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-rw-r--r--include/linux/trace_events.h17
-rw-r--r--include/uapi/linux/bpf.h26
-rw-r--r--kernel/bpf/syscall.c131
-rw-r--r--kernel/trace/bpf_trace.c48
-rw-r--r--kernel/trace/trace_kprobe.c29
-rw-r--r--kernel/trace/trace_uprobe.c22
6 files changed, 273 insertions, 0 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 2bde3eff564c..d34144a3c5b5 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -473,6 +473,9 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info);
int bpf_probe_register(struct bpf_raw_event_map *btp, struct bpf_prog *prog);
int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog);
struct bpf_raw_event_map *bpf_find_raw_tracepoint(const char *name);
+int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
+ u32 *fd_type, const char **buf,
+ u64 *probe_offset, u64 *probe_addr);
#else
static inline unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
{
@@ -504,6 +507,13 @@ static inline struct bpf_raw_event_map *bpf_find_raw_tracepoint(const char *name
{
return NULL;
}
+static inline int bpf_get_perf_event_info(const struct perf_event *event,
+ u32 *prog_id, u32 *fd_type,
+ const char **buf, u64 *probe_offset,
+ u64 *probe_addr)
+{
+ return -EOPNOTSUPP;
+}
#endif
enum {
@@ -560,10 +570,17 @@ extern void perf_trace_del(struct perf_event *event, int flags);
#ifdef CONFIG_KPROBE_EVENTS
extern int perf_kprobe_init(struct perf_event *event, bool is_retprobe);
extern void perf_kprobe_destroy(struct perf_event *event);
+extern int bpf_get_kprobe_info(const struct perf_event *event,
+ u32 *fd_type, const char **symbol,
+ u64 *probe_offset, u64 *probe_addr,
+ bool perf_type_tracepoint);
#endif
#ifdef CONFIG_UPROBE_EVENTS
extern int perf_uprobe_init(struct perf_event *event, bool is_retprobe);
extern void perf_uprobe_destroy(struct perf_event *event);
+extern int bpf_get_uprobe_info(const struct perf_event *event,
+ u32 *fd_type, const char **filename,
+ u64 *probe_offset, bool perf_type_tracepoint);
#endif
extern int ftrace_profile_set_filter(struct perf_event *event, int event_id,
char *filter_str);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index e95fec90c2c1..9b8c6e310e9a 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -97,6 +97,7 @@ enum bpf_cmd {
BPF_RAW_TRACEPOINT_OPEN,
BPF_BTF_LOAD,
BPF_BTF_GET_FD_BY_ID,
+ BPF_TASK_FD_QUERY,
};
enum bpf_map_type {
@@ -380,6 +381,22 @@ union bpf_attr {
__u32 btf_log_size;
__u32 btf_log_level;
};
+
+ struct {
+ __u32 pid; /* input: pid */
+ __u32 fd; /* input: fd */
+ __u32 flags; /* input: flags */
+ __u32 buf_len; /* input/output: buf len */
+ __aligned_u64 buf; /* input/output:
+ * tp_name for tracepoint
+ * symbol for kprobe
+ * filename for uprobe
+ */
+ __u32 prog_id; /* output: prod_id */
+ __u32 fd_type; /* output: BPF_FD_TYPE_* */
+ __u64 probe_offset; /* output: probe_offset */
+ __u64 probe_addr; /* output: probe_addr */
+ } task_fd_query;
} __attribute__((aligned(8)));
/* The description below is an attempt at providing documentation to eBPF
@@ -2557,4 +2574,13 @@ struct bpf_fib_lookup {
__u8 dmac[6]; /* ETH_ALEN */
};
+enum bpf_task_fd_type {
+ BPF_FD_TYPE_RAW_TRACEPOINT, /* tp name */
+ BPF_FD_TYPE_TRACEPOINT, /* tp name */
+ BPF_FD_TYPE_KPROBE, /* (symbol + offset) or addr */
+ BPF_FD_TYPE_KRETPROBE, /* (symbol + offset) or addr */
+ BPF_FD_TYPE_UPROBE, /* filename + offset */
+ BPF_FD_TYPE_URETPROBE, /* filename + offset */
+};
+
#endif /* _UAPI__LINUX_BPF_H__ */
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 788456c18617..388d4feda348 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -18,7 +18,9 @@
#include <linux/vmalloc.h>
#include <linux/mmzone.h>
#include <linux/anon_inodes.h>
+#include <linux/fdtable.h>
#include <linux/file.h>
+#include <linux/fs.h>
#include <linux/license.h>
#include <linux/filter.h>
#include <linux/version.h>
@@ -2178,6 +2180,132 @@ static int bpf_btf_get_fd_by_id(const union bpf_attr *attr)
return btf_get_fd_by_id(attr->btf_id);
}
+static int bpf_task_fd_query_copy(const union bpf_attr *attr,
+ union bpf_attr __user *uattr,
+ u32 prog_id, u32 fd_type,
+ const char *buf, u64 probe_offset,
+ u64 probe_addr)
+{
+ char __user *ubuf = u64_to_user_ptr(attr->task_fd_query.buf);
+ u32 len = buf ? strlen(buf) : 0, input_len;
+ int err = 0;
+
+ if (put_user(len, &uattr->task_fd_query.buf_len))
+ return -EFAULT;
+ input_len = attr->task_fd_query.buf_len;
+ if (input_len && ubuf) {
+ if (!len) {
+ /* nothing to copy, just make ubuf NULL terminated */
+ char zero = '\0';
+
+ if (put_user(zero, ubuf))
+ return -EFAULT;
+ } else if (input_len >= len + 1) {
+ /* ubuf can hold the string with NULL terminator */
+ if (copy_to_user(ubuf, buf, len + 1))
+ return -EFAULT;
+ } else {
+ /* ubuf cannot hold the string with NULL terminator,
+ * do a partial copy with NULL terminator.
