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43366 commits

Author SHA1 Message Date
Song Liu
96d1b7c081 bpf: Add arch_bpf_trampoline_size()
This helper will be used to calculate the size of the trampoline before
allocating the memory.

arch_prepare_bpf_trampoline() for arm64 and riscv64 can use
arch_bpf_trampoline_size() to check the trampoline fits in the image.

OTOH, arch_prepare_bpf_trampoline() for s390 has to call the JIT process
twice, so it cannot use arch_bpf_trampoline_size().

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>  # on s390x
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com> # on riscv
Link: https://lore.kernel.org/r/20231206224054.492250-6-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 17:17:20 -08:00
Song Liu
82583daa2e bpf: Add helpers for trampoline image management
As BPF trampoline of different archs moves from bpf_jit_[alloc|free]_exec()
to bpf_prog_pack_[alloc|free](), we need to use different _alloc, _free for
different archs during the transition. Add the following helpers for this
transition:

void *arch_alloc_bpf_trampoline(unsigned int size);
void arch_free_bpf_trampoline(void *image, unsigned int size);
void arch_protect_bpf_trampoline(void *image, unsigned int size);
void arch_unprotect_bpf_trampoline(void *image, unsigned int size);

The fallback version of these helpers require size <= PAGE_SIZE, but they
are only called with size == PAGE_SIZE. They will be called with size <
PAGE_SIZE when arch_bpf_trampoline_size() helper is introduced later.

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>  # on s390x
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20231206224054.492250-4-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 17:17:20 -08:00
Song Liu
7a3d9a159b bpf: Adjust argument names of arch_prepare_bpf_trampoline()
We are using "im" for "struct bpf_tramp_image" and "tr" for "struct
bpf_trampoline" in most of the code base. The only exception is the
prototype and fallback version of arch_prepare_bpf_trampoline(). Update
them to match the rest of the code base.

We mix "orig_call" and "func_addr" for the argument in different versions
of arch_prepare_bpf_trampoline(). s/orig_call/func_addr/g so they match.

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>  # on s390x
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20231206224054.492250-3-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 17:17:20 -08:00
Song Liu
f08a1c6582 bpf: Let bpf_prog_pack_free handle any pointer
Currently, bpf_prog_pack_free only can only free pointer to struct
bpf_binary_header, which is not flexible. Add a size argument to
bpf_prog_pack_free so that it can handle any pointer.

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>  # on s390x
Reviewed-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20231206224054.492250-2-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 17:17:20 -08:00
Andrii Nakryiko
d734ca7b33 bpf,lsm: add BPF token LSM hooks
Wire up bpf_token_create and bpf_token_free LSM hooks, which allow to
allocate LSM security blob (we add `void *security` field to struct
bpf_token for that), but also control who can instantiate BPF token.
This follows existing pattern for BPF map and BPF prog.

Also add security_bpf_token_allow_cmd() and security_bpf_token_capable()
LSM hooks that allow LSM implementation to control and negate (if
necessary) BPF token's delegation of a specific bpf_cmd and capability,
respectively.

Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-12-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:03:00 -08:00
Andrii Nakryiko
66d636d70a bpf,lsm: refactor bpf_map_alloc/bpf_map_free LSM hooks
Similarly to bpf_prog_alloc LSM hook, rename and extend bpf_map_alloc
hook into bpf_map_create, taking not just struct bpf_map, but also
bpf_attr and bpf_token, to give a fuller context to LSMs.

Unlike bpf_prog_alloc, there is no need to move the hook around, as it
currently is firing right before allocating BPF map ID and FD, which
seems to be a sweet spot.

But like bpf_prog_alloc/bpf_prog_free combo, make sure that bpf_map_free
LSM hook is called even if bpf_map_create hook returned error, as if few
LSMs are combined together it could be that one LSM successfully
allocated security blob for its needs, while subsequent LSM rejected BPF
map creation. The former LSM would still need to free up LSM blob, so we
need to ensure security_bpf_map_free() is called regardless of the
outcome.

Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-11-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
c3dd6e94df bpf,lsm: refactor bpf_prog_alloc/bpf_prog_free LSM hooks
Based on upstream discussion ([0]), rework existing
bpf_prog_alloc_security LSM hook. Rename it to bpf_prog_load and instead
of passing bpf_prog_aux, pass proper bpf_prog pointer for a full BPF
program struct. Also, we pass bpf_attr union with all the user-provided
arguments for BPF_PROG_LOAD command.  This will give LSMs as much
information as we can basically provide.

The hook is also BPF token-aware now, and optional bpf_token struct is
passed as a third argument. bpf_prog_load LSM hook is called after
a bunch of sanity checks were performed, bpf_prog and bpf_prog_aux were
allocated and filled out, but right before performing full-fledged BPF
verification step.

bpf_prog_free LSM hook is now accepting struct bpf_prog argument, for
consistency. SELinux code is adjusted to all new names, types, and
signatures.

Note, given that bpf_prog_load (previously bpf_prog_alloc) hook can be
used by some LSMs to allocate extra security blob, but also by other
LSMs to reject BPF program loading, we need to make sure that
bpf_prog_free LSM hook is called after bpf_prog_load/bpf_prog_alloc one
*even* if the hook itself returned error. If we don't do that, we run
the risk of leaking memory. This seems to be possible today when
combining SELinux and BPF LSM, as one example, depending on their
relative ordering.

Also, for BPF LSM setup, add bpf_prog_load and bpf_prog_free to
sleepable LSM hooks list, as they are both executed in sleepable
context. Also drop bpf_prog_load hook from untrusted, as there is no
issue with refcount or anything else anymore, that originally forced us
to add it to untrusted list in c0c852dd18 ("bpf: Do not mark certain LSM
hook arguments as trusted"). We now trigger this hook much later and it
should not be an issue anymore.

  [0] https://lore.kernel.org/bpf/9fe88aef7deabbe87d3fc38c4aea3c69.paul@paul-moore.com/

Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
8062fb12de bpf: consistently use BPF token throughout BPF verifier logic
Remove remaining direct queries to perfmon_capable() and bpf_capable()
in BPF verifier logic and instead use BPF token (if available) to make
decisions about privileges.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
4cbb270e11 bpf: take into account BPF token when fetching helper protos
Instead of performing unconditional system-wide bpf_capable() and
perfmon_capable() calls inside bpf_base_func_proto() function (and other
similar ones) to determine eligibility of a given BPF helper for a given
program, use previously recorded BPF token during BPF_PROG_LOAD command
handling to inform the decision.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
e1cef620f5 bpf: add BPF token support to BPF_PROG_LOAD command
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>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
ee54b1a910 bpf: add BPF token support to BPF_BTF_LOAD command
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>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
688b7270b3 bpf: add BPF token support to BPF_MAP_CREATE command
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>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
4527358b76 bpf: introduce BPF token object
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>
2023-12-06 10:02:59 -08:00
Andrii Nakryiko
40bba140c6 bpf: add BPF token delegation mount options to BPF FS
Add few new mount options to BPF FS that allow to specify that a given
BPF FS instance allows creation of BPF token (added in the next patch),
and what sort of operations are allowed under BPF token. As such, we get
4 new mount options, each is a bit mask
  - `delegate_cmds` allow to specify which bpf() syscall commands are
    allowed with BPF token derived from this BPF FS instance;
  - if BPF_MAP_CREATE command is allowed, `delegate_maps` specifies
    a set of allowable BPF map types that could be created with BPF token;
  - if BPF_PROG_LOAD command is allowed, `delegate_progs` specifies
    a set of allowable BPF program types that could be loaded with BPF token;
  - if BPF_PROG_LOAD command is allowed, `delegate_attachs` specifies
    a set of allowable BPF program attach types that could be loaded with
    BPF token; delegate_progs and delegate_attachs are meant to be used
    together, as full BPF program type is, in general, determined
    through both program type and program attach type.

Currently, these mount options accept the following forms of values:
  - a special value "any", that enables all possible values of a given
  bit set;
  - numeric value (decimal or hexadecimal, determined by kernel
  automatically) that specifies a bit mask value directly;
  - all the values for a given mount option are combined, if specified
  multiple times. E.g., `mount -t bpf nodev /path/to/mount -o
  delegate_maps=0x1 -o delegate_maps=0x2` will result in a combined 0x3
  mask.

