Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Minor conflict, a CHECK was placed into an if() statement
in net-next, whilst a newline was added to that CHECK
call in 'net'.  Thanks to Daniel for the merge resolution.

Signed-off-by: David S. Miller <davem@davemloft.net>

9 files changed, 518 insertions, 86 deletions

diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index 5f512b1..a6258bc 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -22,17 +22,19 @@ MAP COMMANDS
 =============
 
 |	**bpftool** **map { show | list }**   [*MAP*]
-|	**bpftool** **map dump**    *MAP*
-|	**bpftool** **map update**  *MAP*  **key** [**hex**] *BYTES*   **value** [**hex**] *VALUE* [*UPDATE_FLAGS*]
-|	**bpftool** **map lookup**  *MAP*  **key** [**hex**] *BYTES*
-|	**bpftool** **map getnext** *MAP* [**key** [**hex**] *BYTES*]
-|	**bpftool** **map delete**  *MAP*  **key** [**hex**] *BYTES*
-|	**bpftool** **map pin**     *MAP*  *FILE*
+|	**bpftool** **map dump**       *MAP*
+|	**bpftool** **map update**     *MAP*  **key** *DATA*   **value** *VALUE* [*UPDATE_FLAGS*]
+|	**bpftool** **map lookup**     *MAP*  **key** *DATA*
+|	**bpftool** **map getnext**    *MAP* [**key** *DATA*]
+|	**bpftool** **map delete**     *MAP*  **key** *DATA*
+|	**bpftool** **map pin**        *MAP*  *FILE*
+|	**bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]
 |	**bpftool** **map help**
 |
 |	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
+|	*DATA* := { [**hex**] *BYTES* }
 |	*PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* }
-|	*VALUE* := { *BYTES* | *MAP* | *PROG* }
+|	*VALUE* := { *DATA* | *MAP* | *PROG* }
 |	*UPDATE_FLAGS* := { **any** | **exist** | **noexist** }
 
 DESCRIPTION
@@ -48,7 +50,7 @@ DESCRIPTION
 	**bpftool map dump**    *MAP*
 		  Dump all entries in a given *MAP*.
 
-	**bpftool map update**  *MAP*  **key** [**hex**] *BYTES*   **value** [**hex**] *VALUE* [*UPDATE_FLAGS*]
+	**bpftool map update**  *MAP*  **key** *DATA*   **value** *VALUE* [*UPDATE_FLAGS*]
 		  Update map entry for a given *KEY*.
 
 		  *UPDATE_FLAGS* can be one of: **any** update existing entry
@@ -61,13 +63,13 @@ DESCRIPTION
 		  the bytes are parsed as decimal values, unless a "0x" prefix
 		  (for hexadecimal) or a "0" prefix (for octal) is provided.
 
-	**bpftool map lookup**  *MAP*  **key** [**hex**] *BYTES*
+	**bpftool map lookup**  *MAP*  **key** *DATA*
 		  Lookup **key** in the map.
 
-	**bpftool map getnext** *MAP* [**key** [**hex**] *BYTES*]
+	**bpftool map getnext** *MAP* [**key** *DATA*]
 		  Get next key.  If *key* is not specified, get first key.
 
-	**bpftool map delete**  *MAP*  **key** [**hex**] *BYTES*
+	**bpftool map delete**  *MAP*  **key** *DATA*
 		  Remove entry from the map.
 
 	**bpftool map pin**     *MAP*  *FILE*
@@ -75,6 +77,22 @@ DESCRIPTION
 
 		  Note: *FILE* must be located in *bpffs* mount.
 
+	**bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]
+		  Read events from a BPF_MAP_TYPE_PERF_EVENT_ARRAY map.
+
+		  Install perf rings into a perf event array map and dump
+		  output of any bpf_perf_event_output() call in the kernel.
+		  By default read the number of CPUs on the system and
+		  install perf ring for each CPU in the corresponding index
+		  in the array.
+
+		  If **cpu** and **index** are specified, install perf ring
+		  for given **cpu** at **index** in the array (single ring).
+
+		  Note that installing a perf ring into an array will silently
+		  replace any existing ring.  Any other application will stop
+		  receiving events if it installed its rings earlier.
+
 	**bpftool map help**
 		  Print short help message.
 
