[mirror_ubuntu-bionic-kernel.git] / tools / perf / tests / vmlinux-kallsyms.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/compiler.h>
#include <linux/rbtree.h>
#include <inttypes.h>
#include <string.h>
#include "map.h"
#include "symbol.h"
#include "util.h"
#include "tests.h"
#include "debug.h"
#include "machine.h"

#define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x))

int test__vmlinux_matches_kallsyms(struct test *test __maybe_unused, int subtest __maybe_unused)
{
	int err = -1;
	struct rb_node *nd;
	struct symbol *sym;
	struct map *kallsyms_map, *vmlinux_map, *map;
	struct machine kallsyms, vmlinux;
	enum map_type type = MAP__FUNCTION;
	struct maps *maps = &vmlinux.kmaps.maps[type];
	u64 mem_start, mem_end;
	bool header_printed;

	/*
	 * Step 1:
	 *
	 * Init the machines that will hold kernel, modules obtained from
	 * both vmlinux + .ko files and from /proc/kallsyms split by modules.
	 */
	machine__init(&kallsyms, "", HOST_KERNEL_ID);
	machine__init(&vmlinux, "", HOST_KERNEL_ID);

	/*
	 * Step 2:
	 *
	 * Create the kernel maps for kallsyms and the DSO where we will then
	 * load /proc/kallsyms. Also create the modules maps from /proc/modules
	 * and find the .ko files that match them in /lib/modules/`uname -r`/.
	 */
	if (machine__create_kernel_maps(&kallsyms) < 0) {
		pr_debug("machine__create_kernel_maps ");
		goto out;
	}

	/*
	 * Step 3:
	 *
	 * Load and split /proc/kallsyms into multiple maps, one per module.
	 * Do not use kcore, as this test was designed before kcore support
	 * and has parts that only make sense if using the non-kcore code.
	 * XXX: extend it to stress the kcorre code as well, hint: the list
	 * of modules extracted from /proc/kcore, in its current form, can't
	 * be compacted against the list of modules found in the "vmlinux"
	 * code and with the one got from /proc/modules from the "kallsyms" code.
	 */
	if (__machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, true) <= 0) {
		pr_debug("dso__load_kallsyms ");
		goto out;
	}

	/*
	 * Step 4:
	 *
	 * kallsyms will be internally on demand sorted by name so that we can
	 * find the reference relocation * symbol, i.e. the symbol we will use
	 * to see if the running kernel was relocated by checking if it has the
	 * same value in the vmlinux file we load.
	 */
	kallsyms_map = machine__kernel_map(&kallsyms);

	/*
	 * Step 5:
	 *
	 * Now repeat step 2, this time for the vmlinux file we'll auto-locate.
	 */
	if (machine__create_kernel_maps(&vmlinux) < 0) {
		pr_debug("machine__create_kernel_maps ");
		goto out;
	}

	vmlinux_map = machine__kernel_map(&vmlinux);

	/*
	 * Step 6:
	 *
	 * Locate a vmlinux file in the vmlinux path that has a buildid that
	 * matches the one of the running kernel.
	 *
	 * While doing that look if we find the ref reloc symbol, if we find it
	 * we'll have its ref_reloc_symbol.unrelocated_addr and then
	 * maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
	 * to fixup the symbols.
	 */
	if (machine__load_vmlinux_path(&vmlinux, type) <= 0) {
		pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");
		err = TEST_SKIP;
		goto out;
	}

	err = 0;
	/*
	 * Step 7:
	 *
	 * Now look at the symbols in the vmlinux DSO and check if we find all of them
	 * in the kallsyms dso. For the ones that are in both, check its names and
	 * end addresses too.
	 */
	for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
		struct symbol *pair, *first_pair;

		sym  = rb_entry(nd, struct symbol, rb_node);

		if (sym->start == sym->end)
			continue;

		mem_start = vmlinux_map->unmap_ip(vmlinux_map, sym->start);
		mem_end = vmlinux_map->unmap_ip(vmlinux_map, sym->end);

		first_pair = machine__find_kernel_symbol(&kallsyms, type,
							 mem_start, NULL);
		pair = first_pair;

		if (pair && UM(pair->start) == mem_start) {
next_pair:
			if (strcmp(sym->name, pair->name) == 0) {
				/*
				 * kallsyms don't have the symbol end, so we
				 * set that by using the next symbol start - 1,
				 * in some cases we get this up to a page
				 * wrong, trace_kmalloc when I was developing
				 * this code was one such example, 2106 bytes
				 * off the real size. More than that and we
				 * _really_ have a problem.
				 */
				s64 skew = mem_end - UM(pair->end);
				if (llabs(skew) >= page_size)
					pr_debug("WARN: %#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",
						 mem_start, sym->name, mem_end,
						 UM(pair->end));

