| Message ID | 20191107014640.384083-1-kafai@fb.com |
|---|---|
| State | Accepted |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | bpf: Add array support to btf_struct_access | expand |
On Wed, Nov 6, 2019 at 5:47 PM Martin KaFai Lau <kafai@fb.com> wrote: > > In the bpf interpreter mode, bpf_probe_read_kernel is used to read > from PTR_TO_BTF_ID's kernel object. It currently missed considering > the insn->off. This patch fixes it. > > Fixes: 2a02759ef5f8 ("bpf: Add support for BTF pointers to interpreter") > Signed-off-by: Martin KaFai Lau <kafai@fb.com> > --- Heh :) Acked-by: Andrii Nakryiko <andriin@fb.com> [...]
On Wed, Nov 6, 2019 at 5:46 PM Martin KaFai Lau <kafai@fb.com> wrote: > > In the bpf interpreter mode, bpf_probe_read_kernel is used to read > from PTR_TO_BTF_ID's kernel object. It currently missed considering > the insn->off. This patch fixes it. > > Fixes: 2a02759ef5f8 ("bpf: Add support for BTF pointers to interpreter") > Signed-off-by: Martin KaFai Lau <kafai@fb.com> Applied the 1st patch. 2nd and 3rd will go for 'nit' respin?
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 97e37d82a1cc..c1fde0303280 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -1569,7 +1569,7 @@ static u64 __no_fgcse ___bpf_prog_run(u64 *regs, const struct bpf_insn *insn, u6 #undef LDST #define LDX_PROBE(SIZEOP, SIZE) \ LDX_PROBE_MEM_##SIZEOP: \ - bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) SRC); \ + bpf_probe_read_kernel(&DST, SIZE, (const void *)(long) (SRC + insn->off)); \ CONT; LDX_PROBE(B, 1) LDX_PROBE(H, 2)
In the bpf interpreter mode, bpf_probe_read_kernel is used to read from PTR_TO_BTF_ID's kernel object. It currently missed considering the insn->off. This patch fixes it. Fixes: 2a02759ef5f8 ("bpf: Add support for BTF pointers to interpreter") Signed-off-by: Martin KaFai Lau <kafai@fb.com> --- kernel/bpf/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)