Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 650 insertions, 0 deletions

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
new file mode 100644
index 000000000..41cdddc98
--- /dev/null
+++ b/tools/perf/util/map.c
@@ -0,0 +1,650 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <inttypes.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/string.h>
+#include <linux/zalloc.h>
+#include <uapi/linux/mman.h> /* To get things like MAP_HUGETLB even on older libc headers */
+#include "debug.h"
+#include "dso.h"
+#include "map.h"
+#include "namespaces.h"
+#include "srcline.h"
+#include "symbol.h"
+#include "thread.h"
+#include "vdso.h"
+
+static inline int is_android_lib(const char *filename)
+{
+	return strstarts(filename, "/data/app-lib/") ||
+	       strstarts(filename, "/system/lib/");
+}
+
+static inline bool replace_android_lib(const char *filename, char *newfilename)
+{
+	const char *libname;
+	char *app_abi;
+	size_t app_abi_length, new_length;
+	size_t lib_length = 0;
+
+	libname  = strrchr(filename, '/');
+	if (libname)
+		lib_length = strlen(libname);
+
+	app_abi = getenv("APP_ABI");
+	if (!app_abi)
+		return false;
+
+	app_abi_length = strlen(app_abi);
+
+	if (strstarts(filename, "/data/app-lib/")) {
+		char *apk_path;
+
+		if (!app_abi_length)
+			return false;
+
+		new_length = 7 + app_abi_length + lib_length;
+
+		apk_path = getenv("APK_PATH");
+		if (apk_path) {
+			new_length += strlen(apk_path) + 1;
+			if (new_length > PATH_MAX)
+				return false;
+			snprintf(newfilename, new_length,
+				 "%s/libs/%s/%s", apk_path, app_abi, libname);
+		} else {
+			if (new_length > PATH_MAX)
+				return false;
+			snprintf(newfilename, new_length,
+				 "libs/%s/%s", app_abi, libname);
+		}
+		return true;
+	}
+
+	if (strstarts(filename, "/system/lib/")) {
+		char *ndk, *app;
+		const char *arch;
+		int ndk_length, app_length;
+
+		ndk = getenv("NDK_ROOT");
+		app = getenv("APP_PLATFORM");
+
+		if (!(ndk && app))
+			return false;
+
+		ndk_length = strlen(ndk);
+		app_length = strlen(app);
+
+		if (!(ndk_length && app_length && app_abi_length))
+			return false;
+
+		arch = !strncmp(app_abi, "arm", 3) ? "arm" :
+		       !strncmp(app_abi, "mips", 4) ? "mips" :
+		       !strncmp(app_abi, "x86", 3) ? "x86" : NULL;
+
+		if (!arch)
+			return false;
+
+		new_length = 27 + ndk_length +
+			     app_length + lib_length
+			   + strlen(arch);
+
+		if (new_length > PATH_MAX)
+			return false;
+		snprintf(newfilename, new_length,
+			"%.*s/platforms/%.*s/arch-%s/usr/lib/%s",
+			ndk_length, ndk, app_length, app, arch, libname);
+
+		return true;
+	}
+	return false;
+}
+
+static void map__init(struct map *map, u64 start, u64 end, u64 pgoff,
+		      struct dso *dso, u32 prot, u32 flags)
+{
+	map__set_start(map, start);
+	map__set_end(map, end);
+	map__set_pgoff(map, pgoff);
+	assert(map__reloc(map) == 0);
+	map__set_dso(map, dso__get(dso));
+	refcount_set(map__refcnt(map), 1);
+	RC_CHK_ACCESS(map)->prot = prot;
+	RC_CHK_ACCESS(map)->flags = flags;
+	map__set_mapping_type(map, MAPPING_TYPE__DSO);
+	assert(map__erange_warned(map) == false);
+	assert(map__priv(map) == false);
+	assert(map__hit(map) == false);
+}
+
+struct map *map__new(struct machine *machine, u64 start, u64 len,
+		     u64 pgoff, const struct dso_id *id,
+		     u32 prot, u32 flags,
+		     char *filename, struct thread *thread)
+{
+	struct map *result;
+	RC_STRUCT(map) *map;
+	struct nsinfo *nsi = NULL;
+	struct nsinfo *nnsi;
+
+	map = zalloc(sizeof(*map));
+	if (ADD_RC_CHK(result, map)) {
+		char newfilename[PATH_MAX];
+		struct dso *dso;
+		int anon, no_dso, vdso, android;
+
+		android = is_android_lib(filename);
+		anon = is_anon_memory(filename) || flags & MAP_HUGETLB;
+		vdso = is_vdso_map(filename);
+		no_dso = is_no_dso_memory(filename);
+		nsi = nsinfo__get(thread__nsinfo(thread));
+
+		if ((anon || no_dso) && nsi && (prot & PROT_EXEC)) {
+			snprintf(newfilename, sizeof(newfilename),
+				 "/tmp/perf-%d.map", nsinfo__pid(nsi));
+			filename = newfilename;
+		}
+
+		if (android) {
+			if (replace_android_lib(filename, newfilename))
+				filename = newfilename;
+		}
+
+		if (vdso) {
+			/* The vdso maps are always on the host and not the
+			 * container.  Ensure that we don't use setns to look
+			 * them up.
