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-rw-r--r--samples/bpf/Makefile17
-rw-r--r--samples/bpf/bpf_helpers.h26
-rw-r--r--samples/bpf/bpf_load.c26
-rw-r--r--samples/bpf/map_perf_test_user.c1
-rw-r--r--samples/bpf/offwaketime_kern.c26
-rw-r--r--samples/bpf/spintest_kern.c2
-rw-r--r--samples/bpf/test_overhead_kprobe_kern.c41
-rw-r--r--samples/bpf/test_overhead_tp_kern.c36
-rw-r--r--samples/bpf/test_overhead_user.c162
-rw-r--r--samples/bpf/tracex2_kern.c4
-rw-r--r--samples/bpf/tracex4_kern.c2
11 files changed, 321 insertions, 22 deletions
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 502c9fc8db85..744dd7a16144 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -19,6 +19,7 @@ hostprogs-y += lathist
hostprogs-y += offwaketime
hostprogs-y += spintest
hostprogs-y += map_perf_test
+hostprogs-y += test_overhead
test_verifier-objs := test_verifier.o libbpf.o
test_maps-objs := test_maps.o libbpf.o
@@ -38,6 +39,7 @@ lathist-objs := bpf_load.o libbpf.o lathist_user.o
offwaketime-objs := bpf_load.o libbpf.o offwaketime_user.o
spintest-objs := bpf_load.o libbpf.o spintest_user.o
map_perf_test-objs := bpf_load.o libbpf.o map_perf_test_user.o
+test_overhead-objs := bpf_load.o libbpf.o test_overhead_user.o
# Tell kbuild to always build the programs
always := $(hostprogs-y)
@@ -56,6 +58,8 @@ always += lathist_kern.o
always += offwaketime_kern.o
always += spintest_kern.o
always += map_perf_test_kern.o
+always += test_overhead_tp_kern.o
+always += test_overhead_kprobe_kern.o
HOSTCFLAGS += -I$(objtree)/usr/include
@@ -75,17 +79,12 @@ HOSTLOADLIBES_lathist += -lelf
HOSTLOADLIBES_offwaketime += -lelf
HOSTLOADLIBES_spintest += -lelf
HOSTLOADLIBES_map_perf_test += -lelf -lrt
+HOSTLOADLIBES_test_overhead += -lelf -lrt
-# point this to your LLVM backend with bpf support
-LLC=$(srctree)/tools/bpf/llvm/bld/Debug+Asserts/bin/llc
-
-# asm/sysreg.h inline assmbly used by it is incompatible with llvm.
-# But, ehere is not easy way to fix it, so just exclude it since it is
+# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
+# But, there is no easy way to fix it, so just exclude it since it is
# useless for BPF samples.
$(obj)/%.o: $(src)/%.c
clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
-D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
- -O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@
- clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
- -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
- -O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=asm -o $@.s
+ -O2 -emit-llvm -c $< -o -| llc -march=bpf -filetype=obj -o $@
diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h
index 9363500131a7..7904a2a493de 100644
--- a/samples/bpf/bpf_helpers.h
+++ b/samples/bpf/bpf_helpers.h
@@ -82,6 +82,7 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag
#define PT_REGS_FP(x) ((x)->bp)
#define PT_REGS_RC(x) ((x)->ax)
#define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->ip)
#elif defined(__s390x__)
@@ -94,6 +95,7 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag
#define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
#define PT_REGS_RC(x) ((x)->gprs[2])
#define PT_REGS_SP(x) ((x)->gprs[15])
+#define PT_REGS_IP(x) ((x)->ip)
#elif defined(__aarch64__)
@@ -106,6 +108,30 @@ static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flag
#define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */
#define PT_REGS_RC(x) ((x)->regs[0])
#define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->pc)
+
+#elif defined(__powerpc__)
+
+#define PT_REGS_PARM1(x) ((x)->gpr[3])
+#define PT_REGS_PARM2(x) ((x)->gpr[4])
+#define PT_REGS_PARM3(x) ((x)->gpr[5])
