| Message ID | 20181117185715.25198-5-ard.biesheuvel@linaro.org |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | bpf: permit JIT allocations to be served outside the module region | expand |
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index a6fdaea07c63..e0c702c2f682 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -940,3 +940,14 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) tmp : orig_prog); return prog; } + +void *bpf_jit_alloc_exec(unsigned long size) +{ + return vmalloc_exec(size); +} + +void bpf_jit_binary_free(struct bpf_binary_header *hdr) +{ + bpf_jit_binary_unlock_ro(hdr); + vfree(hdr); +}
The arm64 module region is a 128 MB region that is kept close to the core kernel, in order to ensure that relative branches are always in range. So using the same region for programs that do not have this restriction is wasteful, and preferably avoided. Now that the core BPF JIT code permits the alloc/free routines to be overridden, implement them by simple vmalloc_exec()/vfree() calls, which can be served from anywere. This also solves an issue under KASAN, where shadow memory is needlessly allocated for all BPF programs (which don't require KASAN shadow pages since they are not KASAN instrumented) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> --- arch/arm64/net/bpf_jit_comp.c | 11 +++++++++++ 1 file changed, 11 insertions(+)