+			 */
+			nnsi = nsinfo__copy(nsi);
+			if (nnsi) {
+				nsinfo__put(nsi);
+				nsinfo__clear_need_setns(nnsi);
+				nsi = nnsi;
+			}
+			pgoff = 0;
+			dso = machine__findnew_vdso(machine, thread);
+		} else
+			dso = machine__findnew_dso_id(machine, filename, id);
+
+		if (dso == NULL)
+			goto out_delete;
+
+		assert(!dso__kernel(dso));
+		map__init(result, start, start + len, pgoff, dso, prot, flags);
+
+		if (anon || no_dso) {
+			map->mapping_type = MAPPING_TYPE__IDENTITY;
+
+			/*
+			 * Set memory without DSO as loaded. All map__find_*
+			 * functions still return NULL, and we avoid the
+			 * unnecessary map__load warning.
+			 */
+			if (!(prot & PROT_EXEC))
+				dso__set_loaded(dso);
+		}
+		mutex_lock(dso__lock(dso));
+		dso__set_nsinfo(dso, nsi);
+		mutex_unlock(dso__lock(dso));
+
+		if (!build_id__is_defined(&id->build_id)) {
+			/*
+			 * If the mmap event had no build ID, search for an existing dso from the
+			 * build ID header by name. Otherwise only the dso loaded at the time of
+			 * reading the header will have the build ID set and all future mmaps will
+			 * have it missing.
+			 */
+			struct dso *header_bid_dso = dsos__find(&machine->dsos, filename, false);
+
+			if (header_bid_dso && dso__header_build_id(header_bid_dso)) {
+				dso__set_build_id(dso, dso__bid(header_bid_dso));
+				dso__set_header_build_id(dso, 1);
+			}
+			dso__put(header_bid_dso);
+		}
+		dso__put(dso);
+	}
+	return result;
+out_delete:
+	nsinfo__put(nsi);
+	RC_CHK_FREE(result);
+	return NULL;
+}
+
+/*
+ * Constructor variant for modules (where we know from /proc/modules where
+ * they are loaded) and for vmlinux, where only after we load all the
+ * symbols we'll know where it starts and ends.
+ */
+struct map *map__new2(u64 start, struct dso *dso)
+{
+	struct map *result;
+	RC_STRUCT(map) *map;
+
+	map = calloc(1, sizeof(*map) + (dso__kernel(dso) ? sizeof(struct kmap) : 0));
+	if (ADD_RC_CHK(result, map)) {
+		/* ->end will be filled after we load all the symbols. */
+		map__init(result, start, /*end=*/0, /*pgoff=*/0, dso, /*prot=*/0, /*flags=*/0);
+	}
+
+	return result;
+}
+
+bool __map__is_kernel(const struct map *map)
+{
+	if (!dso__kernel(map__dso(map)))
+		return false;
+	return machine__kernel_map(maps__machine(map__kmaps((struct map *)map))) == map;
+}
+
+bool __map__is_extra_kernel_map(const struct map *map)
+{
+	struct kmap *kmap = __map__kmap((struct map *)map);
+
+	return kmap && kmap->name[0];
+}
+
+bool __map__is_bpf_prog(const struct map *map)
+{
+	const char *name;
+	struct dso *dso = map__dso(map);
+
+	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_PROG_INFO)
+		return true;
+
+	/*
+	 * If PERF_RECORD_BPF_EVENT is not included, the dso will not have
+	 * type of DSO_BINARY_TYPE__BPF_PROG_INFO. In such cases, we can
+	 * guess the type based on name.
