Move the logic of finding and assigning exception callback indices from
BTF sanitization step to program relocations step, which seems more
logical and will unblock moving BTF loading to after relocation step.
Exception callbacks discovery and assignment has no dependency on BTF
being loaded into the kernel, it only uses BTF information. It does need
to happen before subprogram relocations happen, though. Which is why the
split.
No functional changes.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240104013847.3875810-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Move map creation to later during BPF object loading by pre-creating
stable placeholder FDs (utilizing memfd_create()). Use dup2()
syscall to then atomically make those placeholder FDs point to real
kernel BPF map objects.
This change allows to delay BPF map creation to after all the BPF
program relocations. That, in turn, allows to delay BTF finalization and
loading into kernel to after all the relocations as well. We'll take
advantage of the latter in subsequent patches to allow libbpf to adjust
BTF in a way that helps with BPF global function usage.
Clean up a few places where we close map->fd, which now shouldn't
happen, because map->fd should be a valid FD regardless of whether map
was created or not. Surprisingly and nicely it simplifies a bunch of
error handling code. If this change doesn't backfire, I'm tempted to
pre-create such stable FDs for other entities (progs, maybe even BTF).
We previously did some manipulations to make gen_loader work with fake
map FDs, with stable map FDs this hack is not necessary for maps (we
still have it for BTF, but I left it as is for now).
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240104013847.3875810-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
With the upcoming switch to preallocated placeholder FDs for maps,
switch various getters/setter away from checking map->fd. Use
map_is_created() helper that detect whether BPF map can be modified based
on map->obj->loaded state, with special provision for maps set up with
bpf_map__reuse_fd().
For backwards compatibility, we take map_is_created() into account in
bpf_map__fd() getter as well. This way before bpf_object__load() phase
bpf_map__fd() will always return -1, just as before the changes in
subsequent patches adding stable map->fd placeholders.
We also get rid of all internal uses of bpf_map__fd() getter, as it's
more oriented for uses external to libbpf. The above map_is_created()
check actually interferes with some of the internal uses, if map FD is
fetched through bpf_map__fd().
Acked-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20240104013847.3875810-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit 051d44209842 ("net/sched: Retire CBQ qdisc") retired the CBQ qdisc.
Remove UAPI for it. Iproute2 will sync by equally removing it from user space.
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit fb38306ceb9e ("net/sched: Retire ATM qdisc") retired the ATM qdisc.
Remove UAPI for it. Iproute2 will sync by equally removing it from user space.
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit bbe77c14ee61 ("net/sched: Retire dsmark qdisc") retired the dsmark
classifier. Remove UAPI support for it.
Iproute2 will sync by equally removing it from user space.
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 8c710f75256b ("net/sched: Retire tcindex classifier") retired the TC
tcindex classifier.
Remove UAPI for it. Iproute2 will sync by equally removing it from user space.
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 265b4da82dbf ("net/sched: Retire rsvp classifier") retired the TC RSVP
classifier.
Remove UAPI for it. Iproute2 will sync by equally removing it from user space.
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An issue occurred while reading an ELF file in libbpf.c during fuzzing:
Program received signal SIGSEGV, Segmentation fault.
