![Adrian Hunter](/assets/img/avatar_default.png)
The kallsyms maps now may map to kcore and the symbol values now may be file offsets. For comparison with vmlinux the virtual memory address is needed which is obtained by unmapping the symbol value. The "vmlinux symtab matches kallsyms" is adjusted accordingly. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/1375875537-4509-9-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
253 lines
6.7 KiB
C
253 lines
6.7 KiB
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;
|
|
struct machine kallsyms, vmlinux;
|
|
enum map_type type = MAP__FUNCTION;
|
|
struct ref_reloc_sym ref_reloc_sym = { .name = "_stext", };
|
|
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);
|
|
|
|
sym = map__find_symbol_by_name(kallsyms_map, ref_reloc_sym.name, NULL);
|
|
if (sym == NULL) {
|
|
pr_debug("dso__find_symbol_by_name ");
|
|
goto out;
|
|
}
|
|
|
|
ref_reloc_sym.addr = UM(sym->start);
|
|
|
|
/*
|
|
* 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);
|
|
map__kmap(vmlinux_map)->ref_reloc_sym = &ref_reloc_sym;
|
|
|
|
/*
|
|
* 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 (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
|
|
struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
|
|
/*
|
|
* 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,
|
|
(pos->dso->kernel ?
|
|
pos->dso->short_name :
|
|
pos->dso->name));
|
|
if (pair)
|
|
pair->priv = 1;
|
|
else
|
|
map__fprintf(pos, stderr);
|
|
}
|
|
|
|
pr_info("Maps in vmlinux with a different name in kallsyms:\n");
|
|
|
|
for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
|
|
struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
|
|
|
|
mem_start = vmlinux_map->unmap_ip(vmlinux_map, pos->start);
|
|
mem_end = vmlinux_map->unmap_ip(vmlinux_map, pos->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",
|
|
pos->start, pos->end, pos->pgoff, pos->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");
|
|
|
|
for (nd = rb_first(&kallsyms.kmaps.maps[type]);
|
|
nd; nd = rb_next(nd)) {
|
|
struct map *pos = rb_entry(nd, struct map, rb_node);
|
|
|
|
if (!pos->priv)
|
|
map__fprintf(pos, stderr);
|
|
}
|
|
out:
|
|
machine__exit(&kallsyms);
|
|
machine__exit(&vmlinux);
|
|
return err;
|
|
}
|