+#define PT_REGS_PARM4(x) ((x)->gpr[6])
+#define PT_REGS_PARM5(x) ((x)->gpr[7])
+#define PT_REGS_RC(x) ((x)->gpr[3])
+#define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->nip)
#endif
+
+#ifdef __powerpc__
+#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ (ip) = (ctx)->link; })
+#define BPF_KRETPROBE_READ_RET_IP BPF_KPROBE_READ_RET_IP
+#else
+#define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ \
+ bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
+#define BPF_KRETPROBE_READ_RET_IP(ip, ctx) ({ \
+ bpf_probe_read(&(ip), sizeof(ip), \
+ (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
+#endif
+
#endif
diff --git a/samples/bpf/bpf_load.c b/samples/bpf/bpf_load.c
index 58f86bd11b3d..022af71c2bb5 100644
--- a/samples/bpf/bpf_load.c
+++ b/samples/bpf/bpf_load.c
@@ -49,6 +49,7 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
bool is_socket = strncmp(event, "socket", 6) == 0;
bool is_kprobe = strncmp(event, "kprobe/", 7) == 0;
bool is_kretprobe = strncmp(event, "kretprobe/", 10) == 0;
+ bool is_tracepoint = strncmp(event, "tracepoint/", 11) == 0;
enum bpf_prog_type prog_type;
char buf[256];
int fd, efd, err, id;
@@ -63,6 +64,8 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
prog_type = BPF_PROG_TYPE_SOCKET_FILTER;
} else if (is_kprobe || is_kretprobe) {
prog_type = BPF_PROG_TYPE_KPROBE;
+ } else if (is_tracepoint) {
+ prog_type = BPF_PROG_TYPE_TRACEPOINT;
} else {
printf("Unknown event '%s'\n", event);
return -1;
@@ -111,12 +114,23 @@ static int load_and_attach(const char *event, struct bpf_insn *prog, int size)
event, strerror(errno));
return -1;
}
- }
- strcpy(buf, DEBUGFS);
- strcat(buf, "events/kprobes/");
- strcat(buf, event);
- strcat(buf, "/id");
+ strcpy(buf, DEBUGFS);
+ strcat(buf, "events/kprobes/");
+ strcat(buf, event);
+ strcat(buf, "/id");
+ } else if (is_tracepoint) {
+ event += 11;
+
+ if (*event == 0) {
+ printf("event name cannot be empty\n");
+ return -1;
+ }
+ strcpy(buf, DEBUGFS);
+ strcat(buf, "events/");
+ strcat(buf, event);
+ strcat(buf, "/id");
+ }
efd = open(buf, O_RDONLY, 0);
if (efd < 0) {
@@ -304,6 +318,7 @@ int load_bpf_file(char *path)
if (memcmp(shname_prog, "kprobe/", 7) == 0 ||
memcmp(shname_prog, "kretprobe/", 10) == 0 ||
+ memcmp(shname_prog, "tracepoint/", 11) == 0 ||
memcmp(shname_prog, "socket", 6) == 0)
load_and_attach(shname_prog, insns, data_prog->d_size);
}
@@ -320,6 +335,7 @@ int load_bpf_file(char *path)
if (memcmp(shname, "kprobe/", 7) == 0 ||
memcmp(shname, "kretprobe/", 10) == 0 ||
+ memcmp(shname, "tracepoint/", 11) == 0 ||
memcmp(shname, "socket", 6) == 0)
load_and_attach(shname, data->d_buf, data->d_size);
}
diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
index 95af56ec5739..3147377e8fd3 100644
--- a/samples/bpf/map_perf_test_user.c
+++ b/samples/bpf/map_perf_test_user.c
@@ -17,6 +17,7 @@
#include <linux/bpf.h>
#include <string.h>
#include <time.h>
+#include <sys/resource.h>
#include "libbpf.h"
#include "bpf_load.h"
diff --git a/samples/bpf/offwaketime_kern.c b/samples/bpf/offwaketime_kern.c
index c0aa5a9b9c48..983629a31c79 100644
--- a/samples/bpf/offwaketime_kern.c
+++ b/samples/bpf/offwaketime_kern.c
@@ -73,7 +73,7 @@ int waker(struct pt_regs *ctx)
return 0;
}
-static inline int update_counts(struct pt_regs *ctx, u32 pid, u64 delta)
+static inline int update_counts(void *ctx, u32 pid, u64 delta)
{
struct key_t key = {};
struct wokeby_t *woke;
@@ -100,15 +100,33 @@ static inline int update_counts(struct pt_regs *ctx, u32 pid, u64 delta)
return 0;
}
+#if 1
+/* taken from /sys/kernel/debug/tracing/events/sched/sched_switch/format */
+struct sched_switch_args {
+ unsigned long long pad;
