OSCL-LXR linux-6.0.1/​tools/​perf/​util/​symbol-elf.c	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 #include <fcntl.h>
 #include <stdio.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <inttypes.h>
 
 #include "dso.h"
 #include "map.h"
 #include "maps.h"
 #include "symbol.h"
 #include "symsrc.h"
 #include "demangle-ocaml.h"
 #include "demangle-java.h"
 #include "demangle-rust.h"
 #include "machine.h"
 #include "vdso.h"
 #include "debug.h"
 #include "util/copyfile.h"
 #include <linux/ctype.h>
 #include <linux/kernel.h>
 #include <linux/zalloc.h>
 #include <symbol/kallsyms.h>
 #include <internal/lib.h>
 
 #ifndef EM_AARCH64
 #define EM_AARCH64  183  /* ARM 64 bit */
 #endif
 
 #ifndef ELF32_ST_VISIBILITY
 #define ELF32_ST_VISIBILITY(o)  ((o) & 0x03)
 #endif
 
 /* For ELF64 the definitions are the same.  */
 #ifndef ELF64_ST_VISIBILITY
 #define ELF64_ST_VISIBILITY(o)  ELF32_ST_VISIBILITY (o)
 #endif
 
 /* How to extract information held in the st_other field.  */
 #ifndef GELF_ST_VISIBILITY
 #define GELF_ST_VISIBILITY(val) ELF64_ST_VISIBILITY (val)
 #endif
 
 typedef Elf64_Nhdr GElf_Nhdr;
 
 #ifndef DMGL_PARAMS
 #define DMGL_NO_OPTS     0              /* For readability... */
 #define DMGL_PARAMS      (1 << 0)       /* Include function args */
 #define DMGL_ANSI        (1 << 1)       /* Include const, volatile, etc */
 #endif
 
 #ifdef HAVE_LIBBFD_SUPPORT
 #define PACKAGE 'perf'
 #include <bfd.h>
 #else
 #ifdef HAVE_CPLUS_DEMANGLE_SUPPORT
 extern char *cplus_demangle(const char *, int);
 
 static inline char *bfd_demangle(void __maybe_unused *v, const char *c, int i)
 {
     return cplus_demangle(c, i);
 }
 #else
 #ifdef NO_DEMANGLE
 static inline char *bfd_demangle(void __maybe_unused *v,
                  const char __maybe_unused *c,
                  int __maybe_unused i)
 {
     return NULL;
 }
 #endif
 #endif
 #endif
 
 #ifndef HAVE_ELF_GETPHDRNUM_SUPPORT
 static int elf_getphdrnum(Elf *elf, size_t *dst)
 {
     GElf_Ehdr gehdr;
     GElf_Ehdr *ehdr;
 
     ehdr = gelf_getehdr(elf, &gehdr);
     if (!ehdr)
         return -1;
 
     *dst = ehdr->e_phnum;
 
     return 0;
 }
 #endif
 
 #ifndef HAVE_ELF_GETSHDRSTRNDX_SUPPORT
 static int elf_getshdrstrndx(Elf *elf __maybe_unused, size_t *dst __maybe_unused)
 {
     pr_err("%s: update your libelf to > 0.140, this one lacks elf_getshdrstrndx().\n", __func__);
     return -1;
 }
 #endif
 
 #ifndef NT_GNU_BUILD_ID
 #define NT_GNU_BUILD_ID 3
 #endif
 
 /**
  * elf_symtab__for_each_symbol - iterate thru all the symbols
  *
  * @syms: struct elf_symtab instance to iterate
  * @idx: uint32_t idx
  * @sym: GElf_Sym iterator
  */
 #define elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) \
     for (idx = 0, gelf_getsym(syms, idx, &sym);\
          idx < nr_syms; \
          idx++, gelf_getsym(syms, idx, &sym))
 
 static inline uint8_t elf_sym__type(const GElf_Sym *sym)
 {
     return GELF_ST_TYPE(sym->st_info);
 }
 
 static inline uint8_t elf_sym__visibility(const GElf_Sym *sym)
 {
     return GELF_ST_VISIBILITY(sym->st_other);
 }
 
 #ifndef STT_GNU_IFUNC
 #define STT_GNU_IFUNC 10
 #endif
 
 static inline int elf_sym__is_function(const GElf_Sym *sym)
 {
     return (elf_sym__type(sym) == STT_FUNC ||
         elf_sym__type(sym) == STT_GNU_IFUNC) &&
            sym->st_name != 0 &&
            sym->st_shndx != SHN_UNDEF;
 }
 
 static inline bool elf_sym__is_object(const GElf_Sym *sym)
 {
     return elf_sym__type(sym) == STT_OBJECT &&
         sym->st_name != 0 &&
         sym->st_shndx != SHN_UNDEF;
 }
 
 static inline int elf_sym__is_label(const GElf_Sym *sym)
 {
     return elf_sym__type(sym) == STT_NOTYPE &&
         sym->st_name != 0 &&
         sym->st_shndx != SHN_UNDEF &&
         sym->st_shndx != SHN_ABS &&
         elf_sym__visibility(sym) != STV_HIDDEN &&
         elf_sym__visibility(sym) != STV_INTERNAL;
 }
 
 static bool elf_sym__filter(GElf_Sym *sym)
 {
     return elf_sym__is_function(sym) || elf_sym__is_object(sym);
 }
 
 static inline const char *elf_sym__name(const GElf_Sym *sym,
                     const Elf_Data *symstrs)
 {
     return symstrs->d_buf + sym->st_name;
 }
 
 static inline const char *elf_sec__name(const GElf_Shdr *shdr,
                     const Elf_Data *secstrs)
 {
     return secstrs->d_buf + shdr->sh_name;
 }
 
 static inline int elf_sec__is_text(const GElf_Shdr *shdr,
                     const Elf_Data *secstrs)
 {
     return strstr(elf_sec__name(shdr, secstrs), "text") != NULL;
 }
 
 static inline bool elf_sec__is_data(const GElf_Shdr *shdr,
                     const Elf_Data *secstrs)
 {
     return strstr(elf_sec__name(shdr, secstrs), "data") != NULL;
 }
 
 static bool elf_sec__filter(GElf_Shdr *shdr, Elf_Data *secstrs)
 {
     return elf_sec__is_text(shdr, secstrs) || 
            elf_sec__is_data(shdr, secstrs);
 }
 
 static size_t elf_addr_to_index(Elf *elf, GElf_Addr addr)
 {
     Elf_Scn *sec = NULL;
     GElf_Shdr shdr;
     size_t cnt = 1;
 
     while ((sec = elf_nextscn(elf, sec)) != NULL) {
         gelf_getshdr(sec, &shdr);
 
         if ((addr >= shdr.sh_addr) &&
             (addr < (shdr.sh_addr + shdr.sh_size)))
             return cnt;
 
         ++cnt;
     }
 
     return -1;
 }
 
 Elf_Scn *elf_section_by_name(Elf *elf, GElf_Ehdr *ep,
                  GElf_Shdr *shp, const char *name, size_t *idx)
 {
     Elf_Scn *sec = NULL;
     size_t cnt = 1;
 
     /* Elf is corrupted/truncated, avoid calling elf_strptr. */
     if (!elf_rawdata(elf_getscn(elf, ep->e_shstrndx), NULL))
         return NULL;
 
     while ((sec = elf_nextscn(elf, sec)) != NULL) {
         char *str;
 
         gelf_getshdr(sec, shp);
         str = elf_strptr(elf, ep->e_shstrndx, shp->sh_name);
         if (str && !strcmp(name, str)) {
             if (idx)
                 *idx = cnt;
             return sec;
         }
         ++cnt;
     }
 
     return NULL;
 }
 
 static int elf_read_program_header(Elf *elf, u64 vaddr, GElf_Phdr *phdr)
 {
     size_t i, phdrnum;
     u64 sz;
 
     if (elf_getphdrnum(elf, &phdrnum))
         return -1;
 
     for (i = 0; i < phdrnum; i++) {
         if (gelf_getphdr(elf, i, phdr) == NULL)
             return -1;
 
         if (phdr->p_type != PT_LOAD)
             continue;
 
         sz = max(phdr->p_memsz, phdr->p_filesz);
         if (!sz)
             continue;
 
         if (vaddr >= phdr->p_vaddr && (vaddr < phdr->p_vaddr + sz))
             return 0;
     }
 
     /* Not found any valid program header */
     return -1;
 }
 
 static bool want_demangle(bool is_kernel_sym)
 {
     return is_kernel_sym ? symbol_conf.demangle_kernel : symbol_conf.demangle;
 }
 
 static char *demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 {
     int demangle_flags = verbose > 0 ? (DMGL_PARAMS | DMGL_ANSI) : DMGL_NO_OPTS;
     char *demangled = NULL;
 