diff --git a/tools/bpf/bpftool/Documentation/bpftool.rst b/tools/bpf/bpftool/Documentation/bpftool.rst
index 20689a3..564cb0d 100644
--- a/tools/bpf/bpftool/Documentation/bpftool.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool.rst
@@ -23,7 +23,7 @@ SYNOPSIS
 
 	*MAP-COMMANDS* :=
 	{ **show** | **list** | **dump** | **update** | **lookup** | **getnext** | **delete**
-	| **pin** | **help** }
+	| **pin** | **event_pipe** | **help** }
 
 	*PROG-COMMANDS* := { **show** | **list** | **dump jited** | **dump xlated** | **pin**
 	| **load** | **help** }
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 4e69782..892dbf0 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -39,7 +39,12 @@ CC = gcc
 
 CFLAGS += -O2
 CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wshadow -Wno-missing-field-initializers
-CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf -I$(srctree)/kernel/bpf/
+CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
+	-I$(srctree)/kernel/bpf/ \
+	-I$(srctree)/tools/include \
+	-I$(srctree)/tools/include/uapi \
+	-I$(srctree)/tools/lib/bpf \
+	-I$(srctree)/tools/perf
 CFLAGS += -DBPFTOOL_VERSION='"$(BPFTOOL_VERSION)"'
 LIBS = -lelf -lbfd -lopcodes $(LIBBPF)
 
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 852d84a..b301c9b 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -1,6 +1,6 @@
 # bpftool(8) bash completion                               -*- shell-script -*-
 #
-# Copyright (C) 2017 Netronome Systems, Inc.
+# Copyright (C) 2017-2018 Netronome Systems, Inc.
 #
 # This software is dual licensed under the GNU General License
 # Version 2, June 1991 as shown in the file COPYING in the top-level
@@ -79,6 +79,14 @@ _bpftool_get_map_ids()
         command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
 }
 
+_bpftool_get_perf_map_ids()
+{
+    COMPREPLY+=( $( compgen -W "$( bpftool -jp map  2>&1 | \
+        command grep -C2 perf_event_array | \
+        command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )
+}
+
+
 _bpftool_get_prog_ids()
 {
     COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \
@@ -359,10 +367,34 @@ _bpftool()
                     fi
                     return 0
                     ;;
+                event_pipe)
+                    case $prev in
+                        $command)
+                            COMPREPLY=( $( compgen -W "$MAP_TYPE" -- "$cur" ) )
+                            return 0
+                            ;;
+                        id)
+                            _bpftool_get_perf_map_ids
+                            return 0
+                            ;;
+                        cpu)
+                            return 0
+                            ;;
+                        index)
+                            return 0
+                            ;;
+                        *)
+                            _bpftool_once_attr 'cpu'
+                            _bpftool_once_attr 'index'
+                            return 0
+                            ;;
+                    esac
+                    ;;
                 *)
                     [[ $prev == $object ]] && \
                         COMPREPLY=( $( compgen -W 'delete dump getnext help \
-                            lookup pin show list update' -- "$cur" ) )
+                            lookup pin event_pipe show list update' -- \
+                            "$cur" ) )
                     ;;
             esac
             ;;
diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 4659952..32f9e39 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Netronome Systems, Inc.
+ * Copyright (C) 2017-2018 Netronome Systems, Inc.
  *
  * This software is dual licensed under the GNU General License Version 2,
  * June 1991 as shown in the file COPYING in the top-level directory of this
@@ -33,6 +33,7 @@
 
 /* Author: Jakub Kicinski <kubakici@wp.pl> */
 
+#include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
@@ -330,6 +331,16 @@ char *get_fdinfo(int fd, const char *key)
 	return NULL;
 }
 
+void print_data_json(uint8_t *data, size_t len)
+{
+	unsigned int i;
+
+	jsonw_start_array(json_wtr);
+	for (i = 0; i < len; i++)
+		jsonw_printf(json_wtr, "%d", data[i]);
+	jsonw_end_array(json_wtr);
+}
+
 void print_hex_data_json(uint8_t *data, size_t len)
 {
 	unsigned int i;
@@ -420,6 +431,70 @@ void delete_pinned_obj_table(struct pinned_obj_table *tab)
 	}
 }
 
