Messages in this thread | | | Subject | Re: [PATCH v11 2/9] btf: Handle dynamic pointer parameter in kfuncs | From | Daniel Borkmann <> | Date | Mon, 15 Aug 2022 18:45:59 +0200 |
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On 8/12/22 12:18 PM, Roberto Sassu wrote: > Allow the bpf_dynptr_kern parameter to be specified in kfuncs. Also, ensure > that the dynamic pointer is valid and initialized. > > Cc: Joanne Koong <joannelkoong@gmail.com> > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > --- > include/linux/bpf_verifier.h | 3 +++ > kernel/bpf/btf.c | 22 ++++++++++++++++++++++ > kernel/bpf/verifier.c | 4 ++-- > 3 files changed, 27 insertions(+), 2 deletions(-) > > diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h > index 2e3bad8640dc..55876fbdbae2 100644 > --- a/include/linux/bpf_verifier.h > +++ b/include/linux/bpf_verifier.h > @@ -560,6 +560,9 @@ int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state > u32 regno); > int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, > u32 regno, u32 mem_size); > +bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, > + struct bpf_reg_state *reg, > + enum bpf_arg_type arg_type); > > /* this lives here instead of in bpf.h because it needs to dereference tgt_prog */ > static inline u64 bpf_trampoline_compute_key(const struct bpf_prog *tgt_prog, > diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c > index e49b3b6d48ad..86e63f2ee5da 100644 > --- a/kernel/bpf/btf.c > +++ b/kernel/bpf/btf.c > @@ -195,6 +195,10 @@ > i < btf_type_vlen(struct_type); \ > i++, member++) > > +#define stringify_struct(x) \ > + ({ BUILD_BUG_ON(sizeof(struct x) < 0); \ > + __stringify(x); }) > +
I'd say lets move this to include/linux/btf.h with a comment explaining the BUILD_BUG_ON() which ensures the struct actually exits.
If there's ever use outside of BTF, it could be relocated to include/linux/stringify.h.
> DEFINE_IDR(btf_idr); > DEFINE_SPINLOCK(btf_idr_lock); >
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