+ char prev_comm[16];
+ int prev_pid;
+ int prev_prio;
+ long long prev_state;
+ char next_comm[16];
+ int next_pid;
+ int next_prio;
+};
+SEC("tracepoint/sched/sched_switch")
+int oncpu(struct sched_switch_args *ctx)
+{
+ /* record previous thread sleep time */
+ u32 pid = ctx->prev_pid;
+#else
SEC("kprobe/finish_task_switch")
int oncpu(struct pt_regs *ctx)
{
struct task_struct *p = (void *) PT_REGS_PARM1(ctx);
+ /* record previous thread sleep time */
+ u32 pid = _(p->pid);
+#endif
u64 delta, ts, *tsp;
- u32 pid;
- /* record previous thread sleep time */
- pid = _(p->pid);
ts = bpf_ktime_get_ns();
bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
diff --git a/samples/bpf/spintest_kern.c b/samples/bpf/spintest_kern.c
index 4b27619d91a4..ce0167d09cdc 100644
--- a/samples/bpf/spintest_kern.c
+++ b/samples/bpf/spintest_kern.c
@@ -34,7 +34,7 @@ struct bpf_map_def SEC("maps") stackmap = {
#define PROG(foo) \
int foo(struct pt_regs *ctx) \
{ \
- long v = ctx->ip, *val; \
+ long v = PT_REGS_IP(ctx), *val; \
\
val = bpf_map_lookup_elem(&my_map, &v); \
bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
diff --git a/samples/bpf/test_overhead_kprobe_kern.c b/samples/bpf/test_overhead_kprobe_kern.c
new file mode 100644
index 000000000000..468a66a92ef9
--- /dev/null
+++ b/samples/bpf/test_overhead_kprobe_kern.c
@@ -0,0 +1,41 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
+
+SEC("kprobe/__set_task_comm")
+int prog(struct pt_regs *ctx)
+{
+ struct signal_struct *signal;
+ struct task_struct *tsk;
+ char oldcomm[16] = {};
+ char newcomm[16] = {};
+ u16 oom_score_adj;
+ u32 pid;
+
+ tsk = (void *)PT_REGS_PARM1(ctx);
+
+ pid = _(tsk->pid);
+ bpf_probe_read(oldcomm, sizeof(oldcomm), &tsk->comm);
+ bpf_probe_read(newcomm, sizeof(newcomm), (void *)PT_REGS_PARM2(ctx));
+ signal = _(tsk->signal);
+ oom_score_adj = _(signal->oom_score_adj);
+ return 0;
+}
+
+SEC("kprobe/urandom_read")
+int prog2(struct pt_regs *ctx)
+{
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/test_overhead_tp_kern.c b/samples/bpf/test_overhead_tp_kern.c
new file mode 100644
index 000000000000..38f5c0b9da9f
--- /dev/null
+++ b/samples/bpf/test_overhead_tp_kern.c
@@ -0,0 +1,36 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <uapi/linux/bpf.h>
+#include "bpf_helpers.h"
+
+/* from /sys/kernel/debug/tracing/events/task/task_rename/format */
+struct task_rename {
+ __u64 pad;
+ __u32 pid;
+ char oldcomm[16];
+ char newcomm[16];
+ __u16 oom_score_adj;
+};
+SEC("tracepoint/task/task_rename")
+int prog(struct task_rename *ctx)
+{
+ return 0;
+}
+
+/* from /sys/kernel/debug/tracing/events/random/urandom_read/format */
+struct urandom_read {
+ __u64 pad;
+ int got_bits;
+ int pool_left;
+ int input_left;
+};
+SEC("tracepoint/random/urandom_read")
+int prog2(struct urandom_read *ctx)
+{
+ return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_overhead_user.c b/samples/bpf/test_overhead_user.c
new file mode 100644
index 000000000000..d291167fd3c7
--- /dev/null
+++ b/samples/bpf/test_overhead_user.c
@@ -0,0 +1,162 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define _GNU_SOURCE
+#include <sched.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <asm/unistd.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <assert.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <linux/bpf.h>
+#include <string.h>
+#include <time.h>
+#include <sys/resource.h>
+#include "libbpf.h"
+#include "bpf_load.h"
+
+#define MAX_CNT 1000000
+
+static __u64 time_get_ns(void)
+{
+ struct timespec ts;
+
+ clock_gettime(CLOCK_MONOTONIC, &ts);
+ return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+static void test_task_rename(int cpu)
