1 files changed, 574 insertions, 0 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
new file mode 100644
index 000000000000..23f4f7b3b83d
--- /dev/null
+++ b/tools/perf/util/symbol.c
@@ -0,0 +1,574 @@
+#include "util.h"
+#include "../perf.h"
+#include "string.h"
+#include "symbol.h"
+
+#include <libelf.h>
+#include <gelf.h>
+#include <elf.h>
+
+const char *sym_hist_filter;
+
+static struct symbol *symbol__new(uint64_t start, uint64_t len,
+                                  const char *name, unsigned int priv_size,
+                                  uint64_t obj_start, int verbose)
+{
+        size_t namelen = strlen(name) + 1;
+        struct symbol *self = calloc(1, priv_size + sizeof(*self) + namelen);
+
+        if (!self)
+                return NULL;
+
+        if (verbose >= 2)
+                printf("new symbol: %016Lx [%08lx]: %s, hist: %p, obj_start: %p\n",
+                        (__u64)start, len, name, self->hist, (void *)obj_start);
+
+        self->obj_start= obj_start;
+        self->hist = NULL;
+        self->hist_sum = 0;
+
+        if (sym_hist_filter && !strcmp(name, sym_hist_filter))
+                self->hist = calloc(sizeof(__u64), len);
+
+        if (priv_size) {
+                memset(self, 0, priv_size);
+                self = ((void *)self) + priv_size;
+        }
+        self->start = start;
+        self->end   = start + len - 1;
+        memcpy(self->name, name, namelen);
+
+        return self;
+}
+
+static void symbol__delete(struct symbol *self, unsigned int priv_size)
+{
+        free(((void *)self) - priv_size);
+}
+
+static size_t symbol__fprintf(struct symbol *self, FILE *fp)
+{
+        return fprintf(fp, " %llx-%llx %s\n",
+                       self->start, self->end, self->name);
+}
+
+struct dso *dso__new(const char *name, unsigned int sym_priv_size)
+{
+        struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
+
+        if (self != NULL) {
+                strcpy(self->name, name);
+                self->syms = RB_ROOT;
+                self->sym_priv_size = sym_priv_size;
+                self->find_symbol = dso__find_symbol;
+        }
+
+        return self;
+}
+
+static void dso__delete_symbols(struct dso *self)
+{
+        struct symbol *pos;
+        struct rb_node *next = rb_first(&self->syms);
+
+        while (next) {
+                pos = rb_entry(next, struct symbol, rb_node);
+                next = rb_next(&pos->rb_node);
+                rb_erase(&pos->rb_node, &self->syms);
+                symbol__delete(pos, self->sym_priv_size);
+        }
+}
+
+void dso__delete(struct dso *self)
+{
+        dso__delete_symbols(self);
+        free(self);
+}
+
+static void dso__insert_symbol(struct dso *self, struct symbol *sym)
+{
+        struct rb_node **p = &self->syms.rb_node;
+        struct rb_node *parent = NULL;
+        const uint64_t ip = sym->start;
+        struct symbol *s;
+
+        while (*p != NULL) {
+                parent = *p;
+                s = rb_entry(parent, struct symbol, rb_node);
+                if (ip < s->start)
+                        p = &(*p)->rb_left;
+                else
+                        p = &(*p)->rb_right;
+        }
+        rb_link_node(&sym->rb_node, parent, p);
+        rb_insert_color(&sym->rb_node, &self->syms);
+}
+
+struct symbol *dso__find_symbol(struct dso *self, uint64_t ip)
+{
+        struct rb_node *n;
+
+        if (self == NULL)
+                return NULL;
+
+        n = self->syms.rb_node;
+
+        while (n) {
+                struct symbol *s = rb_entry(n, struct symbol, rb_node);
+
+                if (ip < s->start)
+                        n = n->rb_left;
+                else if (ip > s->end)
+                        n = n->rb_right;
+                else
+                        return s;
+        }
+
+        return NULL;
+}
+
+size_t dso__fprintf(struct dso *self, FILE *fp)
+{
+        size_t ret = fprintf(fp, "dso: %s\n", self->name);
+
+        struct rb_node *nd;
+        for (nd = rb_first(&self->syms); nd; nd = rb_next(nd)) {
+                struct symbol *pos = rb_entry(nd, struct symbol, rb_node);
+                ret += symbol__fprintf(pos, fp);
+        }
+
+        return ret;
+}
+
+static int dso__load_kallsyms(struct dso *self, symbol_filter_t filter, int verbose)
+{
+        struct rb_node *nd, *prevnd;
+        char *line = NULL;
+        size_t n;
+        FILE *file = fopen("/proc/kallsyms", "r");
+
+        if (file == NULL)
+                goto out_failure;
+
+        while (!feof(file)) {
+                __u64 start;
+                struct symbol *sym;
+                int line_len, len;
+                char symbol_type;
+
+                line_len = getline(&line, &n, file);
+                if (line_len < 0)
+                        break;
+
+                if (!line)
+                        goto out_failure;
+
+                line[--line_len] = '\0'; /* \n */
+
+                len = hex2u64(line, &start);
+
+                len++;
+                if (len + 2 >= line_len)
+                        continue;
+
+                symbol_type = toupper(line[len]);
+                /*
+                 * We're interested only in code ('T'ext)
+                 */
+                if (symbol_type != 'T' && symbol_type != 'W')
+                        continue;
+                /*
+                 * Well fix up the end later, when we have all sorted.
