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MIPS,bpf: Fix using smp_processor_id() in preemptible splat.

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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 <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Daney 2017-08-18 16:40:31 -07:00 committed by David S. Miller
parent da6817ebc3
commit 8d8d18c328
1 changed files with 14 additions and 14 deletions
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28
arch/mips/net/ebpf_jit.c
View file

@ -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 @@ static int build_one_insn(const struct bpf_insn *insn, struct jit_ctx *ctx,
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;