Merge branch 'linus' into tracing/core

Conflicts:
	kernel/trace/trace_events_filter.c

We use the tracing/core version.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 215 insertions, 66 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 4683b67b5ee4..f1dcede14307 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -7,8 +7,33 @@
 #include <gelf.h>
 #include <elf.h>
 
+#ifndef NO_DEMANGLE
+#include <bfd.h>
+#else
+static inline
+char *bfd_demangle(void __used *v, const char __used *c, int __used i)
+{
+        return NULL;
+}
+#endif
+
 const char *sym_hist_filter;
 
+#ifndef DMGL_PARAMS
+#define DMGL_PARAMS      (1 << 0)       /* Include function args */
+#define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
+#endif
+
+enum dso_origin {
+        DSO__ORIG_KERNEL = 0,
+        DSO__ORIG_JAVA_JIT,
+        DSO__ORIG_FEDORA,
+        DSO__ORIG_UBUNTU,
+        DSO__ORIG_BUILDID,
+        DSO__ORIG_DSO,
+        DSO__ORIG_NOT_FOUND,
+};
+
 static struct symbol *symbol__new(u64 start, u64 len,
                                   const char *name, unsigned int priv_size,
                                   u64 obj_start, int verbose)
@@ -65,6 +90,8 @@ struct dso *dso__new(const char *name, unsigned int sym_priv_size)
                 self->syms = RB_ROOT;
                 self->sym_priv_size = sym_priv_size;
                 self->find_symbol = dso__find_symbol;
+                self->slen_calculated = 0;
+                self->origin = DSO__ORIG_NOT_FOUND;
         }
 
         return self;
@@ -373,36 +400,61 @@ static Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
              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)
+/*
+ * 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).
+ * And always look at the original dso, not at debuginfo packages, that
+ * have the PLT data stripped out (shdr_rel_plt.sh_type == SHT_NOBITS).
+ */
+static int dso__synthesize_plt_symbols(struct  dso *self, 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;
+        GElf_Shdr shdr_rel_plt, shdr_dynsym;
         Elf_Data *reldata, *syms, *symstrs;
-        Elf_Scn *scn_plt_rel, *scn_symstrs;
+        Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
+        size_t dynsym_idx;
+        GElf_Ehdr ehdr;
         char sympltname[1024];
-        int nr = 0, symidx;
+        Elf *elf;
+        int nr = 0, symidx, fd, err = 0;
+
+        fd = open(self->name, O_RDONLY);
+        if (fd < 0)
+                goto out;
+
+        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+        if (elf == NULL)
+                goto out_close;
+
+        if (gelf_getehdr(elf, &ehdr) == NULL)
+                goto out_elf_end;
 
-        scn_plt_rel = elf_section_by_name(elf, ehdr, &shdr_rel_plt,
+        scn_dynsym = elf_section_by_name(elf, &ehdr, &shdr_dynsym,
+                                         ".dynsym", &dynsym_idx);
+        if (scn_dynsym == NULL)
+                goto out_elf_end;
+
+        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,
+                scn_plt_rel = elf_section_by_name(elf, &ehdr, &shdr_rel_plt,
                                                   ".rel.plt", NULL);
                 if (scn_plt_rel == NULL)
-                        return 0;
+                        goto out_elf_end;
         }
 
+        err = -1;
+
         if (shdr_rel_plt.sh_link != dynsym_idx)
-                return 0;
+                goto out_elf_end;
 
-        if (elf_section_by_name(elf, ehdr, &shdr_plt, ".plt", NULL) == NULL)
-                return 0;
+        if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
+                goto out_elf_end;
 
         /*
          * Fetch the relocation section to find the indexes to the GOT
@@ -410,19 +462,19 @@ static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
          */
         reldata = elf_getdata(scn_plt_rel, NULL);
         if (reldata == NULL)
-                return -1;
+                goto out_elf_end;
 
         syms = elf_getdata(scn_dynsym, NULL);
         if (syms == NULL)
-                return -1;
+                goto out_elf_end;
 
