xsk_umem__create() does mmap for fill/comp rings, but xsk_umem__delete()
doesn't do the unmap. This works fine for regular cases, because
xsk_socket__delete() does unmap for the rings. But for the case that
xsk_socket__create_shared() fails, umem rings are not unmapped.
fill_save/comp_save are checked to determine if rings have already be
unmapped by xsk. If fill_save and comp_save are NULL, it means that the
rings have already been used by xsk. Then they are supposed to be
unmapped by xsk_socket__delete(). Otherwise, xsk_umem__delete() does the
unmap.
Fixes: 2f6324a393 ("libbpf: Support shared umems between queues and devices")
Signed-off-by: Cheng Li <lic121@chinatelecom.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220301132623.GA19995@vscode.7~
Allow registering and unregistering custom handlers for BPF program.
This allows user applications and libraries to plug into libbpf's
declarative SEC() definition handling logic. This allows to offload
complex and intricate custom logic into external libraries, but still
provide a great user experience.
One such example is USDT handling library, which has a lot of code and
complexity which doesn't make sense to put into libbpf directly, but it
would be really great for users to be able to specify BPF programs with
something like SEC("usdt/<path-to-binary>:<usdt_provider>:<usdt_name>")
and have correct BPF program type set (BPF_PROGRAM_TYPE_KPROBE, as it is
uprobe) and even support BPF skeleton's auto-attach logic.
In some cases, it might be even good idea to override libbpf's default
handling, like for SEC("perf_event") programs. With custom library, it's
possible to extend logic to support specifying perf event specification
right there in SEC() definition without burdening libbpf with lots of
custom logic or extra library dependecies (e.g., libpfm4). With current
patch it's possible to override libbpf's SEC("perf_event") handling and
specify a completely custom ones.
Further, it's possible to specify a generic fallback handling for any
SEC() that doesn't match any other custom or standard libbpf handlers.
This allows to accommodate whatever legacy use cases there might be, if
necessary.
See doc comments for libbpf_register_prog_handler() and
libbpf_unregister_prog_handler() for detailed semantics.
This patch also bumps libbpf development version to v0.8 and adds new
APIs there.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220305010129.1549719-3-andrii@kernel.org
Allow some BPF program types to support auto-attach only in subste of
cases. Currently, if some BPF program type specifies attach callback, it
is assumed that during skeleton attach operation all such programs
either successfully attach or entire skeleton attachment fails. If some
program doesn't support auto-attachment from skeleton, such BPF program
types shouldn't have attach callback specified.
This is limiting for cases when, depending on how full the SEC("")
definition is, there could either be enough details to support
auto-attach or there might not be and user has to use some specific API
to provide more details at runtime.
One specific example of such desired behavior might be SEC("uprobe"). If
it's specified as just uprobe auto-attach isn't possible. But if it's
SEC("uprobe/<some_binary>:<some_func>") then there are enough details to
support auto-attach. Note that there is a somewhat subtle difference
between auto-attach behavior of BPF skeleton and using "generic"
bpf_program__attach(prog) (which uses the same attach handlers under the
cover). Skeleton allow some programs within bpf_object to not have
auto-attach implemented and doesn't treat that as an error. Instead such
BPF programs are just skipped during skeleton's (optional) attach step.
bpf_program__attach(), on the other hand, is called when user *expects*
auto-attach to work, so if specified program doesn't implement or
doesn't support auto-attach functionality, that will be treated as an
error.
Another improvement to the way libbpf is handling SEC()s would be to not
require providing dummy kernel function name for kprobe. Currently,
SEC("kprobe/whatever") is necessary even if actual kernel function is
determined by user at runtime and bpf_program__attach_kprobe() is used
to specify it. With changes in this patch, it's possible to support both
SEC("kprobe") and SEC("kprobe/<actual_kernel_function"), while only in
the latter case auto-attach will be performed. In the former one, such
kprobe will be skipped during skeleton attach operation.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220305010129.1549719-2-andrii@kernel.org
The page_cnt parameter is used to specify the number of memory pages
allocated for each per-CPU buffer, it must be non-zero and a power of 2.
