sync with latest libbpf

sync with latest libbpf repo

Signed-off-by: Yonghong Song <[email protected]>

docs/kernel-versions.md

@@ -195,6 +195,7 @@ Helper | Kernel version | License | Commit |
 `BPF_FUNC_get_socket_uid()` | 4.12 |  | [`6acc5c291068`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6acc5c2910689fc6ee181bf63085c5efff6a42bd)
 `BPF_FUNC_get_stack()` | 4.18 | GPL | [`de2ff05f48af`](https://git.kernel.org/cgit/linux/kernel/git/davem/net-next.git/commit/?id=de2ff05f48afcde816ff4edb217417f62f624ab5)
 `BPF_FUNC_get_stackid()` | 4.6 | GPL | [`d5a3b1f69186`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d5a3b1f691865be576c2bffa708549b8cdccda19)
+`BPF_FUNC_get_task_stack()` | 5.9 | | [`fa28dcb82a38`](https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next/+/fa28dcb82a38f8e3993b0fae9106b1a80b59e4f0)
 `BPF_FUNC_getsockopt()` | 4.15 |  | [`cd86d1fd2102`](https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=cd86d1fd21025fdd6daf23d1288da405e7ad0ec6)
 `BPF_FUNC_jiffies64()` | 5.5 |  | [`5576b991e9c1`](https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=5576b991e9c1a11d2cc21c4b94fc75ec27603896)
 `BPF_FUNC_ktime_get_boot_ns()` | 5.7 | GPL | [`71d19214776e`](https://kernel.googlesource.com/pub/scm/linux/kernel/git/bpf/bpf-next/+/71d19214776e61b33da48f7c1b46e522c7f78221)
@@ -352,5 +353,5 @@ The list of program types and supported helper functions can be retrieved with:
 |Function Group| Functions|
 |------------------|-------|
 |`Base functions`| `BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_map_peek_elem()` <br> `BPF_FUNC_map_pop_elem()` <br> `BPF_FUNC_map_push_elem()` <br> `BPF_FUNC_get_prandom_u32()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_get_numa_node_id()` <br> `BPF_FUNC_tail_call()` <br> `BPF_FUNC_ktime_get_boot_ns()` <br> `BPF_FUNC_ktime_get_ns()` <br> `BPF_FUNC_trace_printk()` <br> `BPF_FUNC_spin_lock()` <br> `BPF_FUNC_spin_unlock()` |
-|`Tracing functions`|`BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_probe_read()` <br> `BPF_FUNC_ktime_get_boot_ns()` <br> `BPF_FUNC_ktime_get_ns()` <br> `BPF_FUNC_tail_call()` <br> `BPF_FUNC_get_current_pid_tgid()` <br> `BPF_FUNC_get_current_task()` <br> `BPF_FUNC_get_current_uid_gid()` <br> `BPF_FUNC_get_current_comm()` <br> `BPF_FUNC_trace_printk()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_get_numa_node_id()` <br> `BPF_FUNC_perf_event_read()` <br> `BPF_FUNC_probe_write_user()` <br> `BPF_FUNC_current_task_under_cgroup()` <br> `BPF_FUNC_get_prandom_u32()` <br> `BPF_FUNC_probe_read_str()` <br> `BPF_FUNC_get_current_cgroup_id()` <br> `BPF_FUNC_send_signal()` <br> `BPF_FUNC_probe_read_kernel()` <br> `BPF_FUNC_probe_read_kernel_str()` <br> `BPF_FUNC_probe_read_user()` <br> `BPF_FUNC_probe_read_user_str()` <br> `BPF_FUNC_send_signal_thread()` <br> `BPF_FUNC_get_ns_current_pid_tgid()` <br> `BPF_FUNC_xdp_output()`|
+|`Tracing functions`|`BPF_FUNC_map_lookup_elem()` <br> `BPF_FUNC_map_update_elem()` <br> `BPF_FUNC_map_delete_elem()` <br> `BPF_FUNC_probe_read()` <br> `BPF_FUNC_ktime_get_boot_ns()` <br> `BPF_FUNC_ktime_get_ns()` <br> `BPF_FUNC_tail_call()` <br> `BPF_FUNC_get_current_pid_tgid()` <br> `BPF_FUNC_get_current_task()` <br> `BPF_FUNC_get_current_uid_gid()` <br> `BPF_FUNC_get_current_comm()` <br> `BPF_FUNC_trace_printk()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_get_numa_node_id()` <br> `BPF_FUNC_perf_event_read()` <br> `BPF_FUNC_probe_write_user()` <br> `BPF_FUNC_current_task_under_cgroup()` <br> `BPF_FUNC_get_prandom_u32()` <br> `BPF_FUNC_probe_read_str()` <br> `BPF_FUNC_get_current_cgroup_id()` <br> `BPF_FUNC_send_signal()` <br> `BPF_FUNC_probe_read_kernel()` <br> `BPF_FUNC_probe_read_kernel_str()` <br> `BPF_FUNC_probe_read_user()` <br> `BPF_FUNC_probe_read_user_str()` <br> `BPF_FUNC_send_signal_thread()` <br> `BPF_FUNC_get_ns_current_pid_tgid()` <br> `BPF_FUNC_xdp_output()` <br> `BPF_FUNC_get_task_stack()`|
 |`LWT functions`|  `BPF_FUNC_skb_load_bytes()` <br> `BPF_FUNC_skb_pull_data()` <br> `BPF_FUNC_csum_diff()` <br> `BPF_FUNC_get_cgroup_classid()` <br> `BPF_FUNC_get_route_realm()` <br> `BPF_FUNC_get_hash_recalc()` <br> `BPF_FUNC_perf_event_output()` <br> `BPF_FUNC_get_smp_processor_id()` <br> `BPF_FUNC_skb_under_cgroup()`|

