break;
}
- /* Translate pointers into file offsets. */
- GElf_Off offs[i_max] = { 0, };
- find_offsets (mod->main.elf, mod->main_bias, phnum, i_max, addrs,
- offs);
-
- /* Figure out the size of the symbol table. */
- if (offs[i_hash] != 0)
- {
- /* In the original format, .hash says the size of .dynsym. */
-
- size_t entsz = SH_ENTSIZE_HASH (ehdr);
- data = elf_getdata_rawchunk (mod->main.elf,
- offs[i_hash] + entsz, entsz,
- entsz == 4 ? ELF_T_WORD
- : ELF_T_XWORD);
- if (data != NULL)
- mod->syments = (entsz == 4
- ? *(const GElf_Word *) data->d_buf
- : *(const GElf_Xword *) data->d_buf);
- }
- if (offs[i_gnu_hash] != 0 && mod->syments == 0)
- {
- /* In the new format, we can derive it with some work. */
+ /* Translate pointers into file offsets. ADJUST is either zero
+ in case the dynamic segment wasn't adjusted or mod->main_bias. */
+ void translate_offs (GElf_Addr adjust)
+ {
+ GElf_Off offs[i_max] = { 0, };
+ find_offsets (mod->main.elf, adjust, phnum, i_max, addrs, offs);
- const struct
+ /* Figure out the size of the symbol table. */
+ if (offs[i_hash] != 0)
{
- Elf32_Word nbuckets;
- Elf32_Word symndx;
- Elf32_Word maskwords;
- Elf32_Word shift2;
- } *header;
-
- data = elf_getdata_rawchunk (mod->main.elf, offs[i_gnu_hash],
- sizeof *header, ELF_T_WORD);
- if (data != NULL)
- {
- header = data->d_buf;
- Elf32_Word nbuckets = header->nbuckets;
- Elf32_Word symndx = header->symndx;
- GElf_Off buckets_at = (offs[i_gnu_hash] + sizeof *header
- + (gelf_getclass (mod->main.elf)
- * sizeof (Elf32_Word)
- * header->maskwords));
-
- data = elf_getdata_rawchunk (mod->main.elf, buckets_at,
- nbuckets * sizeof (Elf32_Word),
- ELF_T_WORD);
- if (data != NULL && symndx < nbuckets)
- {
- const Elf32_Word *const buckets = data->d_buf;
- Elf32_Word maxndx = symndx;
- for (Elf32_Word bucket = 0; bucket < nbuckets; ++bucket)
- if (buckets[bucket] > maxndx)
- maxndx = buckets[bucket];
-
- GElf_Off hasharr_at = (buckets_at
- + nbuckets * sizeof (Elf32_Word));
- hasharr_at += (maxndx - symndx) * sizeof (Elf32_Word);
- do
- {
- data = elf_getdata_rawchunk (mod->main.elf,
- hasharr_at,
- sizeof (Elf32_Word),
- ELF_T_WORD);
- if (data != NULL
- && (*(const Elf32_Word *) data->d_buf & 1u))
- {
- mod->syments = maxndx + 1;
- break;
- }
- ++maxndx;
- hasharr_at += sizeof (Elf32_Word);
- } while (data != NULL);
- }
- }
- }
- if (offs[i_strtab] > offs[i_symtab] && mod->syments == 0)
- mod->syments = ((offs[i_strtab] - offs[i_symtab])
- / gelf_fsize (mod->main.elf,
- ELF_T_SYM, 1, EV_CURRENT));
+ /* In the original format, .hash says the size of .dynsym. */
+
+ size_t entsz = SH_ENTSIZE_HASH (ehdr);
+ data = elf_getdata_rawchunk (mod->main.elf,
+ offs[i_hash] + entsz, entsz,
+ entsz == 4 ? ELF_T_WORD
+ : ELF_T_XWORD);
+ if (data != NULL)
+ mod->syments = (entsz == 4
+ ? *(const GElf_Word *) data->d_buf
+ : *(const GElf_Xword *) data->d_buf);
+ }
+ if (offs[i_gnu_hash] != 0 && mod->syments == 0)
+ {
+ /* In the new format, we can derive it with some work. */
- if (mod->syments > 0)
- {
- mod->symdata = elf_getdata_rawchunk (mod->main.elf,
- offs[i_symtab],
- gelf_fsize (mod->main.elf,
- ELF_T_SYM,
- mod->syments,
- EV_CURRENT),
- ELF_T_SYM);
- if (mod->symdata != NULL)
- {
- mod->symstrdata = elf_getdata_rawchunk (mod->main.elf,
- offs[i_strtab],
- strsz,
- ELF_T_BYTE);
- if (mod->symstrdata == NULL)
- mod->symdata = NULL;
- }
- if (mod->symdata == NULL)
- mod->symerr = DWFL_E (LIBELF, elf_errno ());
- else
+ const struct
{
- mod->symfile = &mod->main;
- mod->symerr = DWFL_E_NOERROR;
- }
- return;
- }
+ Elf32_Word nbuckets;
+ Elf32_Word symndx;
+ Elf32_Word maskwords;
+ Elf32_Word shift2;
+ } *header;
+
+ data = elf_getdata_rawchunk (mod->main.elf, offs[i_gnu_hash],
+ sizeof *header, ELF_T_WORD);
+ if (data != NULL)
+ {
+ header = data->d_buf;
+ Elf32_Word nbuckets = header->nbuckets;
+ Elf32_Word symndx = header->symndx;
+ GElf_Off buckets_at = (offs[i_gnu_hash] + sizeof *header
+ + (gelf_getclass (mod->main.elf)
+ * sizeof (Elf32_Word)
+ * header->maskwords));
+
+ data = elf_getdata_rawchunk (mod->main.elf, buckets_at,
+ nbuckets * sizeof (Elf32_Word),
+ ELF_T_WORD);
