From: Naveen N. Rao Date: Thu, 1 Jul 2021 15:08:59 +0000 (+0530) Subject: powerpc/bpf: Reject atomic ops in ppc32 JIT X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=307e5042c7bdae15308ef2e9b848833b84122eb0;p=linux.git powerpc/bpf: Reject atomic ops in ppc32 JIT Commit 91c960b0056672 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm") converted BPF_XADD to BPF_ATOMIC and updated all JIT implementations to reject JIT'ing instructions with an immediate value different from BPF_ADD. However, ppc32 BPF JIT was implemented around the same time and didn't include the same change. Update the ppc32 JIT accordingly. Fixes: 51c66ad849a7 ("powerpc/bpf: Implement extended BPF on PPC32") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Naveen N. Rao Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/426699046d89fe50f66ecf74bd31c01eda976ba5.1625145429.git.naveen.n.rao@linux.vnet.ibm.com --- diff --git a/arch/powerpc/net/bpf_jit_comp32.c b/arch/powerpc/net/bpf_jit_comp32.c index cbe5b399ed869..34bb1583fc0cb 100644 --- a/arch/powerpc/net/bpf_jit_comp32.c +++ b/arch/powerpc/net/bpf_jit_comp32.c @@ -773,9 +773,17 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * break; /* - * BPF_STX XADD (atomic_add) + * BPF_STX ATOMIC (atomic ops) */ - case BPF_STX | BPF_XADD | BPF_W: /* *(u32 *)(dst + off) += src */ + case BPF_STX | BPF_ATOMIC | BPF_W: + if (imm != BPF_ADD) { + pr_err_ratelimited("eBPF filter atomic op code %02x (@%d) unsupported\n", + code, i); + return -ENOTSUPP; + } + + /* *(u32 *)(dst + off) += src */ + bpf_set_seen_register(ctx, tmp_reg); /* Get offset into TMP_REG */ EMIT(PPC_RAW_LI(tmp_reg, off)); @@ -789,7 +797,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * PPC_BCC_SHORT(COND_NE, (ctx->idx - 3) * 4); break; - case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */ + case BPF_STX | BPF_ATOMIC | BPF_DW: /* *(u64 *)(dst + off) += src */ return -EOPNOTSUPP; /*