[linux-2.6-block.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 <stdlib.h>
#include "dso.h"
#include "map.h"
#include "symbol.h"
#include "util.h" // page_size
#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;
	struct maps *maps = machine__kernel_maps(&vmlinux);
	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") <= 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) <= 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.
	 */
	map__for_each_symbol(vmlinux_map, sym, 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, mem_start, NULL);
		pair = first_pair;

		if (pair && UM(pair->start) == mem_start) {
next_pair:
			if (arch__compare_symbol_names(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, 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 if (mem_start == kallsyms.vmlinux_map->end) {
			/*
			 * Ignore aliases to _etext, i.e. to the end of the kernel text area,
			 * such as __indirect_thunk_end.
			 */
			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,
						(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, 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 = machine__kernel_maps(&kallsyms);

	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	5	#include <string.h>
215a0d30	6	#include <stdlib.h>
4a3cec84	7	#include "dso.h"
0a4e1ae6 JO	8	#include "map.h"
0a4e1ae6 JO	9	#include "symbol.h"
fb71c86c	10	#include "util.h" // page_size
0a4e1ae6 JO	11	#include "tests.h"
	12	#include "debug.h"
	13	#include "machine.h"
	14
82e75d00 AH	15	#define UM(x) kallsyms_map->unmap_ip(kallsyms_map, (x))
82e75d00 AH	16
81f17c90	17	int test__vmlinux_matches_kallsyms(struct test *test __maybe_unused, int subtest __maybe_unused)
0a4e1ae6 JO	18	{
	19	int err = -1;
	20	struct rb_node *nd;
	21	struct symbol *sym;
4bb7123d	22	struct map kallsyms_map, vmlinux_map, *map;
0a4e1ae6	23	struct machine kallsyms, vmlinux;
68a74186	24	struct maps *maps = machine__kernel_maps(&vmlinux);
d380b348	25	u64 mem_start, mem_end;
54da0769	26	bool header_printed;
0a4e1ae6 JO	27
	28	/*
	29	* Step 1:
	30	*
	31	* Init the machines that will hold kernel, modules obtained from
	32	* both vmlinux + .ko files and from /proc/kallsyms split by modules.
	33	*/
	34	machine__init(&kallsyms, "", HOST_KERNEL_ID);
	35	machine__init(&vmlinux, "", HOST_KERNEL_ID);
	36
	37	/*
	38	* Step 2:
	39	*
	40	* Create the kernel maps for kallsyms and the DSO where we will then
	41	* load /proc/kallsyms. Also create the modules maps from /proc/modules
	42	* and find the .ko files that match them in /lib/modules/`uname -r`/.
	43	*/
	44	if (machine__create_kernel_maps(&kallsyms) < 0) {
	45	pr_debug("machine__create_kernel_maps ");
c0aab59f	46	goto out;
0a4e1ae6 JO	47	}
	48
	49	/*
	50	* Step 3:
	51	*
	52	* Load and split /proc/kallsyms into multiple maps, one per module.
53d0fe68 ACM	53	* Do not use kcore, as this test was designed before kcore support
	54	* and has parts that only make sense if using the non-kcore code.
	55	* XXX: extend it to stress the kcorre code as well, hint: the list
	56	* of modules extracted from /proc/kcore, in its current form, can't
	57	* be compacted against the list of modules found in the "vmlinux"
	58	* code and with the one got from /proc/modules from the "kallsyms" code.
0a4e1ae6	59	*/
329f0ade	60	if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms") <= 0) {
0a4e1ae6 JO	61	pr_debug("dso__load_kallsyms ");
	62	goto out;
	63	}
	64
	65	/*
	66	* Step 4:
	67	*
	68	* kallsyms will be internally on demand sorted by name so that we can
	69	* find the reference relocation * symbol, i.e. the symbol we will use
	70	* to see if the running kernel was relocated by checking if it has the
	71	* same value in the vmlinux file we load.
	72	*/
a5e813c6	73	kallsyms_map = machine__kernel_map(&kallsyms);
0a4e1ae6	74
0a4e1ae6 JO	75	/*
	76	* Step 5:
	77	*
	78	* Now repeat step 2, this time for the vmlinux file we'll auto-locate.
	79	*/
	80	if (machine__create_kernel_maps(&vmlinux) < 0) {
	81	pr_debug("machine__create_kernel_maps ");
	82	goto out;
	83	}
	84
a5e813c6	85	vmlinux_map = machine__kernel_map(&vmlinux);
0a4e1ae6 JO	86
	87	/*
	88	* Step 6:
	89	*
	90	* Locate a vmlinux file in the vmlinux path that has a buildid that
	91	* matches the one of the running kernel.
	92	*
	93	* While doing that look if we find the ref reloc symbol, if we find it
	94	* we'll have its ref_reloc_symbol.unrelocated_addr and then
	95	* maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
	96	* to fixup the symbols.