     /*
      * 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...
      */
     if (!want_demangle(dso->kernel || kmodule))
         return demangled;
 
     demangled = bfd_demangle(NULL, elf_name, demangle_flags);
     if (demangled == NULL) {
         demangled = ocaml_demangle_sym(elf_name);
         if (demangled == NULL) {
             demangled = java_demangle_sym(elf_name, JAVA_DEMANGLE_NORET);
         }
     }
     else if (rust_is_mangled(demangled))
         /*
             * Input to Rust demangling is the BFD-demangled
             * name which it Rust-demangles in place.
             */
         rust_demangle_sym(demangled);
 
     return demangled;
 }
 
 #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))
 
 /*
  * 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).
  */
 int dso__synthesize_plt_symbols(struct dso *dso, struct symsrc *ss)
 {
     uint32_t nr_rel_entries, idx;
     GElf_Sym sym;
     u64 plt_offset, plt_header_size, plt_entry_size;
     GElf_Shdr shdr_plt;
     struct symbol *f;
     GElf_Shdr shdr_rel_plt, shdr_dynsym;
     Elf_Data *reldata, *syms, *symstrs;
     Elf_Scn *scn_plt_rel, *scn_symstrs, *scn_dynsym;
     size_t dynsym_idx;
     GElf_Ehdr ehdr;
     char sympltname[1024];
     Elf *elf;
     int nr = 0, symidx, err = 0;
 
     if (!ss->dynsym)
         return 0;
 
     elf = ss->elf;
     ehdr = ss->ehdr;
 
     scn_dynsym = ss->dynsym;
     shdr_dynsym = ss->dynshdr;
     dynsym_idx = ss->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,
                           ".rel.plt", NULL);
         if (scn_plt_rel == NULL)
             goto out_elf_end;
     }
 
     err = -1;
 
     if (shdr_rel_plt.sh_link != dynsym_idx)
         goto out_elf_end;
 
     if (elf_section_by_name(elf, &ehdr, &shdr_plt, ".plt", NULL) == NULL)
         goto out_elf_end;
 
     /*
      * Fetch the relocation section to find the idxes to the GOT
      * and the symbols in the .dynsym they refer to.
      */
     reldata = elf_getdata(scn_plt_rel, NULL);
     if (reldata == NULL)
         goto out_elf_end;
 
     syms = elf_getdata(scn_dynsym, NULL);
     if (syms == NULL)
         goto out_elf_end;
 
     scn_symstrs = elf_getscn(elf, shdr_dynsym.sh_link);
     if (scn_symstrs == NULL)
         goto out_elf_end;
 
     symstrs = elf_getdata(scn_symstrs, NULL);
     if (symstrs == NULL)
         goto out_elf_end;
 
     if (symstrs->d_size == 0)
         goto out_elf_end;
 
     nr_rel_entries = shdr_rel_plt.sh_size / shdr_rel_plt.sh_entsize;
     plt_offset = shdr_plt.sh_offset;
     switch (ehdr.e_machine) {
         case EM_ARM:
             plt_header_size = 20;
             plt_entry_size = 12;
             break;
 
         case EM_AARCH64:
             plt_header_size = 32;
             plt_entry_size = 16;
             break;
 
         case EM_SPARC:
             plt_header_size = 48;
             plt_entry_size = 12;
             break;
 
         case EM_SPARCV9:
             plt_header_size = 128;
             plt_entry_size = 32;
             break;
 
         default: /* FIXME: s390/alpha/mips/parisc/poperpc/sh/xtensa need to be checked */
             plt_header_size = shdr_plt.sh_entsize;
             plt_entry_size = shdr_plt.sh_entsize;
             break;
     }
     plt_offset += plt_header_size;
 
     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) {
             const char *elf_name = NULL;
             char *demangled = NULL;
             symidx = GELF_R_SYM(pos->r_info);
             gelf_getsym(syms, symidx, &sym);
 
             elf_name = elf_sym__name(&sym, symstrs);
             demangled = demangle_sym(dso, 0, elf_name);
             if (demangled != NULL)
                 elf_name = demangled;
             snprintf(sympltname, sizeof(sympltname),
                  "%s@plt", elf_name);
             free(demangled);
 
             f = symbol__new(plt_offset, plt_entry_size,
                     STB_GLOBAL, STT_FUNC, sympltname);
             if (!f)
                 goto out_elf_end;
 
             plt_offset += plt_entry_size;
             symbols__insert(&dso->symbols, 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) {
             const char *elf_name = NULL;
             char *demangled = NULL;
             symidx = GELF_R_SYM(pos->r_info);
             gelf_getsym(syms, symidx, &sym);
 
             elf_name = elf_sym__name(&sym, symstrs);
             demangled = demangle_sym(dso, 0, elf_name);
             if (demangled != NULL)
                 elf_name = demangled;
             snprintf(sympltname, sizeof(sympltname),
                  "%s@plt", elf_name);
             free(demangled);
 
             f = symbol__new(plt_offset, plt_entry_size,
                     STB_GLOBAL, STT_FUNC, sympltname);
             if (!f)
                 goto out_elf_end;
 
             plt_offset += plt_entry_size;
             symbols__insert(&dso->symbols, f);
             ++nr;
         }
     }
 
     err = 0;
 out_elf_end:
     if (err == 0)
         return nr;
     pr_debug("%s: problems reading %s PLT info.\n",
          __func__, dso->long_name);
     return 0;
 }
 
 char *dso__demangle_sym(struct dso *dso, int kmodule, const char *elf_name)
 {
     return demangle_sym(dso, kmodule, elf_name);
 }
 
 /*
  * Align offset to 4 bytes as needed for note name and descriptor data.
  */
 #define NOTE_ALIGN(n) (((n) + 3) & -4U)
 
 static int elf_read_build_id(Elf *elf, void *bf, size_t size)
 {
     int err = -1;
     GElf_Ehdr ehdr;
     GElf_Shdr shdr;
     Elf_Data *data;
     Elf_Scn *sec;
     Elf_Kind ek;
     void *ptr;
 
     if (size < BUILD_ID_SIZE)
         goto out;
 
     ek = elf_kind(elf);
     if (ek != ELF_K_ELF)
         goto out;
 
     if (gelf_getehdr(elf, &ehdr) == NULL) {
         pr_err("%s: cannot get elf header.\n", __func__);
         goto out;
     }
 
     /*
      * Check following sections for notes:
      *   '.note.gnu.build-id'
      *   '.notes'
      *   '.note' (VDSO specific)
      */
     do {
         sec = elf_section_by_name(elf, &ehdr, &shdr,
                       ".note.gnu.build-id", NULL);
         if (sec)
             break;
 
         sec = elf_section_by_name(elf, &ehdr, &shdr,
                       ".notes", NULL);
         if (sec)
             break;
 
         sec = elf_section_by_name(elf, &ehdr, &shdr,
                       ".note", NULL);
         if (sec)
             break;
 
         return err;
 
     } while (0);
 
     data = elf_getdata(sec, NULL);
     if (data == NULL)
         goto out;
 
     ptr = data->d_buf;
     while (ptr < (data->d_buf + data->d_size)) {
         GElf_Nhdr *nhdr = ptr;
         size_t namesz = NOTE_ALIGN(nhdr->n_namesz),
                descsz = NOTE_ALIGN(nhdr->n_descsz);
         const char *name;
 
         ptr += sizeof(*nhdr);
         name = ptr;
         ptr += namesz;
         if (nhdr->n_type == NT_GNU_BUILD_ID &&
             nhdr->n_namesz == sizeof("GNU")) {
             if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
                 size_t sz = min(size, descsz);
                 memcpy(bf, ptr, sz);
                 memset(bf + sz, 0, size - sz);
                 err = descsz;
                 break;
             }
         }
         ptr += descsz;
     }
 
 out:
     return err;
 }
 
 #ifdef HAVE_LIBBFD_BUILDID_SUPPORT
 
 static int read_build_id(const char *filename, struct build_id *bid)
 {
     size_t size = sizeof(bid->data);
     int err = -1;
     bfd *abfd;
 
     abfd = bfd_openr(filename, NULL);
     if (!abfd)
         return -1;
 
     if (!bfd_check_format(abfd, bfd_object)) {
         pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
         goto out_close;
     }
 
     if (!abfd->build_id || abfd->build_id->size > size)
         goto out_close;
 
     memcpy(bid->data, abfd->build_id->data, abfd->build_id->size);
     memset(bid->data + abfd->build_id->size, 0, size - abfd->build_id->size);
     err = bid->size = abfd->build_id->size;
 
 out_close:
     bfd_close(abfd);
     return err;
 }
 
 #else // HAVE_LIBBFD_BUILDID_SUPPORT
 
 static int read_build_id(const char *filename, struct build_id *bid)
 {
     size_t size = sizeof(bid->data);
     int fd, err = -1;
     Elf *elf;
 
     if (size < BUILD_ID_SIZE)
         goto out;
 
     fd = open(filename, O_RDONLY);
     if (fd < 0)
         goto out;
 
     elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
     if (elf == NULL) {
         pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
         goto out_close;
     }
 
     err = elf_read_build_id(elf, bid->data, size);
     if (err > 0)
         bid->size = err;
 