+                 */
+                sym = symbol__new(start, 0xdead, line + len + 2,
+                                  self->sym_priv_size, 0, verbose);
+
+                if (sym == NULL)
+                        goto out_delete_line;
+
+                if (filter && filter(self, sym))
+                        symbol__delete(sym, self->sym_priv_size);
+                else
+                        dso__insert_symbol(self, sym);
+        }
+
+        /*
+         * Now that we have all sorted out, just set the ->end of all
+         * symbols
+         */
+        prevnd = rb_first(&self->syms);
+
+        if (prevnd == NULL)
+                goto out_delete_line;
+
+        for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
+                struct symbol *prev = rb_entry(prevnd, struct symbol, rb_node),
+                              *curr = rb_entry(nd, struct symbol, rb_node);
+
+                prev->end = curr->start - 1;
+                prevnd = nd;
+        }
+
+        free(line);
+        fclose(file);
+
+        return 0;
+
+out_delete_line:
+        free(line);
+out_failure:
+        return -1;
+}
+
+/**
+ * elf_symtab__for_each_symbol - iterate thru all the symbols
+ *
+ * @self: struct elf_symtab instance to iterate
+ * @index: uint32_t index
+ * @sym: GElf_Sym iterator
+ */
+#define elf_symtab__for_each_symbol(syms, nr_syms, index, sym) \
+        for (index = 0, gelf_getsym(syms, index, &sym);\
+             index < nr_syms; \
+             index++, gelf_getsym(syms, index, &sym))
+
+static inline uint8_t elf_sym__type(const GElf_Sym *sym)
+{
+        return GELF_ST_TYPE(sym->st_info);
+}
+
+static inline int elf_sym__is_function(const GElf_Sym *sym)
+{
+        return elf_sym__type(sym) == STT_FUNC &&
+               sym->st_name != 0 &&
+               sym->st_shndx != SHN_UNDEF &&
+               sym->st_size != 0;
+}
+
+static inline const char *elf_sym__name(const GElf_Sym *sym,
+                                        const Elf_Data *symstrs)
+{
+        return symstrs->d_buf + sym->st_name;
+}
+
+static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
+                                    GElf_Shdr *shp, const char *name,
+                                    size_t *index)
+{
+        Elf_Scn *sec = NULL;
+        size_t cnt = 1;
+
+        while ((sec = elf_nextscn(elf, sec)) != NULL) {
+                char *str;
+
+                gelf_getshdr(sec, shp);
+                str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
+                if (!strcmp(name, str)) {
+                        if (index)
+                                *index = cnt;
+                        break;
+                }
+                ++cnt;
+        }
+
+        return sec;
+}
+
+#define elf_section__for_each_rel(reldata, pos, pos_mem, idx, nr_entries) \
+        for (idx = 0, pos = gelf_getrel(reldata, 0, &pos_mem); \
+             idx < nr_entries; \
+             ++idx, pos = gelf_getrel(reldata, idx, &pos_mem))
+
+#define elf_section__for_each_rela(reldata, pos, pos_mem, idx, nr_entries) \
+        for (idx = 0, pos = gelf_getrela(reldata, 0, &pos_mem); \
+             idx < nr_entries; \
+             ++idx, pos = gelf_getrela(reldata, idx, &pos_mem))
+
+static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
+                                       GElf_Ehdr *ehdr, Elf_Scn *scn_dynsym,
+                                       GElf_Shdr *shdr_dynsym,
+                                       size_t dynsym_idx, int verbose)
+{
+        uint32_t nr_rel_entries, idx;
+        GElf_Sym sym;
+        __u64 plt_offset;
+        GElf_Shdr shdr_plt;
+        struct symbol *f;
+        GElf_Shdr shdr_rel_plt;
+        Elf_Data *reldata, *syms, *symstrs;
+        Elf_Scn *scn_plt_rel, *scn_symstrs;
+        char sympltname[1024];
+        int nr = 0, symidx;
+
+        scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
+                                          ".rela.plt", NULL);
+        if (scn_plt_rel == NULL) {
+                scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
+                                                  ".rel.plt", NULL);
+                if (scn_plt_rel == NULL)
+                        return 0;
+        }
+
+        if (shdr_rel_plt.sh_link != dynsym_idx)
+                return 0;
+
+        if (elf_section_by_name(elf, ehdr, &shdr_plt, ".plt", NULL) == NULL)
+                return 0;
+
+        /*
+         * Fetch the relocation section to find the indexes to the GOT
+         * and the symbols in the .dynsym they refer to.
