![Arnaldo Carvalho de Melo](/assets/img/avatar_default.png)
Not just before, fixing these false positives: [acme@mica linux]$ perf test -v 1 1: vmlinux symtab matches kallsyms: --- start --- Looking at the vmlinux_path (6 entries long) Using //lib/modules/2.6.37-rc5-00180-ge06b6bf/build/vmlinux for symbols 0xffffffff81058dc0: diff name v: sys_vm86old k: sys_ni_syscall 0xffffffff81058dc0: diff name v: sys_vm86 k: sys_ni_syscall 0xffffffff81058dc0: diff name v: sys_subpage_prot k: sys_ni_syscall 0xffffffff810b5f7c: diff name v: probe_kernel_write k: __probe_kernel_write 0xffffffff810b5fe5: diff name v: probe_kernel_read k: __probe_kernel_read 0xffffffff811bc380: diff name v: __memset k: memset 0xffffffff81384a98: diff name v: __sched_text_start k: sleep_on_common 0xffffffff81386750: diff name v: __sched_text_end k: _raw_spin_trylock 0xffffffff8138cee8: diff name v: __irqentry_text_start k: do_IRQ 0xffffffff8138f079: diff name v: __start_notes k: _etext 0xffffffff8138f079: diff name v: __stop_notes k: _etext ---- end ---- vmlinux symtab matches kallsyms: FAILED! [acme@mica linux]$ Some are weak functions, others are just markers, etc. They get in the rb tree with the same addr, so we need to look around to find the symbol with the same name. We were looking just at the previous entries with the same addr, look forward too. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Han Pingtian <phan@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
297 lines
7.3 KiB
C
297 lines
7.3 KiB
C
/*
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* builtin-test.c
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*
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* Builtin regression testing command: ever growing number of sanity tests
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*/
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#include "builtin.h"
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#include "util/cache.h"
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#include "util/debug.h"
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#include "util/parse-options.h"
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#include "util/session.h"
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#include "util/symbol.h"
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#include "util/thread.h"
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static long page_size;
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static int vmlinux_matches_kallsyms_filter(struct map *map __used, struct symbol *sym)
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{
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bool *visited = symbol__priv(sym);
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*visited = true;
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return 0;
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}
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static int test__vmlinux_matches_kallsyms(void)
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{
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int err = -1;
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struct rb_node *nd;
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struct symbol *sym;
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struct map *kallsyms_map, *vmlinux_map;
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struct machine kallsyms, vmlinux;
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enum map_type type = MAP__FUNCTION;
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struct ref_reloc_sym ref_reloc_sym = { .name = "_stext", };
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/*
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* Step 1:
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*
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* Init the machines that will hold kernel, modules obtained from
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* both vmlinux + .ko files and from /proc/kallsyms split by modules.
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*/
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machine__init(&kallsyms, "", HOST_KERNEL_ID);
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machine__init(&vmlinux, "", HOST_KERNEL_ID);
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/*
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* Step 2:
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*
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* Create the kernel maps for kallsyms and the DSO where we will then
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* load /proc/kallsyms. Also create the modules maps from /proc/modules
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* and find the .ko files that match them in /lib/modules/`uname -r`/.
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*/
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if (machine__create_kernel_maps(&kallsyms) < 0) {
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pr_debug("machine__create_kernel_maps ");
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return -1;
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}
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/*
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* Step 3:
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*
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* Load and split /proc/kallsyms into multiple maps, one per module.
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*/
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if (machine__load_kallsyms(&kallsyms, "/proc/kallsyms", type, NULL) <= 0) {
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pr_debug("dso__load_kallsyms ");
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goto out;
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}
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/*
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* Step 4:
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*
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* kallsyms will be internally on demand sorted by name so that we can
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* find the reference relocation * symbol, i.e. the symbol we will use
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* to see if the running kernel was relocated by checking if it has the
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* same value in the vmlinux file we load.
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*/
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kallsyms_map = machine__kernel_map(&kallsyms, type);
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sym = map__find_symbol_by_name(kallsyms_map, ref_reloc_sym.name, NULL);
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if (sym == NULL) {
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pr_debug("dso__find_symbol_by_name ");
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goto out;
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}
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ref_reloc_sym.addr = sym->start;
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/*
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* Step 5:
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*
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* Now repeat step 2, this time for the vmlinux file we'll auto-locate.
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*/
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if (machine__create_kernel_maps(&vmlinux) < 0) {
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pr_debug("machine__create_kernel_maps ");
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goto out;
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}
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vmlinux_map = machine__kernel_map(&vmlinux, type);
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map__kmap(vmlinux_map)->ref_reloc_sym = &ref_reloc_sym;
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/*
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* Step 6:
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*
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* Locate a vmlinux file in the vmlinux path that has a buildid that
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* matches the one of the running kernel.
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*
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* While doing that look if we find the ref reloc symbol, if we find it
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* we'll have its ref_reloc_symbol.unrelocated_addr and then
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* maps__reloc_vmlinux will notice and set proper ->[un]map_ip routines
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* to fixup the symbols.
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*/
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if (machine__load_vmlinux_path(&vmlinux, type,
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vmlinux_matches_kallsyms_filter) <= 0) {
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pr_debug("machine__load_vmlinux_path ");
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goto out;
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}
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err = 0;
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/*
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* Step 7:
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*
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* Now look at the symbols in the vmlinux DSO and check if we find all of them
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* in the kallsyms dso. For the ones that are in both, check its names and
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* end addresses too.
