xref: /linux/tools/perf/arch/x86/util/event.c (revision 22c55fb9eb92395d999b8404d73e58540d11bdd8)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/types.h>
3 #include <linux/string.h>
4 #include <linux/zalloc.h>
5 #include <stdlib.h>
6 
7 #include "../../../util/event.h"
8 #include "../../../util/synthetic-events.h"
9 #include "../../../util/machine.h"
10 #include "../../../util/tool.h"
11 #include "../../../util/map.h"
12 #include "../../../util/debug.h"
13 #include "util/sample.h"
14 
15 #if defined(__x86_64__)
16 
17 struct perf_event__synthesize_extra_kmaps_cb_args {
18 	const struct perf_tool *tool;
19 	perf_event__handler_t process;
20 	struct machine *machine;
21 	union perf_event *event;
22 };
23 
24 static int perf_event__synthesize_extra_kmaps_cb(struct map *map, void *data)
25 {
26 	struct perf_event__synthesize_extra_kmaps_cb_args *args = data;
27 	union perf_event *event = args->event;
28 	struct kmap *kmap;
29 	size_t size;
30 
31 	if (!__map__is_extra_kernel_map(map))
32 		return 0;
33 
34 	kmap = map__kmap(map);
35 
36 	size = sizeof(event->mmap) - sizeof(event->mmap.filename) +
37 		      PERF_ALIGN(strlen(kmap->name) + 1, sizeof(u64)) +
38 		      args->machine->id_hdr_size;
39 
40 	memset(event, 0, size);
41 
42 	event->mmap.header.type = PERF_RECORD_MMAP;
43 
44 	/*
45 	 * kernel uses 0 for user space maps, see kernel/perf_event.c
46 	 * __perf_event_mmap
47 	 */
48 	if (machine__is_host(args->machine))
49 		event->header.misc = PERF_RECORD_MISC_KERNEL;
50 	else
51 		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
52 
53 	event->mmap.header.size = size;
54 
55 	event->mmap.start = map__start(map);
56 	event->mmap.len   = map__size(map);
57 	event->mmap.pgoff = map__pgoff(map);
58 	event->mmap.pid   = args->machine->pid;
59 
60 	strlcpy(event->mmap.filename, kmap->name, PATH_MAX);
61 
62 	if (perf_tool__process_synth_event(args->tool, event, args->machine, args->process) != 0)
63 		return -1;
64 
65 	return 0;
66 }
67 
68 int perf_event__synthesize_extra_kmaps(const struct perf_tool *tool,
69 				       perf_event__handler_t process,
70 				       struct machine *machine)
71 {
72 	int rc;
73 	struct maps *kmaps = machine__kernel_maps(machine);
74 	struct perf_event__synthesize_extra_kmaps_cb_args args = {
75 		.tool = tool,
76 		.process = process,
77 		.machine = machine,
78 		.event = zalloc(sizeof(args.event->mmap) + machine->id_hdr_size),
79 	};
80 
81 	if (!args.event) {
82 		pr_debug("Not enough memory synthesizing mmap event "
83 			 "for extra kernel maps\n");
84 		return -1;
85 	}
86 
87 	rc = maps__for_each_map(kmaps, perf_event__synthesize_extra_kmaps_cb, &args);
88 
89 	free(args.event);
90 	return rc;
91 }
92 
93 #endif
94