+         */
+        reldata = elf_getdata(scn_plt_rel, NULL);
+        if (reldata == NULL)
+                return -1;
+
+        syms = elf_getdata(scn_dynsym, NULL);
+        if (syms == NULL)
+                return -1;
+
+        scn_symstrs = elf_getscn(elf, shdr_dynsym->sh_link);
+        if (scn_symstrs == NULL)
+                return -1;
+
+        symstrs = elf_getdata(scn_symstrs, NULL);
+        if (symstrs == NULL)
+                return -1;
+
+        nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
+        plt_offset = shdr_plt.sh_offset;
+
+        if (shdr_rel_plt.sh_type == SHT_RELA) {
+                GElf_Rela pos_mem, *pos;
+
+                elf_section__for_each_rela(reldata, pos, pos_mem, idx,
+                                           nr_rel_entries) {
+                        symidx = GELF_R_SYM(pos->r_info);
+                        plt_offset += shdr_plt.sh_entsize;
+                        gelf_getsym(syms, symidx, &sym);
+                        snprintf(sympltname, sizeof(sympltname),
+                                 "%s@plt", elf_sym__name(&sym, symstrs));
+
+                        f = symbol__new(plt_offset, shdr_plt.sh_entsize,
+                                        sympltname, self->sym_priv_size, 0, verbose);
+                        if (!f)
+                                return -1;
+
+                        dso__insert_symbol(self, f);
+                        ++nr;
+                }
+        } else if (shdr_rel_plt.sh_type == SHT_REL) {
+                GElf_Rel pos_mem, *pos;
+                elf_section__for_each_rel(reldata, pos, pos_mem, idx,
+                                          nr_rel_entries) {
+                        symidx = GELF_R_SYM(pos->r_info);
+                        plt_offset += shdr_plt.sh_entsize;
+                        gelf_getsym(syms, symidx, &sym);
+                        snprintf(sympltname, sizeof(sympltname),
+                                 "%s@plt", elf_sym__name(&sym, symstrs));
+
+                        f = symbol__new(plt_offset, shdr_plt.sh_entsize,
+                                        sympltname, self->sym_priv_size, 0, verbose);
+                        if (!f)
+                                return -1;
+
+                        dso__insert_symbol(self, f);
+                        ++nr;
+                }
+        } else {
+                /*
+                 * TODO: There are still one more shdr_rel_plt.sh_type
+                 * I have to investigate, but probably should be ignored.