0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
4206 in libbpf.c
(gdb) bt
#0 0x0000000000958e97 in bpf_object.collect_prog_relos () at libbpf.c:4206
#1 0x000000000094f9d6 in bpf_object.collect_relos () at libbpf.c:6706
#2 0x000000000092bef3 in bpf_object_open () at libbpf.c:7437
#3 0x000000000092c046 in bpf_object.open_mem () at libbpf.c:7497
#4 0x0000000000924afa in LLVMFuzzerTestOneInput () at fuzz/bpf-object-fuzzer.c:16
#5 0x000000000060be11 in testblitz_engine::fuzzer::Fuzzer::run_one ()
#6 0x000000000087ad92 in tracing::span::Span::in_scope ()
#7 0x00000000006078aa in testblitz_engine::fuzzer::util::walkdir ()
#8 0x00000000005f3217 in testblitz_engine::entrypoint::main::{{closure}} ()
#9 0x00000000005f2601 in main ()
(gdb)
scn_data was null at this code(tools/lib/bpf/src/libbpf.c):
if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) {
The scn_data is derived from the code above:
scn = elf_sec_by_idx(obj, sec_idx);
scn_data = elf_sec_data(obj, scn);
relo_sec_name = elf_sec_str(obj, shdr->sh_name);
sec_name = elf_sec_name(obj, scn);
if (!relo_sec_name || !sec_name)// don't check whether scn_data is NULL
return -EINVAL;
In certain special scenarios, such as reading a malformed ELF file,
it is possible that scn_data may be a null pointer
Signed-off-by: Mingyi Zhang <zhangmingyi5@huawei.com>
Signed-off-by: Xin Liu <liuxin350@huawei.com>
Signed-off-by: Changye Wu <wuchangye@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231221033947.154564-1-liuxin350@huawei.com
To allow external admin authority to override default BPF FS location
(/sys/fs/bpf) for implicit BPF token creation, teach libbpf to recognize
LIBBPF_BPF_TOKEN_PATH envvar. If it is specified and user application
didn't explicitly specify neither bpf_token_path nor bpf_token_fd
option, it will be treated exactly like bpf_token_path option,
overriding default /sys/fs/bpf location and making BPF token mandatory.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231213190842.3844987-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add BPF token support to BPF object-level functionality.
BPF token is supported by BPF object logic either as an explicitly
provided BPF token from outside (through BPF FS path or explicit BPF
token FD), or implicitly (unless prevented through
bpf_object_open_opts).
Implicit mode is assumed to be the most common one for user namespaced
unprivileged workloads. The assumption is that privileged container
manager sets up default BPF FS mount point at /sys/fs/bpf with BPF token
delegation options (delegate_{cmds,maps,progs,attachs} mount options).
BPF object during loading will attempt to create BPF token from
/sys/fs/bpf location, and pass it for all relevant operations
(currently, map creation, BTF load, and program load).
In this implicit mode, if BPF token creation fails due to whatever
reason (BPF FS is not mounted, or kernel doesn't support BPF token,
etc), this is not considered an error. BPF object loading sequence will
proceed with no BPF token.
In explicit BPF token mode, user provides explicitly either custom BPF
FS mount point path or creates BPF token on their own and just passes
token FD directly. In such case, BPF object will either dup() token FD
(to not require caller to hold onto it for entire duration of BPF object
lifetime) or will attempt to create BPF token from provided BPF FS
location. If BPF token creation fails, that is considered a critical
error and BPF object load fails with an error.
Libbpf provides a way to disable implicit BPF token creation, if it
causes any troubles (BPF token is designed to be completely optional and
shouldn't cause any problems even if provided, but in the world of BPF
LSM, custom security logic can be installed that might change outcome
dependin on the presence of BPF token). To disable libbpf's default BPF
token creation behavior user should provide either invalid BPF token FD
(negative), or empty bpf_token_path option.
BPF token presence can influence libbpf's feature probing, so if BPF
object has associated BPF token, feature probing is instructed to use
BPF object-specific feature detection cache and token FD.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231213190842.3844987-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adjust feature probing callbacks to take into account optional token_fd.
In unprivileged contexts, some feature detectors would fail to detect
kernel support just because BPF program, BPF map, or BTF object can't be
loaded due to privileged nature of those operations. So when BPF object
is loaded with BPF token, this token should be used for feature probing.
This patch is setting support for this scenario, but we don't yet pass
non-zero token FD. This will be added in the next patch.
We also switched BPF cookie detector from using kprobe program to
tracepoint one, as tracepoint is somewhat less dangerous BPF program
type and has higher likelihood of being allowed through BPF token in the
future. This change has no effect on detection behavior.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231213190842.3844987-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add feat_supported() helper that accepts feature cache instead of
bpf_object. This allows low-level code in bpf.c to not know or care
about higher-level concept of bpf_object, yet it will be able to utilize
custom feature checking in cases where BPF token might influence the
outcome.
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231213190842.3844987-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
=== Motivation ===
Similar to reading from CO-RE bitfields, we need a CO-RE aware bitfield
writing wrapper to make the verifier happy.
Two alternatives to this approach are:
1. Use the upcoming `preserve_static_offset` [0] attribute to disable
CO-RE on specific structs.
