[PATCH v1 1/7] perf trace: Raw augmented syscalls fix libbpf 1.0+ compatibility
From: Ian Rogers
Date: Thu Nov 03 2022 - 00:55:04 EST
Don't use deprecated and now broken map style. Avoid use of
tools/perf/include/bpf/bpf.h and use the more regular BPF headers.
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
.../examples/bpf/augmented_raw_syscalls.c | 75 ++++++++++++++-----
1 file changed, 58 insertions(+), 17 deletions(-)
diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c
index a262dcd020f4..13c72fd602c3 100644
--- a/tools/perf/examples/bpf/augmented_raw_syscalls.c
+++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c
@@ -14,13 +14,19 @@
* code that will combine entry/exit in a strace like way.
*/
-#include <unistd.h>
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
#include <linux/limits.h>
-#include <linux/socket.h>
-#include <pid_filter.h>
+#include <stdbool.h>
+#include <sys/socket.h>
/* bpf-output associated map */
-bpf_map(__augmented_syscalls__, PERF_EVENT_ARRAY, int, u32, __NR_CPUS__);
+struct __augmented_syscalls__ {
+ __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+ __type(key, int);
+ __type(value, __u32);
+ __uint(max_entries, __NR_CPUS__);
+} __augmented_syscalls__ SEC(".maps");
/*
* string_args_len: one per syscall arg, 0 means not a string or don't copy it,
@@ -29,24 +35,39 @@ bpf_map(__augmented_syscalls__, PERF_EVENT_ARRAY, int, u32, __NR_CPUS__);
*/
struct syscall {
bool enabled;
- u16 string_args_len[6];
+ __u16 string_args_len[6];
};
-bpf_map(syscalls, ARRAY, int, struct syscall, 512);
+struct syscalls {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __type(key, int);
+ __type(value, struct syscall);
+ __uint(max_entries, 512);
+} syscalls SEC(".maps");
/*
* What to augment at entry?
*
* Pointer arg payloads (filenames, etc) passed from userspace to the kernel
*/
-bpf_map(syscalls_sys_enter, PROG_ARRAY, u32, u32, 512);
+struct syscalls_sys_enter {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __type(key, __u32);
+ __type(value, __u32);
+ __uint(max_entries, 512);
+} syscalls_sys_enter SEC(".maps");
/*
* What to augment at exit?
*
* Pointer arg payloads returned from the kernel (struct stat, etc) to userspace.
*/
-bpf_map(syscalls_sys_exit, PROG_ARRAY, u32, u32, 512);
+struct syscalls_sys_exit {
+ __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+ __type(key, __u32);
+ __type(value, __u32);
+ __uint(max_entries, 512);
+} syscalls_sys_exit SEC(".maps");
struct syscall_enter_args {
unsigned long long common_tp_fields;
@@ -66,7 +87,12 @@ struct augmented_arg {
char value[PATH_MAX];
};
-pid_filter(pids_filtered);
+struct pids_filtered {
+ __uint(type, BPF_MAP_TYPE_HASH);
+ __type(key, pid_t);
+ __type(value, bool);
+ __uint(max_entries, 64);
+} pids_filtered SEC(".maps");
struct augmented_args_payload {
struct syscall_enter_args args;
@@ -79,7 +105,12 @@ struct augmented_args_payload {
};
// We need more tmp space than the BPF stack can give us
-bpf_map(augmented_args_tmp, PERCPU_ARRAY, int, struct augmented_args_payload, 1);
+struct augmented_args_tmp {
+ __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+ __type(key, int);
+ __type(value, struct augmented_args_payload);
+ __uint(max_entries, 1);
+} augmented_args_tmp SEC(".maps");
static inline struct augmented_args_payload *augmented_args_payload(void)
{
@@ -90,14 +121,14 @@ static inline struct augmented_args_payload *augmented_args_payload(void)
static inline int augmented__output(void *ctx, struct augmented_args_payload *args, int len)
{
/* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */
- return perf_event_output(ctx, &__augmented_syscalls__, BPF_F_CURRENT_CPU, args, len);
+ return bpf_perf_event_output(ctx, &__augmented_syscalls__, BPF_F_CURRENT_CPU, args, len);
}
static inline
unsigned int augmented_arg__read_str(struct augmented_arg *augmented_arg, const void *arg, unsigned int arg_len)
{
unsigned int augmented_len = sizeof(*augmented_arg);
- int string_len = probe_read_str(&augmented_arg->value, arg_len, arg);
+ int string_len = bpf_probe_read_str(&augmented_arg->value, arg_len, arg);
augmented_arg->size = augmented_arg->err = 0;
/*
@@ -146,7 +177,7 @@ int sys_enter_connect(struct syscall_enter_args *args)
if (socklen > sizeof(augmented_args->saddr))
socklen = sizeof(augmented_args->saddr);
- probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
+ bpf_probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
return augmented__output(args, augmented_args, len + socklen);
}
@@ -165,7 +196,7 @@ int sys_enter_sendto(struct syscall_enter_args *args)
if (socklen > sizeof(augmented_args->saddr))
socklen = sizeof(augmented_args->saddr);
- probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
+ bpf_probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
return augmented__output(args, augmented_args, len + socklen);
}
@@ -234,6 +265,16 @@ int sys_enter_renameat(struct syscall_enter_args *args)
return augmented__output(args, augmented_args, len);
}
+static pid_t getpid(void)
+{
+ return bpf_get_current_pid_tgid();
+}
+
+static bool pid_filter__has(struct pids_filtered *pids, pid_t pid)
+{
+ return bpf_map_lookup_elem(pids, &pid) != NULL;
+}
+
SEC("raw_syscalls:sys_enter")
int sys_enter(struct syscall_enter_args *args)
{
@@ -257,7 +298,7 @@ int sys_enter(struct syscall_enter_args *args)
if (augmented_args == NULL)
return 1;
- probe_read(&augmented_args->args, sizeof(augmented_args->args), args);
+ bpf_probe_read(&augmented_args->args, sizeof(augmented_args->args), args);
/*
* Jump to syscall specific augmenter, even if the default one,
@@ -278,7 +319,7 @@ int sys_exit(struct syscall_exit_args *args)
if (pid_filter__has(&pids_filtered, getpid()))
return 0;
- probe_read(&exit_args, sizeof(exit_args), args);
+ bpf_probe_read(&exit_args, sizeof(exit_args), args);
/*
* Jump to syscall specific return augmenter, even if the default one,
* "!raw_syscalls:unaugmented" that will just return 1 to return the
@@ -291,4 +332,4 @@ int sys_exit(struct syscall_exit_args *args)
return 0;
}
-license(GPL);
+char _license[] SEC("license") = "GPL";
--
2.38.1.273.g43a17bfeac-goog