Currently, the __perf_buffer__new() function attempts to validate that
the page_cnt is a power of 2 but forgets checking for the case where
page_cnt is zero, we can fix it by replacing 'page_cnt & (page_cnt - 1)'
with 'page_cnt == 0 || (page_cnt & (page_cnt - 1))'.
If so, we also don't need to add a check in perf_buffer__new_v0_6_0() to
make sure that page_cnt is non-zero and the check for zero in
perf_buffer__new_raw_v0_6_0() can also be removed.
The code will be cleaner and more readable.
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220303005921.53436-1-ytcoode@gmail.com
Currently if a declaration appears in the BTF before the definition, the
definition is dumped as a conflicting name, e.g.:
$ bpftool btf dump file vmlinux format raw | grep "'unix_sock'"
[81287] FWD 'unix_sock' fwd_kind=struct
[89336] STRUCT 'unix_sock' size=1024 vlen=14
$ bpftool btf dump file vmlinux format c | grep "struct unix_sock"
struct unix_sock;
struct unix_sock___2 { <--- conflict, the "___2" is unexpected
struct unix_sock___2 *unix_sk;
This causes a compilation error if the dump output is used as a header file.
Fix it by skipping declaration when counting duplicated type names.
Fixes: 351131b51c ("libbpf: add btf_dump API for BTF-to-C conversion")
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220301053250.1464204-2-xukuohai@huawei.com
When a BPF map of type BPF_MAP_TYPE_PERF_EVENT_ARRAY doesn't have the
max_entries parameter set, the map will be created with max_entries set
to the number of available CPUs. When we try to reuse such a pinned map,
map_is_reuse_compat will return false, as max_entries in the map
definition differs from max_entries of the existing map, causing the
following error:
libbpf: couldn't reuse pinned map at '/sys/fs/bpf/m_logging': parameter mismatch
Fix this by overwriting max_entries in the map definition. For this to
work, we need to do this in bpf_object__create_maps, before calling
bpf_object__reuse_map.
Fixes: 57a00f4164 ("libbpf: Add auto-pinning of maps when loading BPF objects")
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220225152355.315204-1-stijn@linux-ipv6.be
The check in the last return statement is unnecessary, we can just return
the ret variable.
But we can simplify the function further by returning 0 immediately if we
find the section size and -ENOENT otherwise.
Thus we can also remove the ret variable.
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220223085244.3058118-1-ytcoode@gmail.com
The check 't->size && t->size != size' is redundant because if t->size
compares unequal to 0, we will just skip straight to sorting variables.
Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220220072750.209215-1-ytcoode@gmail.com
BTFGen needs to run the core relocation logic in order to understand
what are the types involved in a given relocation.
Currently bpf_core_apply_relo() calculates and **applies** a relocation
to an instruction. Having both operations in the same function makes it
difficult to only calculate the relocation without patching the
instruction. This commit splits that logic in two different phases: (1)
calculate the relocation and (2) patch the instruction.
For the first phase bpf_core_apply_relo() is renamed to
bpf_core_calc_relo_insn() who is now only on charge of calculating the
relocation, the second phase uses the already existing
bpf_core_patch_insn(). bpf_object__relocate_core() uses both of them and
the BTFGen will use only bpf_core_calc_relo_insn().
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Rafael David Tinoco <rafael.tinoco@aquasec.com>
Signed-off-by: Lorenzo Fontana <lorenzo.fontana@elastic.co>
Signed-off-by: Leonardo Di Donato <leonardo.didonato@elastic.co>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220215225856.671072-2-mauricio@kinvolk.io
$(or ...) is available since GNU Make 3.81, and useful to shorten the
code in some places.
