map__set_end(machine->vmlinux_map, ~0ULL);
}
-static int machine__update_kernel_mmap(struct machine *machine,
- u64 start, u64 end)
+struct kernel_mmap_mutation_ctx {
+ u64 start;
+ u64 end;
+};
+
+static int kernel_mmap_mutate_cb(struct map *map, void *data)
{
- struct map *orig, *updated;
- int err;
+ struct kernel_mmap_mutation_ctx *ctx = data;
- orig = machine->vmlinux_map;
- updated = map__get(orig);
+ map__set_start(map, ctx->start);
+ map__set_end(map, ctx->end);
+ if (ctx->start == 0 && ctx->end == 0)
+ map__set_end(map, ~0ULL);
+ return 0;
+}
- machine->vmlinux_map = updated;
- maps__remove(machine__kernel_maps(machine), orig);
- machine__set_kernel_mmap(machine, start, end);
- err = maps__insert(machine__kernel_maps(machine), updated);
- map__put(orig);
+static int machine__update_kernel_mmap(struct machine *machine,
+ u64 start, u64 end)
+{
+ struct kernel_mmap_mutation_ctx ctx = { .start = start, .end = end };
- return err;
+ return maps__mutate_mapping(machine__kernel_maps(machine),
+ machine->vmlinux_map,
+ kernel_mmap_mutate_cb, &ctx);
}
int machine__create_kernel_maps(struct machine *machine)
#endif
}
+/**
+ * maps__mutate_mapping - Apply write-protected mutations to a map.
+ * @maps: The maps collection containing the map.
+ * @map: The map to mutate.
+ * @mutate_cb: Callback function that performs the actual mutations.
+ * @data: Private data passed to the callback.
+ *
+ * This acquires the write lock on the maps semaphore to safely protect
+ * concurrent readers from seeing partially mutated or unsorted map boundaries.
+ *
+ * WARNING: Acquiring down_write() here can trigger a recursive self-deadlock if
+ * the caller already holds the read lock (e.g., during maps__for_each_map() or
+ * maps__find() iteration paths that trigger lazy symbol loading). To completely
+ * avoid this deadlock, all kernel/module maps must be pre-loaded up-front (via
+ * maps__load_maps()) under a clean, single-threaded context before entering
+ * multi-threaded event processing loops.
+ */
+int maps__mutate_mapping(struct maps *maps, struct map *map,
+ int (*mutate_cb)(struct map *map, void *data), void *data)
+{
+ int err = 0;
+
+ if (maps) {
+ down_write(maps__lock(maps));
+
+ err = mutate_cb(map, data);
+
+ RC_CHK_ACCESS(maps)->maps_by_address_sorted = false;
+ RC_CHK_ACCESS(maps)->maps_by_name_sorted = false;
+
+ up_write(maps__lock(maps));
+
+#ifdef HAVE_LIBDW_SUPPORT
+ libdw__invalidate_dwfl(maps, maps__libdw_addr_space_dwfl(maps));
+#endif
+ } else {
+ err = mutate_cb(map, data);
+ }
+
+ return err;
+}
+
bool maps__empty(struct maps *maps)
{
bool res;
return ret;
}
+int maps__load_maps(struct maps *maps)
+{
+ struct map **maps_copy;
+ unsigned int nr_maps;
+ int err = 0;
+
+ if (!maps)
+ return 0;
+
+ down_read(maps__lock(maps));
+ nr_maps = maps__nr_maps(maps);
+ if (nr_maps == 0) {
+ up_read(maps__lock(maps));
+ return 0;
+ }
+ maps_copy = calloc(nr_maps, sizeof(*maps_copy));
+ if (!maps_copy) {
+ up_read(maps__lock(maps));
+ return -ENOMEM;
+ }
+ for (unsigned int i = 0; i < nr_maps; i++)
+ maps_copy[i] = map__get(maps__maps_by_address(maps)[i]);
+ up_read(maps__lock(maps));
+
+ for (unsigned int i = 0; i < nr_maps; i++) {
+ if (map__load(maps_copy[i]) < 0) {
+ pr_warning("Failed to load map %s\n", dso__name(map__dso(maps_copy[i])));
+ err = -1;
+ }
+ map__put(maps_copy[i]);
+ }
+ free(maps_copy);
+ return err;
+}
+
void maps__remove_maps(struct maps *maps, bool (*cb)(struct map *map, void *data), void *data)
{
struct map **maps_by_address;
return result;
}
-struct maps__find_symbol_by_name_args {
- struct map **mapp;
- const char *name;
- struct symbol *sym;
-};
-
-static int maps__find_symbol_by_name_cb(struct map *map, void *data)
+struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp)
{
- struct maps__find_symbol_by_name_args *args = data;
+ struct map **maps_copy;
+ unsigned int nr_maps;
+ struct symbol *sym = NULL;
- args->sym = map__find_symbol_by_name(map, args->name);
- if (!args->sym)
- return 0;
+ if (!maps)
+ return NULL;
- if (!map__contains_symbol(map, args->sym)) {
- args->sym = NULL;
- return 0;
+ /*
+ * First, ensure all maps are loaded. We pre-load them outside of any
+ * read-to-write locks to avoid deadlocks. Even if some fail, we proceed.
+ */
+ maps__load_maps(maps);
+
+ /*
+ * Create a local snapshot of the maps while holding the read lock.