				/*
				 * Do not count this as a failure, because we
				 * could really find a case where it's not
				 * possible to get proper function end from
				 * kallsyms.
				 */
				continue;
			} else {
				pair = machine__find_kernel_symbol_by_name(&kallsyms, type, sym->name, NULL);
				if (pair) {
					if (UM(pair->start) == mem_start)
						goto next_pair;

					pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
						 mem_start, sym->name, pair->name);
				} else {
					pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
						 mem_start, sym->name, first_pair->name);
				}

				continue;
			}
		} else
			pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",
				 mem_start, sym->name);

		err = -1;
	}

	if (verbose <= 0)
		goto out;

	header_printed = false;

	for (map = maps__first(maps); map; map = map__next(map)) {
		struct map *
		/*
		 * If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
		 * the kernel will have the path for the vmlinux file being used,
		 * so use the short name, less descriptive but the same ("[kernel]" in
		 * both cases.
		 */
		pair = map_groups__find_by_name(&kallsyms.kmaps, type,
						(map->dso->kernel ?
							map->dso->short_name :
							map->dso->name));
		if (pair) {
			pair->priv = 1;
		} else {
			if (!header_printed) {
				pr_info("WARN: Maps only in vmlinux:\n");
				header_printed = true;
			}
			map__fprintf(map, stderr);
		}
	}

	header_printed = false;

	for (map = maps__first(maps); map; map = map__next(map)) {
		struct map *pair;

		mem_start = vmlinux_map->unmap_ip(vmlinux_map, map->start);
		mem_end = vmlinux_map->unmap_ip(vmlinux_map, map->end);

		pair = map_groups__find(&kallsyms.kmaps, type, mem_start);
		if (pair == NULL || pair->priv)
			continue;

		if (pair->start == mem_start) {
			if (!header_printed) {
				pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n");
				header_printed = true;
			}

			pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
				map->start, map->end, map->pgoff, map->dso->name);
			if (mem_end != pair->end)
				pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64,
					pair->start, pair->end, pair->pgoff);
			pr_info(" %s\n", pair->dso->name);
			pair->priv = 1;
		}
	}

	header_printed = false;

	maps = &kallsyms.kmaps.maps[type];

