map.c

#include "symbol.h"
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "map.h"

const char *map_type__name[MAP__NR_TYPES] = {
	[MAP__FUNCTION] = "Functions",
	[MAP__VARIABLE] = "Variables",
};

static inline int is_anon_memory(const char *filename)
{
	return strcmp(filename, "//anon") == 0;
}

static int strcommon(const char *pathname, char *cwd, int cwdlen)
{
	int n = 0;

	while (n < cwdlen && pathname[n] == cwd[n])
		++n;

	return n;
}

void map__init(struct map *self, enum map_type type,
	       u64 start, u64 end, u64 pgoff, struct dso *dso)
{
	self->type     = type;
	self->start    = start;
	self->end      = end;
	self->pgoff    = pgoff;
	self->dso      = dso;
	self->map_ip   = map__map_ip;
	self->unmap_ip = map__unmap_ip;
	RB_CLEAR_NODE(&self->rb_node);
}

struct map *map__new(u64 start, u64 len, u64 pgoff, u32 pid, char *filename,
		     enum map_type type, char *cwd, int cwdlen)
{
	struct map *self = malloc(sizeof(*self));

	if (self != NULL) {
		char newfilename[PATH_MAX];
		struct dso *dso;
		int anon;

		if (cwd) {
			int n = strcommon(filename, cwd, cwdlen);

			if (n == cwdlen) {
				snprintf(newfilename, sizeof(newfilename),
					 ".%s", filename + n);
				filename = newfilename;
			}
		}

		anon = is_anon_memory(filename);

		if (anon) {
			snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", pid);
			filename = newfilename;
		}

		dso = dsos__findnew(filename);
		if (dso == NULL)
			goto out_delete;

		map__init(self, type, start, start + len, pgoff, dso);

		if (anon) {
set_identity:
			self->map_ip = self->unmap_ip = identity__map_ip;
		} else if (strcmp(filename, "[vdso]") == 0) {
			dso__set_loaded(dso, self->type);
			goto set_identity;
		}
	}
	return self;
out_delete:
	free(self);
	return NULL;
}

void map__delete(struct map *self)
{
	free(self);
}

void map__fixup_start(struct map *self)
{
	struct rb_root *symbols = &self->dso->symbols[self->type];
	struct rb_node *nd = rb_first(symbols);
	if (nd != NULL) {
		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
		self->start = sym->start;
	}
}

void map__fixup_end(struct map *self)
{
	struct rb_root *symbols = &self->dso->symbols[self->type];
	struct rb_node *nd = rb_last(symbols);
	if (nd != NULL) {
		struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
		self->end = sym->end;
	}
}

#define DSO__DELETED "(deleted)"

int map__load(struct map *self, symbol_filter_t filter)
{
	const char *name = self->dso->long_name;
	int nr;

	if (dso__loaded(self->dso, self->type))
		return 0;

	nr = dso__load(self->dso, self, filter);
	if (nr < 0) {
		if (self->dso->has_build_id) {
			char sbuild_id[BUILD_ID_SIZE * 2 + 1];

			build_id__sprintf(self->dso->build_id,
					  sizeof(self->dso->build_id),
					  sbuild_id);
			pr_warning("%s with build id %s not found",
				   name, sbuild_id);
		} else
			pr_warning("Failed to open %s", name);

		pr_warning(", continuing without symbols\n");
		return -1;
	} else if (nr == 0) {
		const size_t len = strlen(name);
		const size_t real_len = len - sizeof(DSO__DELETED);

		if (len > sizeof(DSO__DELETED) &&
		    strcmp(name + real_len + 1, DSO__DELETED) == 0) {
			pr_warning("%.*s was updated, restart the long "
				   "running apps that use it!\n",
				   (int)real_len, name);
		} else {
			pr_warning("no symbols found in %s, maybe install "
				   "a debug package?\n", name);
		}

		return -1;
	}
	/*
	 * Only applies to the kernel, as its symtabs aren't relative like the
	 * module ones.
	 */
	if (self->dso->kernel)
		map__reloc_vmlinux(self);