Ideally, more convenient (for humans) symbolic form derived from
corresponding UAPI enums would be accepted (e.g., `-o
delegate_progs=kprobe|tracepoint`) and I intend to implement this, but
it requires a bunch of UAPI header churn, so I postponed it until this
feature lands upstream or at least there is a definite consensus that
this feature is acceptable and is going to make it, just to minimize
amount of wasted effort and not increase amount of non-essential code to
be reviewed.

Attentive reader will notice that BPF FS is now marked as
FS_USERNS_MOUNT, which theoretically makes it mountable inside non-init
user namespace as long as the process has sufficient *namespaced*
capabilities within that user namespace. But in reality we still
restrict BPF FS to be mountable only by processes with CAP_SYS_ADMIN *in
init userns* (extra check in bpf_fill_super()). FS_USERNS_MOUNT is added
to allow creating BPF FS context object (i.e., fsopen("bpf")) from
inside unprivileged process inside non-init userns, to capture that
userns as the owning userns. It will still be required to pass this
context object back to privileged process to instantiate and mount it.

This manipulation is important, because capturing non-init userns as the
owning userns of BPF FS instance (super block) allows to use that userns
to constraint BPF token to that userns later on (see next patch). So
creating BPF FS with delegation inside unprivileged userns will restrict
derived BPF token objects to only "work" inside that intended userns,
making it scoped to a intended "container". Also, setting these
delegation options requires capable(CAP_SYS_ADMIN), so unprivileged
process cannot set this up without involvement of a privileged process.

There is a set of selftests at the end of the patch set that simulates
this sequence of steps and validates that everything works as intended.
But careful review is requested to make sure there are no missed gaps in
the implementation and testing.

This somewhat subtle set of aspects is the result of previous
discussions ([0]) about various user namespace implications and
interactions with BPF token functionality and is necessary to contain
BPF token inside intended user namespace.

  [0] https://lore.kernel.org/bpf/20230704-hochverdient-lehne-eeb9eeef785e@brauner/

Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:02:58 -08:00
Andrii Nakryiko
909fa05dd3 bpf: align CAP_NET_ADMIN checks with bpf_capable() approach
Within BPF syscall handling code CAP_NET_ADMIN checks stand out a bit
compared to CAP_BPF and CAP_PERFMON checks. For the latter, CAP_BPF or
CAP_PERFMON are checked first, but if they are not set, CAP_SYS_ADMIN
takes over and grants whatever part of BPF syscall is required.

Similar kind of checks that involve CAP_NET_ADMIN are not so consistent.
One out of four uses does follow CAP_BPF/CAP_PERFMON model: during
BPF_PROG_LOAD, if the type of BPF program is "network-related" either
CAP_NET_ADMIN or CAP_SYS_ADMIN is required to proceed.

But in three other cases CAP_NET_ADMIN is required even if CAP_SYS_ADMIN
is set:
  - when creating DEVMAP/XDKMAP/CPU_MAP maps;
  - when attaching CGROUP_SKB programs;
  - when handling BPF_PROG_QUERY command.

This patch is changing the latter three cases to follow BPF_PROG_LOAD
model, that is allowing to proceed under either CAP_NET_ADMIN or
CAP_SYS_ADMIN.

This also makes it cleaner in subsequent BPF token patches to switch
wholesomely to a generic bpf_token_capable(int cap) check, that always
falls back to CAP_SYS_ADMIN if requested capability is missing.

Cc: Jakub Kicinski <kuba@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:02:58 -08:00
Andrii Nakryiko
18a433b620 bpf: track aligned STACK_ZERO cases as imprecise spilled registers
Now that precision backtracing is supporting register spill/fill to/from
stack, there is another oportunity to be exploited here: minimizing
precise STACK_ZERO cases. With a simple code change we can rely on
initially imprecise register spill tracking for cases when register
spilled to stack was a known zero.

This is a very common case for initializing on the stack variables,
including rather large structures. Often times zero has no special
meaning for the subsequent BPF program logic and is often overwritten
with non-zero values soon afterwards. But due to STACK_ZERO vs
STACK_MISC tracking, such initial zero initialization actually causes
duplication of verifier states as STACK_ZERO is clearly different than
STACK_MISC or spilled SCALAR_VALUE register.

The effect of this (now) trivial change is huge, as can be seen below.
These are differences between BPF selftests, Cilium, and Meta-internal
BPF object files relative to previous patch in this series. You can see
improvements ranging from single-digit percentage improvement for
instructions and states, all the way to 50-60% reduction for some of
Meta-internal host agent programs, and even some Cilium programs.

For Meta-internal ones I left only the differences for largest BPF
object files by states/instructions, as there were too many differences
in the overall output. All the differences were improvements, reducting
number of states and thus instructions validated.

Note, Meta-internal BPF object file names are not printed below.
Many copies of balancer_ingress are actually many different
configurations of Katran, so they are different BPF programs, which
explains state reduction going from -16% all the way to 31%, depending
on BPF program logic complexity.

I also tooked a closer look at a few small-ish BPF programs to validate
the behavior. Let's take bpf_iter_netrlink.bpf.o (first row below).
While it's just 8 vs 5 states, verifier log is still pretty long to
include it here. But the reduction in states is due to the following
piece of C code:

        unsigned long ino;

	...

        sk = s->sk_socket;
        if (!sk) {
                ino = 0;
        } else {
                inode = SOCK_INODE(sk);
                bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
        }
        BPF_SEQ_PRINTF(seq, "%-8u %-8lu\n", s->sk_drops.counter, ino);
	return 0;

You can see that in some situations `ino` is zero-initialized, while in
others it's unknown value filled out by bpf_probe_read_kernel(). Before
this change code after if/else branches have to be validated twice. Once
with (precise) ino == 0, due to eager STACK_ZERO logic, and then again
for when ino is just STACK_MISC. But BPF_SEQ_PRINTF() doesn't care about
precise value of ino, so with the change in this patch verifier is able
to prune states from after one of the branches, reducing number of total
states (and instructions) required for successful validation.

Similar principle applies to bigger real-world applications, just at
a much larger scale.

SELFTESTS
=========
File                                     Program                  Insns (A)  Insns (B)  Insns    (DIFF)  States (A)  States (B)  States (DIFF)
---------------------------------------  -----------------------  ---------  ---------  ---------------  ----------  ----------  -------------
bpf_iter_netlink.bpf.linked3.o           dump_netlink                   148        104    -44 (-29.73%)           8           5   -3 (-37.50%)
bpf_iter_unix.bpf.linked3.o              dump_unix                     8474       8404     -70 (-0.83%)         151         147    -4 (-2.65%)
bpf_loop.bpf.linked3.o                   stack_check                    560        324   -236 (-42.14%)          42          24  -18 (-42.86%)
local_storage_bench.bpf.linked3.o        get_local                      120         77    -43 (-35.83%)           9           6   -3 (-33.33%)
loop6.bpf.linked3.o                      trace_virtqueue_add_sgs      10167       9868    -299 (-2.94%)         226         206   -20 (-8.85%)
pyperf600_bpf_loop.bpf.linked3.o         on_event                      4872       3423  -1449 (-29.74%)         322         229  -93 (-28.88%)
strobemeta.bpf.linked3.o                 on_event                    180697     176036   -4661 (-2.58%)        4780        4734   -46 (-0.96%)
test_cls_redirect.bpf.linked3.o          cls_redirect                 65594      65401    -193 (-0.29%)        4230        4212   -18 (-0.43%)
test_global_func_args.bpf.linked3.o      test_cls                       145        136      -9 (-6.21%)          10           9   -1 (-10.00%)
test_l4lb.bpf.linked3.o                  balancer_ingress              4760       2612  -2148 (-45.13%)         113         102   -11 (-9.73%)
test_l4lb_noinline.bpf.linked3.o         balancer_ingress              4845       4877     +32 (+0.66%)         219         221    +2 (+0.91%)
test_l4lb_noinline_dynptr.bpf.linked3.o  balancer_ingress              2072       2087     +15 (+0.72%)          97          98    +1 (+1.03%)
test_seg6_loop.bpf.linked3.o             __add_egr_x                  12440       9975  -2465 (-19.82%)         364         353   -11 (-3.02%)
test_tcp_hdr_options.bpf.linked3.o       estab                         2558       2572     +14 (+0.55%)         179         180    +1 (+0.56%)
test_xdp_dynptr.bpf.linked3.o            _xdp_tx_iptunnel               645        596     -49 (-7.60%)          26          24    -2 (-7.69%)
test_xdp_noinline.bpf.linked3.o          balancer_ingress_v6           3520       3516      -4 (-0.11%)         216         216    +0 (+0.00%)
xdp_synproxy_kern.bpf.linked3.o          syncookie_tc                 82661      81241   -1420 (-1.72%)        5073        5155   +82 (+1.62%)
xdp_synproxy_kern.bpf.linked3.o          syncookie_xdp                84964      82297   -2667 (-3.14%)        5130        5157   +27 (+0.53%)