	for (map = maps__first(maps); map; map = map__next(map)) {
		if (!map->priv) {
			if (!header_printed) {
				pr_info("WARN: Maps only in kallsyms:\n");
				header_printed = true;
			}
			map__fprintf(map, stderr);
		}
	}
out:
	machine__exit(&kallsyms);
	machine__exit(&vmlinux);
	return err;
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
0a4e1ae6 JO	2	#include <linux/compiler.h>
0a4e1ae6 JO	3	#include <linux/rbtree.h>
fd20e811	4	#include <inttypes.h>
0a4e1ae6 JO	5	#include <string.h>
	6	#include "map.h"
	7	#include "symbol.h"
	8	#include "util.h"
	9	#include "tests.h"
	10	#include "debug.h"
	11	#include "machine.h"
	12
82e75d00 AH	13	#define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x))
82e75d00 AH	14
81f17c90	15	int test__vmlinux_matches_kallsyms(struct test *test __maybe_unused, int subtest __maybe_unused)
0a4e1ae6 JO	16	{
	17	int err = -1;
	18	struct rb_node *nd;
	19	struct symbol *sym;
4bb7123d	20	struct map kallsyms_map, vmlinux_map, *map;
0a4e1ae6 JO	21	struct machine kallsyms, vmlinux;
0a4e1ae6 JO	22	enum map_type type = MAP__FUNCTION;
1eee78ae	23	struct maps *maps = &vmlinux.kmaps.maps[type];
d380b348	24	u64 mem_start, mem_end;
54da0769	25	bool header_printed;
0a4e1ae6 JO	26
	27	/*
	28	* Step 1:
	29	*
	30	* Init the machines that will hold kernel, modules obtained from
	31	* both vmlinux + .ko files and from /proc/kallsyms split by modules.
	32	*/
	33	machine__init(&kallsyms, "", HOST_KERNEL_ID);
	34	machine__init(&vmlinux, "", HOST_KERNEL_ID);
	35
	36	/*
	37	* Step 2:
	38	*
	39	* Create the kernel maps for kallsyms and the DSO where we will then
	40	* load /proc/kallsyms. Also create the modules maps from /proc/modules
	41	* and find the .ko files that match them in /lib/modules/`uname -r`/.
	42	*/
	43	if (machine__create_kernel_maps(&kallsyms) < 0) {
	44	pr_debug("machine__create_kernel_maps ");
c0aab59f	45	goto out;
0a4e1ae6 JO	46	}
	47
	48	/*
	49	* Step 3:
	50	*
	51	* Load and split /proc/kallsyms into multiple maps, one per module.
53d0fe68 ACM	52	* Do not use kcore, as this test was designed before kcore support
	53	* and has parts that only make sense if using the non-kcore code.
	54	* XXX: extend it to stress the kcorre code as well, hint: the list
	55	* of modules extracted from /proc/kcore, in its current form, can't
	56	* be compacted against the list of modules found in the "vmlinux"
	57	* code and with the one got from /proc/modules from the "kallsyms" code.
0a4e1ae6	58	*/
be39db9f	59	if (__machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, true) <= 0) {
0a4e1ae6 JO	60	pr_debug("dso__load_kallsyms ");
	61	goto out;
	62	}
	63
	64	/*
	65	* Step 4:
	66	*
	67	* kallsyms will be internally on demand sorted by name so that we can
	68	* find the reference relocation * symbol, i.e. the symbol we will use
	69	* to see if the running kernel was relocated by checking if it has the
	70	* same value in the vmlinux file we load.
	71	*/
a5e813c6	72	kallsyms_map = machine__kernel_map(&kallsyms);
0a4e1ae6	73
0a4e1ae6 JO	74	/*
	75	* Step 5:
	76	*
	77	* Now repeat step 2, this time for the vmlinux file we'll auto-locate.
	78	*/
	79	if (machine__create_kernel_maps(&vmlinux) < 0) {
	80	pr_debug("machine__create_kernel_maps ");
	81	goto out;
	82	}
	83
a5e813c6	84	vmlinux_map = machine__kernel_map(&vmlinux);
0a4e1ae6 JO	85
	86	/*
	87	* Step 6:
	88	*
	89	* Locate a vmlinux file in the vmlinux path that has a buildid that
	90	* matches the one of the running kernel.
	91	*
	92	* While doing that look if we find the ref reloc symbol, if we find it
	93	* we'll have its ref_reloc_symbol.unrelocated_addr and then
	94	* maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
	95	* to fixup the symbols.
	96	*/
be39db9f	97	if (machine__load_vmlinux_path(&vmlinux, type) <= 0) {
531f67bb ACM	98	pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");
531f67bb ACM	99	err = TEST_SKIP;
0a4e1ae6 JO	100	goto out;
	101	}
	102
	103	err = 0;
	104	/*
	105	* Step 7:
	106	*
	107	* Now look at the symbols in the vmlinux DSO and check if we find all of them
	108	* in the kallsyms dso. For the ones that are in both, check its names and
	109	* end addresses too.
	110	*/
	111	for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
	112	struct symbol pair, first_pair;
0a4e1ae6 JO	113
	114	sym = rb_entry(nd, struct symbol, rb_node);
	115
	116	if (sym->start == sym->end)
	117	continue;
	118
d380b348 AH	119	mem_start = vmlinux_map->unmap_ip(vmlinux_map, sym->start);