+{
+ __u64 start_time;
+ char buf[] = "test\n";
+ int i, fd;
+
+ fd = open("/proc/self/comm", O_WRONLY|O_TRUNC);
+ if (fd < 0) {
+ printf("couldn't open /proc\n");
+ exit(1);
+ }
+ start_time = time_get_ns();
+ for (i = 0; i < MAX_CNT; i++)
+ write(fd, buf, sizeof(buf));
+ printf("task_rename:%d: %lld events per sec\n",
+ cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
+ close(fd);
+}
+
+static void test_urandom_read(int cpu)
+{
+ __u64 start_time;
+ char buf[4];
+ int i, fd;
+
+ fd = open("/dev/urandom", O_RDONLY);
+ if (fd < 0) {
+ printf("couldn't open /dev/urandom\n");
+ exit(1);
+ }
+ start_time = time_get_ns();
+ for (i = 0; i < MAX_CNT; i++)
+ read(fd, buf, sizeof(buf));
+ printf("urandom_read:%d: %lld events per sec\n",
+ cpu, MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
+ close(fd);
+}
+
+static void loop(int cpu, int flags)
+{
+ cpu_set_t cpuset;
+
+ CPU_ZERO(&cpuset);
+ CPU_SET(cpu, &cpuset);
+ sched_setaffinity(0, sizeof(cpuset), &cpuset);
+
+ if (flags & 1)
+ test_task_rename(cpu);
+ if (flags & 2)
+ test_urandom_read(cpu);
+}
+
+static void run_perf_test(int tasks, int flags)
+{
+ pid_t pid[tasks];
+ int i;
+
+ for (i = 0; i < tasks; i++) {
+ pid[i] = fork();
+ if (pid[i] == 0) {
+ loop(i, flags);
+ exit(0);
+ } else if (pid[i] == -1) {
+ printf("couldn't spawn #%d process\n", i);
+ exit(1);
+ }
+ }
+ for (i = 0; i < tasks; i++) {
+ int status;
+
+ assert(waitpid(pid[i], &status, 0) == pid[i]);
+ assert(status == 0);
+ }
+}
+
+static void unload_progs(void)
+{
+ close(prog_fd[0]);
+ close(prog_fd[1]);
+ close(event_fd[0]);
+ close(event_fd[1]);
+}
+
+int main(int argc, char **argv)
+{
+ struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
+ char filename[256];
+ int num_cpu = 8;
+ int test_flags = ~0;
+
+ setrlimit(RLIMIT_MEMLOCK, &r);
+
+ if (argc > 1)
+ test_flags = atoi(argv[1]) ? : test_flags;
+ if (argc > 2)
+ num_cpu = atoi(argv[2]) ? : num_cpu;
+
+ if (test_flags & 0x3) {
+ printf("BASE\n");
+ run_perf_test(num_cpu, test_flags);
+ }
+
+ if (test_flags & 0xC) {
+ snprintf(filename, sizeof(filename),
+ "%s_kprobe_kern.o", argv[0]);
+ if (load_bpf_file(filename)) {
+ printf("%s", bpf_log_buf);
+ return 1;
+ }
+ printf("w/KPROBE\n");
+ run_perf_test(num_cpu, test_flags >> 2);
+ unload_progs();
+ }
+
+ if (test_flags & 0x30) {
+ snprintf(filename, sizeof(filename),
+ "%s_tp_kern.o", argv[0]);
+ if (load_bpf_file(filename)) {
+ printf("%s", bpf_log_buf);
+ return 1;
+ }
+ printf("w/TRACEPOINT\n");
+ run_perf_test(num_cpu, test_flags >> 4);
+ unload_progs();
+ }
+
+ return 0;
+}
diff --git a/samples/bpf/tracex2_kern.c b/samples/bpf/tracex2_kern.c
index 09c1adc27d42..6d6eefd0d465 100644
--- a/samples/bpf/tracex2_kern.c
+++ b/samples/bpf/tracex2_kern.c
@@ -27,10 +27,10 @@ int bpf_prog2(struct pt_regs *ctx)
long init_val = 1;
long *value;
- /* x64/s390x specific: read ip of kfree_skb caller.
+ /* read ip of kfree_skb caller.
* non-portable version of __builtin_return_address(0)
*/
- bpf_probe_read(&loc, sizeof(loc), (void *)PT_REGS_RET(ctx));
+ BPF_KPROBE_READ_RET_IP(loc, ctx);
value = bpf_map_lookup_elem(&my_map, &loc);
if (value)
diff --git a/samples/bpf/tracex4_kern.c b/samples/bpf/tracex4_kern.c
index ac4671420cf1..6dd8e384de96 100644
--- a/samples/bpf/tracex4_kern.c
+++ b/samples/bpf/tracex4_kern.c
@@ -40,7 +40,7 @@ int bpf_prog2(struct pt_regs *ctx)
long ip = 0;
/* get ip address of kmem_cache_alloc_node() caller */
- bpf_probe_read(&ip, sizeof(ip), (void *)(PT_REGS_FP(ctx) + sizeof(ip)));
+ BPF_KRETPROBE_READ_RET_IP(ip, ctx);
struct pair v = {
.val = bpf_ktime_get_ns(),
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-29 09:12:56 +0000