+unsigned int get_page_size(void)
+{
+	static int result;
+
+	if (!result)
+		result = getpagesize();
+	return result;
+}
+
+unsigned int get_possible_cpus(void)
+{
+	static unsigned int result;
+	char buf[128];
+	long int n;
+	char *ptr;
+	int fd;
+
+	if (result)
+		return result;
+
+	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
+	if (fd < 0) {
+		p_err("can't open sysfs possible cpus");
+		exit(-1);
+	}
+
+	n = read(fd, buf, sizeof(buf));
+	if (n < 2) {
+		p_err("can't read sysfs possible cpus");
+		exit(-1);
+	}
+	close(fd);
+
+	if (n == sizeof(buf)) {
+		p_err("read sysfs possible cpus overflow");
+		exit(-1);
+	}
+
+	ptr = buf;
+	n = 0;
+	while (*ptr && *ptr != '\n') {
+		unsigned int a, b;
+
+		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {
+			n += b - a + 1;
+
+			ptr = strchr(ptr, '-') + 1;
+		} else if (sscanf(ptr, "%u", &a) == 1) {
+			n++;
+		} else {
+			assert(0);
+		}
+
+		while (isdigit(*ptr))
+			ptr++;
+		if (*ptr == ',')
+			ptr++;
+	}
+
+	result = n;
+
+	return result;
+}
+
 static char *
 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
 {
diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h
index b8e9584..6173cd9 100644
--- a/tools/bpf/bpftool/main.h
+++ b/tools/bpf/bpftool/main.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Netronome Systems, Inc.
+ * Copyright (C) 2017-2018 Netronome Systems, Inc.
  *
  * This software is dual licensed under the GNU General License Version 2,
  * June 1991 as shown in the file COPYING in the top-level directory of this
@@ -117,14 +117,19 @@ int do_pin_fd(int fd, const char *name);
 
 int do_prog(int argc, char **arg);
 int do_map(int argc, char **arg);
+int do_event_pipe(int argc, char **argv);
 int do_cgroup(int argc, char **arg);
 
 int prog_parse_fd(int *argc, char ***argv);
+int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len);
 
 void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes,
 		       const char *arch);
+void print_data_json(uint8_t *data, size_t len);
 void print_hex_data_json(uint8_t *data, size_t len);
 
+unsigned int get_page_size(void);
+unsigned int get_possible_cpus(void);
 const char *ifindex_to_bfd_name_ns(__u32 ifindex, __u64 ns_dev, __u64 ns_ino);
 
 #endif
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index a6cdb64..af6766e 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Netronome Systems, Inc.
+ * Copyright (C) 2017-2018 Netronome Systems, Inc.
  *
  * This software is dual licensed under the GNU General License Version 2,
  * June 1991 as shown in the file COPYING in the top-level directory of this
@@ -34,7 +34,6 @@
 /* Author: Jakub Kicinski <kubakici@wp.pl> */
 
 #include <assert.h>
-#include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdbool.h>
@@ -69,61 +68,6 @@ static const char * const map_type_name[] = {
 	[BPF_MAP_TYPE_CPUMAP]		= "cpumap",
 };
 
-static unsigned int get_possible_cpus(void)
-{
-	static unsigned int result;
-	char buf[128];
-	long int n;
-	char *ptr;
-	int fd;
-
-	if (result)
-		return result;
-
-	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
-	if (fd < 0) {
-		p_err("can't open sysfs possible cpus");
-		exit(-1);
-	}
-
-	n = read(fd, buf, sizeof(buf));
-	if (n < 2) {
-		p_err("can't read sysfs possible cpus");
-		exit(-1);
-	}
-	close(fd);
-
-	if (n == sizeof(buf)) {
-		p_err("read sysfs possible cpus overflow");
-		exit(-1);
-	}
-
-	ptr = buf;
-	n = 0;
-	while (*ptr && *ptr != '\n') {
-		unsigned int a, b;
-
-		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {
-			n += b - a + 1;
-
-			ptr = strchr(ptr, '-') + 1;
-		} else if (sscanf(ptr, "%u", &a) == 1) {
-			n++;
-		} else {
-			assert(0);
-		}
-
-		while (isdigit(*ptr))
-			ptr++;
-		if (*ptr == ',')
-			ptr++;
-	}
-
-	result = n;
-
-	return result;
-}
-
 static bool map_is_per_cpu(__u32 type)
 {
 	return type == BPF_MAP_TYPE_PERCPU_HASH ||
@@ -186,8 +130,7 @@ static int map_parse_fd(int *argc, char ***argv)
 	return -1;
 }
 
