From 1c03e03f9b5278701d4a0e3444b2de3b9ddc244b Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sun, 8 Oct 2017 21:04:15 -0700 Subject: [PATCH] nfp: bpf: pad code with valid nops We need to append up to 8 nops after last instruction to make sure the CPU will not fetch garbage instructions with invalid ECC if the code store was not initialized. Signed-off-by: Jakub Kicinski Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- drivers/net/ethernet/netronome/nfp/bpf/jit.c | 12 +++++++++++- drivers/net/ethernet/netronome/nfp/nfp_asm.h | 2 ++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index f4aedc89bfc8..e0600d037773 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -426,6 +426,11 @@ emit_ld_field(struct nfp_prog *nfp_prog, swreg dst, u8 bmask, swreg src, emit_ld_field_any(nfp_prog, sc, shift, dst, bmask, src, false); } +static void emit_nop(struct nfp_prog *nfp_prog) +{ + __emit_immed(nfp_prog, UR_REG_IMM, UR_REG_IMM, 0, 0, 0, 0, 0, 0, 0); +} + /* --- Wrappers --- */ static bool pack_immed(u32 imm, u16 *val, enum immed_shift *shift) { @@ -1550,7 +1555,7 @@ static void nfp_outro(struct nfp_prog *nfp_prog) static int nfp_translate(struct nfp_prog *nfp_prog) { struct nfp_insn_meta *meta; - int err; + int i, err; nfp_intro(nfp_prog); if (nfp_prog->error) @@ -1582,6 +1587,11 @@ static int nfp_translate(struct nfp_prog *nfp_prog) if (nfp_prog->error) return nfp_prog->error; + for (i = 0; i < NFP_USTORE_PREFETCH_WINDOW; i++) + emit_nop(nfp_prog); + if (nfp_prog->error) + return nfp_prog->error; + return nfp_fixup_branches(nfp_prog); } diff --git a/drivers/net/ethernet/netronome/nfp/nfp_asm.h b/drivers/net/ethernet/netronome/nfp/nfp_asm.h index d95087e5fb73..c4c18dd5630a 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_asm.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_asm.h @@ -362,6 +362,8 @@ int swreg_to_unrestricted(swreg dst, swreg lreg, swreg rreg, int swreg_to_restricted(swreg dst, swreg lreg, swreg rreg, struct nfp_insn_re_regs *reg, bool has_imm8); +#define NFP_USTORE_PREFETCH_WINDOW 8 + int nfp_ustore_check_valid_no_ecc(u64 insn); u64 nfp_ustore_calc_ecc_insn(u64 insn); -- GitLab