diff options
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 | |
parent | 1b2fd38de9fcc73d6994f8f6c7c23ee3435b6a12 (diff) | |
download | linux-5576b991e9c1a11d2cc21c4b94fc75ec27603896.tar.bz2 |
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
-rw-r--r-- | include/linux/bpf.h | 1 | ||||
-rw-r--r-- | include/uapi/linux/bpf.h | 9 | ||||
-rw-r--r-- | kernel/bpf/core.c | 1 | ||||
-rw-r--r-- | kernel/bpf/helpers.c | 12 | ||||
-rw-r--r-- | kernel/bpf/verifier.c | 24 | ||||
-rw-r--r-- | net/core/filter.c | 2 |
6 files changed, 48 insertions, 1 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 05d16615054c..a9687861fd7e 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1414,6 +1414,7 @@ extern const struct bpf_func_proto bpf_get_local_storage_proto; extern const struct bpf_func_proto bpf_strtol_proto; extern const struct bpf_func_proto bpf_strtoul_proto; extern const struct bpf_func_proto bpf_tcp_sock_proto; +extern const struct bpf_func_proto bpf_jiffies64_proto; /* Shared helpers among cBPF and eBPF. */ void bpf_user_rnd_init_once(void); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index e81628eb059c..f1d74a2bd234 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -2886,6 +2886,12 @@ union bpf_attr { * **-EPERM** if no permission to send the *sig*. * * **-EAGAIN** if bpf program can try again. + * + * u64 bpf_jiffies64(void) + * Description + * Obtain the 64bit jiffies + * Return + * The 64 bit jiffies */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3005,7 +3011,8 @@ union bpf_attr { FN(probe_read_user_str), \ FN(probe_read_kernel_str), \ FN(tcp_send_ack), \ - FN(send_signal_thread), + FN(send_signal_thread), \ + FN(jiffies64), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 29d47aae0dd1..973a20d49749 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2137,6 +2137,7 @@ const struct bpf_func_proto bpf_map_pop_elem_proto __weak; const struct bpf_func_proto bpf_map_peek_elem_proto __weak; const struct bpf_func_proto bpf_spin_lock_proto __weak; const struct bpf_func_proto bpf_spin_unlock_proto __weak; +const struct bpf_func_proto bpf_jiffies64_proto __weak; const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index cada974c9f4e..d8b7b110a1c5 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -11,6 +11,7 @@ #include <linux/uidgid.h> #include <linux/filter.h> #include <linux/ctype.h> +#include <linux/jiffies.h> #include "../../lib/kstrtox.h" @@ -312,6 +313,17 @@ void copy_map_value_locked(struct bpf_map *map, void *dst, void *src, preempt_enable(); } +BPF_CALL_0(bpf_jiffies64) +{ + return get_jiffies_64(); +} + +const struct bpf_func_proto bpf_jiffies64_proto = { + .func = bpf_jiffies64, + .gpl_only = false, + .ret_type = RET_INTEGER, +}; + #ifdef CONFIG_CGROUPS BPF_CALL_0(bpf_get_current_cgroup_id) { 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 diff --git a/net/core/filter.c b/net/core/filter.c index 17de6747d9e3..4bf3e4aa8a7a 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5923,6 +5923,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_spin_unlock_proto; case BPF_FUNC_trace_printk: return bpf_get_trace_printk_proto(); + case BPF_FUNC_jiffies64: + return &bpf_jiffies64_proto; default: return NULL; } |