From 0934349866efb8988e2d3997460d6f5caa8b10ba Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= Date: Sun, 26 Apr 2020 09:15:25 -0700 Subject: [PATCH] BACKPORT: bpf: add bpf_ktime_get_boot_ns() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On a device like a cellphone which is constantly suspending and resuming CLOCK_MONOTONIC is not particularly useful for keeping track of or reacting to external network events. Instead you want to use CLOCK_BOOTTIME. Hence add bpf_ktime_get_boot_ns() as a mirror of bpf_ktime_get_ns() based around CLOCK_BOOTTIME instead of CLOCK_MONOTONIC. Signed-off-by: Maciej Żenczykowski Signed-off-by: Alexei Starovoitov (cherry picked from commit 71d19214776e61b33da48f7c1b46e522c7f78221) Change-Id: Ifd62c410dcc5112fd1a473a7e1f70231ca514bc0 --- drivers/media/rc/bpf-lirc.c | 2 ++ include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 27 ++++++++++++++++++++++++++- kernel/bpf/core.c | 1 + kernel/bpf/helpers.c | 12 ++++++++++++ kernel/trace/bpf_trace.c | 2 ++ net/core/filter.c | 2 ++ tools/include/uapi/linux/bpf.h | 27 ++++++++++++++++++++++++++- 8 files changed, 72 insertions(+), 2 deletions(-) diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c index 0a0ce620e4a2..68955a813d7e 100644 --- a/drivers/media/rc/bpf-lirc.c +++ b/drivers/media/rc/bpf-lirc.c @@ -108,6 +108,8 @@ lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_map_peek_elem_proto; case BPF_FUNC_ktime_get_ns: return &bpf_ktime_get_ns_proto; + case BPF_FUNC_ktime_get_boot_ns: + return &bpf_ktime_get_boot_ns_proto; case BPF_FUNC_tail_call: return &bpf_tail_call_proto; case BPF_FUNC_get_prandom_u32: diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 7aa0d8b5aaf0..80c2bf2deb6c 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1046,6 +1046,7 @@ extern const struct bpf_func_proto bpf_get_smp_processor_id_proto; extern const struct bpf_func_proto bpf_get_numa_node_id_proto; extern const struct bpf_func_proto bpf_tail_call_proto; extern const struct bpf_func_proto bpf_ktime_get_ns_proto; +extern const struct bpf_func_proto bpf_ktime_get_boot_ns_proto; extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; extern const struct bpf_func_proto bpf_get_current_comm_proto; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index ca8cc0b3a747..66c03e21bd08 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -570,6 +570,8 @@ union bpf_attr { * u64 bpf_ktime_get_ns(void) * Description * Return the time elapsed since system boot, in nanoseconds. + * Does not include time the system was suspended. + * See: clock_gettime(CLOCK_MONOTONIC) * Return * Current *ktime*. * @@ -2750,6 +2752,14 @@ union bpf_attr { * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies * * **-EPROTONOSUPPORT** IP packet version is not 4 or 6 + * + * u64 bpf_ktime_get_boot_ns(void) + * Description + * Return the time elapsed since system boot, in nanoseconds. + * Does include the time the system was suspended. + * See: clock_gettime(CLOCK_BOOTTIME) + * Return + * Current *ktime*. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -2862,7 +2872,22 @@ union bpf_attr { FN(sk_storage_get), \ FN(sk_storage_delete), \ FN(send_signal), \ - FN(tcp_gen_syncookie), + FN(tcp_gen_syncookie), \ + FN(skb_output), \ + FN(probe_read_user), \ + FN(probe_read_kernel), \ + FN(probe_read_user_str), \ + FN(probe_read_kernel_str), \ + FN(tcp_send_ack), \ + FN(send_signal_thread), \ + FN(jiffies64), \ + FN(read_branch_records), \ + FN(get_ns_current_pid_tgid), \ + FN(xdp_output), \ + FN(get_netns_cookie), \ + FN(get_current_ancestor_cgroup_id), \ + FN(sk_assign), \ + FN(ktime_get_boot_ns), /* 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 f72cc0692275..32991a6aa02a 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2045,6 +2045,7 @@ const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; +const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak; const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 3d23c94b7fb3..d15fc6dcb6d6 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -152,6 +152,18 @@ const struct bpf_func_proto bpf_ktime_get_ns_proto = { .ret_type = RET_INTEGER, }; +BPF_CALL_0(bpf_ktime_get_boot_ns) +{ + /* NMI safe access to clock boottime */ + return ktime_get_boot_fast_ns(); +} + +const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = { + .func = bpf_ktime_get_boot_ns, + .gpl_only = false, + .ret_type = RET_INTEGER, +}; + BPF_CALL_0(bpf_get_current_pid_tgid) { struct task_struct *task = current; diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 2372b861f2cf..5162f16325dd 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -701,6 +701,8 @@ tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_probe_read_proto; case BPF_FUNC_ktime_get_ns: return &bpf_ktime_get_ns_proto; + case BPF_FUNC_ktime_get_boot_ns: + return &bpf_ktime_get_boot_ns_proto; case BPF_FUNC_tail_call: return &bpf_tail_call_proto; case BPF_FUNC_get_current_pid_tgid: diff --git a/net/core/filter.c b/net/core/filter.c index 55f5fda12003..b014861155fa 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -5996,6 +5996,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_tail_call_proto; case BPF_FUNC_ktime_get_ns: return &bpf_ktime_get_ns_proto; + case BPF_FUNC_ktime_get_boot_ns: + return &bpf_ktime_get_boot_ns_proto; default: break; } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 77c6be96d676..62985a8e741d 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -570,6 +570,8 @@ union bpf_attr { * u64 bpf_ktime_get_ns(void) * Description * Return the time elapsed since system boot, in nanoseconds. + * Does not include time the system was suspended. + * See: clock_gettime(CLOCK_MONOTONIC) * Return * Current *ktime*. * @@ -2750,6 +2752,14 @@ union bpf_attr { * **-EOPNOTSUPP** kernel configuration does not enable SYN cookies * * **-EPROTONOSUPPORT** IP packet version is not 4 or 6 + * + * u64 bpf_ktime_get_boot_ns(void) + * Description + * Return the time elapsed since system boot, in nanoseconds. + * Does include the time the system was suspended. + * See: clock_gettime(CLOCK_BOOTTIME) + * Return + * Current *ktime*. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -2862,7 +2872,22 @@ union bpf_attr { FN(sk_storage_get), \ FN(sk_storage_delete), \ FN(send_signal), \ - FN(tcp_gen_syncookie), + FN(tcp_gen_syncookie), \ + FN(skb_output), \ + FN(probe_read_user), \ + FN(probe_read_kernel), \ + FN(probe_read_user_str), \ + FN(probe_read_kernel_str), \ + FN(tcp_send_ack), \ + FN(send_signal_thread), \ + FN(jiffies64), \ + FN(read_branch_records), \ + FN(get_ns_current_pid_tgid), \ + FN(xdp_output), \ + FN(get_netns_cookie), \ + FN(get_current_ancestor_cgroup_id), \ + FN(sk_assign), \ + FN(ktime_get_boot_ns), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call