META-INTERNAL
=============
Program                                 Insns (A)  Insns (B)  Insns      (DIFF)  States (A)  States (B)  States   (DIFF)
--------------------------------------  ---------  ---------  -----------------  ----------  ----------  ---------------
balancer_ingress                            27925      23608    -4317 (-15.46%)        1488        1482      -6 (-0.40%)
balancer_ingress                            31824      27546    -4278 (-13.44%)        1658        1652      -6 (-0.36%)
balancer_ingress                            32213      27935    -4278 (-13.28%)        1689        1683      -6 (-0.36%)
balancer_ingress                            32213      27935    -4278 (-13.28%)        1689        1683      -6 (-0.36%)
balancer_ingress                            31824      27546    -4278 (-13.44%)        1658        1652      -6 (-0.36%)
balancer_ingress                            38647      29562    -9085 (-23.51%)        2069        1835   -234 (-11.31%)
balancer_ingress                            38647      29562    -9085 (-23.51%)        2069        1835   -234 (-11.31%)
balancer_ingress                            40339      30792    -9547 (-23.67%)        2193        1934   -259 (-11.81%)
balancer_ingress                            37321      29055    -8266 (-22.15%)        1972        1795    -177 (-8.98%)
balancer_ingress                            38176      29753    -8423 (-22.06%)        2008        1831    -177 (-8.81%)
balancer_ingress                            29193      20910    -8283 (-28.37%)        1599        1422   -177 (-11.07%)
balancer_ingress                            30013      21452    -8561 (-28.52%)        1645        1447   -198 (-12.04%)
balancer_ingress                            28691      24290    -4401 (-15.34%)        1545        1531     -14 (-0.91%)
balancer_ingress                            34223      28965    -5258 (-15.36%)        1984        1875    -109 (-5.49%)
balancer_ingress                            35481      26158    -9323 (-26.28%)        2095        1806   -289 (-13.79%)
balancer_ingress                            35481      26158    -9323 (-26.28%)        2095        1806   -289 (-13.79%)
balancer_ingress                            35868      26455    -9413 (-26.24%)        2140        1827   -313 (-14.63%)
balancer_ingress                            35868      26455    -9413 (-26.24%)        2140        1827   -313 (-14.63%)
balancer_ingress                            35481      26158    -9323 (-26.28%)        2095        1806   -289 (-13.79%)
balancer_ingress                            35481      26158    -9323 (-26.28%)        2095        1806   -289 (-13.79%)
balancer_ingress                            34844      29485    -5359 (-15.38%)        2036        1918    -118 (-5.80%)
fbflow_egress                                3256       2652     -604 (-18.55%)         218         192    -26 (-11.93%)
fbflow_ingress                               1026        944       -82 (-7.99%)          70          63     -7 (-10.00%)
sslwall_tc_egress                            8424       7360    -1064 (-12.63%)         498         458     -40 (-8.03%)
syar_accept_protect                         15040       9539    -5501 (-36.58%)         364         220   -144 (-39.56%)
syar_connect_tcp_v6                         15036       9535    -5501 (-36.59%)         360         216   -144 (-40.00%)
syar_connect_udp_v4                         15039       9538    -5501 (-36.58%)         361         217   -144 (-39.89%)
syar_connect_connect4_protect4              24805      15833    -8972 (-36.17%)         756         480   -276 (-36.51%)
syar_lsm_file_open                         167772     151813    -15959 (-9.51%)        1836        1667    -169 (-9.20%)
syar_namespace_create_new                   14805       9304    -5501 (-37.16%)         353         209   -144 (-40.79%)
syar_python3_detect                         17531      12030    -5501 (-31.38%)         391         247   -144 (-36.83%)
syar_ssh_post_fork                          16412      10911    -5501 (-33.52%)         405         261   -144 (-35.56%)
syar_enter_execve                           14728       9227    -5501 (-37.35%)         345         201   -144 (-41.74%)
syar_enter_execveat                         14728       9227    -5501 (-37.35%)         345         201   -144 (-41.74%)
syar_exit_execve                            16622      11121    -5501 (-33.09%)         376         232   -144 (-38.30%)
syar_exit_execveat                          16622      11121    -5501 (-33.09%)         376         232   -144 (-38.30%)
syar_syscalls_kill                          15288       9787    -5501 (-35.98%)         398         254   -144 (-36.18%)
syar_task_enter_pivot_root                  14898       9397    -5501 (-36.92%)         357         213   -144 (-40.34%)
syar_syscalls_setreuid                      16678      11177    -5501 (-32.98%)         429         285   -144 (-33.57%)
syar_syscalls_setuid                        16678      11177    -5501 (-32.98%)         429         285   -144 (-33.57%)
syar_syscalls_process_vm_readv              14959       9458    -5501 (-36.77%)         364         220   -144 (-39.56%)
syar_syscalls_process_vm_writev             15757      10256    -5501 (-34.91%)         390         246   -144 (-36.92%)
do_uprobe                                   15519      10018    -5501 (-35.45%)         373         229   -144 (-38.61%)
edgewall                                   179715      55783  -123932 (-68.96%)       12607        3999  -8608 (-68.28%)
bictcp_state                                 7570       4131    -3439 (-45.43%)         496         269   -227 (-45.77%)
cubictcp_state                               7570       4131    -3439 (-45.43%)         496         269   -227 (-45.77%)
tcp_rate_skb_delivered                        447        272     -175 (-39.15%)          29          18    -11 (-37.93%)
kprobe__bbr_set_state                        4566       2615    -1951 (-42.73%)         209         124    -85 (-40.67%)
kprobe__bictcp_state                         4566       2615    -1951 (-42.73%)         209         124    -85 (-40.67%)
inet_sock_set_state                          1501       1337     -164 (-10.93%)          93          85      -8 (-8.60%)
tcp_retransmit_skb                           1145        981     -164 (-14.32%)          67          59     -8 (-11.94%)
tcp_retransmit_synack                        1183        951     -232 (-19.61%)          67          55    -12 (-17.91%)
bpf_tcptuner                                 1459       1187     -272 (-18.64%)          99          80    -19 (-19.19%)
tw_egress                                     801        776       -25 (-3.12%)          69          66      -3 (-4.35%)
tw_ingress                                    795        770       -25 (-3.14%)          69          66      -3 (-4.35%)
ttls_tc_ingress                             19025      19383      +358 (+1.88%)         470         465      -5 (-1.06%)
ttls_nat_egress                               490        299     -191 (-38.98%)          33          20    -13 (-39.39%)
ttls_nat_ingress                              448        285     -163 (-36.38%)          32          21    -11 (-34.38%)
tw_twfw_egress                             511127     212071  -299056 (-58.51%)       16733        8504  -8229 (-49.18%)
tw_twfw_ingress                            500095     212069  -288026 (-57.59%)       16223        8504  -7719 (-47.58%)
tw_twfw_tc_eg                              511113     212064  -299049 (-58.51%)       16732        8504  -8228 (-49.18%)
tw_twfw_tc_in                              500095     212069  -288026 (-57.59%)       16223        8504  -7719 (-47.58%)
tw_twfw_egress                              12632      12435      -197 (-1.56%)         276         260     -16 (-5.80%)
tw_twfw_ingress                             12631      12454      -177 (-1.40%)         278         261     -17 (-6.12%)
tw_twfw_tc_eg                               12595      12435      -160 (-1.27%)         274         259     -15 (-5.47%)
tw_twfw_tc_in                               12631      12454      -177 (-1.40%)         278         261     -17 (-6.12%)
tw_xdp_dump                                   266        209      -57 (-21.43%)           9           8     -1 (-11.11%)