-static int
-map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
+int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
 {
 	int err;
 	int fd;
@@ -873,23 +816,25 @@ static int do_help(int argc, char **argv)
 
 	fprintf(stderr,
 		"Usage: %s %s { show | list }   [MAP]\n"
-		"       %s %s dump    MAP\n"
-		"       %s %s update  MAP  key [hex] BYTES value [hex] VALUE [UPDATE_FLAGS]\n"
-		"       %s %s lookup  MAP  key [hex] BYTES\n"
-		"       %s %s getnext MAP [key [hex] BYTES]\n"
-		"       %s %s delete  MAP  key [hex] BYTES\n"
-		"       %s %s pin     MAP  FILE\n"
+		"       %s %s dump       MAP\n"
+		"       %s %s update     MAP  key DATA value VALUE [UPDATE_FLAGS]\n"
+		"       %s %s lookup     MAP  key DATA\n"
+		"       %s %s getnext    MAP [key DATA]\n"
+		"       %s %s delete     MAP  key DATA\n"
+		"       %s %s pin        MAP  FILE\n"
+		"       %s %s event_pipe MAP [cpu N index M]\n"
 		"       %s %s help\n"
 		"\n"
 		"       MAP := { id MAP_ID | pinned FILE }\n"
+		"       DATA := { [hex] BYTES }\n"
 		"       " HELP_SPEC_PROGRAM "\n"
-		"       VALUE := { BYTES | MAP | PROG }\n"
+		"       VALUE := { DATA | MAP | PROG }\n"
 		"       UPDATE_FLAGS := { any | exist | noexist }\n"
 		"       " HELP_SPEC_OPTIONS "\n"
 		"",
 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
-		bin_name, argv[-2], bin_name, argv[-2]);
+		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
 
 	return 0;
 }
@@ -904,6 +849,7 @@ static const struct cmd cmds[] = {
 	{ "getnext",	do_getnext },
 	{ "delete",	do_delete },
 	{ "pin",	do_pin },
+	{ "event_pipe",	do_event_pipe },
 	{ 0 }
 };
 
diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c
new file mode 100644
index 0000000..c5a2ced
--- /dev/null
+++ b/tools/bpf/bpftool/map_perf_ring.c
@@ -0,0 +1,347 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2018 Netronome Systems, Inc. */
+/* 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 <errno.h>
+#include <fcntl.h>
+#include <libbpf.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <linux/bpf.h>
+#include <linux/perf_event.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/syscall.h>
+
+#include <bpf.h>
+#include <perf-sys.h>
+
+#include "main.h"
+
+#define MMAP_PAGE_CNT	16
+
+static bool stop;
+
+struct event_ring_info {
+	int fd;
+	int key;
+	unsigned int cpu;
+	void *mem;
+};
+
+struct perf_event_sample {
+	struct perf_event_header header;
+	__u32 size;
+	unsigned char data[];
+};
+
+static void int_exit(int signo)
+{
+	fprintf(stderr, "Stopping...\n");
+	stop = true;
+}
+
+static void
+print_bpf_output(struct event_ring_info *ring, struct perf_event_sample *e)
+{
+	struct {
+		struct perf_event_header header;
+		__u64 id;
+		__u64 lost;
+	} *lost = (void *)e;
+	struct timespec ts;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &ts)) {
+		perror("Can't read clock for timestamp");
+		return;
+	}
+
+	if (json_output) {
+		jsonw_start_object(json_wtr);
+		jsonw_name(json_wtr, "timestamp");
+		jsonw_uint(json_wtr, ts.tv_sec * 1000000000ull + ts.tv_nsec);
+		jsonw_name(json_wtr, "type");
+		jsonw_uint(json_wtr, e->header.type);
+		jsonw_name(json_wtr, "cpu");
+		jsonw_uint(json_wtr, ring->cpu);
+		jsonw_name(json_wtr, "index");
+		jsonw_uint(json_wtr, ring->key);
+		if (e->header.type == PERF_RECORD_SAMPLE) {
+			jsonw_name(json_wtr, "data");
+			print_data_json(e->data, e->size);
+		} else if (e->header.type == PERF_RECORD_LOST) {
+			jsonw_name(json_wtr, "lost");
+			jsonw_start_object(json_wtr);
+			jsonw_name(json_wtr, "id");
+			jsonw_uint(json_wtr, lost->id);
+			jsonw_name(json_wtr, "count");
+			jsonw_uint(json_wtr, lost->lost);
+			jsonw_end_object(json_wtr);
+		}
+		jsonw_end_object(json_wtr);
+	} else {
+		if (e->header.type == PERF_RECORD_SAMPLE) {
+			printf("== @%ld.%ld CPU: %d index: %d =====\n",
+			       (long)ts.tv_sec, ts.tv_nsec,
+			       ring->cpu, ring->key);
+			fprint_hex(stdout, e->data, e->size, " ");
+			printf("\n");
+		} else if (e->header.type == PERF_RECORD_LOST) {
+			printf("lost %lld events\n", lost->lost);
+		} else {
+			printf("unknown event type=%d size=%d\n",
+			       e->header.type, e->header.size);
+		}
+	}
+}
+
+static void
+perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len)
+{
+	volatile struct perf_event_mmap_page *header = ring->mem;
+	__u64 buffer_size = MMAP_PAGE_CNT * get_page_size();
+	__u64 data_tail = header->data_tail;
+	__u64 data_head = header->data_head;
+	void *base, *begin, *end;
+
+	asm volatile("" ::: "memory"); /* in real code it should be smp_rmb() */
+	if (data_head == data_tail)
+		return;
+
+	base = ((char *)header) + get_page_size();
+
+	begin = base + data_tail % buffer_size;
+	end = base + data_head % buffer_size;
+
+	while (begin != end) {
+		struct perf_event_sample *e;
+
+		e = begin;
+		if (begin + e->header.size > base + buffer_size) {
+			long len = base + buffer_size - begin;
+
+			if (*buf_len < e->header.size) {
+				free(*buf);
+				*buf = malloc(e->header.size);
+				if (!*buf) {
+					fprintf(stderr,
+						"can't allocate memory");
+					stop = true;
+					return;
+				}
+				*buf_len = e->header.size;
+			}
+
+			memcpy(*buf, begin, len);
+			memcpy(*buf + len, base, e->header.size - len);
+			e = (void *)*buf;
+			begin = base + e->header.size - len;
+		} else if (begin + e->header.size == base + buffer_size) {
+			begin = base;
+		} else {
+			begin += e->header.size;
+		}
+
+		print_bpf_output(ring, e);
+	}
+
+	__sync_synchronize(); /* smp_mb() */
+	header->data_tail = data_head;
+}
+
+static int perf_mmap_size(void)
+{
+	return get_page_size() * (MMAP_PAGE_CNT + 1);
+}
+
+static void *perf_event_mmap(int fd)
+{
+	int mmap_size = perf_mmap_size();
+	void *base;
+
+	base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+	if (base == MAP_FAILED) {
+		p_err("event mmap failed: %s\n", strerror(errno));
+		return NULL;
+	}
+
+	return base;
+}
+
+static void perf_event_unmap(void *mem)
+{
