From 8d8d18c3283f0cf72f6ac41f337d5b6f818649b6 Mon Sep 17 00:00:00 2001 From: David Daney Date: Fri, 18 Aug 2017 16:40:31 -0700 Subject: [PATCH] MIPS,bpf: Fix using smp_processor_id() in preemptible splat. If the kernel is configured with preemption enabled we were getting warning stack traces for use of current_cpu_type(). Fix by moving the test between preempt_disable()/preempt_enable() and caching the results of the CPU type tests for use during code generation. Signed-off-by: David Daney Signed-off-by: David S. Miller --- arch/mips/net/ebpf_jit.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/arch/mips/net/ebpf_jit.c b/arch/mips/net/ebpf_jit.c index 3f87b96da5c4..721216b0f8e4 100644 --- a/arch/mips/net/ebpf_jit.c +++ b/arch/mips/net/ebpf_jit.c @@ -113,6 +113,7 @@ struct jit_ctx { u64 *reg_val_types; unsigned int long_b_conversion:1; unsigned int gen_b_offsets:1; + unsigned int use_bbit_insns:1; }; static void set_reg_val_type(u64 *rvt, int reg, enum reg_val_type type) @@ -655,19 +656,6 @@ static int emit_bpf_tail_call(struct jit_ctx *ctx, int this_idx) return build_int_epilogue(ctx, MIPS_R_T9); } -static bool use_bbit_insns(void) -{ - switch (current_cpu_type()) { - case CPU_CAVIUM_OCTEON: - case CPU_CAVIUM_OCTEON_PLUS: - case CPU_CAVIUM_OCTEON2: - case CPU_CAVIUM_OCTEON3: - return true; - default: - return false; - } -} - static bool is_bad_offset(int b_off) { return b_off > 0x1ffff || b_off < -0x20000; @@ -1198,7 +1186,7 @@ jeq_common: if (dst < 0) return dst; - if (use_bbit_insns() && hweight32((u32)insn->imm) == 1) { + if (ctx->use_bbit_insns && hweight32((u32)insn->imm) == 1) { if ((insn + 1)->code == (BPF_JMP | BPF_EXIT) && insn->off == 1) { b_off = b_imm(exit_idx, ctx); if (is_bad_offset(b_off)) @@ -1853,6 +1841,18 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) memset(&ctx, 0, sizeof(ctx)); + preempt_disable(); + switch (current_cpu_type()) { + case CPU_CAVIUM_OCTEON: + case CPU_CAVIUM_OCTEON_PLUS: + case CPU_CAVIUM_OCTEON2: + case CPU_CAVIUM_OCTEON3: + ctx.use_bbit_insns = 1; + default: + ctx.use_bbit_insns = 0; + } + preempt_enable(); + ctx.offsets = kcalloc(prog->len + 1, sizeof(*ctx.offsets), GFP_KERNEL); if (ctx.offsets == NULL) goto out_err;