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authorAlan Modra <amodra@gmail.com>2015-11-03 19:33:27 +1030
committerAlan Modra <amodra@gmail.com>2015-11-03 22:52:05 +1030
commitab2733963604205afbcc1bc164048864e955c8ff (patch)
treea8d2e374a0645586e7e4f0c1edda2ed2bf488e92 /binutils
parentc1e7d6a827c40a56816e3cd8e3815790197fa41b (diff)
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readelf verdef and verneed
readelf ought to notify when a symbol wrongly has both a version definition and a needed version. This patch does that, and removes the heuristic that only defined symbols in SHT_NOBITS sections have verneed entries. * readelf (process_version_sections): Check DT_VERNEED and DT_VERDEF for all symbols. Report "*both*" should a symbol have both a verneed and verdef. (get_symbol_version_string): Reduce indentation by early exits. Don't use SHT_NOBITS heuristic to detect case where a defined symbol has a verneed entry.
Diffstat (limited to 'binutils')
-rw-r--r--binutils/ChangeLog9
-rw-r--r--binutils/readelf.c298
2 files changed, 143 insertions, 164 deletions
diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index e972c7e..8779082 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,12 @@
+2015-11-03 Alan Modra <amodra@gmail.com>
+
+ * readelf (process_version_sections): Check DT_VERNEED and
+ DT_VERDEF for all symbols. Report "*both*" should a symbol
+ have both a verneed and verdef.
+ (get_symbol_version_string): Reduce indentation by early
+ exits. Don't use SHT_NOBITS heuristic to detect case where a
+ defined symbol has a verneed entry.
+
2015-10-30 Nick Clifton <nickc@redhat.com>
* po/zh_CN.po: Updated (simplified) Chinese translation.
diff --git a/binutils/readelf.c b/binutils/readelf.c
index 70a84e5..d5dd46f 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -9889,8 +9889,8 @@ process_version_sections (FILE * file)
for (cnt = 0; cnt < total; cnt += 4)
{
int j, nn;
- int check_def, check_need;
- char * name;
+ char *name;
+ char *invalid = _("*invalid*");
printf (" %03x:", cnt);
@@ -9917,20 +9917,8 @@ process_version_sections (FILE * file)
break;
}
- check_def = 1;
- check_need = 1;
- if (symbols[cnt + j].st_shndx >= elf_header.e_shnum
- || section_headers[symbols[cnt + j].st_shndx].sh_type
- != SHT_NOBITS)
- {
- if (symbols[cnt + j].st_shndx == SHN_UNDEF)
- check_def = 0;
- else
- check_need = 0;
- }
-
- if (check_need
- && version_info[DT_VERSIONTAGIDX (DT_VERNEED)])
+ name = NULL;
+ if (version_info[DT_VERSIONTAGIDX (DT_VERNEED)])
{
Elf_Internal_Verneed ivn;
unsigned long offset;
@@ -9979,14 +9967,9 @@ process_version_sections (FILE * file)
ivna.vna_name = BYTE_GET (evna.vna_name);
if (ivna.vna_name >= string_sec->sh_size)
- name = _("*invalid*");
+ name = invalid;
else
name = strtab + ivna.vna_name;
- nn += printf ("(%s%-*s",
- name,
- 12 - (int) strlen (name),
- ")");
- check_def = 0;
break;
}
@@ -9995,7 +9978,7 @@ process_version_sections (FILE * file)
while (ivn.vn_next);
}
- if (check_def && data[cnt + j] != 0x8001
+ if (data[cnt + j] != 0x8001
&& version_info[DT_VERSIONTAGIDX (DT_VERDEF)])
{
Elf_Internal_Verdef ivd;
@@ -10043,15 +10026,18 @@ process_version_sections (FILE * file)
ivda.vda_name = BYTE_GET (evda.vda_name);
if (ivda.vda_name >= string_sec->sh_size)
- name = _("*invalid*");
+ name = invalid;
+ else if (name != NULL && name != invalid)
+ name = _("*both*");
else
name = strtab + ivda.vda_name;
- nn += printf ("(%s%-*s",
- name,
- 12 - (int) strlen (name),
- ")");
}
}
+ if (name != NULL)
+ nn += printf ("(%s%-*s",
+ name,
+ 12 - (int) strlen (name),
+ ")");