src/cc/compat/linux/virtual_bpf.h

@@ -3287,6 +3287,39 @@ union bpf_attr {
  *		Dynamically cast a *sk* pointer to a *udp6_sock* pointer.
  *	Return
  *		*sk* if casting is valid, or NULL otherwise.
+ *
+ * long bpf_get_task_stack(struct task_struct *task, void *buf, u32 size, u64 flags)
+ *	Description
+ *		Return a user or a kernel stack in bpf program provided buffer.
+ *		To achieve this, the helper needs *task*, which is a valid
+ *		pointer to struct task_struct. To store the stacktrace, the
+ *		bpf program provides *buf* with	a nonnegative *size*.
+ *
+ *		The last argument, *flags*, holds the number of stack frames to
+ *		skip (from 0 to 255), masked with
+ *		**BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
+ *		the following flags:
+ *
+ *		**BPF_F_USER_STACK**
+ *			Collect a user space stack instead of a kernel stack.
+ *		**BPF_F_USER_BUILD_ID**
+ *			Collect buildid+offset instead of ips for user stack,
+ *			only valid if **BPF_F_USER_STACK** is also specified.
+ *
+ *		**bpf_get_task_stack**\ () can collect up to
+ *		**PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
+ *		to sufficient large buffer size. Note that
+ *		this limit can be controlled with the **sysctl** program, and
+ *		that it should be manually increased in order to profile long
+ *		user stacks (such as stacks for Java programs). To do so, use:
+ *
+ *		::
+ *
+ *			# sysctl kernel.perf_event_max_stack=<new value>
+ *	Return
+ *		A non-negative value equal to or less than *size* on success,
+ *		or a negative error in case of failure.
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -3429,7 +3462,9 @@ union bpf_attr {
 	FN(skc_to_tcp_sock),		\
 	FN(skc_to_tcp_timewait_sock),	\
 	FN(skc_to_tcp_request_sock),	\
-	FN(skc_to_udp6_sock),
+	FN(skc_to_udp6_sock),		\
+	FN(get_task_stack),		\
+	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

src/cc/export/helpers.h

@@ -758,6 +758,11 @@ static struct tcp_request_sock *(*bpf_skc_to_tcp_request_sock)(void *sk) =
 static struct udp6_sock *(*bpf_skc_to_udp6_sock)(void *sk) =
   (void *)BPF_FUNC_skc_to_udp6_sock;
 
+struct task_struct;
+static long (*bpf_get_task_stack)(struct task_struct *task, void *buf,
+				  __u32 size, __u64 flags) =
+  (void *)BPF_FUNC_get_task_stack;
+
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions
  */

src/cc/libbpf.c

@@ -237,6 +237,7 @@ static struct bpf_helper helpers[] = {
   {"skc_to_tcp_timewait_sock", "5.9"},
   {"skc_to_tcp_request_sock", "5.9"},
   {"skc_to_udp6_sock", "5.9"},
+  {"bpf_get_task_stack", "5.9"},
 };
 
 static uint64_t ptr_to_u64(void *ptr)