     elf_end(elf);
 out_close:
     close(fd);
 out:
     return err;
 }
 
 #endif // HAVE_LIBBFD_BUILDID_SUPPORT
 
 int filename__read_build_id(const char *filename, struct build_id *bid)
 {
     struct kmod_path m = { .name = NULL, };
     char path[PATH_MAX];
     int err;
 
     if (!filename)
         return -EFAULT;
 
     err = kmod_path__parse(&m, filename);
     if (err)
         return -1;
 
     if (m.comp) {
         int error = 0, fd;
 
         fd = filename__decompress(filename, path, sizeof(path), m.comp, &error);
         if (fd < 0) {
             pr_debug("Failed to decompress (error %d) %s\n",
                  error, filename);
             return -1;
         }
         close(fd);
         filename = path;
     }
 
     err = read_build_id(filename, bid);
 
     if (m.comp)
         unlink(filename);
     return err;
 }
 
 int sysfs__read_build_id(const char *filename, struct build_id *bid)
 {
     size_t size = sizeof(bid->data);
     int fd, err = -1;
 
     fd = open(filename, O_RDONLY);
     if (fd < 0)
         goto out;
 
     while (1) {
         char bf[BUFSIZ];
         GElf_Nhdr nhdr;
         size_t namesz, descsz;
 
         if (read(fd, &nhdr, sizeof(nhdr)) != sizeof(nhdr))
             break;
 
         namesz = NOTE_ALIGN(nhdr.n_namesz);
         descsz = NOTE_ALIGN(nhdr.n_descsz);
         if (nhdr.n_type == NT_GNU_BUILD_ID &&
             nhdr.n_namesz == sizeof("GNU")) {
             if (read(fd, bf, namesz) != (ssize_t)namesz)
                 break;
             if (memcmp(bf, "GNU", sizeof("GNU")) == 0) {
                 size_t sz = min(descsz, size);
                 if (read(fd, bid->data, sz) == (ssize_t)sz) {
                     memset(bid->data + sz, 0, size - sz);
                     bid->size = sz;
                     err = 0;
                     break;
                 }
             } else if (read(fd, bf, descsz) != (ssize_t)descsz)
                 break;
         } else {
             int n = namesz + descsz;
 
             if (n > (int)sizeof(bf)) {
                 n = sizeof(bf);
                 pr_debug("%s: truncating reading of build id in sysfs file %s: n_namesz=%u, n_descsz=%u.\n",
                      __func__, filename, nhdr.n_namesz, nhdr.n_descsz);
             }
             if (read(fd, bf, n) != n)
                 break;
         }
     }
     close(fd);
 out:
     return err;
 }
 
 #ifdef HAVE_LIBBFD_SUPPORT
 
 int filename__read_debuglink(const char *filename, char *debuglink,
                  size_t size)
 {
     int err = -1;
     asection *section;
     bfd *abfd;
 
     abfd = bfd_openr(filename, NULL);
     if (!abfd)
         return -1;
 
     if (!bfd_check_format(abfd, bfd_object)) {
         pr_debug2("%s: cannot read %s bfd file.\n", __func__, filename);
         goto out_close;
     }
 
     section = bfd_get_section_by_name(abfd, ".gnu_debuglink");
     if (!section)
         goto out_close;
 
     if (section->size > size)
         goto out_close;
 
     if (!bfd_get_section_contents(abfd, section, debuglink, 0,
                       section->size))
         goto out_close;
 
     err = 0;
 
 out_close:
     bfd_close(abfd);
     return err;
 }
 
 #else
 
 int filename__read_debuglink(const char *filename, char *debuglink,
                  size_t size)
 {
     int fd, err = -1;
     Elf *elf;
     GElf_Ehdr ehdr;
     GElf_Shdr shdr;
     Elf_Data *data;
     Elf_Scn *sec;
     Elf_Kind ek;
 
     fd = open(filename, O_RDONLY);
     if (fd < 0)
         goto out;
 
     elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
     if (elf == NULL) {
         pr_debug2("%s: cannot read %s ELF file.\n", __func__, filename);
         goto out_close;
     }
 
     ek = elf_kind(elf);
     if (ek != ELF_K_ELF)
         goto out_elf_end;
 
     if (gelf_getehdr(elf, &ehdr) == NULL) {
         pr_err("%s: cannot get elf header.\n", __func__);
         goto out_elf_end;
     }
 
     sec = elf_section_by_name(elf, &ehdr, &shdr,
                   ".gnu_debuglink", NULL);
     if (sec == NULL)
         goto out_elf_end;
 
     data = elf_getdata(sec, NULL);
     if (data == NULL)
         goto out_elf_end;
 
     /* the start of this section is a zero-terminated string */
     strncpy(debuglink, data->d_buf, size);
 
     err = 0;
 
 out_elf_end:
     elf_end(elf);
 out_close:
     close(fd);
 out:
     return err;
 }
 
 #endif
 
 static int dso__swap_init(struct dso *dso, unsigned char eidata)
 {
     static unsigned int const endian = 1;
 
     dso->needs_swap = DSO_SWAP__NO;
 
     switch (eidata) {
     case ELFDATA2LSB:
         /* We are big endian, DSO is little endian. */
         if (*(unsigned char const *)&endian != 1)
             dso->needs_swap = DSO_SWAP__YES;
         break;
 
     case ELFDATA2MSB:
         /* We are little endian, DSO is big endian. */
         if (*(unsigned char const *)&endian != 0)
             dso->needs_swap = DSO_SWAP__YES;
         break;
 
     default:
         pr_err("unrecognized DSO data encoding %d\n", eidata);
         return -EINVAL;
     }
 
     return 0;
 }
 
 bool symsrc__possibly_runtime(struct symsrc *ss)
 {
     return ss->dynsym || ss->opdsec;
 }
 
 bool symsrc__has_symtab(struct symsrc *ss)
 {
     return ss->symtab != NULL;
 }
 
 void symsrc__destroy(struct symsrc *ss)
 {
     zfree(&ss->name);
     elf_end(ss->elf);
     close(ss->fd);
 }
 
 bool elf__needs_adjust_symbols(GElf_Ehdr ehdr)
 {
     /*
      * Usually vmlinux is an ELF file with type ET_EXEC for most
      * architectures; except Arm64 kernel is linked with option
      * '-share', so need to check type ET_DYN.
      */
     return ehdr.e_type == ET_EXEC || ehdr.e_type == ET_REL ||
            ehdr.e_type == ET_DYN;
 }
 
 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
          enum dso_binary_type type)
 {
     GElf_Ehdr ehdr;
     Elf *elf;
     int fd;
 
     if (dso__needs_decompress(dso)) {
         fd = dso__decompress_kmodule_fd(dso, name);
         if (fd < 0)
             return -1;
 
         type = dso->symtab_type;
     } else {
         fd = open(name, O_RDONLY);
         if (fd < 0) {
             dso->load_errno = errno;
             return -1;
         }
     }
 
     elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
     if (elf == NULL) {
         pr_debug("%s: cannot read %s ELF file.\n", __func__, name);
         dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
         goto out_close;
     }
 
     if (gelf_getehdr(elf, &ehdr) == NULL) {
         dso->load_errno = DSO_LOAD_ERRNO__INVALID_ELF;
         pr_debug("%s: cannot get elf header.\n", __func__);
         goto out_elf_end;
     }
 
     if (dso__swap_init(dso, ehdr.e_ident[EI_DATA])) {
         dso->load_errno = DSO_LOAD_ERRNO__INTERNAL_ERROR;
         goto out_elf_end;
     }
 
     /* Always reject images with a mismatched build-id: */
     if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
         u8 build_id[BUILD_ID_SIZE];
         struct build_id bid;
         int size;
 
         size = elf_read_build_id(elf, build_id, BUILD_ID_SIZE);
         if (size <= 0) {
             dso->load_errno = DSO_LOAD_ERRNO__CANNOT_READ_BUILDID;
             goto out_elf_end;
         }
 
         build_id__init(&bid, build_id, size);
         if (!dso__build_id_equal(dso, &bid)) {
             pr_debug("%s: build id mismatch for %s.\n", __func__, name);
             dso->load_errno = DSO_LOAD_ERRNO__MISMATCHING_BUILDID;
             goto out_elf_end;
         }
     }
 
     ss->is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
 
     ss->symtab = elf_section_by_name(elf, &ehdr, &ss->symshdr, ".symtab",
             NULL);
     if (ss->symshdr.sh_type != SHT_SYMTAB)
         ss->symtab = NULL;
 
     ss->dynsym_idx = 0;
     ss->dynsym = elf_section_by_name(elf, &ehdr, &ss->dynshdr, ".dynsym",
             &ss->dynsym_idx);
     if (ss->dynshdr.sh_type != SHT_DYNSYM)
         ss->dynsym = NULL;
 
     ss->opdidx = 0;
     ss->opdsec = elf_section_by_name(elf, &ehdr, &ss->opdshdr, ".opd",
             &ss->opdidx);
     if (ss->opdshdr.sh_type != SHT_PROGBITS)
         ss->opdsec = NULL;
 
     if (dso->kernel == DSO_SPACE__USER)
         ss->adjust_symbols = true;
     else
         ss->adjust_symbols = elf__needs_adjust_symbols(ehdr);
 
     ss->name   = strdup(name);
     if (!ss->name) {
         dso->load_errno = errno;
         goto out_elf_end;
     }
 
     ss->elf    = elf;
     ss->fd     = fd;
     ss->ehdr   = ehdr;
     ss->type   = type;
 
     return 0;
 
 out_elf_end:
     elf_end(elf);
 out_close:
     close(fd);
     return -1;
 }
 
 /**
  * ref_reloc_sym_not_found - has kernel relocation symbol been found.
  * @kmap: kernel maps and relocation reference symbol
  *
  * This function returns %true if we are dealing with the kernel maps and the
  * relocation reference symbol has not yet been found.  Otherwise %false is
  * returned.
  */
 static bool ref_reloc_sym_not_found(struct kmap *kmap)
 {
     return kmap && kmap->ref_reloc_sym && kmap->ref_reloc_sym->name &&
            !kmap->ref_reloc_sym->unrelocated_addr;
 }
 