if (nn < 18)
printf ("%*c", 18 - nn, ' ');
@@ -10460,172 +10446,156 @@ get_symbol_version_string (FILE *file, int is_dynsym,
enum versioned_symbol_info *sym_info,
unsigned short *vna_other)
{
- const char *version_string = NULL;
+ unsigned char data[2];
+ unsigned short vers_data;
+ unsigned long offset;
- if (is_dynsym
- && version_info[DT_VERSIONTAGIDX (DT_VERSYM)] != 0)
- {
- unsigned char data[2];
- unsigned short vers_data;
- unsigned long offset;
- int is_nobits;
- int check_def;
+ if (!is_dynsym
+ || version_info[DT_VERSIONTAGIDX (DT_VERSYM)] == 0)
+ return NULL;
- offset = offset_from_vma
- (file, version_info[DT_VERSIONTAGIDX (DT_VERSYM)],
- sizeof data + si * sizeof (vers_data));
+ offset = offset_from_vma (file, version_info[DT_VERSIONTAGIDX (DT_VERSYM)],
+ sizeof data + si * sizeof (vers_data));
- if (get_data (&data, file, offset + si * sizeof (vers_data),
- sizeof (data), 1, _("version data")) == NULL)
- return NULL;
+ if (get_data (&data, file, offset + si * sizeof (vers_data),
+ sizeof (data), 1, _("version data")) == NULL)
+ return NULL;
+
+ vers_data = byte_get (data, 2);
- vers_data = byte_get (data, 2);
+ if ((vers_data & VERSYM_HIDDEN) == 0 && vers_data <= 1)
+ return NULL;
- is_nobits = (section_headers != NULL
- && psym->st_shndx < elf_header.e_shnum
- && section_headers[psym->st_shndx].sh_type
- == SHT_NOBITS);
+ /* Usually we'd only see verdef for defined symbols, and verneed for
+ undefined symbols. However, symbols defined by the linker in
+ .dynbss for variables copied from a shared library in order to
+ avoid text relocations are defined yet have verneed. We could
+ use a heuristic to detect the special case, for example, check
+ for verneed first on symbols defined in SHT_NOBITS sections, but
+ it is simpler and more reliable to just look for both verdef and
+ verneed. .dynbss might not be mapped to a SHT_NOBITS section. */
- check_def = (psym->st_shndx != SHN_UNDEF);
+ if (psym->st_shndx != SHN_UNDEF
+ && vers_data != 0x8001
+ && version_info[DT_VERSIONTAGIDX (DT_VERDEF)])
+ {
+ Elf_Internal_Verdef ivd;
+ Elf_Internal_Verdaux ivda;
+ Elf_External_Verdaux evda;
+ unsigned long off;
- if ((vers_data & VERSYM_HIDDEN) || vers_data > 1)
+ off = offset_from_vma (file,
+ version_info[DT_VERSIONTAGIDX (DT_VERDEF)],
+ sizeof (Elf_External_Verdef));
+
+ do
{
- if (version_info[DT_VERSIONTAGIDX (DT_VERNEED)]
- && (is_nobits || ! check_def))
+ Elf_External_Verdef evd;
+
+ if (get_data (&evd, file, off, sizeof (evd), 1,
+ _("version def")) == NULL)
+ {
+ ivd.vd_ndx = 0;
+ ivd.vd_aux = 0;
+ ivd.vd_next = 0;
+ }
+ else
{
- Elf_External_Verneed evn;
- Elf_Internal_Verneed ivn;
- Elf_Internal_Vernaux ivna;
+ ivd.vd_ndx = BYTE_GET (evd.vd_ndx);
+ ivd.vd_aux = BYTE_GET (evd.vd_aux);
+ ivd.vd_next = BYTE_GET (evd.vd_next);
+ }
- /* We must test both. */
- offset = offset_from_vma
- (file, version_info[DT_VERSIONTAGIDX (DT_VERNEED)],
- sizeof evn);
+ off += ivd.vd_next;
+ }
+ while (ivd.vd_ndx != (vers_data & VERSYM_VERSION) && ivd.vd_next != 0);
- do
- {
- unsigned long vna_off;
+ if (ivd.vd_ndx == (vers_data & VERSYM_VERSION))
+ {
+ off -= ivd.vd_next;
+ off += ivd.vd_aux;
- if (get_data (&evn, file, offset, sizeof (evn), 1,
- _("version need")) == NULL)
- {
- ivna.vna_next = 0;
- ivna.vna_other = 0;
- ivna.vna_name = 0;
- break;
- }
+ if (get_data (&evda, file, off, sizeof (evda), 1,
+ _("version def aux")) != NULL)
+ {
+ ivda.vda_name = BYTE_GET (evda.vda_name);
- ivn.vn_aux = BYTE_GET (evn.vn_aux);
- ivn.vn_next = BYTE_GET (evn.vn_next);
+ if (psym->st_name != ivda.vda_name)
+ {