Covert as follows:
$(if A,A,B) --> $(or A,B)
This patch also converts:
$(if A, A, B) --> $(or A, B)
Strictly speaking, the latter is not an equivalent conversion because
GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B)
expands to " A", while $(or A, B) expands to "A".
Anyway, preceding spaces are not significant in the code hunks I touched.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
When receiving netlink messages, libbpf was using a statically allocated
stack buffer of 4k bytes. This happened to work fine on systems with a 4k
page size, but on systems with larger page sizes it can lead to truncated
messages. The user-visible impact of this was that libbpf would insist no
XDP program was attached to some interfaces because that bit of the netlink
message got chopped off.
Fix this by switching to a dynamically allocated buffer; we borrow the
approach from iproute2 of using recvmsg() with MSG_PEEK|MSG_TRUNC to get
the actual size of the pending message before receiving it, adjusting the
buffer as necessary. While we're at it, also add retries on interrupted
system calls around the recvmsg() call.
v2:
- Move peek logic to libbpf_netlink_recv(), don't double free on ENOMEM.
Fixes: 8bbb77b7c7 ("libbpf: Add various netlink helpers")
Reported-by: Zhiqian Guan <zhguan@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20220211234819.612288-1-toke@redhat.com
Prepare light skeleton to be used in the kernel module and in the user space.
The look and feel of lskel.h is mostly the same with the difference that for
user space the skel->rodata is the same pointer before and after skel_load
operation, while in the kernel the skel->rodata after skel_open and the
skel->rodata after skel_load are different pointers.
Typical usage of skeleton remains the same for kernel and user space:
skel = my_bpf__open();
skel->rodata->my_global_var = init_val;
err = my_bpf__load(skel);
err = my_bpf__attach(skel);
// access skel->rodata->my_global_var;
// access skel->bss->another_var;
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209232001.27490-3-alexei.starovoitov@gmail.com
On ppc64le architecture __s64 is long int and requires %ld. Cast to
ssize_t and use %zd to avoid architecture-specific specifiers.
Fixes: 4172843ed4 ("libbpf: Fix signedness bug in btf_dump_array_data()")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220209063909.1268319-1-andrii@kernel.org
Add syscall-specific variant of BPF_KPROBE named BPF_KPROBE_SYSCALL ([0]).
The new macro hides the underlying way of getting syscall input arguments.
With the new macro, the following code:
SEC("kprobe/__x64_sys_close")
int BPF_KPROBE(do_sys_close, struct pt_regs *regs)
{
int fd;
fd = PT_REGS_PARM1_CORE(regs);
/* do something with fd */
}
can be written as:
SEC("kprobe/__x64_sys_close")
int BPF_KPROBE_SYSCALL(do_sys_close, int fd)
{
/* do something with fd */
}
[0] Closes: https://github.com/libbpf/libbpf/issues/425
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220207143134.2977852-2-hengqi.chen@gmail.com
On s390, the first syscall argument should be accessed via orig_gpr2
(see arch/s390/include/asm/syscall.h). Currently gpr[2] is used
instead, leading to bpf_syscall_macro test failure.
orig_gpr2 cannot be added to user_pt_regs, since its layout is a part
of the ABI. Therefore provide access to it only through
PT_REGS_PARM1_CORE_SYSCALL() by using a struct pt_regs flavor.
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-11-iii@linux.ibm.com
On arm64, the first syscall argument should be accessed via orig_x0
(see arch/arm64/include/asm/syscall.h). Currently regs[0] is used
instead, leading to bpf_syscall_macro test failure.
orig_x0 cannot be added to struct user_pt_regs, since its layout is a
part of the ABI. Therefore provide access to it only through
PT_REGS_PARM1_CORE_SYSCALL() by using a struct pt_regs flavor.
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-10-iii@linux.ibm.com
riscv does not select ARCH_HAS_SYSCALL_WRAPPER, so its syscall
handlers take "unpacked" syscall arguments. Indicate this to libbpf
using PT_REGS_SYSCALL_REGS macro.