 /**
  * ref_reloc - kernel relocation offset.
  * @kmap: kernel maps and relocation reference symbol
  *
  * This function returns the offset of kernel addresses as determined by using
  * the relocation reference symbol i.e. if the kernel has not been relocated
  * then the return value is zero.
  */
 static u64 ref_reloc(struct kmap *kmap)
 {
     if (kmap && kmap->ref_reloc_sym &&
         kmap->ref_reloc_sym->unrelocated_addr)
         return kmap->ref_reloc_sym->addr -
                kmap->ref_reloc_sym->unrelocated_addr;
     return 0;
 }
 
 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 maps *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 && !kmodule) {
             *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);
                 maps__remove(kmaps, map);
                 maps__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 = maps__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 (curr_dso->kernel)
             map__kmap(curr_map)->kmaps = kmaps;
 
         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;
         maps__insert(kmaps, curr_map);
         /*
          * Add it before we drop the reference to curr_map, i.e. while
          * we still are sure to have a reference to this DSO via
          * *curr_map->dso.
          */
         dsos__add(&kmaps->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;
 }
 
 static int
 dso__load_sym_internal(struct dso *dso, struct map *map, struct symsrc *syms_ss,
                struct symsrc *runtime_ss, int kmodule, int dynsym)
 {
     struct kmap *kmap = dso->kernel ? map__kmap(map) : NULL;
     struct maps *kmaps = kmap ? map__kmaps(map) : NULL;
     struct map *curr_map = map;
     struct dso *curr_dso = dso;
     Elf_Data *symstrs, *secstrs, *secstrs_run, *secstrs_sym;
     uint32_t nr_syms;
     int err = -1;
     uint32_t idx;
     GElf_Ehdr ehdr;
     GElf_Shdr shdr;
     GElf_Shdr tshdr;
     Elf_Data *syms, *opddata = NULL;
     GElf_Sym sym;
     Elf_Scn *sec, *sec_strndx;
     Elf *elf;
     int nr = 0;
     bool remap_kernel = false, adjust_kernel_syms = false;
 
     if (kmap && !kmaps)
         return -1;
 
     elf = syms_ss->elf;
     ehdr = syms_ss->ehdr;
     if (dynsym) {
         sec  = syms_ss->dynsym;
         shdr = syms_ss->dynshdr;
     } else {
         sec =  syms_ss->symtab;
         shdr = syms_ss->symshdr;
     }
 
     if (elf_section_by_name(runtime_ss->elf, &runtime_ss->ehdr, &tshdr,
                 ".text", NULL))
         dso->text_offset = tshdr.sh_addr - tshdr.sh_offset;
 
     if (runtime_ss->opdsec)
         opddata = elf_rawdata(runtime_ss->opdsec, NULL);
 
     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;
 
     sec_strndx = elf_getscn(runtime_ss->elf, runtime_ss->ehdr.e_shstrndx);
     if (sec_strndx == NULL)
         goto out_elf_end;
 
     secstrs_run = elf_getdata(sec_strndx, NULL);
     if (secstrs_run == NULL)
         goto out_elf_end;
 
     sec_strndx = elf_getscn(elf, ehdr.e_shstrndx);
     if (sec_strndx == NULL)
         goto out_elf_end;
 
     secstrs_sym = elf_getdata(sec_strndx, NULL);
     if (secstrs_sym == NULL)
         goto out_elf_end;
 
     nr_syms = shdr.sh_size / shdr.sh_entsize;
 
     memset(&sym, 0, sizeof(sym));
 
     /*
      * The kernel relocation symbol is needed in advance in order to adjust
      * kernel maps correctly.
      */
     if (ref_reloc_sym_not_found(kmap)) {
         elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
             const char *elf_name = elf_sym__name(&sym, symstrs);
 
             if (strcmp(elf_name, kmap->ref_reloc_sym->name))
                 continue;
             kmap->ref_reloc_sym->unrelocated_addr = sym.st_value;
             map->reloc = kmap->ref_reloc_sym->addr -
                      kmap->ref_reloc_sym->unrelocated_addr;
             break;
         }
     }
 
     /*
      * Handle any relocation of vdso necessary because older kernels
      * attempted to prelink vdso to its virtual address.
      */
     if (dso__is_vdso(dso))
         map->reloc = map->start - dso->text_offset;
 
     dso->adjust_symbols = runtime_ss->adjust_symbols || ref_reloc(kmap);
     /*
      * Initial kernel and module mappings do not map to the dso.
      * Flag the fixups.
      */
     if (dso->kernel) {
         remap_kernel = true;
         adjust_kernel_syms = dso->adjust_symbols;
     }
     elf_symtab__for_each_symbol(syms, nr_syms, idx, sym) {
         struct symbol *f;
         const char *elf_name = elf_sym__name(&sym, symstrs);
         char *demangled = NULL;
         int is_label = elf_sym__is_label(&sym);
         const char *section_name;
         bool used_opd = false;
 
         if (!is_label && !elf_sym__filter(&sym))
             continue;
 
         /* Reject ARM ELF "mapping symbols": these aren't unique and
          * don't identify functions, so will confuse the profile
          * output: */
         if (ehdr.e_machine == EM_ARM || ehdr.e_machine == EM_AARCH64) {
             if (elf_name[0] == '$' && strchr("adtx", elf_name[1])
                 && (elf_name[2] == '\0' || elf_name[2] == '.'))
                 continue;
         }
 
         if (runtime_ss->opdsec && sym.st_shndx == runtime_ss->opdidx) {
             u32 offset = sym.st_value - syms_ss->opdshdr.sh_addr;
             u64 *opd = opddata->d_buf + offset;
             sym.st_value = DSO__SWAP(dso, u64, *opd);
             sym.st_shndx = elf_addr_to_index(runtime_ss->elf,
                     sym.st_value);
             used_opd = true;
         }
 
         /*
          * When loading symbols in a data mapping, ABS symbols (which
          * has a value of SHN_ABS in its st_shndx) failed at
          * elf_getscn().  And it marks the loading as a failure so
          * already loaded symbols cannot be fixed up.
          *
          * I'm not sure what should be done. Just ignore them for now.
          * - Namhyung Kim
          */
         if (sym.st_shndx == SHN_ABS)
             continue;
 
         sec = elf_getscn(syms_ss->elf, sym.st_shndx);
         if (!sec)
             goto out_elf_end;
 
         gelf_getshdr(sec, &shdr);
 
         /*
          * If the attribute bit SHF_ALLOC is not set, the section
          * doesn't occupy memory during process execution.
          * E.g. ".gnu.warning.*" section is used by linker to generate
          * warnings when calling deprecated functions, the symbols in
          * the section aren't loaded to memory during process execution,
          * so skip them.
          */
         if (!(shdr.sh_flags & SHF_ALLOC))
             continue;
 
         secstrs = secstrs_sym;
 
         /*
          * We have to fallback to runtime when syms' section header has
          * NOBITS set. NOBITS results in file offset (sh_offset) not
          * being incremented. So sh_offset used below has different
          * values for syms (invalid) and runtime (valid).
          */
         if (shdr.sh_type == SHT_NOBITS) {
             sec = elf_getscn(runtime_ss->elf, sym.st_shndx);
             if (!sec)
                 goto out_elf_end;
 
             gelf_getshdr(sec, &shdr);
             secstrs = secstrs_run;
         }
 
         if (is_label && !elf_sec__filter(&shdr, secstrs))
             continue;
 
         section_name = elf_sec__name(&shdr, secstrs);
 