-        scn_symstrs = elf_getscn(elf, shdr_dynsym->sh_link);
+        scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
         if (scn_symstrs == NULL)
-                return -1;
+                goto out_elf_end;
 
         symstrs = elf_getdata(scn_symstrs, NULL);
         if (symstrs == NULL)
-                return -1;
+                goto out_elf_end;
 
         nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
         plt_offset = shdr_plt.sh_offset;
@@ -441,7 +493,7 @@ static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
                                         sympltname, self->sym_priv_size, 0, verbose);
                         if (!f)
-                                return -1;
+                                goto out_elf_end;
 
                         dso__insert_symbol(self, f);
                         ++nr;
@@ -459,19 +511,25 @@ static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
                         f = symbol__new(plt_offset, shdr_plt.sh_entsize,
                                         sympltname, self->sym_priv_size, 0, verbose);
                         if (!f)
-                                return -1;
+                                goto out_elf_end;
 
                         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;
+        err = 0;
+out_elf_end:
+        elf_end(elf);
+out_close:
+        close(fd);
+
+        if (err == 0)
+                return nr;
+out:
+        fprintf(stderr, "%s: problems reading %s PLT info.\n",
+                __func__, self->name);
+        return 0;
 }
 
 static int dso__load_sym(struct dso *self, int fd, const char *name,
@@ -485,10 +543,9 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
         GElf_Shdr shdr;
         Elf_Data *syms;
         GElf_Sym sym;
-        Elf_Scn *sec, *sec_dynsym, *sec_strndx;
+        Elf_Scn *sec, *sec_strndx;
         Elf *elf;
-        size_t dynsym_idx;
-        int nr = 0;
+        int nr = 0, kernel = !strcmp("[kernel]", self->name);
 
         elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
         if (elf == NULL) {
@@ -504,32 +561,11 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
                 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)
+                sec = elf_section_by_name(elf, &ehdr, &shdr, ".dynsym", NULL);
+                if (sec == NULL)
                         goto out_elf_end;
-
-                sec = sec_dynsym;
-                gelf_getshdr(sec, &shdr);
         }
 
         syms = elf_getdata(sec, NULL);
@@ -549,18 +585,23 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
                 goto out_elf_end;
 
         secstrs = elf_getdata(sec_strndx, NULL);
-        if (symstrs == NULL)
+        if (secstrs == NULL)
                 goto out_elf_end;
 
         nr_syms = shdr.sh_size / shdr.sh_entsize;
 
         memset(&sym, 0, sizeof(sym));
-        self->adjust_symbols = (ehdr.e_type == ET_EXEC ||
+        if (!kernel) {
+                self->adjust_symbols = (ehdr.e_type == ET_EXEC ||
                                 elf_section_by_name(elf, &ehdr, &shdr,
                                                      ".gnu.prelink_undo",
                                                      NULL) != NULL);
+        } else self->adjust_symbols = 0;
+
         elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
                 struct symbol *f;
+                const char *name;
+                char *demangled;
                 u64 obj_start;
                 struct section *section = NULL;
                 int is_label = elf_sym__is_label(&sym);
@@ -599,10 +640,19 @@ static int dso__load_sym(struct dso *self, int fd, const char *name,
                                 goto out_elf_end;
                         }
                 }
+                /*
+                 * We need to figure out if the object was created from C++ sources
+                 * DWARF DW_compile_unit has this, but we don't always have access
+                 * to it...
+                 */
+                name = elf_sym__name(&sym, symstrs);
+                demangled = bfd_demangle(NULL, name, DMGL_PARAMS | DMGL_ANSI);
+                if (demangled != NULL)
+                        name = demangled;
 
-                f = symbol__new(sym.st_value, sym.st_size,
-                                elf_sym__name(&sym, symstrs),
+                f = symbol__new(sym.st_value, sym.st_size, name,
                                 self->sym_priv_size, obj_start, verbose);
+                free(demangled);
                 if (!f)
                         goto out_elf_end;
 