+	 */
+	name = dso__short_name(dso);
+	return name && (strstr(name, "bpf_prog_") == name);
+}
+
+bool __map__is_bpf_image(const struct map *map)
+{
+	const char *name;
+	struct dso *dso = map__dso(map);
+
+	if (dso__binary_type(dso) == DSO_BINARY_TYPE__BPF_IMAGE)
+		return true;
+
+	/*
+	 * If PERF_RECORD_KSYMBOL is not included, the dso will not have
+	 * type of DSO_BINARY_TYPE__BPF_IMAGE. In such cases, we can
+	 * guess the type based on name.
+	 */
+	name = dso__short_name(dso);
+	return name && is_bpf_image(name);
+}
+
+bool __map__is_ool(const struct map *map)
+{
+	const struct dso *dso = map__dso(map);
+
+	return dso && dso__binary_type(dso) == DSO_BINARY_TYPE__OOL;
+}
+
+bool map__has_symbols(const struct map *map)
+{
+	return dso__has_symbols(map__dso(map));
+}
+
+static void map__exit(struct map *map)
+{
+	BUG_ON(refcount_read(map__refcnt(map)) != 0);
+	dso__zput(RC_CHK_ACCESS(map)->dso);
+}
+
+void map__delete(struct map *map)
+{
+	map__exit(map);
+	RC_CHK_FREE(map);
+}
+
+void map__put(struct map *map)
+{
+	if (map && refcount_dec_and_test(map__refcnt(map)))
+		map__delete(map);
+	else
+		RC_CHK_PUT(map);
+}
+
+void map__fixup_start(struct map *map)
+{
+	struct dso *dso = map__dso(map);
+	struct rb_root_cached *symbols = dso__symbols(dso);
+	struct rb_node *nd = rb_first_cached(symbols);
+
+	if (nd != NULL) {
+		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
+
+		map__set_start(map, sym->start);
+	}
+}
+
+void map__fixup_end(struct map *map)
+{
+	struct dso *dso = map__dso(map);
+	struct rb_root_cached *symbols = dso__symbols(dso);
+	struct rb_node *nd = rb_last(&symbols->rb_root);
+
+	if (nd != NULL) {
+		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
+		map__set_end(map, sym->end);
+	}
+}
+
+#define DSO__DELETED "(deleted)"
+
+int map__load(struct map *map)
+{
+	struct dso *dso = map__dso(map);
+	const char *name = dso__long_name(dso);
+	int nr;
+
+	if (dso__loaded(dso))
+		return 0;
+
+	nr = dso__load(dso, map);
+	if (nr < 0) {
+		if (dso__has_build_id(dso)) {
+			char sbuild_id[SBUILD_ID_SIZE];
+
+			build_id__snprintf(dso__bid(dso), sbuild_id, sizeof(sbuild_id));
+			pr_debug("%s with build id %s not found", name, sbuild_id);
+		} else
+			pr_debug("Failed to open %s", name);
+
+		pr_debug(", continuing without symbols\n");
+		return -1;
+	} else if (nr == 0) {
+#ifdef HAVE_LIBELF_SUPPORT
+		const size_t len = strlen(name);
+		const size_t real_len = len - sizeof(DSO__DELETED);
+
+		if (len > sizeof(DSO__DELETED) &&
+		    strcmp(name + real_len + 1, DSO__DELETED) == 0) {
+			pr_debug("%.*s was updated (is prelink enabled?). "
+				"Restart the long running apps that use it!\n",
+				   (int)real_len, name);
+		} else {
+			pr_debug("no symbols found in %s, maybe install a debug package?\n", name);
+		}
+#endif
+		return -1;
+	}
+
+	return 0;
+}
+
+struct symbol *map__find_symbol(struct map *map, u64 addr)
+{
+	if (map__load(map) < 0)
+		return NULL;
+
+	return dso__find_symbol(map__dso(map), addr);
+}
+
+struct symbol *map__find_symbol_by_name_idx(struct map *map, const char *name, size_t *idx)
+{
+	struct dso *dso;
+