+ *sym_info = ((vers_data & VERSYM_HIDDEN) != 0
+ ? symbol_hidden : symbol_public);
+ return (ivda.vda_name < strtab_size
+ ? strtab + ivda.vda_name : _("<corrupt>"));
+ }
+ }
+ }
+ }
- vna_off = offset + ivn.vn_aux;
+ if (version_info[DT_VERSIONTAGIDX (DT_VERNEED)])
+ {
+ Elf_External_Verneed evn;
+ Elf_Internal_Verneed ivn;
+ Elf_Internal_Vernaux ivna;
- do
- {
- Elf_External_Vernaux evna;
+ offset = offset_from_vma (file,
+ version_info[DT_VERSIONTAGIDX (DT_VERNEED)],
+ sizeof evn);
+ do
+ {
+ unsigned long vna_off;
- if (get_data (&evna, file, vna_off,
- sizeof (evna), 1,
- _("version need aux (3)")) == NULL)
- {
- ivna.vna_next = 0;
- ivna.vna_other = 0;
- ivna.vna_name = 0;
- }
- else
- {
- ivna.vna_other = BYTE_GET (evna.vna_other);
- ivna.vna_next = BYTE_GET (evna.vna_next);
- ivna.vna_name = BYTE_GET (evna.vna_name);
- }
+ if (get_data (&evn, file, offset, sizeof (evn), 1,
+ _("version need")) == NULL)
+ {
+ ivna.vna_next = 0;
+ ivna.vna_other = 0;
+ ivna.vna_name = 0;
+ break;
+ }
- vna_off += ivna.vna_next;
- }
- while (ivna.vna_other != vers_data
- && ivna.vna_next != 0);
+ ivn.vn_aux = BYTE_GET (evn.vn_aux);
+ ivn.vn_next = BYTE_GET (evn.vn_next);
- if (ivna.vna_other == vers_data)
- break;
+ vna_off = offset + ivn.vn_aux;
- offset += ivn.vn_next;
- }
- while (ivn.vn_next != 0);
+ do
+ {
+ Elf_External_Vernaux evna;
- if (ivna.vna_other == vers_data)
+ if (get_data (&evna, file, vna_off, sizeof (evna), 1,
+ _("version need aux (3)")) == NULL)
{
- *sym_info = symbol_undefined;
- *vna_other = ivna.vna_other;
- version_string = (ivna.vna_name < strtab_size
- ? strtab + ivna.vna_name
- : _("<corrupt>"));
- check_def = 0;
+ ivna.vna_next = 0;
+ ivna.vna_other = 0;
+ ivna.vna_name = 0;
}
- else if (! is_nobits)
- error (_("bad dynamic symbol\n"));
else
- check_def = 1;
- }
-
- if (check_def)
- {
- if (vers_data != 0x8001
- && version_info[DT_VERSIONTAGIDX (DT_VERDEF)])
{
- Elf_Internal_Verdef ivd;
- Elf_Internal_Verdaux ivda;
- Elf_External_Verdaux evda;
- unsigned long off;
-
- off = offset_from_vma
- (file,
- version_info[DT_VERSIONTAGIDX (DT_VERDEF)],
- sizeof (Elf_External_Verdef));
-
- do
- {
- Elf_External_Verdef evd;
-
- if (get_data (&evd, file, off, sizeof (evd),
- 1, _("version def")) == NULL)
- {
- ivd.vd_ndx = 0;
- ivd.vd_aux = 0;
- ivd.vd_next = 0;
- }
- else
- {
- ivd.vd_ndx = BYTE_GET (evd.vd_ndx);
- ivd.vd_aux = BYTE_GET (evd.vd_aux);
- ivd.vd_next = BYTE_GET (evd.vd_next);
- }
-
- off += ivd.vd_next;
- }
- while (ivd.vd_ndx != (vers_data & VERSYM_VERSION)
- && ivd.vd_next != 0);
+ ivna.vna_other = BYTE_GET (evna.vna_other);
+ ivna.vna_next = BYTE_GET (evna.vna_next);
+ ivna.vna_name = BYTE_GET (evna.vna_name);
+ }
- off -= ivd.vd_next;
- off += ivd.vd_aux;
+ vna_off += ivna.vna_next;
+ }
+ while (ivna.vna_other != vers_data && ivna.vna_next != 0);
- if (get_data (&evda, file, off, sizeof (evda),
- 1, _("version def aux")) == NULL)
- return version_string;
+ if (ivna.vna_other == vers_data)
+ break;
- ivda.vda_name = BYTE_GET (evda.vda_name);
+ offset += ivn.vn_next;
+ }
+ while (ivn.vn_next != 0);
- if (psym->st_name != ivda.vda_name)
- {
- *sym_info = ((vers_data & VERSYM_HIDDEN) != 0
- ? symbol_hidden : symbol_public);
- version_string = (ivda.vda_name < strtab_size
- ? strtab + ivda.vda_name
- : _("<corrupt>"));
- }
- }
- }
+ if (ivna.vna_other == vers_data)
+ {
+ *sym_info = symbol_undefined;
+ *vna_other = ivna.vna_other;
+ return (ivna.vna_name < strtab_size
+ ? strtab + ivna.vna_name : _("<corrupt>"));
}
}
- return version_string;
+ return NULL;
}
/* Dump the symbol table. */