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-7-iii@linux.ibm.com
riscv registers are accessed via struct user_regs_struct, not struct
pt_regs. The program counter member in this struct is called pc, not
epc. The frame pointer is called s0, not fp.
Fixes: 3cc31d7940 ("libbpf: Normalize PT_REGS_xxx() macro definitions")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-6-iii@linux.ibm.com
powerpc does not select ARCH_HAS_SYSCALL_WRAPPER, so its syscall
handlers take "unpacked" syscall arguments. Indicate this to libbpf
using PT_REGS_SYSCALL_REGS macro.
Reported-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-5-iii@linux.ibm.com
Architectures that select ARCH_HAS_SYSCALL_WRAPPER pass a pointer to
struct pt_regs to syscall handlers, others unpack it into individual
function parameters. Introduce a macro to describe what a particular
arch does.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220209021745.2215452-3-iii@linux.ibm.com
The btf__resolve_size() function returns negative error codes so
"elem_size" must be signed for the error handling to work.
Fixes: 920d16af9b ("libbpf: BTF dumper support for typed data")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20220208071552.GB10495@kili
libbpf_set_strict_mode() checks that the passed mode doesn't contain
extra bits for LIBBPF_STRICT_* flags that don't exist yet.
It makes it difficult for applications to disable some strict flags as
something like "LIBBPF_STRICT_ALL & ~LIBBPF_STRICT_MAP_DEFINITIONS"
is rejected by this check and they have to use a rather complicated
formula to calculate it.[0]
One possibility is to change LIBBPF_STRICT_ALL to only contain the bits
of all existing LIBBPF_STRICT_* flags instead of 0xffffffff. However
it's not possible because the idea is that applications compiled against
older libbpf_legacy.h would still be opting into latest
LIBBPF_STRICT_ALL features.[1]
The other possibility is to remove that check so something like
"LIBBPF_STRICT_ALL & ~LIBBPF_STRICT_MAP_DEFINITIONS" is allowed. It's
what this commit does.
[0]: https://lore.kernel.org/bpf/20220204220435.301896-1-mauricio@kinvolk.io/
[1]: https://lore.kernel.org/bpf/CAEf4BzaTWa9fELJLh+bxnOb0P1EMQmaRbJVG0L+nXZdy0b8G3Q@mail.gmail.com/
Fixes: 93b8952d22 ("libbpf: deprecate legacy BPF map definitions")
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220207145052.124421-2-mauricio@kinvolk.io
There are cases where clang compiler is packaged in a way
readelf is a symbolic link to llvm-readelf. In such cases,
llvm-readelf will be used instead of default binutils readelf,
and the following error will appear during libbpf build:
Warning: Num of global symbols in
/home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/sharedobjs/libbpf-in.o (367)
does NOT match with num of versioned symbols in
/home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf.so libbpf.map (383).
Please make sure all LIBBPF_API symbols are versioned in libbpf.map.
--- /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_global_syms.tmp ...
+++ /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/build/libbpf/libbpf_versioned_syms.tmp ...
@@ -324,6 +324,22 @@
btf__str_by_offset
btf__type_by_id
btf__type_cnt
+LIBBPF_0.0.1
+LIBBPF_0.0.2
+LIBBPF_0.0.3
+LIBBPF_0.0.4
+LIBBPF_0.0.5
+LIBBPF_0.0.6
+LIBBPF_0.0.7
+LIBBPF_0.0.8
+LIBBPF_0.0.9
+LIBBPF_0.1.0
+LIBBPF_0.2.0
+LIBBPF_0.3.0
+LIBBPF_0.4.0
+LIBBPF_0.5.0
+LIBBPF_0.6.0
+LIBBPF_0.7.0
libbpf_attach_type_by_name
libbpf_find_kernel_btf
libbpf_find_vmlinux_btf_id
make[2]: *** [Makefile:184: check_abi] Error 1
make[1]: *** [Makefile:140: all] Error 2
The above failure is due to different printouts for some ABS
versioned symbols. For example, with the same libbpf.so,
$ /bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS
134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0
202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0
...
