful of small cleanups such as tidying up comments and
removing unused declarations"
* tag 'audit-pr-20221003' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: remove selinux_audit_rule_update() declaration
audit: use time_after to compare time
audit: free audit_proctitle only on task exit
audit: explicitly check audit_context->context enum value
audit: audit_context pid unused, context enum comment fix
audit: fix repeated words in comments
Pull x86 cleanups from Borislav Petkov:
- The usual round of smaller fixes and cleanups all over the tree
* tag 'x86_cleanups_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cpu: Include the header of init_ia32_feat_ctl()'s prototype
x86/uaccess: Improve __try_cmpxchg64_user_asm() for x86_32
x86: Fix various duplicate-word comment typos
x86/boot: Remove superfluous type casting from arch/x86/boot/bitops.h
Pull x86 cache resource control updates from Borislav Petkov:
- More work by James Morse to disentangle the resctrl filesystem
generic code from the architectural one with the endgoal of plugging
ARM's MPAM implementation into it too so that the user interface
remains the same
- Properly restore the MSR_MISC_FEATURE_CONTROL value instead of
blindly overwriting it to 0
* tag 'x86_cache_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes
x86/resctrl: Add resctrl_rmid_realloc_limit to abstract x86's boot_cpu_data
x86/resctrl: Rename and change the units of resctrl_cqm_threshold
x86/resctrl: Move get_corrected_mbm_count() into resctrl_arch_rmid_read()
x86/resctrl: Move mbm_overflow_count() into resctrl_arch_rmid_read()
x86/resctrl: Pass the required parameters into resctrl_arch_rmid_read()
x86/resctrl: Abstract __rmid_read()
x86/resctrl: Allow per-rmid arch private storage to be reset
x86/resctrl: Add per-rmid arch private storage for overflow and chunks
x86/resctrl: Calculate bandwidth from the previous __mon_event_count() chunks
x86/resctrl: Allow update_mba_bw() to update controls directly
x86/resctrl: Remove architecture copy of mbps_val
x86/resctrl: Switch over to the resctrl mbps_val list
x86/resctrl: Create mba_sc configuration in the rdt_domain
x86/resctrl: Abstract and use supports_mba_mbps()
x86/resctrl: Remove set_mba_sc()s control array re-initialisation
x86/resctrl: Add domain offline callback for resctrl work
x86/resctrl: Group struct rdt_hw_domain cleanup
x86/resctrl: Add domain online callback for resctrl work
x86/resctrl: Merge mon_capable and mon_enabled
...
Pull x75 microcode loader updates from Borislav Petkov:
- Get rid of a single ksize() usage
- By popular demand, print the previous microcode revision an update
was done over
- Remove more code related to the now gone MICROCODE_OLD_INTERFACE
- Document the problems stemming from microcode late loading
* tag 'x86_microcode_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode/AMD: Track patch allocation size explicitly
x86/microcode: Print previous version of microcode after reload
x86/microcode: Remove ->request_microcode_user()
x86/microcode: Document the whole late loading problem
Pull x86 paravirt fix from Borislav Petkov:
- Ensure paravirt patching site descriptors are aligned properly so
that code can do proper arithmetic with their addresses
* tag 'x86_paravirt_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/paravirt: Ensure proper alignment
Pull misc x86 fixes from Borislav Petkov:
- Drop misleading "RIP" from the opcodes dumping message
- Correct APM entry's Konfig help text
* tag 'x86_misc_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/dumpstack: Don't mention RIP in "Code: "
x86/Kconfig: Specify idle=poll instead of no-hlt
Pull x86 asm update from Borislav Petkov:
- Use the __builtin_ffs/ctzl() compiler builtins for the constant
argument case in the kernel's optimized ffs()/ffz() helpers in order
to make use of the compiler's constant folding optmization passes.
* tag 'x86_asm_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/asm/bitops: Use __builtin_ctzl() to evaluate constant expressions
x86/asm/bitops: Use __builtin_ffs() to evaluate constant expressions
Pull x86 core fixes from Borislav Petkov:
- Make sure an INT3 is slapped after every unconditional retpoline JMP
as both vendors suggest
- Clean up pciserial a bit
* tag 'x86_core_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86,retpoline: Be sure to emit INT3 after JMP *%\reg
x86/earlyprintk: Clean up pciserial
Pull x86 APIC update from Borislav Petkov:
- Add support for locking the APIC in X2APIC mode to prevent SGX
enclave leaks
* tag 'x86_apic_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apic: Don't disable x2APIC if locked
Pull x86 RAS updates from Borislav Petkov:
- Fix the APEI MCE callback handler to consult the hardware about the
granularity of the memory error instead of hard-coding it
- Offline memory pages on Intel machines after 2 errors reported per
page
* tag 'ras_core_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Retrieve poison range from hardware
RAS/CEC: Reduce offline page threshold for Intel systems
Pull x86 cpu updates from Borislav Petkov:
- Print the CPU number at segfault time.
The number printed is not always accurate (preemption is enabled at
that time) but the print string contains "likely" and after a lot of
back'n'forth on this, this was the consensus that was reached. See
thread at [1].
- After a *lot* of testing and polishing, finally the clear_user()
improvements to inline REP; STOSB by default
Link: https://lore.kernel.org/r/5d62c1d0-7425-d5bb-ecb5-1dc3b4d7d245@intel.com [1]
* tag 'x86_cpu_for_v6.1_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Print likely CPU at segfault time
x86/clear_user: Make it faster