+ if (data != NULL && symndx < nbuckets)
+ {
+ const Elf32_Word *const buckets = data->d_buf;
+ Elf32_Word maxndx = symndx;
+ for (Elf32_Word bucket = 0; bucket < nbuckets; ++bucket)
+ if (buckets[bucket] > maxndx)
+ maxndx = buckets[bucket];
+
+ GElf_Off hasharr_at = (buckets_at
+ + nbuckets * sizeof (Elf32_Word));
+ hasharr_at += (maxndx - symndx) * sizeof (Elf32_Word);
+ do
+ {
+ data = elf_getdata_rawchunk (mod->main.elf,
+ hasharr_at,
+ sizeof (Elf32_Word),
+ ELF_T_WORD);
+ if (data != NULL
+ && (*(const Elf32_Word *) data->d_buf & 1u))
+ {
+ mod->syments = maxndx + 1;
+ break;
+ }
+ ++maxndx;
+ hasharr_at += sizeof (Elf32_Word);
+ } while (data != NULL);
+ }
+ }
+ }
+ if (offs[i_strtab] > offs[i_symtab] && mod->syments == 0)
+ mod->syments = ((offs[i_strtab] - offs[i_symtab])
+ / gelf_fsize (mod->main.elf,
+ ELF_T_SYM, 1, EV_CURRENT));
+
+ if (mod->syments > 0)
+ {
+ mod->symdata = elf_getdata_rawchunk (mod->main.elf,
+ offs[i_symtab],
+ gelf_fsize (mod->main.elf,
+ ELF_T_SYM,
+ mod->syments,
+ EV_CURRENT),
+ ELF_T_SYM);
+ if (mod->symdata != NULL)
+ {
+ mod->symstrdata = elf_getdata_rawchunk (mod->main.elf,
+ offs[i_strtab],
+ strsz,
+ ELF_T_BYTE);
+ if (mod->symstrdata == NULL)
+ mod->symdata = NULL;
+ }
+ if (mod->symdata == NULL)
+ mod->symerr = DWFL_E (LIBELF, elf_errno ());
+ else
+ {
+ mod->symfile = &mod->main;
+ mod->symerr = DWFL_E_NOERROR;
+ }
+ }
+ }
+
+ /* First try unadjusted, like ELF files from disk, vdso.
+ Then try for already adjusted dynamic section, like ELF
+ from remote memory. */
+ translate_offs (0);
+ if (mod->symfile == NULL)
+ translate_offs (mod->main_bias);
+
+ return;
}
}
}
--- /dev/null
+/* Test program for getting symbol table from vdso module.
+ Copyright (C) 2014 Red Hat, Inc.
+ This file is part of elfutils.
+
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ elfutils is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include <config.h>
+#include <assert.h>
+#include <errno.h>
+#include <error.h>
+#include <inttypes.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include ELFUTILS_HEADER(dwfl)
+
+#ifndef __linux__
+int
+main (int argc __attribute__ ((unused)), char **argv)
+{
+ printf ("Getting the vdso is unsupported.\n");
+ return 77;
+}
+#else /* __linux__ */
+static bool vdso_seen = false;
+
+static int
+module_callback (Dwfl_Module *mod, void **userdata __attribute__((unused)),
+ const char *name, Dwarf_Addr start __attribute__((unused)),
+ void *arg __attribute__((unused)))
+{
+ /* We can only recognize the vdso by inspecting the "magic name". */
+ if (strncmp ("[vdso: ", name, 7) == 0)
+ {
+ int syms = dwfl_module_getsymtab (mod);
+ printf ("vdso syms: %d\n", syms);
+ if (syms < 0)
+ error (2, 0, "dwfl_module_getsymtab: %s", dwfl_errmsg (-1));
+ vdso_seen = true;
+
+ for (int i = 0; i < syms; i++)
+ {
+ GElf_Sym sym;
+ GElf_Addr addr;
+ const char *sname = dwfl_module_getsym_info (mod, i, &sym, &addr,
+ NULL, NULL, NULL);
+ assert (sname != NULL);
+ printf ("%d: '%s' %" PRIx64 " (%" PRIx64 ")\n",
+ i, sname, sym.st_value, addr);
+ }
+ }
+
+ return DWARF_CB_OK;
+}
+
+int
+main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))
+{
+ static char *debuginfo_path;
+ static const Dwfl_Callbacks proc_callbacks =
+ {
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ .debuginfo_path = &debuginfo_path,
+
+ .find_elf = dwfl_linux_proc_find_elf,
+ };
+ Dwfl *dwfl = dwfl_begin (&proc_callbacks);
+ if (dwfl == NULL)
+ error (2, 0, "dwfl_begin: %s", dwfl_errmsg (-1));
+
+ /* Take our parent as "arbitrary" process to inspect. */
+ pid_t pid = getppid();
+
+ int result = dwfl_linux_proc_report (dwfl, pid);
+ if (result < 0)
+ error (2, 0, "dwfl_linux_proc_report: %s", dwfl_errmsg (-1));
+ else if (result > 0)
+ error (2, result, "dwfl_linux_proc_report");
+
+ if (dwfl_report_end (dwfl, NULL, NULL) != 0)
+ error (2, 0, "dwfl_report_end: %s", dwfl_errmsg (-1));
+
+ if (dwfl_getmodules (dwfl, module_callback, NULL, 0) != 0)
+ error (1, 0, "dwfl_getmodules: %s", dwfl_errmsg (-1));
+
+ return vdso_seen ? 0 : -1;
+}
+
+#endif /* ! __linux__ */
projects / thirdparty / elfutils.git / commitdiff