	97	*/
1d1a2654	98	if (machine__load_vmlinux_path(&vmlinux) <= 0) {
531f67bb ACM	99	pr_debug("Couldn't find a vmlinux that matches the kernel running on this machine, skipping test\n");
531f67bb ACM	100	err = TEST_SKIP;
0a4e1ae6 JO	101	goto out;
	102	}
	103
	104	err = 0;
	105	/*
	106	* Step 7:
	107	*
	108	* Now look at the symbols in the vmlinux DSO and check if we find all of them
	109	* in the kallsyms dso. For the ones that are in both, check its names and
	110	* end addresses too.
	111	*/
d05b861e	112	map__for_each_symbol(vmlinux_map, sym, nd) {
0a4e1ae6	113	struct symbol pair, first_pair;
0a4e1ae6 JO	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
107cad95	123	first_pair = machine__find_kernel_symbol(&kallsyms, mem_start, NULL);
0a4e1ae6 JO	124	pair = first_pair;
0a4e1ae6 JO	125
82e75d00	126	if (pair && UM(pair->start) == mem_start) {
0a4e1ae6	127	next_pair:
ab6e9a99	128	if (arch__compare_symbol_names(sym->name, pair->name) == 0) {
0a4e1ae6 JO	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 {
107cad95	152	pair = machine__find_kernel_symbol_by_name(&kallsyms, 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	165	}
93f678b9 ACM	166	} else if (mem_start == kallsyms.vmlinux_map->end) {
	167	/*
	168	* Ignore aliases to _etext, i.e. to the end of the kernel text area,
	169	* such as __indirect_thunk_end.
	170	*/
	171	continue;
	172	} else {
e267769e	173	pr_debug("ERR : %#" PRIx64 ": %s not on kallsyms\n",
d380b348	174	mem_start, sym->name);
93f678b9	175	}
0a4e1ae6 JO	176
	177	err = -1;
	178	}
	179
bb963e16	180	if (verbose <= 0)
0a4e1ae6 JO	181	goto out;
0a4e1ae6 JO	182
54da0769	183	header_printed = false;
0a4e1ae6	184
4bb7123d ACM	185	for (map = maps__first(maps); map; map = map__next(map)) {
4bb7123d ACM	186	struct map *
0a4e1ae6 JO	187	/*
	188	* If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
	189	* the kernel will have the path for the vmlinux file being used,
	190	* so use the short name, less descriptive but the same ("[kernel]" in
	191	* both cases.
	192	*/
83cf774b	193	pair = map_groups__find_by_name(&kallsyms.kmaps,
4bb7123d ACM	194	(map->dso->kernel ?
	195	map->dso->short_name :
	196	map->dso->name));
54da0769	197	if (pair) {
0a4e1ae6	198	pair->priv = 1;
54da0769 ACM	199	} else {
	200	if (!header_printed) {
	201	pr_info("WARN: Maps only in vmlinux:\n");
	202	header_printed = true;
	203	}
4bb7123d	204	map__fprintf(map, stderr);
54da0769	205	}
0a4e1ae6 JO	206	}
0a4e1ae6 JO	207
54da0769	208	header_printed = false;
0a4e1ae6	209
4bb7123d ACM	210	for (map = maps__first(maps); map; map = map__next(map)) {
4bb7123d ACM	211	struct map *pair;
0a4e1ae6	212
4bb7123d ACM	213	mem_start = vmlinux_map->unmap_ip(vmlinux_map, map->start);
4bb7123d ACM	214	mem_end = vmlinux_map->unmap_ip(vmlinux_map, map->end);
d380b348	215
abe5449d	216	pair = map_groups__find(&kallsyms.kmaps, mem_start);
0a4e1ae6 JO	217	if (pair == NULL \|\| pair->priv)
	218	continue;
	219
d380b348	220	if (pair->start == mem_start) {
54da0769 ACM	221	if (!header_printed) {
	222	pr_info("WARN: Maps in vmlinux with a different name in kallsyms:\n");
	223	header_printed = true;
	224	}
	225
e267769e	226	pr_info("WARN: %" PRIx64 "-%" PRIx64 " %" PRIx64 " %s in kallsyms as",
4bb7123d	227	map->start, map->end, map->pgoff, map->dso->name);
d380b348	228	if (mem_end != pair->end)
e267769e	229	pr_info(":\nWARN: *%" PRIx64 "-%" PRIx64 " %" PRIx64,
0a4e1ae6 JO	230	pair->start, pair->end, pair->pgoff);
	231	pr_info(" %s\n", pair->dso->name);
	232	pair->priv = 1;
	233	}
	234	}
	235
54da0769	236	header_printed = false;
0a4e1ae6	237
68a74186	238	maps = machine__kernel_maps(&kallsyms);
0a4e1ae6	239
4bb7123d	240	for (map = maps__first(maps); map; map = map__next(map)) {
54da0769 ACM	241	if (!map->priv) {
	242	if (!header_printed) {
	243	pr_info("WARN: Maps only in kallsyms:\n");
	244	header_printed = true;
	245	}
4bb7123d	246	map__fprintf(map, stderr);
54da0769	247	}
0a4e1ae6 JO	248	}
0a4e1ae6 JO	249	out:
c0aab59f ACM	250	machine__exit(&kallsyms);
c0aab59f ACM	251	machine__exit(&vmlinux);
0a4e1ae6 JO	252	return err;
0a4e1ae6 JO	253	}