+	if (map__load(map) < 0)
+		return NULL;
+
+	dso = map__dso(map);
+	dso__sort_by_name(dso);
+
+	return dso__find_symbol_by_name(dso, name, idx);
+}
+
+struct symbol *map__find_symbol_by_name(struct map *map, const char *name)
+{
+	size_t idx;
+
+	return map__find_symbol_by_name_idx(map, name, &idx);
+}
+
+struct map *map__clone(struct map *from)
+{
+	struct map *result;
+	RC_STRUCT(map) *map;
+	size_t size = sizeof(RC_STRUCT(map));
+	struct dso *dso = map__dso(from);
+
+	if (dso && dso__kernel(dso))
+		size += sizeof(struct kmap);
+
+	map = memdup(RC_CHK_ACCESS(from), size);
+	if (ADD_RC_CHK(result, map)) {
+		refcount_set(&map->refcnt, 1);
+		map->dso = dso__get(dso);
+	}
+
+	return result;
+}
+
+size_t map__fprintf(struct map *map, FILE *fp)
+{
+	const struct dso *dso = map__dso(map);
+
+	return fprintf(fp, " %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s\n",
+		       map__start(map), map__end(map), map__pgoff(map), dso__name(dso));
+}
+
+static bool prefer_dso_long_name(const struct dso *dso, bool print_off)
+{
+	return dso__long_name(dso) &&
+	       (symbol_conf.show_kernel_path ||
+		(print_off && (dso__name(dso)[0] == '[' || dso__is_kcore(dso))));
+}
+
+static size_t __map__fprintf_dsoname(struct map *map, bool print_off, FILE *fp)
+{
+	char buf[symbol_conf.pad_output_len_dso + 1];
+	const char *dsoname = "[unknown]";
+	const struct dso *dso = map ? map__dso(map) : NULL;
+
+	if (dso) {
+		if (prefer_dso_long_name(dso, print_off))
+			dsoname = dso__long_name(dso);
+		else
+			dsoname = dso__name(dso);
+	}
+
+	if (symbol_conf.pad_output_len_dso) {
+		scnprintf_pad(buf, symbol_conf.pad_output_len_dso, "%s", dsoname);
+		dsoname = buf;
+	}
+
+	return fprintf(fp, "%s", dsoname);
+}
+
+size_t map__fprintf_dsoname(struct map *map, FILE *fp)
+{
+	return __map__fprintf_dsoname(map, false, fp);
+}
+
+size_t map__fprintf_dsoname_dsoff(struct map *map, bool print_off, u64 addr, FILE *fp)
+{
+	const struct dso *dso = map ? map__dso(map) : NULL;
+	int printed = 0;
+
+	if (print_off && (!dso || !dso__is_object_file(dso)))
+		print_off = false;
+	printed += fprintf(fp, " (");
+	printed += __map__fprintf_dsoname(map, print_off, fp);
+	if (print_off)
+		printed += fprintf(fp, "+0x%" PRIx64, addr);
+	printed += fprintf(fp, ")");
+
+	return printed;
+}
+
+char *map__srcline(struct map *map, u64 addr, struct symbol *sym)
+{
+	if (map == NULL)
+		return SRCLINE_UNKNOWN;
+
+	return get_srcline(map__dso(map), map__rip_2objdump(map, addr), sym, true, true, addr);
+}
+
+int map__fprintf_srcline(struct map *map, u64 addr, const char *prefix,
+			 FILE *fp)
+{
+	const struct dso *dso = map ? map__dso(map) : NULL;
+	int ret = 0;
+
+	if (dso) {
+		char *srcline = map__srcline(map, addr, NULL);
+		if (srcline != SRCLINE_UNKNOWN)
+			ret = fprintf(fp, "%s%s", prefix, srcline);
+		zfree_srcline(&srcline);
+	}
+	return ret;
+}
+
+void srccode_state_free(struct srccode_state *state)
+{
+	zfree(&state->srcfile);
+	state->line = 0;
+}
+
+static const struct kmap *__map__const_kmap(const struct map *map);
+
+/**
+ * map__rip_2objdump - convert symbol start address to objdump address.