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*/
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for (nd = rb_first(&vmlinux_map->dso->symbols[type]); nd; nd = rb_next(nd)) {
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struct symbol *pair, *first_pair;
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bool backwards = true;
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sym = rb_entry(nd, struct symbol, rb_node);
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if (sym->start == sym->end)
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continue;
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first_pair = machine__find_kernel_symbol(&kallsyms, type, sym->start, NULL, NULL);
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pair = first_pair;
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if (pair && pair->start == sym->start) {
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next_pair:
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if (strcmp(sym->name, pair->name) == 0) {
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/*
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* kallsyms don't have the symbol end, so we
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* set that by using the next symbol start - 1,
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* in some cases we get this up to a page
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* wrong, trace_kmalloc when I was developing
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* this code was one such example, 2106 bytes
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* off the real size. More than that and we
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* _really_ have a problem.
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*/
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s64 skew = sym->end - pair->end;
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if (llabs(skew) < page_size)
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continue;
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pr_debug("%#Lx: diff end addr for %s v: %#Lx k: %#Lx\n",
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sym->start, sym->name, sym->end, pair->end);
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} else {
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struct rb_node *nnd;
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detour:
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nnd = backwards ? rb_prev(&pair->rb_node) :
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rb_next(&pair->rb_node);
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if (nnd) {
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struct symbol *next = rb_entry(nnd, struct symbol, rb_node);
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if (next->start == sym->start) {
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pair = next;
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goto next_pair;
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}
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}
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if (backwards) {
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backwards = false;
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pair = first_pair;
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goto detour;
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}
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pr_debug("%#Lx: diff name v: %s k: %s\n",
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sym->start, sym->name, pair->name);
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}
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} else
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pr_debug("%#Lx: %s not on kallsyms\n", sym->start, sym->name);
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err = -1;
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}
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if (!verbose)
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goto out;
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pr_info("Maps only in vmlinux:\n");
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for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
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struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
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/*
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* If it is the kernel, kallsyms is always "[kernel.kallsyms]", while
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* the kernel will have the path for the vmlinux file being used,
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* so use the short name, less descriptive but the same ("[kernel]" in
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* both cases.
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*/
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pair = map_groups__find_by_name(&kallsyms.kmaps, type,
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(pos->dso->kernel ?
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pos->dso->short_name :
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pos->dso->name));
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if (pair)
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pair->priv = 1;
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else
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map__fprintf(pos, stderr);
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}
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pr_info("Maps in vmlinux with a different name in kallsyms:\n");
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for (nd = rb_first(&vmlinux.kmaps.maps[type]); nd; nd = rb_next(nd)) {
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struct map *pos = rb_entry(nd, struct map, rb_node), *pair;
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pair = map_groups__find(&kallsyms.kmaps, type, pos->start);
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if (pair == NULL || pair->priv)
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continue;
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if (pair->start == pos->start) {
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pair->priv = 1;
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pr_info(" %Lx-%Lx %Lx %s in kallsyms as",
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pos->start, pos->end, pos->pgoff, pos->dso->name);
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if (pos->pgoff != pair->pgoff || pos->end != pair->end)
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pr_info(": \n*%Lx-%Lx %Lx",
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pair->start, pair->end, pair->pgoff);
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pr_info(" %s\n", pair->dso->name);
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pair->priv = 1;
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}
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}
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pr_info("Maps only in kallsyms:\n");
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for (nd = rb_first(&kallsyms.kmaps.maps[type]);
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nd; nd = rb_next(nd)) {
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struct map *pos = rb_entry(nd, struct map, rb_node);
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if (!pos->priv)
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map__fprintf(pos, stderr);
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}
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out:
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return err;
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}
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static struct test {
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const char *desc;
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int (*func)(void);
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} tests[] = {
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{
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.desc = "vmlinux symtab matches kallsyms",
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.func = test__vmlinux_matches_kallsyms,
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},
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{
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.func = NULL,
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},
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};
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static int __cmd_test(void)
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{
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int i = 0;
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page_size = sysconf(_SC_PAGE_SIZE);
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while (tests[i].func) {
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int err;
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pr_info("%2d: %s:", i + 1, tests[i].desc);
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pr_debug("\n--- start ---\n");
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err = tests[i].func();
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pr_debug("---- end ----\n%s:", tests[i].desc);
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pr_info(" %s\n", err ? "FAILED!\n" : "Ok");
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++i;
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}
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return 0;
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}
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static const char * const test_usage[] = {
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"perf test [<options>]",
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NULL,
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};
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static const struct option test_options[] = {
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OPT_INTEGER('v', "verbose", &verbose,
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"be more verbose (show symbol address, etc)"),
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OPT_END()
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};
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int cmd_test(int argc, const char **argv, const char *prefix __used)
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{
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argc = parse_options(argc, argv, test_options, test_usage, 0);
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if (argc)
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usage_with_options(test_usage, test_options);
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symbol_conf.priv_size = sizeof(int);
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symbol_conf.sort_by_name = true;
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symbol_conf.try_vmlinux_path = true;
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if (symbol__init() < 0)
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return -1;
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setup_pager();
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return __cmd_test();
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}
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