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Commit 4e0d1e8b authored by Arnaldo Carvalho de Melo's avatar Arnaldo Carvalho de Melo
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perf symbols: Split kernel symbol processing from dso__load_sym()

More should be done to split this function, removing stuff map
relocation steps from the actual symbol table loading.

Arch specific stuff also should go elsewhere, to tools/arch/ and
we should have it keyed by data from the perf_env either in the
perf.data header or from the running environment.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-236gyo6cx6iet90u3uc01cws@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 857140e8
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+108 −97
Original line number Diff line number Diff line
@@ -797,6 +797,110 @@ static u64 ref_reloc(struct kmap *kmap)
void __weak arch__sym_update(struct symbol *s __maybe_unused,
		GElf_Sym *sym __maybe_unused) { }

static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
				      GElf_Sym *sym, GElf_Shdr *shdr,
				      struct map_groups *kmaps, struct kmap *kmap,
				      struct dso **curr_dsop, struct map **curr_mapp,
				      const char *section_name,
				      bool adjust_kernel_syms, bool kmodule, bool *remap_kernel)
{
	struct dso *curr_dso = *curr_dsop;
	struct map *curr_map;
	char dso_name[PATH_MAX];

	/* Adjust symbol to map to file offset */
	if (adjust_kernel_syms)
		sym->st_value -= shdr->sh_addr - shdr->sh_offset;

	if (strcmp(section_name, (curr_dso->short_name + dso->short_name_len)) == 0)
		return 0;

	if (strcmp(section_name, ".text") == 0) {
		/*
		 * The initial kernel mapping is based on
		 * kallsyms and identity maps.  Overwrite it to
		 * map to the kernel dso.
		 */
		if (*remap_kernel && dso->kernel) {
			*remap_kernel = false;
			map->start = shdr->sh_addr + ref_reloc(kmap);
			map->end = map->start + shdr->sh_size;
			map->pgoff = shdr->sh_offset;
			map->map_ip = map__map_ip;
			map->unmap_ip = map__unmap_ip;
			/* Ensure maps are correctly ordered */
			if (kmaps) {
				map__get(map);
				map_groups__remove(kmaps, map);
				map_groups__insert(kmaps, map);
				map__put(map);
			}
		}

		/*
		 * The initial module mapping is based on
		 * /proc/modules mapped to offset zero.
		 * Overwrite it to map to the module dso.
		 */
		if (*remap_kernel && kmodule) {
			*remap_kernel = false;
			map->pgoff = shdr->sh_offset;
		}

		*curr_mapp = map;
		*curr_dsop = dso;
		return 0;
	}

	if (!kmap)
		return 0;

	snprintf(dso_name, sizeof(dso_name), "%s%s", dso->short_name, section_name);

	curr_map = map_groups__find_by_name(kmaps, dso_name);
	if (curr_map == NULL) {
		u64 start = sym->st_value;

		if (kmodule)
			start += map->start + shdr->sh_offset;

		curr_dso = dso__new(dso_name);
		if (curr_dso == NULL)
			return -1;
		curr_dso->kernel = dso->kernel;
		curr_dso->long_name = dso->long_name;
		curr_dso->long_name_len = dso->long_name_len;
		curr_map = map__new2(start, curr_dso);
		dso__put(curr_dso);
		if (curr_map == NULL)
			return -1;

		if (adjust_kernel_syms) {
			curr_map->start  = shdr->sh_addr + ref_reloc(kmap);
			curr_map->end	 = curr_map->start + shdr->sh_size;
			curr_map->pgoff	 = shdr->sh_offset;
		} else {
			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
		}
		curr_dso->symtab_type = dso->symtab_type;
		map_groups__insert(kmaps, curr_map);
		/*
		 * Add it before we drop the referece to curr_map, i.e. while
		 * we still are sure to have a reference to this DSO via
		 * *curr_map->dso.
		 */
		dsos__add(&map->groups->machine->dsos, curr_dso);
		/* kmaps already got it */
		map__put(curr_map);
		dso__set_loaded(curr_dso);
		*curr_mapp = curr_map;
		*curr_dsop = curr_dso;
	} else
		*curr_dsop = curr_map->dso;

	return 0;
}

int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
		  struct symsrc *runtime_ss, int kmodule)
{
@@ -973,102 +1077,9 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
			--sym.st_value;

		if (dso->kernel || kmodule) {
			char dso_name[PATH_MAX];