2. Use broader byte-sized writes to write to bitfields.
(1) is a bit hard to use. It requires specific and not-very-obvious
annotations to bpftool generated vmlinux.h. It's also not generally
available in released LLVM versions yet.
(2) makes the code quite hard to read and write. And especially if
BPF_CORE_READ_BITFIELD() is already being used, it makes more sense to
to have an inverse helper for writing.
=== Implementation details ===
Since the logic is a bit non-obvious, I thought it would be helpful
to explain exactly what's going on.
To start, it helps by explaining what LSHIFT_U64 (lshift) and RSHIFT_U64
(rshift) is designed to mean. Consider the core of the
BPF_CORE_READ_BITFIELD() algorithm:
val <<= __CORE_RELO(s, field, LSHIFT_U64);
val = val >> __CORE_RELO(s, field, RSHIFT_U64);
Basically what happens is we lshift to clear the non-relevant (blank)
higher order bits. Then we rshift to bring the relevant bits (bitfield)
down to LSB position (while also clearing blank lower order bits). To
illustrate:
Start: ........XXX......
Lshift: XXX......00000000
Rshift: 00000000000000XXX
where `.` means blank bit, `0` means 0 bit, and `X` means bitfield bit.
After the two operations, the bitfield is ready to be interpreted as a
regular integer.
Next, we want to build an alternative (but more helpful) mental model
on lshift and rshift. That is, to consider:
* rshift as the total number of blank bits in the u64
* lshift as number of blank bits left of the bitfield in the u64
Take a moment to consider why that is true by consulting the above
diagram.
With this insight, we can now define the following relationship:
bitfield
_
| |
0.....00XXX0...00
| | | |
|______| | |
lshift | |
|____|
(rshift - lshift)
That is, we know the number of higher order blank bits is just lshift.
And the number of lower order blank bits is (rshift - lshift).
Finally, we can examine the core of the write side algorithm:
mask = (~0ULL << rshift) >> lshift; // 1
val = (val & ~mask) | ((nval << rpad) & mask); // 2
1. Compute a mask where the set bits are the bitfield bits. The first
left shift zeros out exactly the number of blank bits, leaving a
bitfield sized set of 1s. The subsequent right shift inserts the
correct amount of higher order blank bits.
2. On the left of the `|`, mask out the bitfield bits. This creates
0s where the new bitfield bits will go. On the right of the `|`,
bring nval into the correct bit position and mask out any bits
that fall outside of the bitfield. Finally, by bor'ing the two
halves, we get the final set of bits to write back.
[0]: https://reviews.llvm.org/D133361
Co-developed-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Co-developed-by: Jonathan Lemon <jlemon@aviatrix.com>
Signed-off-by: Jonathan Lemon <jlemon@aviatrix.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/4d3dd215a4fd57d980733886f9c11a45e1a9adf3.1702325874.git.dxu@dxuuu.xyz
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Before the change on `i686-linux` `systemd` build failed as:
$ bpftool gen object src/core/bpf/socket_bind/socket-bind.bpf.o src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o
Error: failed to link 'src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o': Invalid argument (22)
After the change it fails as:
$ bpftool gen object src/core/bpf/socket_bind/socket-bind.bpf.o src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o
libbpf: ELF section #9 has inconsistent alignment addr=8 != d=4 in src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o
Error: failed to link 'src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o': Invalid argument (22)
Now it's slightly easier to figure out what is wrong with an ELF file.
Signed-off-by: Sergei Trofimovich <slyich@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20231208215100.435876-1-slyich@gmail.com
In libbpf, when determining whether we need to load vmlinux btf, we're
currently (among other things) checking whether there is any struct_ops
program present in the object. This works for most realistic struct_ops
maps, as a struct_ops map is of course typically composed of one or more
struct_ops programs. However, that technically need not be the case. A
struct_ops interface could be defined which allows a map to be specified
which one or more non-prog fields, and which provides default behavior
if no struct_ops progs is actually provided otherwise. For sched_ext,
for example, you technically only need to specify the name of the
scheduler in the struct_ops map, with the core scheduler logic providing
default behavior if no prog is actually specified.