	120	mem_end = vmlinux_map->unmap_ip(vmlinux_map, sym->end);
	121
	122	first_pair = machine__find_kernel_symbol(&kallsyms, type,
be39db9f	123	mem_start, NULL);
0a4e1ae6 JO	124	pair = first_pair;
0a4e1ae6 JO	125
82e75d00	126	if (pair && UM(pair->start) == mem_start) {
0a4e1ae6 JO	127	next_pair:
	128	if (strcmp(sym->name, pair->name) == 0) {
	129	/*
	130	* kallsyms don't have the symbol end, so we
	131	* set that by using the next symbol start - 1,
	132	* in some cases we get this up to a page
	133	* wrong, trace_kmalloc when I was developing
	134	* this code was one such example, 2106 bytes
	135	* off the real size. More than that and we
	136	* _really_ have a problem.
	137	*/
82e75d00	138	s64 skew = mem_end - UM(pair->end);
5888a8c2	139	if (llabs(skew) >= page_size)
e267769e	140	pr_debug("WARN: %#" PRIx64 ": diff end addr for %s v: %#" PRIx64 " k: %#" PRIx64 "\n",
d380b348	141	mem_start, sym->name, mem_end,
82e75d00	142	UM(pair->end));
5888a8c2 JO	143
	144	/*
	145	* Do not count this as a failure, because we
	146	* could really find a case where it's not
	147	* possible to get proper function end from
	148	* kallsyms.
	149	*/
	150	continue;
0a4e1ae6	151	} else {
be39db9f	152	pair = machine__find_kernel_symbol_by_name(&kallsyms, type, sym->name, NULL);
ab414dcd ACM	153	if (pair) {
ab414dcd ACM	154	if (UM(pair->start) == mem_start)
0a4e1ae6	155	goto next_pair;
0a4e1ae6	156
7e1b6595	157	pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
ab414dcd	158	mem_start, sym->name, pair->name);
6566feaf	159	} else {
7e1b6595	160	pr_debug("WARN: %#" PRIx64 ": diff name v: %s k: %s\n",
6566feaf	161	mem_start, sym->name, first_pair->name);
0a4e1ae6	162	}
7e1b6595 ACM	163
7e1b6595 ACM	164	continue;
0a4e1ae6 JO	165	}
0a4e1ae6 JO	166	} else
e267769e	167	pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",
d380b348	168	mem_start, sym->name);
0a4e1ae6 JO	169
	170	err = -1;
	171	}
	172
bb963e16	173	if (verbose <= 0)
0a4e1ae6 JO	174	goto out;
0a4e1ae6 JO	175
54da0769	176	header_printed = false;
0a4e1ae6	177
4bb7123d ACM	178	for (map = maps__first(maps); map; map = map__next(map)) {
4bb7123d ACM	179	struct map *
0a4e1ae6 JO	180	/*
	181	* If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
	182	* the kernel will have the path for the vmlinux file being used,
	183	* so use the short name, less descriptive but the same ("[kernel]" in
	184	* both cases.
	185	*/
	186	pair = map_groups__find_by_name(&kallsyms.kmaps, type,
4bb7123d ACM	187	(map->dso->kernel ?
	188	map->dso->short_name :
	189	map->dso->name));
54da0769	190	if (pair) {
0a4e1ae6	191	pair->priv = 1;
54da0769 ACM	192	} else {
	193	if (!header_printed) {
	194	pr_info("WARN: Maps only in vmlinux:\n");
	195	header_printed = true;
	196	}
4bb7123d	197	map__fprintf(map, stderr);
54da0769	198	}
0a4e1ae6 JO	199	}
0a4e1ae6 JO	200
54da0769	201	header_printed = false;
0a4e1ae6	202
4bb7123d ACM	203	for (map = maps__first(maps); map; map = map__next(map)) {
4bb7123d ACM	204	struct map *pair;
0a4e1ae6	205
4bb7123d ACM	206	mem_start = vmlinux_map->unmap_ip(vmlinux_map, map->start);
4bb7123d ACM	207	mem_end = vmlinux_map->unmap_ip(vmlinux_map, map->end);
d380b348 AH	208
d380b348 AH	209	pair = map_groups__find(&kallsyms.kmaps, type, mem_start);
0a4e1ae6 JO	210	if (pair == NULL \|\| pair->priv)
	211	continue;
	212
d380b348	213	if (pair->start == mem_start) {
54da0769 ACM	214	if (!header_printed) {
	215	pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n");
	216	header_printed = true;
	217	}
	218
e267769e	219	pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
4bb7123d	220	map->start, map->end, map->pgoff, map->dso->name);
d380b348	221	if (mem_end != pair->end)
e267769e	222	pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64,
0a4e1ae6 JO	223	pair->start, pair->end, pair->pgoff);
	224	pr_info(" %s\n", pair->dso->name);
	225	pair->priv = 1;
	226	}
	227	}
	228
54da0769	229	header_printed = false;
0a4e1ae6	230
4bb7123d	231	maps = &kallsyms.kmaps.maps[type];
0a4e1ae6	232
4bb7123d	233	for (map = maps__first(maps); map; map = map__next(map)) {
54da0769 ACM	234	if (!map->priv) {
	235	if (!header_printed) {
	236	pr_info("WARN: Maps only in kallsyms:\n");
	237	header_printed = true;
	238	}
4bb7123d	239	map__fprintf(map, stderr);
54da0769	240	}
0a4e1ae6 JO	241	}
0a4e1ae6 JO	242	out:
c0aab59f ACM	243	machine__exit(&kallsyms);
c0aab59f ACM	244	machine__exit(&vmlinux);
0a4e1ae6 JO	245	return err;
0a4e1ae6 JO	246	}