			/* Adjust symbol to map to file offset */
			if (adjust_kernel_syms)
				sym.st_value -= shdr.sh_addr - shdr.sh_offset;

			if (strcmp(section_name,
				   (curr_dso->short_name +
				    dso->short_name_len)) == 0)
				goto new_symbol;

			if (strcmp(section_name, ".text") == 0) {
				/*
				 * The initial kernel mapping is based on
				 * kallsyms and identity maps.  Overwrite it to
				 * map to the kernel dso.
				 */
				if (remap_kernel && dso->kernel) {
					remap_kernel = false;
					map->start = shdr.sh_addr +
						     ref_reloc(kmap);
					map->end = map->start + shdr.sh_size;
					map->pgoff = shdr.sh_offset;
					map->map_ip = map__map_ip;
					map->unmap_ip = map__unmap_ip;
					/* Ensure maps are correctly ordered */
					if (kmaps) {
						map__get(map);
						map_groups__remove(kmaps, map);
						map_groups__insert(kmaps, map);
						map__put(map);
					}
				}

				/*
				 * The initial module mapping is based on
				 * /proc/modules mapped to offset zero.
				 * Overwrite it to map to the module dso.
				 */
				if (remap_kernel && kmodule) {
					remap_kernel = false;
					map->pgoff = shdr.sh_offset;
				}

				curr_map = map;
				curr_dso = dso;
				goto new_symbol;
			}

			if (!kmap)
				goto new_symbol;

			snprintf(dso_name, sizeof(dso_name),
				 "%s%s", dso->short_name, section_name);

			curr_map = map_groups__find_by_name(kmaps, dso_name);
			if (curr_map == NULL) {
				u64 start = sym.st_value;

				if (kmodule)
					start += map->start + shdr.sh_offset;

				curr_dso = dso__new(dso_name);
				if (curr_dso == NULL)
			if (dso__process_kernel_symbol(dso, map, &sym, &shdr, kmaps, kmap, &curr_dso, &curr_map,
						       section_name, adjust_kernel_syms, kmodule, &remap_kernel))
				goto out_elf_end;
				curr_dso->kernel = dso->kernel;
				curr_dso->long_name = dso->long_name;
				curr_dso->long_name_len = dso->long_name_len;
				curr_map = map__new2(start, curr_dso);
				dso__put(curr_dso);
				if (curr_map == NULL) {
					goto out_elf_end;
				}
				if (adjust_kernel_syms) {
					curr_map->start = shdr.sh_addr +
							  ref_reloc(kmap);
					curr_map->end = curr_map->start +
							shdr.sh_size;
					curr_map->pgoff = shdr.sh_offset;
				} else {
					curr_map->map_ip = identity__map_ip;
					curr_map->unmap_ip = identity__map_ip;
				}
				curr_dso->symtab_type = dso->symtab_type;
				map_groups__insert(kmaps, curr_map);
				/*
				 * Add it before we drop the referece to curr_map,
				 * i.e. while we still are sure to have a reference
				 * to this DSO via curr_map->dso.
				 */
				dsos__add(&map->groups->machine->dsos, curr_dso);
				/* kmaps already got it */
				map__put(curr_map);
				dso__set_loaded(curr_dso);
			} else
				curr_dso = curr_map->dso;
		} else if ((used_opd && runtime_ss->adjust_symbols) ||
			   (!used_opd && syms_ss->adjust_symbols)) {
			pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
@@ -1077,7 +1088,7 @@ int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
				  (u64)shdr.sh_offset);
			sym.st_value -= shdr.sh_addr - shdr.sh_offset;
		}
new_symbol:

		demangled = demangle_sym(dso, kmodule, elf_name);
		if (demangled != NULL)
			elf_name = demangled;