$ /opt/llvm/bin/readelf --dyn-syms --wide tools/lib/bpf/libbpf.so | grep "LIBBPF" | grep ABS
134: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.5.0@@LIBBPF_0.5.0
202: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.6.0@@LIBBPF_0.6.0
...
The binutils readelf doesn't print out the symbol LIBBPF_* version and llvm-readelf does.
Such a difference caused libbpf build failure with llvm-readelf.
The proposed fix filters out all ABS symbols as they are not part of the comparison.
This works for both binutils readelf and llvm-readelf.
Reported-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220204214355.502108-1-yhs@fb.com
Open-code bpf_map__is_offload_neutral() logic in one place in
to-be-deprecated bpf_prog_load_xattr2.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220202225916.3313522-2-andrii@kernel.org
Open code raw_tracepoint_open and link_create used by light skeleton
to be able to avoid full libbpf eventually.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220131220528.98088-4-alexei.starovoitov@gmail.com
Open code low level bpf commands used by light skeleton to
be able to avoid full libbpf eventually.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220131220528.98088-3-alexei.starovoitov@gmail.com
Deprecate xdp_cpumap, xdp_devmap and classifier sec definitions.
Introduce xdp/devmap and xdp/cpumap definitions according to the
standard for SEC("") in libbpf:
- prog_type.prog_flags/attach_place
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/5c7bd9426b3ce6a31d9a4b1f97eb299e1467fc52.1643727185.git.lorenzo@kernel.org
btf_ext__{func,line}_info_rec_size functions are used in conjunction
with already-deprecated btf_ext__reloc_{func,line}_info functions. Since
struct btf_ext is opaque to the user it was necessary to expose rec_size
getters in the past.
btf_ext__reloc_{func,line}_info were deprecated in commit 8505e8709b
("libbpf: Implement generalized .BTF.ext func/line info adjustment")
as they're not compatible with support for multiple programs per
section. It was decided[0] that users of these APIs should implement their
own .btf.ext parsing to access this data, in which case the rec_size
getters are unnecessary. So deprecate them from libbpf 0.7.0 onwards.
[0] Closes: https://github.com/libbpf/libbpf/issues/277
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220201014610.3522985-1-davemarchevsky@fb.com
Not sure why these APIs were added in the first place instead of
a completely generic (and not requiring constantly adding new APIs with
each new BPF program type) bpf_program__type() and
bpf_program__set_type() APIs. But as it is right now, there are 13 such
specialized is_type/set_type APIs, while latest kernel is already at 30+
BPF program types.
Instead of completing the set of APIs and keep chasing kernel's
bpf_prog_type enum, deprecate existing subset and recommend generic
bpf_program__type() and bpf_program__set_type() APIs.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Deprecated bpf_map__resize() in favor of bpf_map__set_max_entries()
setter. In addition to having a surprising name (users often don't
realize that they need to use bpf_map__resize()), the name also implies
some magic way of resizing BPF map after it is created, which is clearly
not the case.
Another minor annoyance is that bpf_map__resize() disallows 0 value for
max_entries, which in some cases is totally acceptable (e.g., like for
BPF perf buf case to let libbpf auto-create one buffer per each
available CPU core).
[0] Closes: https://github.com/libbpf/libbpf/issues/304
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Currently, rcx is read as the fourth parameter of syscall on x86_64.
But x86_64 Linux System Call convention uses r10 actually.
This commit adds the wrapper for users who want to access to
syscall params to analyze the user space.
Signed-off-by: Kenta Tada <Kenta.Tada@sony.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220124141622.4378-3-Kenta.Tada@sony.com
Deprecate bpf_object__open_buffer() API in favor of the unified
opts-based bpf_object__open_mem() API.
Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220125005923.418339-2-christylee@fb.com
This adds a new bpf section "iter.s" to allow bpf iterator programs to
be sleepable.
Signed-off-by: Kenny Yu <kennyyu@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124185403.468466-4-kennyyu@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce support for the following SEC entries for XDP frags
property:
- SEC("xdp.frags")
- SEC("xdp.frags/devmap")
- SEC("xdp.frags/cpumap")
Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/af23b6e4841c171ad1af01917839b77847a4bc27.1642758637.git.lorenzo@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce 4 new netlink-based XDP APIs for attaching, detaching, and
querying XDP programs:
- bpf_xdp_attach;
- bpf_xdp_detach;
- bpf_xdp_query;
- bpf_xdp_query_id.
These APIs replace bpf_set_link_xdp_fd, bpf_set_link_xdp_fd_opts,
bpf_get_link_xdp_id, and bpf_get_link_xdp_info APIs ([0]). The latter
don't follow a consistent naming pattern and some of them use
non-extensible approaches (e.g., struct xdp_link_info which can't be
modified without breaking libbpf ABI).
The approach I took with these low-level XDP APIs is similar to what we
did with low-level TC APIs. There is a nice duality of bpf_tc_attach vs
bpf_xdp_attach, and so on. I left bpf_xdp_attach() to support detaching
when -1 is specified for prog_fd for generality and convenience, but
bpf_xdp_detach() is preferred due to clearer naming and associated
semantics. Both bpf_xdp_attach() and bpf_xdp_detach() accept the same
opts struct allowing to specify expected old_prog_fd.
While doing the refactoring, I noticed that old APIs require users to
specify opts with old_fd == -1 to declare "don't care about already
attached XDP prog fd" condition. Otherwise, FD 0 is assumed, which is
essentially never an intended behavior. So I made this behavior
consistent with other kernel and libbpf APIs, in which zero FD means "no
FD". This seems to be more in line with the latest thinking in BPF land
and should cause less user confusion, hopefully.
For querying, I left two APIs, both more generic bpf_xdp_query()
allowing to query multiple IDs and attach mode, but also
a specialization of it, bpf_xdp_query_id(), which returns only requested
prog_id. Uses of prog_id returning bpf_get_link_xdp_id() were so
prevalent across selftests and samples, that it seemed a very common use
case and using bpf_xdp_query() for doing it felt very cumbersome with
a highly branches if/else chain based on flags and attach mode.
Old APIs are scheduled for deprecation in libbpf 0.8 release.
[0] Closes: https://github.com/libbpf/libbpf/issues/309
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20220120061422.2710637-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Enact deprecation of legacy BPF map definition in SEC("maps") ([0]). For
the definitions themselves introduce LIBBPF_STRICT_MAP_DEFINITIONS flag
for libbpf strict mode. If it is set, error out on any struct
bpf_map_def-based map definition. If not set, libbpf will print out
a warning for each legacy BPF map to raise awareness that it goes away.
For any use of BPF_ANNOTATE_KV_PAIR() macro providing a legacy way to
associate BTF key/value type information with legacy BPF map definition,
warn through libbpf's pr_warn() error message (but don't fail BPF object
open).
BPF-side struct bpf_map_def is marked as deprecated. User-space struct
bpf_map_def has to be used internally in libbpf, so it is left
untouched. It should be enough for bpf_map__def() to be marked
deprecated to raise awareness that it goes away.
bpftool is an interesting case that utilizes libbpf to open BPF ELF
object to generate skeleton. As such, even though bpftool itself uses
full on strict libbpf mode (LIBBPF_STRICT_ALL), it has to relax it a bit
for BPF map definition handling to minimize unnecessary disruptions. So
opt-out of LIBBPF_STRICT_MAP_DEFINITIONS for bpftool. User's code that
will later use generated skeleton will make its own decision whether to
enforce LIBBPF_STRICT_MAP_DEFINITIONS or not.