         /* On ARM, symbols for thumb functions have 1 added to
          * the symbol address as a flag - remove it */
         if ((ehdr.e_machine == EM_ARM) &&
             (GELF_ST_TYPE(sym.st_info) == STT_FUNC) &&
             (sym.st_value & 1))
             --sym.st_value;
 
         if (dso->kernel) {
             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;
         } else if ((used_opd && runtime_ss->adjust_symbols) ||
                (!used_opd && syms_ss->adjust_symbols)) {
             GElf_Phdr phdr;
 
             if (elf_read_program_header(syms_ss->elf,
                             (u64)sym.st_value, &phdr)) {
                 pr_debug4("%s: failed to find program header for "
                        "symbol: %s st_value: %#" PRIx64 "\n",
                        __func__, elf_name, (u64)sym.st_value);
                 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
                     "sh_addr: %#" PRIx64 " sh_offset: %#" PRIx64 "\n",
                     __func__, (u64)sym.st_value, (u64)shdr.sh_addr,
                     (u64)shdr.sh_offset);
                 /*
                  * Fail to find program header, let's rollback
                  * to use shdr.sh_addr and shdr.sh_offset to
                  * calibrate symbol's file address, though this
                  * is not necessary for normal C ELF file, we
                  * still need to handle java JIT symbols in this
                  * case.
                  */
                 sym.st_value -= shdr.sh_addr - shdr.sh_offset;
             } else {
                 pr_debug4("%s: adjusting symbol: st_value: %#" PRIx64 " "
                     "p_vaddr: %#" PRIx64 " p_offset: %#" PRIx64 "\n",
                     __func__, (u64)sym.st_value, (u64)phdr.p_vaddr,
                     (u64)phdr.p_offset);
                 sym.st_value -= phdr.p_vaddr - phdr.p_offset;
             }
         }
 
         demangled = demangle_sym(dso, kmodule, elf_name);
         if (demangled != NULL)
             elf_name = demangled;
 
         f = symbol__new(sym.st_value, sym.st_size,
                 GELF_ST_BIND(sym.st_info),
                 GELF_ST_TYPE(sym.st_info), elf_name);
         free(demangled);
         if (!f)
             goto out_elf_end;
 
         arch__sym_update(f, &sym);
 
         __symbols__insert(&curr_dso->symbols, f, dso->kernel);
         nr++;
     }
 
     /*
      * For misannotated, zeroed, ASM function sizes.
      */
     if (nr > 0) {
         symbols__fixup_end(&dso->symbols, false);
         symbols__fixup_duplicate(&dso->symbols);
         if (kmap) {
             /*
              * We need to fixup this here too because we create new
              * maps here, for things like vsyscall sections.
              */
             maps__fixup_end(kmaps);
         }
     }
     err = nr;
 out_elf_end:
     return err;
 }
 
 int dso__load_sym(struct dso *dso, struct map *map, struct symsrc *syms_ss,
           struct symsrc *runtime_ss, int kmodule)
 {
     int nr = 0;
     int err = -1;
 
     dso->symtab_type = syms_ss->type;
     dso->is_64_bit = syms_ss->is_64_bit;
     dso->rel = syms_ss->ehdr.e_type == ET_REL;
 
     /*
      * Modules may already have symbols from kallsyms, but those symbols
      * have the wrong values for the dso maps, so remove them.
      */
     if (kmodule && syms_ss->symtab)
         symbols__delete(&dso->symbols);
 
     if (!syms_ss->symtab) {
         /*
          * If the vmlinux is stripped, fail so we will fall back
          * to using kallsyms. The vmlinux runtime symbols aren't
          * of much use.
          */
         if (dso->kernel)
             return err;
     } else  {
         err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
                          kmodule, 0);
         if (err < 0)
             return err;
         nr = err;
     }
 
     if (syms_ss->dynsym) {
         err = dso__load_sym_internal(dso, map, syms_ss, runtime_ss,
                          kmodule, 1);
         if (err < 0)
             return err;
         err += nr;
     }
 
     return err;
 }
 
 static int elf_read_maps(Elf *elf, bool exe, mapfn_t mapfn, void *data)
 {
     GElf_Phdr phdr;
     size_t i, phdrnum;
     int err;
     u64 sz;
 
     if (elf_getphdrnum(elf, &phdrnum))
         return -1;
 
     for (i = 0; i < phdrnum; i++) {
         if (gelf_getphdr(elf, i, &phdr) == NULL)
             return -1;
         if (phdr.p_type != PT_LOAD)
             continue;
         if (exe) {
             if (!(phdr.p_flags & PF_X))
                 continue;
         } else {
             if (!(phdr.p_flags & PF_R))
                 continue;
         }
         sz = min(phdr.p_memsz, phdr.p_filesz);
         if (!sz)
             continue;
         err = mapfn(phdr.p_vaddr, sz, phdr.p_offset, data);
         if (err)
             return err;
     }
     return 0;
 }
 
 int file__read_maps(int fd, bool exe, mapfn_t mapfn, void *data,
             bool *is_64_bit)
 {
     int err;
     Elf *elf;
 
     elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
     if (elf == NULL)
         return -1;
 
     if (is_64_bit)
         *is_64_bit = (gelf_getclass(elf) == ELFCLASS64);
 
     err = elf_read_maps(elf, exe, mapfn, data);
 
     elf_end(elf);
     return err;
 }
 
 enum dso_type dso__type_fd(int fd)
 {
     enum dso_type dso_type = DSO__TYPE_UNKNOWN;
     GElf_Ehdr ehdr;
     Elf_Kind ek;
     Elf *elf;
 
     elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
     if (elf == NULL)
         goto out;
 
     ek = elf_kind(elf);
     if (ek != ELF_K_ELF)
         goto out_end;
 
     if (gelf_getclass(elf) == ELFCLASS64) {
         dso_type = DSO__TYPE_64BIT;
         goto out_end;
     }
 
     if (gelf_getehdr(elf, &ehdr) == NULL)
         goto out_end;
 
     if (ehdr.e_machine == EM_X86_64)
         dso_type = DSO__TYPE_X32BIT;
     else
         dso_type = DSO__TYPE_32BIT;
 out_end:
     elf_end(elf);
 out:
     return dso_type;
 }
 
 static int copy_bytes(int from, off_t from_offs, int to, off_t to_offs, u64 len)
 {
     ssize_t r;
     size_t n;
     int err = -1;
     char *buf = malloc(page_size);
 
     if (buf == NULL)
         return -1;
 
     if (lseek(to, to_offs, SEEK_SET) != to_offs)
         goto out;
 
     if (lseek(from, from_offs, SEEK_SET) != from_offs)
         goto out;
 
     while (len) {
         n = page_size;
         if (len < n)
             n = len;
         /* Use read because mmap won't work on proc files */
         r = read(from, buf, n);
         if (r < 0)
             goto out;
         if (!r)
             break;
         n = r;
         r = write(to, buf, n);
         if (r < 0)
             goto out;
         if ((size_t)r != n)
             goto out;
         len -= n;
     }
 
     err = 0;
 out:
     free(buf);
     return err;
 }
 
 struct kcore {
     int fd;
     int elfclass;
     Elf *elf;
     GElf_Ehdr ehdr;
 };
 
 static int kcore__open(struct kcore *kcore, const char *filename)
 {
     GElf_Ehdr *ehdr;
 
     kcore->fd = open(filename, O_RDONLY);
     if (kcore->fd == -1)
         return -1;
 
     kcore->elf = elf_begin(kcore->fd, ELF_C_READ, NULL);
     if (!kcore->elf)
         goto out_close;
 
     kcore->elfclass = gelf_getclass(kcore->elf);
     if (kcore->elfclass == ELFCLASSNONE)
         goto out_end;
 
     ehdr = gelf_getehdr(kcore->elf, &kcore->ehdr);
     if (!ehdr)
         goto out_end;
 
     return 0;
 
 out_end:
     elf_end(kcore->elf);
 out_close:
     close(kcore->fd);
     return -1;
 }
 
 static int kcore__init(struct kcore *kcore, char *filename, int elfclass,
                bool temp)
 {
     kcore->elfclass = elfclass;
 
     if (temp)
         kcore->fd = mkstemp(filename);
     else
         kcore->fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0400);
     if (kcore->fd == -1)
         return -1;
 
     kcore->elf = elf_begin(kcore->fd, ELF_C_WRITE, NULL);
     if (!kcore->elf)
         goto out_close;
 
     if (!gelf_newehdr(kcore->elf, elfclass))
         goto out_end;
 
     memset(&kcore->ehdr, 0, sizeof(GElf_Ehdr));
 
     return 0;
 
 out_end:
     elf_end(kcore->elf);
 out_close:
     close(kcore->fd);
     unlink(filename);
     return -1;
 }
 
 static void kcore__close(struct kcore *kcore)
 {
     elf_end(kcore->elf);
     close(kcore->fd);
 }
 
 static int kcore__copy_hdr(struct kcore *from, struct kcore *to, size_t count)
 {
     GElf_Ehdr *ehdr = &to->ehdr;
     GElf_Ehdr *kehdr = &from->ehdr;
 