+ */
+ char zero = '\0';
+
+ err = -ENOSPC;
+ if (copy_to_user(ubuf, buf, input_len - 1))
+ return -EFAULT;
+ if (put_user(zero, ubuf + input_len - 1))
+ return -EFAULT;
+ }
+ }
+
+ if (put_user(prog_id, &uattr->task_fd_query.prog_id) ||
+ put_user(fd_type, &uattr->task_fd_query.fd_type) ||
+ put_user(probe_offset, &uattr->task_fd_query.probe_offset) ||
+ put_user(probe_addr, &uattr->task_fd_query.probe_addr))
+ return -EFAULT;
+
+ return err;
+}
+
+#define BPF_TASK_FD_QUERY_LAST_FIELD task_fd_query.probe_addr
+
+static int bpf_task_fd_query(const union bpf_attr *attr,
+ union bpf_attr __user *uattr)
+{
+ pid_t pid = attr->task_fd_query.pid;
+ u32 fd = attr->task_fd_query.fd;
+ const struct perf_event *event;
+ struct files_struct *files;
+ struct task_struct *task;
+ struct file *file;
+ int err;
+
+ if (CHECK_ATTR(BPF_TASK_FD_QUERY))
+ return -EINVAL;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (attr->task_fd_query.flags != 0)
+ return -EINVAL;
+
+ task = get_pid_task(find_vpid(pid), PIDTYPE_PID);
+ if (!task)
+ return -ENOENT;
+
+ files = get_files_struct(task);
+ put_task_struct(task);
+ if (!files)
+ return -ENOENT;
+
+ err = 0;
+ spin_lock(&files->file_lock);
+ file = fcheck_files(files, fd);
+ if (!file)
+ err = -EBADF;
+ else
+ get_file(file);
+ spin_unlock(&files->file_lock);
+ put_files_struct(files);
+
+ if (err)
+ goto out;
+
+ if (file->f_op == &bpf_raw_tp_fops) {
+ struct bpf_raw_tracepoint *raw_tp = file->private_data;
+ struct bpf_raw_event_map *btp = raw_tp->btp;
+
+ err = bpf_task_fd_query_copy(attr, uattr,
+ raw_tp->prog->aux->id,
+ BPF_FD_TYPE_RAW_TRACEPOINT,
+ btp->tp->name, 0, 0);
+ goto put_file;
+ }
+
+ event = perf_get_event(file);
+ if (!IS_ERR(event)) {
+ u64 probe_offset, probe_addr;
+ u32 prog_id, fd_type;
+ const char *buf;
+
+ err = bpf_get_perf_event_info(event, &prog_id, &fd_type,
+ &buf, &probe_offset,
+ &probe_addr);
+ if (!err)
+ err = bpf_task_fd_query_copy(attr, uattr, prog_id,
+ fd_type, buf,
+ probe_offset,
+ probe_addr);
+ goto put_file;
+ }
+
+ err = -ENOTSUPP;
+put_file:
+ fput(file);
+out:
+ return err;
+}
+
SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size)
{
union bpf_attr attr = {};
@@ -2264,6 +2392,9 @@ SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, siz
case BPF_BTF_GET_FD_BY_ID:
err = bpf_btf_get_fd_by_id(&attr);
break;
+ case BPF_TASK_FD_QUERY:
+ err = bpf_task_fd_query(&attr, uattr);
+ break;
default:
err = -EINVAL;
break;
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index ce2cbbff27e4..81fdf2fc94ac 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -14,6 +14,7 @@
#include <linux/uaccess.h>
#include <linux/ctype.h>
#include <linux/kprobes.h>
+#include <linux/syscalls.h>
#include <linux/error-injection.h>
#include "trace_probe.h"
@@ -1163,3 +1164,50 @@ int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog)
mutex_unlock(&bpf_event_mutex);
return err;
}
+
+int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id,
+ u32 *fd_type, const char **buf,
+ u64 *probe_offset, u64 *probe_addr)
+{
+ bool is_tracepoint, is_syscall_tp;