If we were to define and try to load such a struct_ops map, we would
crash in libbpf when initializing it as obj->btf_vmlinux will be NULL:
Reading symbols from minimal...
(gdb) r
Starting program: minimal_example
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
Program received signal SIGSEGV, Segmentation fault.
0x000055555558308c in btf__type_cnt (btf=0x0) at btf.c:612
612 return btf->start_id + btf->nr_types;
(gdb) bt
type_name=0x5555555d99e3 "sched_ext_ops", kind=4) at btf.c:914
kind=4) at btf.c:942
type=0x7fffffffe558, type_id=0x7fffffffe548, ...
data_member=0x7fffffffe568) at libbpf.c:948
kern_btf=0x0) at libbpf.c:1017
at libbpf.c:8059
So as to account for such bare-bones struct_ops maps, let's update
obj_needs_vmlinux_btf() to also iterate over an obj's maps and check
whether any of them are struct_ops maps.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20231208061704.400463-1-void@manifault.com
To stay consistent with the naming pattern used for similar cases in BPF
UAPI (__MAX_BPF_ATTACH_TYPE, etc), rename MAX_BPF_LINK_TYPE into
__MAX_BPF_LINK_TYPE.
Also similar to MAX_BPF_ATTACH_TYPE and MAX_BPF_REG, add:
#define MAX_BPF_LINK_TYPE __MAX_BPF_LINK_TYPE
Not all __MAX_xxx enums have such #define, so I'm not sure if we should
add it or not, but I figured I'll start with a completely backwards
compatible way, and we can drop that, if necessary.
Also adjust a selftest that used MAX_BPF_LINK_TYPE enum.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231206190920.1651226-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow user to specify token_fd for bpf_btf_load() API that wraps
kernel's BPF_BTF_LOAD command. This allows loading BTF from unprivileged
process as long as it has BPF token allowing BPF_BTF_LOAD command, which
can be created and delegated by privileged process.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-15-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add basic support of BPF token to BPF_PROG_LOAD. Wire through a set of
allowed BPF program types and attach types, derived from BPF FS at BPF
token creation time. Then make sure we perform bpf_token_capable()
checks everywhere where it's relevant.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Accept BPF token FD in BPF_BTF_LOAD command to allow BTF data loading
through delegated BPF token. BTF loading is a pretty straightforward
operation, so as long as BPF token is created with allow_cmds granting
BPF_BTF_LOAD command, kernel proceeds to parsing BTF data and creating
BTF object.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Allow providing token_fd for BPF_MAP_CREATE command to allow controlled
BPF map creation from unprivileged process through delegated BPF token.
Wire through a set of allowed BPF map types to BPF token, derived from
BPF FS at BPF token creation time. This, in combination with allowed_cmds
allows to create a narrowly-focused BPF token (controlled by privileged
agent) with a restrictive set of BPF maps that application can attempt
to create.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add new kind of BPF kernel object, BPF token. BPF token is meant to
allow delegating privileged BPF functionality, like loading a BPF
program or creating a BPF map, from privileged process to a *trusted*
unprivileged process, all while having a good amount of control over which
privileged operations could be performed using provided BPF token.
This is achieved through mounting BPF FS instance with extra delegation
mount options, which determine what operations are delegatable, and also
constraining it to the owning user namespace (as mentioned in the
previous patch).
BPF token itself is just a derivative from BPF FS and can be created
through a new bpf() syscall command, BPF_TOKEN_CREATE, which accepts BPF
FS FD, which can be attained through open() API by opening BPF FS mount
point. Currently, BPF token "inherits" delegated command, map types,
prog type, and attach type bit sets from BPF FS as is. In the future,
having an BPF token as a separate object with its own FD, we can allow
to further restrict BPF token's allowable set of things either at the
creation time or after the fact, allowing the process to guard itself
further from unintentionally trying to load undesired kind of BPF
programs. But for now we keep things simple and just copy bit sets as is.
When BPF token is created from BPF FS mount, we take reference to the
BPF super block's owning user namespace, and then use that namespace for
checking all the {CAP_BPF, CAP_PERFMON, CAP_NET_ADMIN, CAP_SYS_ADMIN}
capabilities that are normally only checked against init userns (using
capable()), but now we check them using ns_capable() instead (if BPF
token is provided). See bpf_token_capable() for details.