CILIUM
=========
File           Program                           Insns (A)  Insns (B)  Insns     (DIFF)  States (A)  States (B)  States  (DIFF)
-------------  --------------------------------  ---------  ---------  ----------------  ----------  ----------  --------------
bpf_host.o     cil_to_netdev                          6047       4578   -1469 (-24.29%)         362         249  -113 (-31.22%)
bpf_host.o     handle_lxc_traffic                     2227       1585    -642 (-28.83%)         156         103   -53 (-33.97%)
bpf_host.o     tail_handle_ipv4_from_netdev           2244       1458    -786 (-35.03%)         163         106   -57 (-34.97%)
bpf_host.o     tail_handle_nat_fwd_ipv4              21022      10479  -10543 (-50.15%)        1289         670  -619 (-48.02%)
bpf_host.o     tail_handle_nat_fwd_ipv6              15433      11375   -4058 (-26.29%)         905         643  -262 (-28.95%)
bpf_host.o     tail_ipv4_host_policy_ingress          2219       1367    -852 (-38.40%)         161          96   -65 (-40.37%)
bpf_host.o     tail_nodeport_nat_egress_ipv4         22460      19862   -2598 (-11.57%)        1469        1293  -176 (-11.98%)
bpf_host.o     tail_nodeport_nat_ingress_ipv4         5526       3534   -1992 (-36.05%)         366         243  -123 (-33.61%)
bpf_host.o     tail_nodeport_nat_ingress_ipv6         5132       4256    -876 (-17.07%)         241         219    -22 (-9.13%)
bpf_host.o     tail_nodeport_nat_ipv6_egress          3702       3542     -160 (-4.32%)         215         205    -10 (-4.65%)
bpf_lxc.o      tail_handle_nat_fwd_ipv4              21022      10479  -10543 (-50.15%)        1289         670  -619 (-48.02%)
bpf_lxc.o      tail_handle_nat_fwd_ipv6              15433      11375   -4058 (-26.29%)         905         643  -262 (-28.95%)
bpf_lxc.o      tail_ipv4_ct_egress                    5073       3374   -1699 (-33.49%)         262         172   -90 (-34.35%)
bpf_lxc.o      tail_ipv4_ct_ingress                   5093       3385   -1708 (-33.54%)         262         172   -90 (-34.35%)
bpf_lxc.o      tail_ipv4_ct_ingress_policy_only       5093       3385   -1708 (-33.54%)         262         172   -90 (-34.35%)
bpf_lxc.o      tail_ipv6_ct_egress                    4593       3878    -715 (-15.57%)         194         151   -43 (-22.16%)
bpf_lxc.o      tail_ipv6_ct_ingress                   4606       3891    -715 (-15.52%)         194         151   -43 (-22.16%)
bpf_lxc.o      tail_ipv6_ct_ingress_policy_only       4606       3891    -715 (-15.52%)         194         151   -43 (-22.16%)
bpf_lxc.o      tail_nodeport_nat_ingress_ipv4         5526       3534   -1992 (-36.05%)         366         243  -123 (-33.61%)
bpf_lxc.o      tail_nodeport_nat_ingress_ipv6         5132       4256    -876 (-17.07%)         241         219    -22 (-9.13%)
bpf_overlay.o  tail_handle_nat_fwd_ipv4              20524      10114  -10410 (-50.72%)        1271         638  -633 (-49.80%)
bpf_overlay.o  tail_nodeport_nat_egress_ipv4         22718      19490   -3228 (-14.21%)        1475        1275  -200 (-13.56%)
bpf_overlay.o  tail_nodeport_nat_ingress_ipv4         5526       3534   -1992 (-36.05%)         366         243  -123 (-33.61%)
bpf_overlay.o  tail_nodeport_nat_ingress_ipv6         5132       4256    -876 (-17.07%)         241         219    -22 (-9.13%)
bpf_overlay.o  tail_nodeport_nat_ipv6_egress          3638       3548      -90 (-2.47%)         209         203     -6 (-2.87%)
bpf_overlay.o  tail_rev_nodeport_lb4                  4368       3820    -548 (-12.55%)         248         215   -33 (-13.31%)
bpf_overlay.o  tail_rev_nodeport_lb6                  2867       2428    -439 (-15.31%)         167         140   -27 (-16.17%)
bpf_sock.o     cil_sock6_connect                      1718       1703      -15 (-0.87%)         100          99     -1 (-1.00%)
bpf_xdp.o      tail_handle_nat_fwd_ipv4              12917      12443     -474 (-3.67%)         875         849    -26 (-2.97%)
bpf_xdp.o      tail_handle_nat_fwd_ipv6              13515      13264     -251 (-1.86%)         715         702    -13 (-1.82%)
bpf_xdp.o      tail_lb_ipv4                          39492      36367    -3125 (-7.91%)        2430        2251   -179 (-7.37%)
bpf_xdp.o      tail_lb_ipv6                          80441      78058    -2383 (-2.96%)        3647        3523   -124 (-3.40%)
bpf_xdp.o      tail_nodeport_ipv6_dsr                 1038        901    -137 (-13.20%)          61          55     -6 (-9.84%)
bpf_xdp.o      tail_nodeport_nat_egress_ipv4         13027      12096     -931 (-7.15%)         868         809    -59 (-6.80%)
bpf_xdp.o      tail_nodeport_nat_ingress_ipv4         7617       5900   -1717 (-22.54%)         522         413  -109 (-20.88%)
bpf_xdp.o      tail_nodeport_nat_ingress_ipv6         7575       7395     -180 (-2.38%)         383         374     -9 (-2.35%)
bpf_xdp.o      tail_rev_nodeport_lb4                  6808       6739      -69 (-1.01%)         403         396     -7 (-1.74%)
bpf_xdp.o      tail_rev_nodeport_lb6                 16173      15847     -326 (-2.02%)        1010         990    -20 (-1.98%)

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231205184248.1502704-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-05 13:40:21 -08:00
Andrii Nakryiko
e322f0bcb8 bpf: preserve constant zero when doing partial register restore
Similar to special handling of STACK_ZERO, when reading 1/2/4 bytes from
stack from slot that has register spilled into it and that register has
a constant value zero, preserve that zero and mark spilled register as
precise for that. This makes spilled const zero register and STACK_ZERO
cases equivalent in their behavior.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231205184248.1502704-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-05 13:40:21 -08:00
Andrii Nakryiko
eaf18febd6 bpf: preserve STACK_ZERO slots on partial reg spills
Instead of always forcing STACK_ZERO slots to STACK_MISC, preserve it in
situations where this is possible. E.g., when spilling register as
1/2/4-byte subslots on the stack, all the remaining bytes in the stack
slot do not automatically become unknown. If we knew they contained
zeroes, we can preserve those STACK_ZERO markers.

Add a helper mark_stack_slot_misc(), similar to scrub_spilled_slot(),
but that doesn't overwrite either STACK_INVALID nor STACK_ZERO. Note
that we need to take into account possibility of being in unprivileged
mode, in which case STACK_INVALID is forced to STACK_MISC for correctness,
as treating STACK_INVALID as equivalent STACK_MISC is only enabled in
privileged mode.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231205184248.1502704-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-05 13:40:20 -08:00
Andrii Nakryiko
ab125ed3ec bpf: fix check for attempt to corrupt spilled pointer
When register is spilled onto a stack as a 1/2/4-byte register, we set
slot_type[BPF_REG_SIZE - 1] (plus potentially few more below it,
depending on actual spill size). So to check if some stack slot has
spilled register we need to consult slot_type[7], not slot_type[0].

To avoid the need to remember and double-check this in the future, just
use is_spilled_reg() helper.

Fixes: 27113c59b6 ("bpf: Check the other end of slot_type for STACK_SPILL")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231205184248.1502704-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-05 13:40:20 -08:00
Andrii Nakryiko
41f6f64e69 bpf: support non-r10 register spill/fill to/from stack in precision tracking
Use instruction (jump) history to record instructions that performed
register spill/fill to/from stack, regardless if this was done through
read-only r10 register, or any other register after copying r10 into it
*and* potentially adjusting offset.