+	if (munmap(mem, perf_mmap_size()))
+		fprintf(stderr, "Can't unmap ring memory!\n");
+}
+
+static int bpf_perf_event_open(int map_fd, int key, int cpu)
+{
+	struct perf_event_attr attr = {
+		.sample_type = PERF_SAMPLE_RAW,
+		.type = PERF_TYPE_SOFTWARE,
+		.config = PERF_COUNT_SW_BPF_OUTPUT,
+	};
+	int pmu_fd;
+
+	pmu_fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
+	if (pmu_fd < 0) {
+		p_err("failed to open perf event %d for CPU %d", key, cpu);
+		return -1;
+	}
+
+	if (bpf_map_update_elem(map_fd, &key, &pmu_fd, BPF_ANY)) {
+		p_err("failed to update map for event %d for CPU %d", key, cpu);
+		goto err_close;
+	}
+	if (ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0)) {
+		p_err("failed to enable event %d for CPU %d", key, cpu);
+		goto err_close;
+	}
+
+	return pmu_fd;
+
+err_close:
+	close(pmu_fd);
+	return -1;
+}
+
+int do_event_pipe(int argc, char **argv)
+{
+	int i, nfds, map_fd, index = -1, cpu = -1;
+	struct bpf_map_info map_info = {};
+	struct event_ring_info *rings;
+	size_t tmp_buf_sz = 0;
+	void *tmp_buf = NULL;
+	struct pollfd *pfds;
+	__u32 map_info_len;
+	bool do_all = true;
+
+	map_info_len = sizeof(map_info);
+	map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
+	if (map_fd < 0)
+		return -1;
+
+	if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
+		p_err("map is not a perf event array");
+		goto err_close_map;
+	}
+
+	while (argc) {
+		if (argc < 2)
+			BAD_ARG();
+
+		if (is_prefix(*argv, "cpu")) {
+			char *endptr;
+
+			NEXT_ARG();
+			cpu = strtoul(*argv, &endptr, 0);
+			if (*endptr) {
+				p_err("can't parse %s as CPU ID", **argv);
+				goto err_close_map;
+			}
+
+			NEXT_ARG();
+		} else if (is_prefix(*argv, "index")) {
+			char *endptr;
+
+			NEXT_ARG();
+			index = strtoul(*argv, &endptr, 0);
+			if (*endptr) {
+				p_err("can't parse %s as index", **argv);
+				goto err_close_map;
+			}
+
+			NEXT_ARG();
+		} else {
+			BAD_ARG();
+		}
+
+		do_all = false;
+	}
+
+	if (!do_all) {
+		if (index == -1 || cpu == -1) {
+			p_err("cpu and index must be specified together");
+			goto err_close_map;
+		}
+
+		nfds = 1;
+	} else {
+		nfds = min(get_possible_cpus(), map_info.max_entries);
+		cpu = 0;
+		index = 0;
+	}
+
+	rings = calloc(nfds, sizeof(rings[0]));
+	if (!rings)
+		goto err_close_map;
+
+	pfds = calloc(nfds, sizeof(pfds[0]));
+	if (!pfds)
+		goto err_free_rings;
+
+	for (i = 0; i < nfds; i++) {
+		rings[i].cpu = cpu + i;
+		rings[i].key = index + i;
+
+		rings[i].fd = bpf_perf_event_open(map_fd, rings[i].key,
+						  rings[i].cpu);
+		if (rings[i].fd < 0)
+			goto err_close_fds_prev;
+
+		rings[i].mem = perf_event_mmap(rings[i].fd);
+		if (!rings[i].mem)
+			goto err_close_fds_current;
+
+		pfds[i].fd = rings[i].fd;
+		pfds[i].events = POLLIN;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGHUP, int_exit);
+	signal(SIGTERM, int_exit);
+
+	if (json_output)
+		jsonw_start_array(json_wtr);
+
+	while (!stop) {
+		poll(pfds, nfds, 200);
+		for (i = 0; i < nfds; i++)
+			perf_event_read(&rings[i], &tmp_buf, &tmp_buf_sz);
+	}
+	free(tmp_buf);
+
+	if (json_output)
+		jsonw_end_array(json_wtr);
+
+	for (i = 0; i < nfds; i++) {
+		perf_event_unmap(rings[i].mem);
+		close(rings[i].fd);
+	}
+	free(pfds);
+	free(rings);
+	close(map_fd);
+
+	return 0;
+
+err_close_fds_prev:
+	while (i--) {
+		perf_event_unmap(rings[i].mem);
+err_close_fds_current:
+		close(rings[i].fd);
+	}
+	free(pfds);
+err_free_rings:
+	free(rings);
+err_close_map:
+	close(map_fd);
+	return -1;
+}
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index e71a0a1..9bdfdf2 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -96,7 +96,10 @@ static void print_boot_time(__u64 nsecs, char *buf, unsigned int size)
 		return;
 	}
 
-	strftime(buf, size, "%b %d/%H:%M", &load_tm);
+	if (json_output)
+		strftime(buf, size, "%s", &load_tm);
+	else
+		strftime(buf, size, "%FT%T%z", &load_tm);
 }
 
 static int prog_fd_by_tag(unsigned char *tag)
@@ -245,7 +248,8 @@ static void print_prog_json(struct bpf_prog_info *info, int fd)
 		print_boot_time(info->load_time, buf, sizeof(buf));
 
 		/* Piggy back on load_time, since 0 uid is a valid one */
-		jsonw_string_field(json_wtr, "loaded_at", buf);
+		jsonw_name(json_wtr, "loaded_at");
+		jsonw_printf(json_wtr, "%s", buf);
 		jsonw_uint_field(json_wtr, "uid", info->created_by_uid);
 	}