     memcpy(ehdr->e_ident, kehdr->e_ident, EI_NIDENT);
     ehdr->e_type      = kehdr->e_type;
     ehdr->e_machine   = kehdr->e_machine;
     ehdr->e_version   = kehdr->e_version;
     ehdr->e_entry     = 0;
     ehdr->e_shoff     = 0;
     ehdr->e_flags     = kehdr->e_flags;
     ehdr->e_phnum     = count;
     ehdr->e_shentsize = 0;
     ehdr->e_shnum     = 0;
     ehdr->e_shstrndx  = 0;
 
     if (from->elfclass == ELFCLASS32) {
         ehdr->e_phoff     = sizeof(Elf32_Ehdr);
         ehdr->e_ehsize    = sizeof(Elf32_Ehdr);
         ehdr->e_phentsize = sizeof(Elf32_Phdr);
     } else {
         ehdr->e_phoff     = sizeof(Elf64_Ehdr);
         ehdr->e_ehsize    = sizeof(Elf64_Ehdr);
         ehdr->e_phentsize = sizeof(Elf64_Phdr);
     }
 
     if (!gelf_update_ehdr(to->elf, ehdr))
         return -1;
 
     if (!gelf_newphdr(to->elf, count))
         return -1;
 
     return 0;
 }
 
 static int kcore__add_phdr(struct kcore *kcore, int idx, off_t offset,
                u64 addr, u64 len)
 {
     GElf_Phdr phdr = {
         .p_type     = PT_LOAD,
         .p_flags    = PF_R | PF_W | PF_X,
         .p_offset   = offset,
         .p_vaddr    = addr,
         .p_paddr    = 0,
         .p_filesz   = len,
         .p_memsz    = len,
         .p_align    = page_size,
     };
 
     if (!gelf_update_phdr(kcore->elf, idx, &phdr))
         return -1;
 
     return 0;
 }
 
 static off_t kcore__write(struct kcore *kcore)
 {
     return elf_update(kcore->elf, ELF_C_WRITE);
 }
 
 struct phdr_data {
     off_t offset;
     off_t rel;
     u64 addr;
     u64 len;
     struct list_head node;
     struct phdr_data *remaps;
 };
 
 struct sym_data {
     u64 addr;
     struct list_head node;
 };
 
 struct kcore_copy_info {
     u64 stext;
     u64 etext;
     u64 first_symbol;
     u64 last_symbol;
     u64 first_module;
     u64 first_module_symbol;
     u64 last_module_symbol;
     size_t phnum;
     struct list_head phdrs;
     struct list_head syms;
 };
 
 #define kcore_copy__for_each_phdr(k, p) \
     list_for_each_entry((p), &(k)->phdrs, node)
 
 static struct phdr_data *phdr_data__new(u64 addr, u64 len, off_t offset)
 {
     struct phdr_data *p = zalloc(sizeof(*p));
 
     if (p) {
         p->addr   = addr;
         p->len    = len;
         p->offset = offset;
     }
 
     return p;
 }
 
 static struct phdr_data *kcore_copy_info__addnew(struct kcore_copy_info *kci,
                          u64 addr, u64 len,
                          off_t offset)
 {
     struct phdr_data *p = phdr_data__new(addr, len, offset);
 
     if (p)
         list_add_tail(&p->node, &kci->phdrs);
 
     return p;
 }
 
 static void kcore_copy__free_phdrs(struct kcore_copy_info *kci)
 {
     struct phdr_data *p, *tmp;
 
     list_for_each_entry_safe(p, tmp, &kci->phdrs, node) {
         list_del_init(&p->node);
         free(p);
     }
 }
 
 static struct sym_data *kcore_copy__new_sym(struct kcore_copy_info *kci,
                         u64 addr)
 {
     struct sym_data *s = zalloc(sizeof(*s));
 
     if (s) {
         s->addr = addr;
         list_add_tail(&s->node, &kci->syms);
     }
 
     return s;
 }
 
 static void kcore_copy__free_syms(struct kcore_copy_info *kci)
 {
     struct sym_data *s, *tmp;
 
     list_for_each_entry_safe(s, tmp, &kci->syms, node) {
         list_del_init(&s->node);
         free(s);
     }
 }
 
 static int kcore_copy__process_kallsyms(void *arg, const char *name, char type,
                     u64 start)
 {
     struct kcore_copy_info *kci = arg;
 
     if (!kallsyms__is_function(type))
         return 0;
 
     if (strchr(name, '[')) {
         if (!kci->first_module_symbol || start < kci->first_module_symbol)
             kci->first_module_symbol = start;
         if (start > kci->last_module_symbol)
             kci->last_module_symbol = start;
         return 0;
     }
 
     if (!kci->first_symbol || start < kci->first_symbol)
         kci->first_symbol = start;
 
     if (!kci->last_symbol || start > kci->last_symbol)
         kci->last_symbol = start;
 
     if (!strcmp(name, "_stext")) {
         kci->stext = start;
         return 0;
     }
 
     if (!strcmp(name, "_etext")) {
         kci->etext = start;
         return 0;
     }
 
     if (is_entry_trampoline(name) && !kcore_copy__new_sym(kci, start))
         return -1;
 
     return 0;
 }
 
 static int kcore_copy__parse_kallsyms(struct kcore_copy_info *kci,
                       const char *dir)
 {
     char kallsyms_filename[PATH_MAX];
 
     scnprintf(kallsyms_filename, PATH_MAX, "%s/kallsyms", dir);
 
     if (symbol__restricted_filename(kallsyms_filename, "/proc/kallsyms"))
         return -1;
 
     if (kallsyms__parse(kallsyms_filename, kci,
                 kcore_copy__process_kallsyms) < 0)
         return -1;
 
     return 0;
 }
 
 static int kcore_copy__process_modules(void *arg,
                        const char *name __maybe_unused,
                        u64 start, u64 size __maybe_unused)
 {
     struct kcore_copy_info *kci = arg;
 
     if (!kci->first_module || start < kci->first_module)
         kci->first_module = start;
 
     return 0;
 }
 
 static int kcore_copy__parse_modules(struct kcore_copy_info *kci,
                      const char *dir)
 {
     char modules_filename[PATH_MAX];
 
     scnprintf(modules_filename, PATH_MAX, "%s/modules", dir);
 
     if (symbol__restricted_filename(modules_filename, "/proc/modules"))
         return -1;
 
     if (modules__parse(modules_filename, kci,
                kcore_copy__process_modules) < 0)
         return -1;
 
     return 0;
 }
 
 static int kcore_copy__map(struct kcore_copy_info *kci, u64 start, u64 end,
                u64 pgoff, u64 s, u64 e)
 {
     u64 len, offset;
 
     if (s < start || s >= end)
         return 0;
 
     offset = (s - start) + pgoff;
     len = e < end ? e - s : end - s;
 
     return kcore_copy_info__addnew(kci, s, len, offset) ? 0 : -1;
 }
 
 static int kcore_copy__read_map(u64 start, u64 len, u64 pgoff, void *data)
 {
     struct kcore_copy_info *kci = data;
     u64 end = start + len;
     struct sym_data *sdat;
 
     if (kcore_copy__map(kci, start, end, pgoff, kci->stext, kci->etext))
         return -1;
 
     if (kcore_copy__map(kci, start, end, pgoff, kci->first_module,
                 kci->last_module_symbol))
         return -1;
 
     list_for_each_entry(sdat, &kci->syms, node) {
         u64 s = round_down(sdat->addr, page_size);
 
         if (kcore_copy__map(kci, start, end, pgoff, s, s + len))
             return -1;
     }
 
     return 0;
 }
 
 static int kcore_copy__read_maps(struct kcore_copy_info *kci, Elf *elf)
 {
     if (elf_read_maps(elf, true, kcore_copy__read_map, kci) < 0)
         return -1;
 
     return 0;
 }
 
 static void kcore_copy__find_remaps(struct kcore_copy_info *kci)
 {
     struct phdr_data *p, *k = NULL;
     u64 kend;
 
     if (!kci->stext)
         return;
 
     /* Find phdr that corresponds to the kernel map (contains stext) */
     kcore_copy__for_each_phdr(kci, p) {
         u64 pend = p->addr + p->len - 1;
 
         if (p->addr <= kci->stext && pend >= kci->stext) {
             k = p;
             break;
         }
     }
 
     if (!k)
         return;
 
     kend = k->offset + k->len;
 