To make this work reliably, we push extra per-instruction flags into
instruction history, encoding stack slot index (spi) and stack frame
number in extra 10 bit flags we take away from prev_idx in instruction
history. We don't touch idx field for maximum performance, as it's
checked most frequently during backtracking.

This change removes basically the last remaining practical limitation of
precision backtracking logic in BPF verifier. It fixes known
deficiencies, but also opens up new opportunities to reduce number of
verified states, explored in the subsequent patches.

There are only three differences in selftests' BPF object files
according to veristat, all in the positive direction (less states).

File                                    Program        Insns (A)  Insns (B)  Insns  (DIFF)  States (A)  States (B)  States (DIFF)
--------------------------------------  -------------  ---------  ---------  -------------  ----------  ----------  -------------
test_cls_redirect_dynptr.bpf.linked3.o  cls_redirect        2987       2864  -123 (-4.12%)         240         231    -9 (-3.75%)
xdp_synproxy_kern.bpf.linked3.o         syncookie_tc       82848      82661  -187 (-0.23%)        5107        5073   -34 (-0.67%)
xdp_synproxy_kern.bpf.linked3.o         syncookie_xdp      85116      84964  -152 (-0.18%)        5162        5130   -32 (-0.62%)

Note, I avoided renaming jmp_history to more generic insn_hist to
minimize number of lines changed and potential merge conflicts between
bpf and bpf-next trees.

Notice also cur_hist_entry pointer reset to NULL at the beginning of
instruction verification loop. This pointer avoids the problem of
relying on last jump history entry's insn_idx to determine whether we
already have entry for current instruction or not. It can happen that we
added jump history entry because current instruction is_jmp_point(), but
also we need to add instruction flags for stack access. In this case, we
don't want to entries, so we need to reuse last added entry, if it is
present.

Relying on insn_idx comparison has the same ambiguity problem as the one
that was fixed recently in [0], so we avoid that.

  [0] https://patchwork.kernel.org/project/netdevbpf/patch/20231110002638.4168352-3-andrii@kernel.org/

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reported-by: Tao Lyu <tao.lyu@epfl.ch>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231205184248.1502704-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-05 13:40:20 -08:00
Hou Tao
af66bfd3c8 bpf: Optimize the free of inner map
When removing the inner map from the outer map, the inner map will be
freed after one RCU grace period and one RCU tasks trace grace
period, so it is certain that the bpf program, which may access the
inner map, has exited before the inner map is freed.

However there is no need to wait for one RCU tasks trace grace period if
the outer map is only accessed by non-sleepable program. So adding
sleepable_refcnt in bpf_map and increasing sleepable_refcnt when adding
the outer map into env->used_maps for sleepable program. Although the
max number of bpf program is INT_MAX - 1, the number of bpf programs
which are being loaded may be greater than INT_MAX, so using atomic64_t
instead of atomic_t for sleepable_refcnt. When removing the inner map
from the outer map, using sleepable_refcnt to decide whether or not a
RCU tasks trace grace period is needed before freeing the inner map.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-04 17:50:26 -08:00
Hou Tao
8766733641 bpf: Defer the free of inner map when necessary
When updating or deleting an inner map in map array or map htab, the map
may still be accessed by non-sleepable program or sleepable program.
However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map
directly through bpf_map_put(), if the ref-counter is the last one
(which is true for most cases), the inner map will be freed by
ops->map_free() in a kworker. But for now, most .map_free() callbacks
don't use synchronize_rcu() or its variants to wait for the elapse of a
RCU grace period, so after the invocation of ops->map_free completes,
the bpf program which is accessing the inner map may incur
use-after-free problem.

Fix the free of inner map by invoking bpf_map_free_deferred() after both
one RCU grace period and one tasks trace RCU grace period if the inner
map has been removed from the outer map before. The deferment is
accomplished by using call_rcu() or call_rcu_tasks_trace() when
releasing the last ref-counter of bpf map. The newly-added rcu_head
field in bpf_map shares the same storage space with work field to
reduce the size of bpf_map.

Fixes: bba1dc0b55 ("bpf: Remove redundant synchronize_rcu.")
Fixes: 638e4b825d ("bpf: Allows per-cpu maps and map-in-map in sleepable programs")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-04 17:50:26 -08:00
Hou Tao
79d93b3c6f bpf: Set need_defer as false when clearing fd array during map free
Both map deletion operation, map release and map free operation use
fd_array_map_delete_elem() to remove the element from fd array and
need_defer is always true in fd_array_map_delete_elem(). For the map
deletion operation and map release operation, need_defer=true is
necessary, because the bpf program, which accesses the element in fd
array, may still alive. However for map free operation, it is certain
that the bpf program which owns the fd array has already been exited, so
setting need_defer as false is appropriate for map free operation.

So fix it by adding need_defer parameter to bpf_fd_array_map_clear() and
adding a new helper __fd_array_map_delete_elem() to handle the map
deletion, map release and map free operations correspondingly.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-04 17:50:26 -08:00
Hou Tao
20c20bd11a bpf: Add map and need_defer parameters to .map_fd_put_ptr()
map is the pointer of outer map, and need_defer needs some explanation.
need_defer tells the implementation to defer the reference release of
the passed element and ensure that the element is still alive before
the bpf program, which may manipulate it, exits.

The following three cases will invoke map_fd_put_ptr() and different
need_defer values will be passed to these callers:

1) release the reference of the old element in the map during map update
   or map deletion. The release must be deferred, otherwise the bpf
   program may incur use-after-free problem, so need_defer needs to be
   true.
2) release the reference of the to-be-added element in the error path of
   map update. The to-be-added element is not visible to any bpf
   program, so it is OK to pass false for need_defer parameter.
3) release the references of all elements in the map during map release.
   Any bpf program which has access to the map must have been exited and
   released, so need_defer=false will be OK.

These two parameters will be used by the following patches to fix the
potential use-after-free problem for map-in-map.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-04 17:50:26 -08:00
Hou Tao
169410eba2 bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers
These three bpf_map_{lookup,update,delete}_elem() helpers are also
available for sleepable bpf program, so add the corresponding lock
assertion for sleepable bpf program, otherwise the following warning
will be reported when a sleepable bpf program manipulates bpf map under
interpreter mode (aka bpf_jit_enable=0):

  WARNING: CPU: 3 PID: 4985 at kernel/bpf/helpers.c:40 ......
  CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ......
  RIP: 0010:bpf_map_lookup_elem+0x54/0x60
  ......
  Call Trace:
   <TASK>
   ? __warn+0xa5/0x240
   ? bpf_map_lookup_elem+0x54/0x60
   ? report_bug+0x1ba/0x1f0
   ? handle_bug+0x40/0x80
   ? exc_invalid_op+0x18/0x50
   ? asm_exc_invalid_op+0x1b/0x20
   ? __pfx_bpf_map_lookup_elem+0x10/0x10
   ? rcu_lockdep_current_cpu_online+0x65/0xb0
   ? rcu_is_watching+0x23/0x50
   ? bpf_map_lookup_elem+0x54/0x60
   ? __pfx_bpf_map_lookup_elem+0x10/0x10
   ___bpf_prog_run+0x513/0x3b70
   __bpf_prog_run32+0x9d/0xd0
   ? __bpf_prog_enter_sleepable_recur+0xad/0x120
   ? __bpf_prog_enter_sleepable_recur+0x3e/0x120
   bpf_trampoline_6442580665+0x4d/0x1000
   __x64_sys_getpgid+0x5/0x30
   ? do_syscall_64+0x36/0xb0
   entry_SYSCALL_64_after_hwframe+0x6e/0x76
   </TASK>

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-04 17:50:26 -08:00
Andrei Matei
5bd90cdc65 bpf: Minor logging improvement
One place where we were logging a register was only logging the variable
part, not also the fixed part.

Signed-off-by: Andrei Matei <andreimatei1@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231204011248.2040084-1-andreimatei1@gmail.com
2023-12-04 15:57:27 +01:00
Andrii Nakryiko
81eff2e364 bpf: simplify tnum output if a fully known constant
Emit tnum representation as just a constant if all bits are known.
Use decimal-vs-hex logic to determine exact format of emitted
constant value, just like it's done for register range values.
For that move tnum_strn() to kernel/bpf/log.c to reuse decimal-vs-hex
determination logic and constants.

Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-12-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02 11:36:51 -08:00
Andrii Nakryiko
eabe518de5 bpf: enforce precision of R0 on program/async callback return
Given we enforce a valid range for program and async callback return
value, we must mark R0 as precise to avoid incorrect state pruning.

Fixes: b5dc0163d8 ("bpf: precise scalar_value tracking")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02 11:36:51 -08:00
Andrii Nakryiko
0ef24c8dfa bpf: unify async callback and program retval checks
Use common logic to verify program return values and async callback
return values. This allows to avoid duplication of any extra steps
necessary, like precision marking, which will be added in the next
patch.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02 11:36:50 -08:00
Andrii Nakryiko
c871d0e00f bpf: enforce precise retval range on program exit
Similarly to subprog/callback logic, enforce return value of BPF program
using more precise smin/smax range.

We need to adjust a bunch of tests due to a changed format of an error
message.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02 11:36:50 -08:00
Andrii Nakryiko
8fa4ecd49b bpf: enforce exact retval range on subprog/callback exit
Instead of relying on potentially imprecise tnum representation of
expected return value range for callbacks and subprogs, validate that
smin/smax range satisfy exact expected range of return values.

E.g., if callback would need to return [0, 2] range, tnum can't
represent this precisely and instead will allow [0, 3] range. By
checking smin/smax range, we can make sure that subprog/callback indeed
returns only valid [0, 2] range.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02 11:36:50 -08:00
Andrii Nakryiko
0acd03a5bd bpf: enforce precision of R0 on callback return
Given verifier checks actual value, r0 has to be precise, so we need to
propagate precision properly. r0 also has to be marked as read,
otherwise subsequent state comparisons will ignore such register as
unimportant and precision won't really help here.

Fixes: 69c087ba62 ("bpf: Add bpf_for_each_map_elem() helper")
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02 11:36:50 -08:00
Andrii Nakryiko
5fad52bee3 bpf: provide correct register name for exception callback retval check
bpf_throw() is checking R1, so let's report R1 in the log.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-02 11:36:50 -08:00
Song Liu
ac9c05e0e4 bpf: Add kfunc bpf_get_file_xattr
It is common practice for security solutions to store tags/labels in
xattrs. To implement similar functionalities in BPF LSM, add new kfunc
bpf_get_file_xattr().

The first use case of bpf_get_file_xattr() is to implement file
verifications with asymmetric keys. Specificially, security applications
could use fsverity for file hashes and use xattr to store file signatures.
(kfunc for fsverity hash will be added in a separate commit.)

Currently, only xattrs with "user." prefix can be read with kfunc
bpf_get_file_xattr(). As use cases evolve, we may add a dedicated prefix
for bpf_get_file_xattr().

To avoid recursion, bpf_get_file_xattr can be only called from LSM hooks.

Signed-off-by: Song Liu <song@kernel.org>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: KP Singh <kpsingh@kernel.org>
Link: https://lore.kernel.org/r/20231129234417.856536-2-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-01 16:21:03 -08:00
Jakub Kicinski
753c8608f3 bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-11-30

We've added 30 non-merge commits during the last 7 day(s) which contain
a total of 58 files changed, 1598 insertions(+), 154 deletions(-).

The main changes are:

1) Add initial TX metadata implementation for AF_XDP with support in mlx5
   and stmmac drivers. Two types of offloads are supported right now, that
   is, TX timestamp and TX checksum offload, from Stanislav Fomichev with
   stmmac implementation from Song Yoong Siang.

2) Change BPF verifier logic to validate global subprograms lazily instead
   of unconditionally before the main program, so they can be guarded using
   BPF CO-RE techniques, from Andrii Nakryiko.

3) Add BPF link_info support for uprobe multi link along with bpftool
   integration for the latter, from Jiri Olsa.

4) Use pkg-config in BPF selftests to determine ld flags which is
   in particular needed for linking statically, from Akihiko Odaki.

5) Fix a few BPF selftest failures to adapt to the upcoming LLVM18,
   from Yonghong Song.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (30 commits)
  bpf/tests: Remove duplicate JSGT tests
  selftests/bpf: Add TX side to xdp_hw_metadata
  selftests/bpf: Convert xdp_hw_metadata to XDP_USE_NEED_WAKEUP
  selftests/bpf: Add TX side to xdp_metadata
  selftests/bpf: Add csum helpers
  selftests/xsk: Support tx_metadata_len
  xsk: Add option to calculate TX checksum in SW
  xsk: Validate xsk_tx_metadata flags
  xsk: Document tx_metadata_len layout
  net: stmmac: Add Tx HWTS support to XDP ZC
  net/mlx5e: Implement AF_XDP TX timestamp and checksum offload
  tools: ynl: Print xsk-features from the sample
  xsk: Add TX timestamp and TX checksum offload support
  xsk: Support tx_metadata_len
  selftests/bpf: Use pkg-config for libelf
  selftests/bpf: Override PKG_CONFIG for static builds
  selftests/bpf: Choose pkg-config for the target
  bpftool: Add support to display uprobe_multi links
  selftests/bpf: Add link_info test for uprobe_multi link
  selftests/bpf: Use bpf_link__destroy in fill_link_info tests
  ...
====================

Conflicts:

Documentation/netlink/specs/netdev.yaml:
  839ff60df3 ("net: page_pool: add nlspec for basic access to page pools")
  48eb03dd26 ("xsk: Add TX timestamp and TX checksum offload support")
https://lore.kernel.org/all/20231201094705.1ee3cab8@canb.auug.org.au/

While at it also regen, tree is dirty after:
  48eb03dd26 ("xsk: Add TX timestamp and TX checksum offload support")
looks like code wasn't re-rendered after "render-max" was removed.

Link: https://lore.kernel.org/r/20231130145708.32573-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-30 16:58:42 -08:00
Jakub Kicinski
975f2d73a9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-30 16:11:19 -08:00
Linus Torvalds
6172a5180f Including fixes from bpf and wifi.
Current release - regressions:
 
   - neighbour: fix __randomize_layout crash in struct neighbour
 
   - r8169: fix deadlock on RTL8125 in jumbo mtu mode
 
 Previous releases - regressions:
 
   - wifi:
     - mac80211: fix warning at station removal time
     - cfg80211: fix CQM for non-range use
 
   - tools: ynl-gen: fix unexpected response handling
 
   - octeontx2-af: fix possible buffer overflow
 
   - dpaa2: recycle the RX buffer only after all processing done
 
   - rswitch: fix missing dev_kfree_skb_any() in error path
 
 Previous releases - always broken:
 
   - ipv4: fix uaf issue when receiving igmp query packet
 
   - wifi: mac80211: fix debugfs deadlock at device removal time
 
   - bpf:
     - sockmap: af_unix stream sockets need to hold ref for pair sock
     - netdevsim: don't accept device bound programs
 
   - selftests: fix a char signedness issue
 
   - dsa: mv88e6xxx: fix marvell 6350 probe crash
 
   - octeontx2-pf: restore TC ingress police rules when interface is up
 
   - wangxun: fix memory leak on msix entry
 
   - ravb: keep reverse order of operations in ravb_remove()
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf and wifi.