+                 */
+        }
+
+        return nr;
+}
+
+static int dso__load_sym(struct dso *self, int fd, const char *name,
+                         symbol_filter_t filter, int verbose)
+{
+        Elf_Data *symstrs;
+        uint32_t nr_syms;
+        int err = -1;
+        uint32_t index;
+        GElf_Ehdr ehdr;
+        GElf_Shdr shdr;
+        Elf_Data *syms;
+        GElf_Sym sym;
+        Elf_Scn *sec, *sec_dynsym;
+        Elf *elf;
+        size_t dynsym_idx;
+        int nr = 0;
+
+        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+        if (elf == NULL) {
+                if (verbose)
+                        fprintf(stderr, "%s: cannot read %s ELF file.\n",
+                                __func__, name);
+                goto out_close;
+        }
+
+        if (gelf_getehdr(elf, &ehdr) == NULL) {
+                if (verbose)
+                        fprintf(stderr, "%s: cannot get elf header.\n", __func__);
+                goto out_elf_end;
+        }
+
+        /*
+         * We need to check if we have a .dynsym, so that we can handle the
+         * .plt, synthesizing its symbols, that aren't on the symtabs (be it
+         * .dynsym or .symtab)
+         */
+        sec_dynsym = elf_section_by_name(elf, &ehdr, &shdr,
+                                         ".dynsym", &dynsym_idx);
+        if (sec_dynsym != NULL) {
+                nr = dso__synthesize_plt_symbols(self, elf, &ehdr,
+                                                 sec_dynsym, &shdr,
+                                                 dynsym_idx, verbose);
+                if (nr < 0)
+                        goto out_elf_end;
+        }
+
+        /*
+         * But if we have a full .symtab (that is a superset of .dynsym) we
+         * should add the symbols not in the .dynsyn
+         */
+        sec = elf_section_by_name(elf, &ehdr, &shdr, ".symtab", NULL);
+        if (sec == NULL) {
+                if (sec_dynsym == NULL)
+                        goto out_elf_end;
+
+                sec = sec_dynsym;
+                gelf_getshdr(sec, &shdr);
+        }
+
+        syms = elf_getdata(sec, NULL);
+        if (syms == NULL)
+                goto out_elf_end;
+
+        sec = elf_getscn(elf, shdr.sh_link);
+        if (sec == NULL)
+                goto out_elf_end;
+
+        symstrs = elf_getdata(sec, NULL);
+        if (symstrs == NULL)
+                goto out_elf_end;
+
+        nr_syms = shdr.sh_size / shdr.sh_entsize;
+
+        elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
+                struct symbol *f;
+                uint64_t obj_start;
+
+                if (!elf_sym__is_function(&sym))
+                        continue;
+
+                sec = elf_getscn(elf, sym.st_shndx);
+                if (!sec)
+                        goto out_elf_end;
+
+                gelf_getshdr(sec, &shdr);
+                obj_start = sym.st_value;
+
+                sym.st_value -= shdr.sh_addr - shdr.sh_offset;
+
+                f = symbol__new(sym.st_value, sym.st_size,
+                                elf_sym__name(&sym, symstrs),
+                                self->sym_priv_size, obj_start, verbose);
+                if (!f)
+                        goto out_elf_end;
+
+                if (filter && filter(self, f))
+                        symbol__delete(f, self->sym_priv_size);
+                else {
+                        dso__insert_symbol(self, f);
+                        nr++;
+                }
+        }
+
+        err = nr;
+out_elf_end:
+        elf_end(elf);
+out_close:
+        return err;
+}
+
+int dso__load(struct dso *self, symbol_filter_t filter, int verbose)
+{
+        int size = strlen(self->name) + sizeof("/usr/lib/debug%s.debug");
+        char *name = malloc(size);
+        int variant = 0;
+        int ret = -1;
+        int fd;
+
+        if (!name)
+                return -1;
+
+more:
+        do {
+                switch (variant) {
+                case 0: /* Fedora */
+                        snprintf(name, size, "/usr/lib/debug%s.debug", self->name);
+                        break;
+                case 1: /* Ubuntu */
+                        snprintf(name, size, "/usr/lib/debug%s", self->name);
+                        break;
+                case 2: /* Sane people */
+                        snprintf(name, size, "%s", self->name);
+                        break;
+
+                default:
+                        goto out;
+                }
+                variant++;
+
+                fd = open(name, O_RDONLY);
+        } while (fd < 0);
+
+        ret = dso__load_sym(self, fd, name, filter, verbose);
+        close(fd);
+
+        /*
+         * Some people seem to have debuginfo files _WITHOUT_ debug info!?!?
+         */
+        if (!ret)
+                goto more;
+
+out:
+        free(name);
+        return ret;
+}
+
+static int dso__load_vmlinux(struct dso *self, const char *vmlinux,
+                             symbol_filter_t filter, int verbose)
+{
+        int err, fd = open(vmlinux, O_RDONLY);
+
+        if (fd < 0)
+                return -1;
+
+        err = dso__load_sym(self, fd, vmlinux, filter, verbose);
+        close(fd);
+
+        return err;
+}
+
+int dso__load_kernel(struct dso *self, const char *vmlinux,
+                     symbol_filter_t filter, int verbose)
+{
+        int err = -1;
+
+        if (vmlinux)
+                err = dso__load_vmlinux(self, vmlinux, filter, verbose);
+
+        if (err)
+                err = dso__load_kallsyms(self, filter, verbose);
+
+        return err;
+}
+
+void symbol__init(void)
+{
+        elf_version(EV_CURRENT);
+}