// 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;
|
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
|
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;
|
}
|
