[linux-2.6-block.git] / tools / perf / tests / vmlinux-kallsyms.c

#include <linux/compiler.h>
#include <linux/rbtree.h>
#include <string.h>
#include "map.h"
#include "symbol.h"
#include "util.h"
#include "tests.h"
#include "debug.h"
#include "machine.h"

static int vmlinux_matches_kallsyms_filter(struct map *map __maybe_unused,
					   struct symbol *sym)
{
	bool *visited = symbol__priv(sym);
	*visited = true;
	return 0;
}

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

int test__vmlinux_matches_kallsyms(void)
{
	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;

	/*
	 * 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.
	 */
	if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 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, type);

	/*
	 * 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, type);

	/*
	 * 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,
				       vmlinux_matches_kallsyms_filter) <= 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;
		bool backwards = true;

		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, 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("%#" 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 {
				struct rb_node *nnd;
detour:
				nnd = backwards ? rb_prev(&pair->rb_node) :
						  rb_next(&pair->rb_node);
				if (nnd) {
					struct symbol *next = rb_entry(nnd, struct symbol, rb_node);

					if (UM(next->start) == mem_start) {
						pair = next;
						goto next_pair;
					}
				}

				if (backwards) {
					backwards = false;
					pair = first_pair;
					goto detour;
				}

				pr_debug("%#" PRIx64 ": diff name v: %s k: %s\n",
					 mem_start, sym->name, pair->name);
			}
		} else
			pr_debug("%#" PRIx64 ": %s not on kallsyms\n",
				 mem_start, sym->name);

		err = -1;
	}

	if (!verbose)
		goto out;

	pr_info("Maps only in vmlinux:\n");

	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
			map__fprintf(map, stderr);
	}

	pr_info("Maps in vmlinux with a different name in kallsyms:\n");

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

	pr_info("Maps only in kallsyms:\n");

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

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