+ struct bpf_prog *prog;
+ int flags, err = 0;
+
+ prog = event->prog;
+ if (!prog)
+ return -ENOENT;
+
+ /* not supporting BPF_PROG_TYPE_PERF_EVENT yet */
+ if (prog->type == BPF_PROG_TYPE_PERF_EVENT)
+ return -EOPNOTSUPP;
+
+ *prog_id = prog->aux->id;
+ flags = event->tp_event->flags;
+ is_tracepoint = flags & TRACE_EVENT_FL_TRACEPOINT;
+ is_syscall_tp = is_syscall_trace_event(event->tp_event);
+
+ if (is_tracepoint || is_syscall_tp) {
+ *buf = is_tracepoint ? event->tp_event->tp->name
+ : event->tp_event->name;
+ *fd_type = BPF_FD_TYPE_TRACEPOINT;
+ *probe_offset = 0x0;
+ *probe_addr = 0x0;
+ } else {
+ /* kprobe/uprobe */
+ err = -EOPNOTSUPP;
+#ifdef CONFIG_KPROBE_EVENTS
+ if (flags & TRACE_EVENT_FL_KPROBE)
+ err = bpf_get_kprobe_info(event, fd_type, buf,
+ probe_offset, probe_addr,
+ event->attr.type == PERF_TYPE_TRACEPOINT);
+#endif
+#ifdef CONFIG_UPROBE_EVENTS
+ if (flags & TRACE_EVENT_FL_UPROBE)
+ err = bpf_get_uprobe_info(event, fd_type, buf,
+ probe_offset,
+ event->attr.type == PERF_TYPE_TRACEPOINT);
+#endif
+ }
+
+ return err;
+}
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 02aed76e0978..daa81571b22a 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1287,6 +1287,35 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
head, NULL);
}
NOKPROBE_SYMBOL(kretprobe_perf_func);
+
+int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
+ const char **symbol, u64 *probe_offset,
+ u64 *probe_addr, bool perf_type_tracepoint)
+{
+ const char *pevent = trace_event_name(event->tp_event);
+ const char *group = event->tp_event->class->system;
+ struct trace_kprobe *tk;
+
+ if (perf_type_tracepoint)
+ tk = find_trace_kprobe(pevent, group);
+ else
+ tk = event->tp_event->data;
+ if (!tk)
+ return -EINVAL;
+
+ *fd_type = trace_kprobe_is_return(tk) ? BPF_FD_TYPE_KRETPROBE
+ : BPF_FD_TYPE_KPROBE;
+ if (tk->symbol) {
+ *symbol = tk->symbol;
+ *probe_offset = tk->rp.kp.offset;
+ *probe_addr = 0;
+ } else {
+ *symbol = NULL;
+ *probe_offset = 0;
+ *probe_addr = (unsigned long)tk->rp.kp.addr;
+ }
+ return 0;
+}
#endif /* CONFIG_PERF_EVENTS */
/*
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index ac892878dbe6..bf89a51e740d 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1161,6 +1161,28 @@ static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func,
{
__uprobe_perf_func(tu, func, regs, ucb, dsize);
}
+
+int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type,
+ const char **filename, u64 *probe_offset,
+ bool perf_type_tracepoint)
+{
+ const char *pevent = trace_event_name(event->tp_event);
+ const char *group = event->tp_event->class->system;
+ struct trace_uprobe *tu;
+
+ if (perf_type_tracepoint)
+ tu = find_probe_event(pevent, group);
+ else
+ tu = event->tp_event->data;
+ if (!tu)
+ return -EINVAL;
+
+ *fd_type = is_ret_probe(tu) ? BPF_FD_TYPE_URETPROBE
+ : BPF_FD_TYPE_UPROBE;
+ *filename = tu->filename;
+ *probe_offset = tu->offset;
+ return 0;
+}
#endif /* CONFIG_PERF_EVENTS */
static int
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-06 09:46:05 +0000