     /* Find phdrs that remap the kernel */
     kcore_copy__for_each_phdr(kci, p) {
         u64 pend = p->offset + p->len;
 
         if (p == k)
             continue;
 
         if (p->offset >= k->offset && pend <= kend)
             p->remaps = k;
     }
 }
 
 static void kcore_copy__layout(struct kcore_copy_info *kci)
 {
     struct phdr_data *p;
     off_t rel = 0;
 
     kcore_copy__find_remaps(kci);
 
     kcore_copy__for_each_phdr(kci, p) {
         if (!p->remaps) {
             p->rel = rel;
             rel += p->len;
         }
         kci->phnum += 1;
     }
 
     kcore_copy__for_each_phdr(kci, p) {
         struct phdr_data *k = p->remaps;
 
         if (k)
             p->rel = p->offset - k->offset + k->rel;
     }
 }
 
 static int kcore_copy__calc_maps(struct kcore_copy_info *kci, const char *dir,
                  Elf *elf)
 {
     if (kcore_copy__parse_kallsyms(kci, dir))
         return -1;
 
     if (kcore_copy__parse_modules(kci, dir))
         return -1;
 
     if (kci->stext)
         kci->stext = round_down(kci->stext, page_size);
     else
         kci->stext = round_down(kci->first_symbol, page_size);
 
     if (kci->etext) {
         kci->etext = round_up(kci->etext, page_size);
     } else if (kci->last_symbol) {
         kci->etext = round_up(kci->last_symbol, page_size);
         kci->etext += page_size;
     }
 
     if (kci->first_module_symbol &&
         (!kci->first_module || kci->first_module_symbol < kci->first_module))
         kci->first_module = kci->first_module_symbol;
 
     kci->first_module = round_down(kci->first_module, page_size);
 
     if (kci->last_module_symbol) {
         kci->last_module_symbol = round_up(kci->last_module_symbol,
                            page_size);
         kci->last_module_symbol += page_size;
     }
 
     if (!kci->stext || !kci->etext)
         return -1;
 
     if (kci->first_module && !kci->last_module_symbol)
         return -1;
 
     if (kcore_copy__read_maps(kci, elf))
         return -1;
 
     kcore_copy__layout(kci);
 
     return 0;
 }
 
 static int kcore_copy__copy_file(const char *from_dir, const char *to_dir,
                  const char *name)
 {
     char from_filename[PATH_MAX];
     char to_filename[PATH_MAX];
 
     scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
     scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
 
     return copyfile_mode(from_filename, to_filename, 0400);
 }
 
 static int kcore_copy__unlink(const char *dir, const char *name)
 {
     char filename[PATH_MAX];
 
     scnprintf(filename, PATH_MAX, "%s/%s", dir, name);
 
     return unlink(filename);
 }
 
 static int kcore_copy__compare_fds(int from, int to)
 {
     char *buf_from;
     char *buf_to;
     ssize_t ret;
     size_t len;
     int err = -1;
 
     buf_from = malloc(page_size);
     buf_to = malloc(page_size);
     if (!buf_from || !buf_to)
         goto out;
 
     while (1) {
         /* Use read because mmap won't work on proc files */
         ret = read(from, buf_from, page_size);
         if (ret < 0)
             goto out;
 
         if (!ret)
             break;
 
         len = ret;
 
         if (readn(to, buf_to, len) != (int)len)
             goto out;
 
         if (memcmp(buf_from, buf_to, len))
             goto out;
     }
 
     err = 0;
 out:
     free(buf_to);
     free(buf_from);
     return err;
 }
 
 static int kcore_copy__compare_files(const char *from_filename,
                      const char *to_filename)
 {
     int from, to, err = -1;
 
     from = open(from_filename, O_RDONLY);
     if (from < 0)
         return -1;
 
     to = open(to_filename, O_RDONLY);
     if (to < 0)
         goto out_close_from;
 
     err = kcore_copy__compare_fds(from, to);
 
     close(to);
 out_close_from:
     close(from);
     return err;
 }
 
 static int kcore_copy__compare_file(const char *from_dir, const char *to_dir,
                     const char *name)
 {
     char from_filename[PATH_MAX];
     char to_filename[PATH_MAX];
 
     scnprintf(from_filename, PATH_MAX, "%s/%s", from_dir, name);
     scnprintf(to_filename, PATH_MAX, "%s/%s", to_dir, name);
 
     return kcore_copy__compare_files(from_filename, to_filename);
 }
 
 /**
  * kcore_copy - copy kallsyms, modules and kcore from one directory to another.
  * @from_dir: from directory
  * @to_dir: to directory
  *
  * This function copies kallsyms, modules and kcore files from one directory to
  * another.  kallsyms and modules are copied entirely.  Only code segments are
  * copied from kcore.  It is assumed that two segments suffice: one for the
  * kernel proper and one for all the modules.  The code segments are determined
  * from kallsyms and modules files.  The kernel map starts at _stext or the
  * lowest function symbol, and ends at _etext or the highest function symbol.
  * The module map starts at the lowest module address and ends at the highest
  * module symbol.  Start addresses are rounded down to the nearest page.  End
  * addresses are rounded up to the nearest page.  An extra page is added to the
  * highest kernel symbol and highest module symbol to, hopefully, encompass that
  * symbol too.  Because it contains only code sections, the resulting kcore is
  * unusual.  One significant peculiarity is that the mapping (start -> pgoff)
  * is not the same for the kernel map and the modules map.  That happens because
  * the data is copied adjacently whereas the original kcore has gaps.  Finally,
  * kallsyms file is compared with its copy to check that modules have not been
  * loaded or unloaded while the copies were taking place.
  *
  * Return: %0 on success, %-1 on failure.
  */
 int kcore_copy(const char *from_dir, const char *to_dir)
 {
     struct kcore kcore;
     struct kcore extract;
     int idx = 0, err = -1;
     off_t offset, sz;
     struct kcore_copy_info kci = { .stext = 0, };
     char kcore_filename[PATH_MAX];
     char extract_filename[PATH_MAX];
     struct phdr_data *p;
 
     INIT_LIST_HEAD(&kci.phdrs);
     INIT_LIST_HEAD(&kci.syms);
 
     if (kcore_copy__copy_file(from_dir, to_dir, "kallsyms"))
         return -1;
 
     if (kcore_copy__copy_file(from_dir, to_dir, "modules"))
         goto out_unlink_kallsyms;
 
     scnprintf(kcore_filename, PATH_MAX, "%s/kcore", from_dir);
     scnprintf(extract_filename, PATH_MAX, "%s/kcore", to_dir);
 
     if (kcore__open(&kcore, kcore_filename))
         goto out_unlink_modules;
 
     if (kcore_copy__calc_maps(&kci, from_dir, kcore.elf))
         goto out_kcore_close;
 
     if (kcore__init(&extract, extract_filename, kcore.elfclass, false))
         goto out_kcore_close;
 
     if (kcore__copy_hdr(&kcore, &extract, kci.phnum))
         goto out_extract_close;
 
     offset = gelf_fsize(extract.elf, ELF_T_EHDR, 1, EV_CURRENT) +
          gelf_fsize(extract.elf, ELF_T_PHDR, kci.phnum, EV_CURRENT);
     offset = round_up(offset, page_size);
 
     kcore_copy__for_each_phdr(&kci, p) {
         off_t offs = p->rel + offset;
 
         if (kcore__add_phdr(&extract, idx++, offs, p->addr, p->len))
             goto out_extract_close;
     }
 
     sz = kcore__write(&extract);
     if (sz < 0 || sz > offset)
         goto out_extract_close;
 
     kcore_copy__for_each_phdr(&kci, p) {
         off_t offs = p->rel + offset;
 
         if (p->remaps)
             continue;
         if (copy_bytes(kcore.fd, p->offset, extract.fd, offs, p->len))
             goto out_extract_close;
     }
 
     if (kcore_copy__compare_file(from_dir, to_dir, "kallsyms"))
         goto out_extract_close;
 
     err = 0;
 
 out_extract_close:
     kcore__close(&extract);
     if (err)
         unlink(extract_filename);
 out_kcore_close:
     kcore__close(&kcore);
 out_unlink_modules:
     if (err)
         kcore_copy__unlink(to_dir, "modules");
 out_unlink_kallsyms:
     if (err)
         kcore_copy__unlink(to_dir, "kallsyms");
 
     kcore_copy__free_phdrs(&kci);
     kcore_copy__free_syms(&kci);
 
     return err;
 }
 
 int kcore_extract__create(struct kcore_extract *kce)
 {
     struct kcore kcore;
     struct kcore extract;
     size_t count = 1;
     int idx = 0, err = -1;
     off_t offset = page_size, sz;
 
     if (kcore__open(&kcore, kce->kcore_filename))
         return -1;
 
     strcpy(kce->extract_filename, PERF_KCORE_EXTRACT);
     if (kcore__init(&extract, kce->extract_filename, kcore.elfclass, true))
         goto out_kcore_close;
 
     if (kcore__copy_hdr(&kcore, &extract, count))
         goto out_extract_close;
 
     if (kcore__add_phdr(&extract, idx, offset, kce->addr, kce->len))
         goto out_extract_close;
 
     sz = kcore__write(&extract);
     if (sz < 0 || sz > offset)
         goto out_extract_close;
 
     if (copy_bytes(kcore.fd, kce->offs, extract.fd, offset, kce->len))
         goto out_extract_close;
 
     err = 0;
 
 out_extract_close:
     kcore__close(&extract);
     if (err)
         unlink(kce->extract_filename);
 out_kcore_close:
     kcore__close(&kcore);
 
     return err;
 }
 
 void kcore_extract__delete(struct kcore_extract *kce)
 {
     unlink(kce->extract_filename);
 }
 