  Current release - regressions:

   - neighbour: fix __randomize_layout crash in struct neighbour

   - r8169: fix deadlock on RTL8125 in jumbo mtu mode

  Previous releases - regressions:

   - wifi:
       - mac80211: fix warning at station removal time
       - cfg80211: fix CQM for non-range use

   - tools: ynl-gen: fix unexpected response handling

   - octeontx2-af: fix possible buffer overflow

   - dpaa2: recycle the RX buffer only after all processing done

   - rswitch: fix missing dev_kfree_skb_any() in error path

  Previous releases - always broken:

   - ipv4: fix uaf issue when receiving igmp query packet

   - wifi: mac80211: fix debugfs deadlock at device removal time

   - bpf:
       - sockmap: af_unix stream sockets need to hold ref for pair sock
       - netdevsim: don't accept device bound programs

   - selftests: fix a char signedness issue

   - dsa: mv88e6xxx: fix marvell 6350 probe crash

   - octeontx2-pf: restore TC ingress police rules when interface is up

   - wangxun: fix memory leak on msix entry

   - ravb: keep reverse order of operations in ravb_remove()"

* tag 'net-6.7-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (51 commits)
  net: ravb: Keep reverse order of operations in ravb_remove()
  net: ravb: Stop DMA in case of failures on ravb_open()
  net: ravb: Start TX queues after HW initialization succeeded
  net: ravb: Make write access to CXR35 first before accessing other EMAC registers
  net: ravb: Use pm_runtime_resume_and_get()
  net: ravb: Check return value of reset_control_deassert()
  net: libwx: fix memory leak on msix entry
  ice: Fix VF Reset paths when interface in a failed over aggregate
  bpf, sockmap: Add af_unix test with both sockets in map
  bpf, sockmap: af_unix stream sockets need to hold ref for pair sock
  tools: ynl-gen: always construct struct ynl_req_state
  ethtool: don't propagate EOPNOTSUPP from dumps
  ravb: Fix races between ravb_tx_timeout_work() and net related ops
  r8169: prevent potential deadlock in rtl8169_close
  r8169: fix deadlock on RTL8125 in jumbo mtu mode
  neighbour: Fix __randomize_layout crash in struct neighbour
  octeontx2-pf: Restore TC ingress police rules when interface is up
  octeontx2-pf: Fix adding mbox work queue entry when num_vfs > 64
  net: stmmac: xgmac: Disable FPE MMC interrupts
  octeontx2-af: Fix possible buffer overflow
  ...
2023-12-01 08:24:46 +09:00
Jiri Olsa
e56fdbfb06 bpf: Add link_info support for uprobe multi link
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
2023-11-28 21:50:09 -08:00
Jiri Olsa
4930b7f53a bpf: Store ref_ctr_offsets values in bpf_uprobe array
We will need to return ref_ctr_offsets values through link_info
interface in following change, so we need to keep them around.

Storing ref_ctr_offsets values directly into bpf_uprobe array.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20231125193130.834322-3-jolsa@kernel.org
2023-11-28 21:50:09 -08:00
Hou Tao
75a442581d bpf: Add missed allocation hint for bpf_mem_cache_alloc_flags()
bpf_mem_cache_alloc_flags() may call __alloc() directly when there is no
free object in free list, but it doesn't initialize the allocation hint
for the returned pointer. It may lead to bad memory dereference when
freeing the pointer, so fix it by initializing the allocation hint.

Fixes: 822fb26bdb ("bpf: Add a hint to allocated objects.")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231111043821.2258513-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-26 18:00:26 -08:00
Linus Torvalds
1d0dbc3d16 Fix lockdep block chain corruption resulting in KASAN warnings.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-urgent-2023-11-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking fix from Ingo Molnar:
 "Fix lockdep block chain corruption resulting in KASAN warnings"

* tag 'locking-urgent-2023-11-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix block chain corruption
2023-11-26 08:30:11 -08:00
Peter Zijlstra
bca4104b00 lockdep: Fix block chain corruption
Kent reported an occasional KASAN splat in lockdep. Mark then noted:

> I suspect the dodgy access is to chain_block_buckets[-1], which hits the last 4
> bytes of the redzone and gets (incorrectly/misleadingly) attributed to
> nr_large_chain_blocks.

That would mean @size == 0, at which point size_to_bucket() returns -1
and the above happens.

alloc_chain_hlocks() has 'size - req', for the first with the
precondition 'size >= rq', which allows the 0.

This code is trying to split a block, del_chain_block() takes what we
need, and add_chain_block() puts back the remainder, except in the
above case the remainder is 0 sized and things go sideways.

Fixes: 810507fe6f ("locking/lockdep: Reuse freed chain_hlocks entries")
Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lkml.kernel.org/r/20231121114126.GH8262@noisy.programming.kicks-ass.net
2023-11-24 11:04:54 +01:00
Andrii Nakryiko
2afae08c9d bpf: Validate global subprogs lazily
Slightly change BPF verifier logic around eagerness and order of global
subprog validation. Instead of going over every global subprog eagerly
and validating it before main (entry) BPF program is verified, turn it
around. Validate main program first, mark subprogs that were called from
main program for later verification, but otherwise assume it is valid.
Afterwards, go over marked global subprogs and validate those,
potentially marking some more global functions as being called. Continue
this process until all (transitively) callable global subprogs are
validated. It's a BFS traversal at its heart and will always converge.

This is an important change because it allows to feature-gate some
subprograms that might not be verifiable on some older kernel, depending
on supported set of features.

E.g., at some point, global functions were allowed to accept a pointer
to memory, which size is identified by user-provided type.
Unfortunately, older kernels don't support this feature. With BPF CO-RE
approach, the natural way would be to still compile BPF object file once
and guard calls to this global subprog with some CO-RE check or using
.rodata variables. That's what people do to guard usage of new helpers
or kfuncs, and any other new BPF-side feature that might be missing on
old kernels.

That's currently impossible to do with global subprogs, unfortunately,
because they are eagerly and unconditionally validated. This patch set
aims to change this, so that in the future when global funcs gain new
features, those can be guarded using BPF CO-RE techniques in the same
fashion as any other new kernel feature.

Two selftests had to be adjusted in sync with these changes.

test_global_func12 relied on eager global subprog validation failing
before main program failure is detected (unknown return value). Fix by
making sure that main program is always valid.

verifier_subprog_precision's parent_stack_slot_precise subtest relied on
verifier checkpointing heuristic to do a checkpoint at instruction #5,
but that's no longer true because we don't have enough jumps validated
before reaching insn #5 due to global subprogs being validated later.

Other than that, no changes, as one would expect.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231124035937.403208-3-andrii@kernel.org
2023-11-24 10:40:06 +01:00
Andrii Nakryiko
491dd8edec bpf: Emit global subprog name in verifier logs
We have the name, instead of emitting just func#N to identify global
subprog, augment verifier log messages with actual function name to make
it more user-friendly.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231124035937.403208-2-andrii@kernel.org
2023-11-24 10:40:06 +01:00
Jakub Kicinski
45c226dde7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

drivers/net/ethernet/intel/ice/ice_main.c
  c9663f79cd ("ice: adjust switchdev rebuild path")
  7758017911 ("ice: restore timestamp configuration after device reset")
https://lore.kernel.org/all/20231121211259.3348630-1-anthony.l.nguyen@intel.com/

Adjacent changes:

kernel/bpf/verifier.c
  bb124da69c ("bpf: keep track of max number of bpf_loop callback iterations")
  5f99f312bd ("bpf: add register bounds sanity checks and sanitization")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-23 12:20:58 -08:00
Linus Torvalds
d3fa86b1a7 Including fixes from bpf.
Current release - regressions:
 
  - Revert "net: r8169: Disable multicast filter for RTL8168H
    and RTL8107E"
 
  - kselftest: rtnetlink: fix ip route command typo
 
 Current release - new code bugs:
 
  - s390/ism: make sure ism driver implies smc protocol in kconfig
 
  - two build fixes for tools/net
 
 Previous releases - regressions:
 
  - rxrpc: couple of ACK/PING/RTT handling fixes
 
 Previous releases - always broken:
 
  - bpf: verify bpf_loop() callbacks as if they are called unknown
    number of times
 
  - improve stability of auto-bonding with Hyper-V
 
  - account BPF-neigh-redirected traffic in interface statistics
 
 Misc:
 
  - net: fill in some more MODULE_DESCRIPTION()s
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf.