	return 0;
}

struct symbol *map__find_symbol(struct map *self, u64 addr,
				symbol_filter_t filter)
{
	if (map__load(self, filter) < 0)
		return NULL;

	return dso__find_symbol(self->dso, self->type, addr);
}

struct symbol *map__find_symbol_by_name(struct map *self, const char *name,
					symbol_filter_t filter)
{
	if (map__load(self, filter) < 0)
		return NULL;

	if (!dso__sorted_by_name(self->dso, self->type))
		dso__sort_by_name(self->dso, self->type);

	return dso__find_symbol_by_name(self->dso, self->type, name);
}

struct map *map__clone(struct map *self)
{
	struct map *map = malloc(sizeof(*self));

	if (!map)
		return NULL;

	memcpy(map, self, sizeof(*self));

	return map;
}

int map__overlap(struct map *l, struct map *r)
{
	if (l->start > r->start) {
		struct map *t = l;
		l = r;
		r = t;
	}

	if (l->end > r->start)
		return 1;

	return 0;
}

size_t map__fprintf(struct map *self, FILE *fp)
{
	return fprintf(fp, " %Lx-%Lx %Lx %s\n",
		       self->start, self->end, self->pgoff, self->dso->name);
}

/*
 * objdump wants/reports absolute IPs for ET_EXEC, and RIPs for ET_DYN.
 * map->dso->adjust_symbols==1 for ET_EXEC-like cases.
 */
u64 map__rip_2objdump(struct map *map, u64 rip)
{
	u64 addr = map->dso->adjust_symbols ?
			map->unmap_ip(map, rip) :	/* RIP -> IP */
			rip;
	return addr;
}

u64 map__objdump_2ip(struct map *map, u64 addr)
{
	u64 ip = map->dso->adjust_symbols ?
			addr :
			map->unmap_ip(map, addr);	/* RIP -> IP */
	return ip;
}

struct symbol *map_groups__find_symbol(struct map_groups *self,
				       enum map_type type, u64 addr,
				       symbol_filter_t filter)
{
	struct map *map = map_groups__find(self, type, addr);

	if (map != NULL)
		return map__find_symbol(map, map->map_ip(map, addr), filter);

	return NULL;
}

static u64 map__reloc_map_ip(struct map *map, u64 ip)
{
	return ip + (s64)map->pgoff;
}

static u64 map__reloc_unmap_ip(struct map *map, u64 ip)
{
	return ip - (s64)map->pgoff;
}

void map__reloc_vmlinux(struct map *self)
{
	struct kmap *kmap = map__kmap(self);
	s64 reloc;

	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->unrelocated_addr)
		return;

	reloc = (kmap->ref_reloc_sym->unrelocated_addr -
		 kmap->ref_reloc_sym->addr);

	if (!reloc)
		return;

	self->map_ip   = map__reloc_map_ip;
	self->unmap_ip = map__reloc_unmap_ip;
	self->pgoff    = reloc;
}

void maps__insert(struct rb_root *maps, struct map *map)
{
	struct rb_node **p = &maps->rb_node;
	struct rb_node *parent = NULL;
	const u64 ip = map->start;
	struct map *m;

	while (*p != NULL) {
		parent = *p;
		m = rb_entry(parent, struct map, rb_node);
		if (ip < m->start)
			p = &(*p)->rb_left;
		else
			p = &(*p)->rb_right;
	}

	rb_link_node(&map->rb_node, parent, p);
	rb_insert_color(&map->rb_node, maps);
}

struct map *maps__find(struct rb_root *maps, u64 ip)
{
	struct rb_node **p = &maps->rb_node;
	struct rb_node *parent = NULL;
	struct map *m;

	while (*p != NULL) {
		parent = *p;
		m = rb_entry(parent, struct map, rb_node);
		if (ip < m->start)
			p = &(*p)->rb_left;
		else if (ip > m->end)
			p = &(*p)->rb_right;
		else
			return m;
	}

	return NULL;
}