samples/bpf: Make samples more libbpf-centric

Switch all of the sample code to use the function names from
tools/lib/bpf so that they're consistent with that, and to declare their
own log buffers. This allow the next commit to be purely devoted to
getting rid of the duplicate library in samples/bpf.

Committer notes:

Testing it:

On a fedora rawhide container, with clang/llvm 3.9, sharing the host
linux kernel git tree:

  # make O=/tmp/build/linux/ headers_install
  # make O=/tmp/build/linux -C samples/bpf/

Since I forgot to make it privileged, just tested it outside the
container, using what it generated:

  # uname -a
  Linux jouet 4.9.0-rc8+ #1 SMP Mon Dec 12 11:20:49 BRT 2016 x86_64 x86_64 x86_64 GNU/Linux
  # cd /var/lib/docker/devicemapper/mnt/c43e09a53ff56c86a07baf79847f00e2cc2a17a1e2220e1adbf8cbc62734feda/rootfs/tmp/build/linux/samples/bpf/
  # ls -la offwaketime
  -rwxr-xr-x. 1 root root 24200 Dec 15 12:19 offwaketime
  # file offwaketime
  offwaketime: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=c940d3f127d5e66cdd680e42d885cb0b64f8a0e4, not stripped
  # readelf -SW offwaketime_kern.o  | grep PROGBITS
  [ 2] .text             PROGBITS        0000000000000000 000040 000000 00  AX  0   0  4
  [ 3] kprobe/try_to_wake_up PROGBITS        0000000000000000 000040 0000d8 00  AX  0   0  8
  [ 5] tracepoint/sched/sched_switch PROGBITS        0000000000000000 000118 000318 00  AX  0   0  8
  [ 7] maps              PROGBITS        0000000000000000 000430 000050 00  WA  0   0  4
  [ 8] license           PROGBITS        0000000000000000 000480 000004 00  WA  0   0  1
  [ 9] version           PROGBITS        0000000000000000 000484 000004 00  WA  0   0  4
  # ./offwaketime | head -5
  swapper/1;start_secondary;cpu_startup_entry;schedule_preempt_disabled;schedule;__schedule;-;---;; 106
  CPU 0/KVM;entry_SYSCALL_64_fastpath;sys_ioctl;do_vfs_ioctl;kvm_vcpu_ioctl;kvm_arch_vcpu_ioctl_run;kvm_vcpu_block;schedule;__schedule;-;try_to_wake_up;swake_up_locked;swake_up;apic_timer_expired;apic_timer_fn;__hrtimer_run_queues;hrtimer_interrupt;local_apic_timer_interrupt;smp_apic_timer_interrupt;__irqentry_text_start;cpuidle_enter;call_cpuidle;cpu_startup_entry;start_secondary;;swapper/3 2
  Compositor;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;futex_requeue;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;SoftwareVsyncTh 5
  firefox;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;__schedule;-;try_to_wake_up;pollwake;__wake_up_common;__wake_up_sync_key;pipe_write;__vfs_write;vfs_write;sys_write;entry_SYSCALL_64_fastpath;;Timer 13
  JS Helper;entry_SYSCALL_64_fastpath;sys_futex;do_futex;futex_wait;futex_wait_queue_me;schedule;__schedule;-;try_to_wake_up;do_futex;sys_futex;entry_SYSCALL_64_fastpath;;firefox 2
  #

Signed-off-by: Joe Stringer <joe@ovn.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20161214224342.12858-2-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 11 insertions, 12 deletions

diff --git a/samples/bpf/libbpf.c b/samples/bpf/libbpf.c
index 9ce707bf02a7..6f076abdca35 100644
--- a/samples/bpf/libbpf.c
+++ b/samples/bpf/libbpf.c
@@ -32,7 +32,7 @@ int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
 	return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
 }
 
-int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
+int bpf_map_update_elem(int fd, void *key, void *value, unsigned long long flags)
 {
 	union bpf_attr attr = {
 		.map_fd = fd,
@@ -44,7 +44,7 @@ int bpf_update_elem(int fd, void *key, void *value, unsigned long long flags)
 	return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
 }
 
-int bpf_lookup_elem(int fd, void *key, void *value)
+int bpf_map_lookup_elem(int fd, void *key, void *value)
 {
 	union bpf_attr attr = {
 		.map_fd = fd,
@@ -55,7 +55,7 @@ int bpf_lookup_elem(int fd, void *key, void *value)
 	return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
 }
 
-int bpf_delete_elem(int fd, void *key)
+int bpf_map_delete_elem(int fd, void *key)
 {
 	union bpf_attr attr = {
 		.map_fd = fd,
@@ -65,7 +65,7 @@ int bpf_delete_elem(int fd, void *key)
 	return syscall(__NR_bpf, BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
 }
 
-int bpf_get_next_key(int fd, void *key, void *next_key)
+int bpf_map_get_next_key(int fd, void *key, void *next_key)
 {
 	union bpf_attr attr = {
 		.map_fd = fd,
@@ -78,19 +78,18 @@ int bpf_get_next_key(int fd, void *key, void *next_key)
 
 #define ROUND_UP(x, n) (((x) + (n) - 1u) & ~((n) - 1u))
 
-char bpf_log_buf[LOG_BUF_SIZE];
-
-int bpf_prog_load(enum bpf_prog_type prog_type,
-		  const struct bpf_insn *insns, int prog_len,
-		  const char *license, int kern_version)
+int bpf_load_program(enum bpf_prog_type prog_type,
+		     const struct bpf_insn *insns, int prog_len,
+		     const char *license, int kern_version,
+		     char *log_buf, size_t log_buf_sz)
 {
 	union bpf_attr attr = {
 		.prog_type = prog_type,
 		.insns = ptr_to_u64((void *) insns),
 		.insn_cnt = prog_len / sizeof(struct bpf_insn),
 		.license = ptr_to_u64((void *) license),
-		.log_buf = ptr_to_u64(bpf_log_buf),
-		.log_size = LOG_BUF_SIZE,
+		.log_buf = ptr_to_u64(log_buf),
+		.log_size = log_buf_sz,
 		.log_level = 1,
 	};
 
@@ -99,7 +98,7 @@ int bpf_prog_load(enum bpf_prog_type prog_type,
 	 */
 	attr.kern_version = kern_version;
 
-	bpf_log_buf[0] = 0;
+	log_buf[0] = 0;
 
 	return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
 }