diff options
| author |   David Miller <davem@davemloft.net> | 2020-02-24 15:01:43 +0100 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2020-02-24 16:20:09 -0800 |
| commit | 3d9f773cf2876c01a505b9fe27270901d464e90a (patch) | |
| tree | d5ed0350db81b38cf8c0234d7c066f65595addff /net/core/flow_dissector.c | |
| parent | bpf: Replace cant_sleep() with cant_migrate() (diff) | |
| download | linux-dev-3d9f773cf2876c01a505b9fe27270901d464e90a.tar.xz linux-dev-3d9f773cf2876c01a505b9fe27270901d464e90a.zip | |
bpf: Use bpf_prog_run_pin_on_cpu() at simple call sites.
All of these cases are strictly of the form:
preempt_disable();
BPF_PROG_RUN(...);
preempt_enable();
Replace this with bpf_prog_run_pin_on_cpu() which wraps BPF_PROG_RUN()
with:
migrate_disable();
BPF_PROG_RUN(...);
migrate_enable();
On non RT enabled kernels this maps to preempt_disable/enable() and on RT
enabled kernels this solely prevents migration, which is sufficient as
there is no requirement to prevent reentrancy to any BPF program from a
preempting task. The only requirement is that the program stays on the same
CPU.
Therefore, this is a trivially correct transformation.
The seccomp loop does not need protection over the loop. It only needs
protection per BPF filter program
[ tglx: Converted to bpf_prog_run_pin_on_cpu() ]
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200224145643.691493094@linutronix.de
Diffstat (limited to '')
| -rw-r--r-- | net/core/flow_dissector.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index a1670dff0629..3eff84824c8b 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -920,9 +920,7 @@ bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP); flow_keys->flags = flags; - preempt_disable(); - result = BPF_PROG_RUN(prog, ctx); - preempt_enable(); + result = bpf_prog_run_pin_on_cpu(prog, ctx); flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen); flow_keys->thoff = clamp_t(u16, flow_keys->thoff, |