Such setup means that BPF token in itself is not sufficient to grant BPF
functionality. User namespaced process has to *also* have necessary
combination of capabilities inside that user namespace. So while
previously CAP_BPF was useless when granted within user namespace, now
it gains a meaning and allows container managers and sys admins to have
a flexible control over which processes can and need to use BPF
functionality within the user namespace (i.e., container in practice).
And BPF FS delegation mount options and derived BPF tokens serve as
a per-container "flag" to grant overall ability to use bpf() (plus further
restrict on which parts of bpf() syscalls are treated as namespaced).
Note also, BPF_TOKEN_CREATE command itself requires ns_capable(CAP_BPF)
within the BPF FS owning user namespace, rounding up the ns_capable()
story of BPF token.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This change actually defines the (initial) metadata layout
that should be used by AF_XDP userspace (xsk_tx_metadata).
The first field is flags which requests appropriate offloads,
followed by the offload-specific fields. The supported per-device
offloads are exported via netlink (new xsk-flags).
The offloads themselves are still implemented in a bit of a
framework-y fashion that's left from my initial kfunc attempt.
I'm introducing new xsk_tx_metadata_ops which drivers are
supposed to implement. The drivers are also supposed
to call xsk_tx_metadata_request/xsk_tx_metadata_complete in
the right places. Since xsk_tx_metadata_{request,_complete}
are static inline, we don't incur any extra overhead doing
indirect calls.
The benefit of this scheme is as follows:
- keeps all metadata layout parsing away from driver code
- makes it easy to grep and see which drivers implement what
- don't need any extra flags to maintain to keep track of what
offloads are implemented; if the callback is implemented - the offload
is supported (used by netlink reporting code)
Two offloads are defined right now:
1. XDP_TXMD_FLAGS_CHECKSUM: skb-style csum_start+csum_offset
2. XDP_TXMD_FLAGS_TIMESTAMP: writes TX timestamp back into metadata
area upon completion (tx_timestamp field)
XDP_TXMD_FLAGS_TIMESTAMP is also implemented for XDP_COPY mode: it writes
SW timestamp from the skb destructor (note I'm reusing hwtstamps to pass
metadata pointer).
The struct is forward-compatible and can be extended in the future
by appending more fields.
Reviewed-by: Song Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231127190319.1190813-3-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
For zerocopy mode, tx_desc->addr can point to an arbitrary offset
and carry some TX metadata in the headroom. For copy mode, there
is no way currently to populate skb metadata.
Introduce new tx_metadata_len umem config option that indicates how many
bytes to treat as metadata. Metadata bytes come prior to tx_desc address
(same as in RX case).
The size of the metadata has mostly the same constraints as XDP:
- less than 256 bytes
- 8-byte aligned (compared to 4-byte alignment on xdp, due to 8-byte
timestamp in the completion)
- non-zero
This data is not interpreted in any way right now.
Reviewed-by: Song Yoong Siang <yoong.siang.song@intel.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20231127190319.1190813-2-sdf@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adding support to get uprobe_link details through bpf_link_info
interface.
Adding new struct uprobe_multi to struct bpf_link_info to carry
the uprobe_multi link details.
The uprobe_multi.count is passed from user space to denote size
of array fields (offsets/ref_ctr_offsets/cookies). The actual
array size is stored back to uprobe_multi.count (allowing user
to find out the actual array size) and array fields are populated
up to the user passed size.
All the non-array fields (path/count/flags/pid) are always set.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20231125193130.834322-4-jolsa@kernel.org
The vmtest action is used by several workflows: test, pahole, ondemand.
At the same time, vmtest action requires valid access rights to /dev/kvm
and is the only action that uses it.
This commit moves /dev/kvm permissions setup from test workflow to
vmtest action, in order to make sure that setup logic is shared by all
workflows that run vmtest.
Should fix CI failures like [1].
[1] https://github.com/libbpf/libbpf/actions/runs/7104762048/job/19340484589
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Without needing to modify tons of BPF selftests file, make sure we don't
pass BPF_F_TEST_REG_INVARIANTS to kernel, to make BPF selftests work on
4.9 and 5.5 kernels.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