+ * This prevents deadlocking if iteration triggers further map insertions.
+ */
+ down_read(maps__lock(maps));
+ nr_maps = maps__nr_maps(maps);
+ maps_copy = calloc(nr_maps, sizeof(*maps_copy));
+ if (maps_copy) {
+ for (unsigned int i = 0; i < nr_maps; i++) {
+ struct map *map = maps__maps_by_address(maps)[i];
+
+ maps_copy[i] = map__get(map);
+ }
}
+ up_read(maps__lock(maps));
- if (args->mapp != NULL)
- *args->mapp = map__get(map);
- return 1;
-}
+ if (!maps_copy)
+ return NULL;
-struct symbol *maps__find_symbol_by_name(struct maps *maps, const char *name, struct map **mapp)
-{
- struct maps__find_symbol_by_name_args args = {
- .mapp = mapp,
- .name = name,
- .sym = NULL,
- };
+ for (unsigned int i = 0; i < nr_maps; i++) {
+ struct map *map = maps_copy[i];
+
+ sym = map__find_symbol_by_name(map, name);
+ if (sym && map__contains_symbol(map, sym)) {
+ if (mapp)
+ *mapp = map__get(map);
+ break;
+ }
+ sym = NULL;
+ }
+
+ for (unsigned int i = 0; i < nr_maps; i++)
+ map__put(maps_copy[i]);
- maps__for_each_map(maps, maps__find_symbol_by_name_cb, &args);
- return args.sym;
+ free(maps_copy);
+ return sym;
}
int maps__find_ams(struct maps *maps, struct addr_map_symbol *ams)
size_t maps__fprintf(struct maps *maps, FILE *fp);
+int maps__load_maps(struct maps *maps);
int maps__insert(struct maps *maps, struct map *map);
void maps__remove(struct maps *maps, struct map *map);
+int maps__mutate_mapping(struct maps *maps, struct map *map,
+ int (*mutate_cb)(struct map *map, void *data), void *data);
struct map *maps__find(struct maps *maps, u64 addr);
struct symbol *maps__find_symbol(struct maps *maps, u64 addr, struct map **mapp);
void __weak arch__sym_update(struct symbol *s __maybe_unused,
GElf_Sym *sym __maybe_unused) { }
+struct remap_kernel_ctx {
+ u64 sh_addr;
+ u64 sh_size;
+ u64 sh_offset;
+ struct kmap *kmap;
+};
+
+static int remap_kernel_cb(struct map *map, void *data)
+{
+ struct remap_kernel_ctx *ctx = data;
+
+ map__set_start(map, ctx->sh_addr + ref_reloc(ctx->kmap));
+ map__set_end(map, map__start(map) + ctx->sh_size);
+ map__set_pgoff(map, ctx->sh_offset);
+ map__set_mapping_type(map, MAPPING_TYPE__DSO);
+ return 0;
+}
+
static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
GElf_Sym *sym, GElf_Shdr *shdr,
struct maps *kmaps, struct kmap *kmap,
* map to the kernel dso.
*/
if (*remap_kernel && dso__kernel(dso) && !kmodule) {
+ struct remap_kernel_ctx ctx = {
+ .sh_addr = shdr->sh_addr,
+ .sh_size = shdr->sh_size,
+ .sh_offset = shdr->sh_offset,
+ .kmap = kmap
+ };
+
*remap_kernel = false;
- map__set_start(map, shdr->sh_addr + ref_reloc(kmap));
- map__set_end(map, map__start(map) + shdr->sh_size);
- map__set_pgoff(map, shdr->sh_offset);
- map__set_mapping_type(map, MAPPING_TYPE__DSO);
- /* Ensure maps are correctly ordered */
- if (kmaps) {
- int err;
- struct map *tmp = map__get(map);
-
- maps__remove(kmaps, map);
- err = maps__insert(kmaps, map);
- map__put(tmp);
- if (err)
- return err;
- }
+ maps__mutate_mapping(kmaps, map, remap_kernel_cb, &ctx);
}
/*
#include <symbol/kallsyms.h>
#include <sys/utsname.h>
+static int map_fixup_cb(struct map *map, void *data __maybe_unused)
+{
+ map__fixup_start(map);
+ map__fixup_end(map);
+ return 0;
+}
+
static int dso__load_kernel_sym(struct dso *dso, struct map *map);
static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
free(kallsyms_allocated_filename);
if (err > 0 && !dso__is_kcore(dso)) {
+ struct maps *kmaps = map__kmaps(map);
+
dso__set_binary_type(dso, DSO_BINARY_TYPE__KALLSYMS);
dso__set_long_name(dso, DSO__NAME_KALLSYMS, false);
- map__fixup_start(map);
- map__fixup_end(map);
+ maps__mutate_mapping(kmaps, map, map_fixup_cb, NULL);
}
return err;
if (err > 0)
pr_debug("Using %s for symbols\n", kallsyms_filename);
if (err > 0 && !dso__is_kcore(dso)) {
+ struct maps *kmaps = map__kmaps(map);
+
dso__set_binary_type(dso, DSO_BINARY_TYPE__GUEST_KALLSYMS);
dso__set_long_name(dso, machine->mmap_name, false);
- map__fixup_start(map);
- map__fixup_end(map);
+ maps__mutate_mapping(kmaps, map, map_fixup_cb, NULL);
}
return err;
projects / thirdparty / linux.git / commitdiff