There are few tests in selftests/bpf that are consciously using legacy
BPF map definitions to test libbpf functionality. For those, temporary
opt out of LIBBPF_STRICT_MAP_DEFINITIONS mode for the duration of those
tests.
[0] Closes: https://github.com/libbpf/libbpf/issues/272
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220120060529.1890907-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add a hashmap to map the string offsets from a source btf to the
string offsets from a target btf to reduce overheads.
btf__add_btf() calls btf__add_str() to add strings from a source to a
target btf. It causes many string comparisons, and it is a major
hotspot when adding a big btf. btf__add_str() uses strcmp() to check
if a hash entry is the right one. The extra hashmap here compares
offsets of strings, that are much cheaper. It remembers the results
of btf__add_str() for later uses to reduce the cost.
We are parallelizing BTF encoding for pahole by creating separated btf
instances for worker threads. These per-thread btf instances will be
added to the btf instance of the main thread by calling btf__add_str()
to deduplicate and write out. With this patch and -j4, the running
time of pahole drops to about 6.0s from 6.6s.
The following lines are the summary of 'perf stat' w/o the change.
6.668126396 seconds time elapsed
13.451054000 seconds user
0.715520000 seconds sys
The following lines are the summary w/ the change.
5.986973919 seconds time elapsed
12.939903000 seconds user
0.724152000 seconds sys
V4 fixes a bug of error checking against the pointer returned by
hashmap__new().
[v3] https://lore.kernel.org/bpf/20220118232053.2113139-1-kuifeng@fb.com/
[v2] https://lore.kernel.org/bpf/20220114193713.461349-1-kuifeng@fb.com/
Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220119180214.255634-1-kuifeng@fb.com
The btf.h header included with libbpf contains inline helper functions to
check for various BTF kinds. These helpers directly reference the
BTF_KIND_* constants defined in the kernel header, and because the header
file is included in user applications, this happens in the user application
compile units.
This presents a problem if a user application is compiled on a system with
older kernel headers because the constants are not available. To avoid
this, add #defines of the constants directly in btf.h before using them.
Since the kernel header moved to an enum for BTF_KIND_*, the #defines can
shadow the enum values without any errors, so we only need #ifndef guards
for the constants that predates the conversion to enum. We group these so
there's only one guard for groups of values that were added together.
[0] Closes: https://github.com/libbpf/libbpf/issues/436
Fixes: 223f903e9c ("bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG")
Fixes: 5b84bd1036 ("libbpf: Add support for BTF_KIND_TAG")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/bpf/20220118141327.34231-1-toke@redhat.com
All fields accessed via bpf_map_def can now be accessed via
appropirate getters and setters. Mark bpf_map__def() API as deprecated.
Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220108004218.355761-6-christylee@fb.com
When I checked the code in skeleton header file generated with my own
bpf prog, I found there may be possible NULL pointer dereference when
destroying skeleton. Then I checked the in-tree bpf progs, finding that is
a common issue. Let's take the generated samples/bpf/xdp_redirect_cpu.skel.h
for example. Below is the generated code in
xdp_redirect_cpu__create_skeleton():
xdp_redirect_cpu__create_skeleton
struct bpf_object_skeleton *s;
s = (struct bpf_object_skeleton *)calloc(1, sizeof(*s));
if (!s)
goto error;
...
error:
bpf_object__destroy_skeleton(s);
return -ENOMEM;
After goto error, the NULL 's' will be deferenced in
bpf_object__destroy_skeleton().
We can simply fix this issue by just adding a NULL check in
bpf_object__destroy_skeleton().
Fixes: d66562fba1 ("libbpf: Add BPF object skeleton support")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220108134739.32541-1-laoar.shao@gmail.com
All xattr APIs are being dropped, let's converge to the convention used in
high-level APIs and rename bpf_prog_attach_xattr to bpf_prog_attach_opts.
Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220107184604.3668544-2-christylee@fb.com