@@ -622,11 +672,85 @@ out_close:
         return err;
 }
 
+#define BUILD_ID_SIZE 128
+
+static char *dso__read_build_id(struct dso *self, int verbose)
+{
+        int i;
+        GElf_Ehdr ehdr;
+        GElf_Shdr shdr;
+        Elf_Data *build_id_data;
+        Elf_Scn *sec;
+        char *build_id = NULL, *bid;
+        unsigned char *raw;
+        Elf *elf;
+        int fd = open(self->name, O_RDONLY);
+
+        if (fd < 0)
+                goto out;
+
+        elf = elf_begin(fd, ELF_C_READ_MMAP, NULL);
+        if (elf == NULL) {
+                if (verbose)
+                        fprintf(stderr, "%s: cannot read %s ELF file.\n",
+                                __func__, self->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;
+        }
+
+        sec = elf_section_by_name(elf, &ehdr, &shdr, ".note.gnu.build-id", NULL);
+        if (sec == NULL)
+                goto out_elf_end;
+
+        build_id_data = elf_getdata(sec, NULL);
+        if (build_id_data == NULL)
+                goto out_elf_end;
+        build_id = malloc(BUILD_ID_SIZE);
+        if (build_id == NULL)
+                goto out_elf_end;
+        raw = build_id_data->d_buf + 16;
+        bid = build_id;
+
+        for (i = 0; i < 20; ++i) {
+                sprintf(bid, "%02x", *raw);
+                ++raw;
+                bid += 2;
+        }
+        if (verbose >= 2)
+                printf("%s(%s): %s\n", __func__, self->name, build_id);
+out_elf_end:
+        elf_end(elf);
+out_close:
+        close(fd);
+out:
+        return build_id;
+}
+
+char dso__symtab_origin(const struct dso *self)
+{
+        static const char origin[] = {
+                [DSO__ORIG_KERNEL] =   'k',
+                [DSO__ORIG_JAVA_JIT] = 'j',
+                [DSO__ORIG_FEDORA] =   'f',
+                [DSO__ORIG_UBUNTU] =   'u',
+                [DSO__ORIG_BUILDID] =  'b',
+                [DSO__ORIG_DSO] =      'd',
+        };
+
+        if (self == NULL || self->origin == DSO__ORIG_NOT_FOUND)
+                return '!';
+        return origin[self->origin];
+}
+
 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 size = PATH_MAX;
+        char *name = malloc(size), *build_id = NULL;
         int ret = -1;
         int fd;
 
@@ -635,26 +759,43 @@ int dso__load(struct dso *self, symbol_filter_t filter, int verbose)
 
         self->adjust_symbols = 0;
 
-        if (strncmp(self->name, "/tmp/perf-", 10) == 0)
-                return dso__load_perf_map(self, filter, verbose);
+        if (strncmp(self->name, "/tmp/perf-", 10) == 0) {
+                ret = dso__load_perf_map(self, filter, verbose);
+                self->origin = ret > 0 ? DSO__ORIG_JAVA_JIT :
+                                         DSO__ORIG_NOT_FOUND;
+                return ret;
+        }
+
+        self->origin = DSO__ORIG_FEDORA - 1;
 
 more:
         do {
-                switch (variant) {
-                case 0: /* Fedora */
+                self->origin++;
+                switch (self->origin) {
+                case DSO__ORIG_FEDORA:
                         snprintf(name, size, "/usr/lib/debug%s.debug", self->name);
                         break;
-                case 1: /* Ubuntu */
+                case DSO__ORIG_UBUNTU:
                         snprintf(name, size, "/usr/lib/debug%s", self->name);
                         break;
-                case 2: /* Sane people */
+                case DSO__ORIG_BUILDID:
+                        build_id = dso__read_build_id(self, verbose);
+                        if (build_id != NULL) {
+                                snprintf(name, size,
+                                         "/usr/lib/debug/.build-id/%.2s/%s.debug",
+                                        build_id, build_id + 2);
+                                free(build_id);
+                                break;
+                        }
+                        self->origin++;
+                        /* Fall thru */
+                case DSO__ORIG_DSO:
                         snprintf(name, size, "%s", self->name);
                         break;
 
                 default:
                         goto out;
                 }
-                variant++;
 
                 fd = open(name, O_RDONLY);
         } while (fd < 0);
@@ -668,6 +809,11 @@ more:
         if (!ret)
                 goto more;
 
+        if (ret > 0) {
+                int nr_plt = dso__synthesize_plt_symbols(self, verbose);
+                if (nr_plt > 0)
+                        ret += nr_plt;
+        }
 out:
         free(name);
         return ret;
@@ -785,6 +931,9 @@ int dso__load_kernel(struct dso *self, const char *vmlinux,
         if (err <= 0)
                 err = dso__load_kallsyms(self, filter, verbose);
 
+        if (err > 0)
+                self->origin = DSO__ORIG_KERNEL;
+
         return err;
 }