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 /kernel/seccomp.c | |
| parent | 37e1d9202225635772b32e340294208367279c2b (diff) | |
| download | linux-3d9f773cf2876c01a505b9fe27270901d464e90a.tar.gz | |
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 'kernel/seccomp.c')
| -rw-r--r-- | kernel/seccomp.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/seccomp.c b/kernel/seccomp.c index b6ea3dcb57bf..787041eb011b 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -268,16 +268,14 @@ static u32 seccomp_run_filters(const struct seccomp_data *sd, * All filters in the list are evaluated and the lowest BPF return * value always takes priority (ignoring the DATA). */ - preempt_disable(); for (; f; f = f->prev) { - u32 cur_ret = BPF_PROG_RUN(f->prog, sd); + u32 cur_ret = bpf_prog_run_pin_on_cpu(f->prog, sd); if (ACTION_ONLY(cur_ret) < ACTION_ONLY(ret)) { ret = cur_ret; *match = f; } } - preempt_enable(); return ret; } #endif /* CONFIG_SECCOMP_FILTER */ |