  Current release - regressions:

   - Revert "net: r8169: Disable multicast filter for RTL8168H and
     RTL8107E"

   - kselftest: rtnetlink: fix ip route command typo

  Current release - new code bugs:

   - s390/ism: make sure ism driver implies smc protocol in kconfig

   - two build fixes for tools/net

  Previous releases - regressions:

   - rxrpc: couple of ACK/PING/RTT handling fixes

  Previous releases - always broken:

   - bpf: verify bpf_loop() callbacks as if they are called unknown
     number of times

   - improve stability of auto-bonding with Hyper-V

   - account BPF-neigh-redirected traffic in interface statistics

  Misc:

   - net: fill in some more MODULE_DESCRIPTION()s"

* tag 'net-6.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (58 commits)
  tools: ynl: fix duplicate op name in devlink
  tools: ynl: fix header path for nfsd
  net: ipa: fix one GSI register field width
  tls: fix NULL deref on tls_sw_splice_eof() with empty record
  net: axienet: Fix check for partial TX checksum
  vsock/test: fix SEQPACKET message bounds test
  i40e: Fix adding unsupported cloud filters
  ice: restore timestamp configuration after device reset
  ice: unify logic for programming PFINT_TSYN_MSK
  ice: remove ptp_tx ring parameter flag
  amd-xgbe: propagate the correct speed and duplex status
  amd-xgbe: handle the corner-case during tx completion
  amd-xgbe: handle corner-case during sfp hotplug
  net: veth: fix ethtool stats reporting
  octeontx2-pf: Fix ntuple rule creation to direct packet to VF with higher Rx queue than its PF
  net: usb: qmi_wwan: claim interface 4 for ZTE MF290
  Revert "net: r8169: Disable multicast filter for RTL8168H and RTL8107E"
  net/smc: avoid data corruption caused by decline
  nfc: virtual_ncidev: Add variable to check if ndev is running
  dpll: Fix potential msg memleak when genlmsg_put_reply failed
  ...
2023-11-23 10:40:13 -08:00
Jakub Kicinski
53475287da bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-11-21

We've added 85 non-merge commits during the last 12 day(s) which contain
a total of 63 files changed, 4464 insertions(+), 1484 deletions(-).

The main changes are:

1) Huge batch of verifier changes to improve BPF register bounds logic
   and range support along with a large test suite, and verifier log
   improvements, all from Andrii Nakryiko.

2) Add a new kfunc which acquires the associated cgroup of a task within
   a specific cgroup v1 hierarchy where the latter is identified by its id,
   from Yafang Shao.

3) Extend verifier to allow bpf_refcount_acquire() of a map value field
   obtained via direct load which is a use-case needed in sched_ext,
   from Dave Marchevsky.

4) Fix bpf_get_task_stack() helper to add the correct crosstask check
   for the get_perf_callchain(), from Jordan Rome.

5) Fix BPF task_iter internals where lockless usage of next_thread()
   was wrong. The rework also simplifies the code, from Oleg Nesterov.

6) Fix uninitialized tail padding via LIBBPF_OPTS_RESET, and another
   fix for certain BPF UAPI structs to fix verifier failures seen
   in bpf_dynptr usage, from Yonghong Song.

7) Add BPF selftest fixes for map_percpu_stats flakes due to per-CPU BPF
   memory allocator not being able to allocate per-CPU pointer successfully,
   from Hou Tao.

8) Add prep work around dynptr and string handling for kfuncs which
   is later going to be used by file verification via BPF LSM and fsverity,
   from Song Liu.

9) Improve BPF selftests to update multiple prog_tests to use ASSERT_*
   macros, from Yuran Pereira.

10) Optimize LPM trie lookup to check prefixlen before walking the trie,
    from Florian Lehner.

11) Consolidate virtio/9p configs from BPF selftests in config.vm file
    given they are needed consistently across archs, from Manu Bretelle.

12) Small BPF verifier refactor to remove register_is_const(),
    from Shung-Hsi Yu.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (85 commits)
  selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in vmlinux
  selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in bpf_obj_id
  selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in bind_perm
  selftests/bpf: Replaces the usage of CHECK calls for ASSERTs in bpf_tcp_ca
  selftests/bpf: reduce verboseness of reg_bounds selftest logs
  bpf: bpf_iter_task_next: use next_task(kit->task) rather than next_task(kit->pos)
  bpf: bpf_iter_task_next: use __next_thread() rather than next_thread()
  bpf: task_group_seq_get_next: use __next_thread() rather than next_thread()
  bpf: emit frameno for PTR_TO_STACK regs if it differs from current one
  bpf: smarter verifier log number printing logic
  bpf: omit default off=0 and imm=0 in register state log
  bpf: emit map name in register state if applicable and available
  bpf: print spilled register state in stack slot
  bpf: extract register state printing
  bpf: move verifier state printing code to kernel/bpf/log.c
  bpf: move verbose_linfo() into kernel/bpf/log.c
  bpf: rename BPF_F_TEST_SANITY_STRICT to BPF_F_TEST_REG_INVARIANTS
  bpf: Remove test for MOVSX32 with offset=32
  selftests/bpf: add iter test requiring range x range logic
  veristat: add ability to set BPF_F_TEST_SANITY_STRICT flag with -r flag
  ...
====================

Link: https://lore.kernel.org/r/20231122000500.28126-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-21 17:53:20 -08:00
Eduard Zingerman
bb124da69c bpf: keep track of max number of bpf_loop callback iterations
In some cases verifier can't infer convergence of the bpf_loop()
iteration. E.g. for the following program:

    static int cb(__u32 idx, struct num_context* ctx)
    {
        ctx->i++;
        return 0;
    }

    SEC("?raw_tp")
    int prog(void *_)
    {
        struct num_context ctx = { .i = 0 };
        __u8 choice_arr[2] = { 0, 1 };

        bpf_loop(2, cb, &ctx, 0);
        return choice_arr[ctx.i];
    }

Each 'cb' simulation would eventually return to 'prog' and reach
'return choice_arr[ctx.i]' statement. At which point ctx.i would be
marked precise, thus forcing verifier to track multitude of separate
states with {.i=0}, {.i=1}, ... at bpf_loop() callback entry.

This commit allows "brute force" handling for such cases by limiting
number of callback body simulations using 'umax' value of the first
bpf_loop() parameter.

For this, extend bpf_func_state with 'callback_depth' field.
Increment this field when callback visiting state is pushed to states
traversal stack. For frame #N it's 'callback_depth' field counts how
many times callback with frame depth N+1 had been executed.
Use bpf_func_state specifically to allow independent tracking of
callback depths when multiple nested bpf_loop() calls are present.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-11-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-20 18:36:40 -08:00
Eduard Zingerman
cafe2c2150 bpf: widening for callback iterators
Callbacks are similar to open coded iterators, so add imprecise
widening logic for callback body processing. This makes callback based
loops behave identically to open coded iterators, e.g. allowing to
verify programs like below:

  struct ctx { u32 i; };
  int cb(u32 idx, struct ctx* ctx)
  {
          ++ctx->i;
          return 0;
  }
  ...
  struct ctx ctx = { .i = 0 };
  bpf_loop(100, cb, &ctx, 0);
  ...

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-9-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-20 18:36:40 -08:00
Eduard Zingerman
ab5cfac139 bpf: verify callbacks as if they are called unknown number of times
Prior to this patch callbacks were handled as regular function calls,
execution of callback body was modeled exactly once.
This patch updates callbacks handling logic as follows:
- introduces a function push_callback_call() that schedules callback
  body verification in env->head stack;
- updates prepare_func_exit() to reschedule callback body verification
  upon BPF_EXIT;
- as calls to bpf_*_iter_next(), calls to callback invoking functions
  are marked as checkpoints;
- is_state_visited() is updated to stop callback based iteration when
  some identical parent state is found.

Paths with callback function invoked zero times are now verified first,
which leads to necessity to modify some selftests:
- the following negative tests required adding release/unlock/drop
  calls to avoid previously masked unrelated error reports:
  - cb_refs.c:underflow_prog
  - exceptions_fail.c:reject_rbtree_add_throw
  - exceptions_fail.c:reject_with_cp_reference
- the following precision tracking selftests needed change in expected
  log trace:
  - verifier_subprog_precision.c:callback_result_precise
    (note: r0 precision is no longer propagated inside callback and
           I think this is a correct behavior)
  - verifier_subprog_precision.c:parent_callee_saved_reg_precise_with_callback
  - verifier_subprog_precision.c:parent_stack_slot_precise_with_callback

Reported-by: Andrew Werner <awerner32@gmail.com>
Closes: https://lore.kernel.org/bpf/CA+vRuzPChFNXmouzGG+wsy=6eMcfr1mFG0F3g7rbg-sedGKW3w@mail.gmail.com/
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20231121020701.26440-7-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-20 18:35:44 -08:00