+ * @map: memory map
+ * @rip: symbol start address
+ *
+ * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
+ * map->dso->adjust_symbols==1 for ET_EXEC-like cases except ET_REL which is
+ * relative to section start.
+ *
+ * Return: Address suitable for passing to "objdump --start-address="
+ */
+u64 map__rip_2objdump(const struct map *map, u64 rip)
+{
+	const struct kmap *kmap = __map__const_kmap(map);
+	const struct dso *dso = map__dso(map);
+
+	/*
+	 * vmlinux does not have program headers for PTI entry trampolines and
+	 * kcore may not either. However the trampoline object code is on the
+	 * main kernel map, so just use that instead.
+	 */
+	if (kmap && is_entry_trampoline(kmap->name) && kmap->kmaps) {
+		struct machine *machine = maps__machine(kmap->kmaps);
+
+		if (machine) {
+			struct map *kernel_map = machine__kernel_map(machine);
+
+			if (kernel_map)
+				map = kernel_map;
+		}
+	}
+
+	if (!dso__adjust_symbols(dso))
+		return rip;
+
+	if (dso__rel(dso))
+		return rip - map__pgoff(map);
+
+	if (dso__kernel(dso) == DSO_SPACE__USER)
+		return rip + dso__text_offset(dso);
+
+	return map__unmap_ip(map, rip) - map__reloc(map);
+}
+
+/**
+ * map__objdump_2mem - convert objdump address to a memory address.
+ * @map: memory map
+ * @ip: objdump address
+ *
+ * Closely related to map__rip_2objdump(), this function takes an address from
+ * objdump and converts it to a memory address.  Note this assumes that @map
+ * contains the address.  To be sure the result is valid, check it forwards
+ * e.g. map__rip_2objdump(map__map_ip(map, map__objdump_2mem(map, ip))) == ip
+ *
+ * Return: Memory address.
+ */
+u64 map__objdump_2mem(const struct map *map, u64 ip)
+{
+	const struct dso *dso = map__dso(map);
+
+	if (!dso__adjust_symbols(dso))
+		return map__unmap_ip(map, ip);
+
+	if (dso__rel(dso))
+		return map__unmap_ip(map, ip + map__pgoff(map));
+
+	if (dso__kernel(dso) == DSO_SPACE__USER)
+		return map__unmap_ip(map, ip - dso__text_offset(dso));
+
+	return ip + map__reloc(map);
+}
+
+/* convert objdump address to relative address.  (To be removed) */
+u64 map__objdump_2rip(const struct map *map, u64 ip)
+{
+	const struct dso *dso = map__dso(map);
+
+	if (!dso__adjust_symbols(dso))
+		return ip;
+
+	if (dso__rel(dso))
+		return ip + map__pgoff(map);
+
+	if (dso__kernel(dso) == DSO_SPACE__USER)
+		return ip - dso__text_offset(dso);
+
+	return map__map_ip(map, ip + map__reloc(map));
+}
+
+bool map__contains_symbol(const struct map *map, const struct symbol *sym)
+{
+	u64 ip = map__unmap_ip(map, sym->start);
+
+	return ip >= map__start(map) && ip < map__end(map);
+}
+
+struct kmap *__map__kmap(struct map *map)
+{
+	const struct dso *dso = map__dso(map);
+
+	if (!dso || !dso__kernel(dso))
+		return NULL;
+	return (struct kmap *)(&RC_CHK_ACCESS(map)[1]);
+}
+
+static const struct kmap *__map__const_kmap(const struct map *map)
+{
+	const struct dso *dso = map__dso(map);
+
+	if (!dso || !dso__kernel(dso))
+		return NULL;
+	return (struct kmap *)(&RC_CHK_ACCESS(map)[1]);
+}
+
+struct kmap *map__kmap(struct map *map)
+{
+	struct kmap *kmap = __map__kmap(map);
+
+	if (!kmap)
+		pr_err("Internal error: map__kmap with a non-kernel map\n");
+	return kmap;
+}
+
+struct maps *map__kmaps(struct map *map)
+{
+	struct kmap *kmap = map__kmap(map);
+
+	if (!kmap || !kmap->kmaps) {
+		pr_err("Internal error: map__kmaps with a non-kernel map\n");
+		return NULL;
+	}
+	return kmap->kmaps;
+}