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| author | Martin KaFai Lau <kafai@fb.com> | 2020-01-22 15:36:46 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-01-22 16:30:10 -0800 |
| commit | 5576b991e9c1a11d2cc21c4b94fc75ec27603896 (patch) | |
| tree | 6254c1eec41a9c3e2108eb955920573d61f8c19b /kernel/bpf/verifier.c | |
| parent | 1b2fd38de9fcc73d6994f8f6c7c23ee3435b6a12 (diff) | |
| download | lwn-5576b991e9c1a11d2cc21c4b94fc75ec27603896.tar.gz lwn-5576b991e9c1a11d2cc21c4b94fc75ec27603896.zip | |
bpf: Add BPF_FUNC_jiffies64
This patch adds a helper to read the 64bit jiffies. It will be used
in a later patch to implement the bpf_cubic.c.
The helper is inlined for jit_requested and 64 BITS_PER_LONG
as the map_gen_lookup(). Other cases could be considered together
with map_gen_lookup() if needed.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200122233646.903260-1-kafai@fb.com
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9fe94f64f0ec..734abaa02123 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -9445,6 +9445,30 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) goto patch_call_imm; } + if (prog->jit_requested && BITS_PER_LONG == 64 && + insn->imm == BPF_FUNC_jiffies64) { + struct bpf_insn ld_jiffies_addr[2] = { + BPF_LD_IMM64(BPF_REG_0, + (unsigned long)&jiffies), + }; + + insn_buf[0] = ld_jiffies_addr[0]; + insn_buf[1] = ld_jiffies_addr[1]; + insn_buf[2] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, + BPF_REG_0, 0); + cnt = 3; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, + cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } + patch_call_imm: fn = env->ops->get_func_proto(insn->imm, env->prog); /* all functions that have prototype and verifier allowed |