 #ifdef HAVE_GELF_GETNOTE_SUPPORT
 
 static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off)
 {
     if (!base_off)
         return;
 
     if (tmp->bit32)
         tmp->addr.a32[SDT_NOTE_IDX_LOC] =
             tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off -
             tmp->addr.a32[SDT_NOTE_IDX_BASE];
     else
         tmp->addr.a64[SDT_NOTE_IDX_LOC] =
             tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off -
             tmp->addr.a64[SDT_NOTE_IDX_BASE];
 }
 
 static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr,
                   GElf_Addr base_off)
 {
     if (!base_off)
         return;
 
     if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR])
         tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
     else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR])
         tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off);
 }
 
 /**
  * populate_sdt_note : Parse raw data and identify SDT note
  * @elf: elf of the opened file
  * @data: raw data of a section with description offset applied
  * @len: note description size
  * @type: type of the note
  * @sdt_notes: List to add the SDT note
  *
  * Responsible for parsing the @data in section .note.stapsdt in @elf and
  * if its an SDT note, it appends to @sdt_notes list.
  */
 static int populate_sdt_note(Elf **elf, const char *data, size_t len,
                  struct list_head *sdt_notes)
 {
     const char *provider, *name, *args;
     struct sdt_note *tmp = NULL;
     GElf_Ehdr ehdr;
     GElf_Shdr shdr;
     int ret = -EINVAL;
 
     union {
         Elf64_Addr a64[NR_ADDR];
         Elf32_Addr a32[NR_ADDR];
     } buf;
 
     Elf_Data dst = {
         .d_buf = &buf, .d_type = ELF_T_ADDR, .d_version = EV_CURRENT,
         .d_size = gelf_fsize((*elf), ELF_T_ADDR, NR_ADDR, EV_CURRENT),
         .d_off = 0, .d_align = 0
     };
     Elf_Data src = {
         .d_buf = (void *) data, .d_type = ELF_T_ADDR,
         .d_version = EV_CURRENT, .d_size = dst.d_size, .d_off = 0,
         .d_align = 0
     };
 
     tmp = (struct sdt_note *)calloc(1, sizeof(struct sdt_note));
     if (!tmp) {
         ret = -ENOMEM;
         goto out_err;
     }
 
     INIT_LIST_HEAD(&tmp->note_list);
 
     if (len < dst.d_size + 3)
         goto out_free_note;
 
     /* Translation from file representation to memory representation */
     if (gelf_xlatetom(*elf, &dst, &src,
               elf_getident(*elf, NULL)[EI_DATA]) == NULL) {
         pr_err("gelf_xlatetom : %s\n", elf_errmsg(-1));
         goto out_free_note;
     }
 
     /* Populate the fields of sdt_note */
     provider = data + dst.d_size;
 
     name = (const char *)memchr(provider, '\0', data + len - provider);
     if (name++ == NULL)
         goto out_free_note;
 
     tmp->provider = strdup(provider);
     if (!tmp->provider) {
         ret = -ENOMEM;
         goto out_free_note;
     }
     tmp->name = strdup(name);
     if (!tmp->name) {
         ret = -ENOMEM;
         goto out_free_prov;
     }
 
     args = memchr(name, '\0', data + len - name);
 
     /*
      * There is no argument if:
      * - We reached the end of the note;
      * - There is not enough room to hold a potential string;
      * - The argument string is empty or just contains ':'.
      */
     if (args == NULL || data + len - args < 2 ||
         args[1] == ':' || args[1] == '\0')
         tmp->args = NULL;
     else {
         tmp->args = strdup(++args);
         if (!tmp->args) {
             ret = -ENOMEM;
             goto out_free_name;
         }
     }
 
     if (gelf_getclass(*elf) == ELFCLASS32) {
         memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
         tmp->bit32 = true;
     } else {
         memcpy(&tmp->addr, &buf, 3 * sizeof(Elf64_Addr));
         tmp->bit32 = false;
     }
 
     if (!gelf_getehdr(*elf, &ehdr)) {
         pr_debug("%s : cannot get elf header.\n", __func__);
         ret = -EBADF;
         goto out_free_args;
     }
 
     /* Adjust the prelink effect :
      * Find out the .stapsdt.base section.
      * This scn will help us to handle prelinking (if present).
      * Compare the retrieved file offset of the base section with the
      * base address in the description of the SDT note. If its different,
      * then accordingly, adjust the note location.
      */
     if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL))
         sdt_adjust_loc(tmp, shdr.sh_offset);
 
     /* Adjust reference counter offset */
     if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL))
         sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset);
 
     list_add_tail(&tmp->note_list, sdt_notes);
     return 0;
 
 out_free_args:
     zfree(&tmp->args);
 out_free_name:
     zfree(&tmp->name);
 out_free_prov:
     zfree(&tmp->provider);
 out_free_note:
     free(tmp);
 out_err:
     return ret;
 }
 
 /**
  * construct_sdt_notes_list : constructs a list of SDT notes
  * @elf : elf to look into
  * @sdt_notes : empty list_head
  *
  * Scans the sections in 'elf' for the section
  * .note.stapsdt. It, then calls populate_sdt_note to find
  * out the SDT events and populates the 'sdt_notes'.
  */
 static int construct_sdt_notes_list(Elf *elf, struct list_head *sdt_notes)
 {
     GElf_Ehdr ehdr;
     Elf_Scn *scn = NULL;
     Elf_Data *data;
     GElf_Shdr shdr;
     size_t shstrndx, next;
     GElf_Nhdr nhdr;
     size_t name_off, desc_off, offset;
     int ret = 0;
 
     if (gelf_getehdr(elf, &ehdr) == NULL) {
         ret = -EBADF;
         goto out_ret;
     }
     if (elf_getshdrstrndx(elf, &shstrndx) != 0) {
         ret = -EBADF;
         goto out_ret;
     }
 
     /* Look for the required section */
     scn = elf_section_by_name(elf, &ehdr, &shdr, SDT_NOTE_SCN, NULL);
     if (!scn) {
         ret = -ENOENT;
         goto out_ret;
     }
 
     if ((shdr.sh_type != SHT_NOTE) || (shdr.sh_flags & SHF_ALLOC)) {
         ret = -ENOENT;
         goto out_ret;
     }
 
     data = elf_getdata(scn, NULL);
 
     /* Get the SDT notes */
     for (offset = 0; (next = gelf_getnote(data, offset, &nhdr, &name_off,
                           &desc_off)) > 0; offset = next) {
         if (nhdr.n_namesz == sizeof(SDT_NOTE_NAME) &&
             !memcmp(data->d_buf + name_off, SDT_NOTE_NAME,
                 sizeof(SDT_NOTE_NAME))) {
             /* Check the type of the note */
             if (nhdr.n_type != SDT_NOTE_TYPE)
                 goto out_ret;
 
             ret = populate_sdt_note(&elf, ((data->d_buf) + desc_off),
                         nhdr.n_descsz, sdt_notes);
             if (ret < 0)
                 goto out_ret;
         }
     }
     if (list_empty(sdt_notes))
         ret = -ENOENT;
 
 out_ret:
     return ret;
 }
 
 /**
  * get_sdt_note_list : Wrapper to construct a list of sdt notes
  * @head : empty list_head
  * @target : file to find SDT notes from
  *
  * This opens the file, initializes
  * the ELF and then calls construct_sdt_notes_list.
  */
 int get_sdt_note_list(struct list_head *head, const char *target)
 {
     Elf *elf;
     int fd, ret;
 
     fd = open(target, O_RDONLY);
     if (fd < 0)
         return -EBADF;
 
     elf = elf_begin(fd, PERF_ELF_C_READ_MMAP, NULL);
     if (!elf) {
         ret = -EBADF;
         goto out_close;
     }
     ret = construct_sdt_notes_list(elf, head);
     elf_end(elf);
 out_close:
     close(fd);
     return ret;
 }
 
 /**
  * cleanup_sdt_note_list : free the sdt notes' list
  * @sdt_notes: sdt notes' list
  *
  * Free up the SDT notes in @sdt_notes.
  * Returns the number of SDT notes free'd.
  */
 int cleanup_sdt_note_list(struct list_head *sdt_notes)
 {
     struct sdt_note *tmp, *pos;
     int nr_free = 0;
 
     list_for_each_entry_safe(pos, tmp, sdt_notes, note_list) {
         list_del_init(&pos->note_list);
         zfree(&pos->args);
         zfree(&pos->name);
         zfree(&pos->provider);
         free(pos);
         nr_free++;
     }
     return nr_free;
 }
 
 /**
  * sdt_notes__get_count: Counts the number of sdt events
  * @start: list_head to sdt_notes list
  *
  * Returns the number of SDT notes in a list
  */
 int sdt_notes__get_count(struct list_head *start)
 {
     struct sdt_note *sdt_ptr;
     int count = 0;
 
     list_for_each_entry(sdt_ptr, start, note_list)
         count++;
     return count;
 }
 #endif
 
 void symbol__elf_init(void)
 {
     elf_version(EV_CURRENT);
 }

This page was automatically generated by the 2.1.0 LXR engine. The LXR team