RE: [RFC-v5] Fix .text section offset for windows DLL (was Calling __stdcall functions in the inferior)

Pierre Muller
2012-12-13T10:48:15Z

[-- Attachment #1: Type: text/plain, Size: 4543 bytes --]

After asmwarrior clarifications
that my patch alone didn't cause any crash,
I finally committed the patch,
after adding the changes suggested by Joel below.

The final patch is attached.

Concerning Pedro's comments,
I will answer to them in his last reply.

Thanks to all,

Pierre Muller

> -----Message d'origine-----
> De : gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] De la part de Joel Brobecker
> Envoyé : vendredi 7 décembre 2012 08:11
> À : Pierre Muller
> Cc : 'asmwarrior'; 'Eli Zaretskii'; gdb-patches@sourceware.org
> Objet : Re: [RFC-v5] Fix .text section offset for windows DLL (was Calling
> __stdcall functions in the inferior)
>
> > 2012-11-25 Pierre Muller <muller@sourceware.org>
> >
> > * coff-pe-read.h (pe_text_section_offset): Declare new function.
> > * coff-pe-read.c (debug_coff_pe_read): New static variable.
> > (struct read_pe_section_data): Add section_name field.
> > (IMAGE_SCN_CNT_CODE): New macro, if not already defined.
> > (IMAGE_SCN_CNT_INITIALIZED_DATA): Ditto.
> > (IMAGE_SCN_CNT_UNINITIALIZED_DATA): Ditto.
> > (get_pe_section_index): New function.
> > (struct pe_sections_info): New type.
> > (get_section_vmas): Use new struct pe_sections_info.
> > (add_pe_exported_sym): Handle unnamed exported function.
> > (add_pe_forwarded_sym): New function.
> > (read_pe_truncate_name): Truncate at last dot.
> > (pe_as16): New function.
> > (read_pe_exported_syms): Use ordinal of function to
> > retrieve correct RVA address of function and handle
> > forwarded symbol.
> > (pe_text_section_offset): New function.
> > (show_debug_coff_pe_read): New function.
> > (_initialize_coff_pe_read): New function adding
> > 'set/show debug coff_pe_read' commands.
> >
> > * windows-tdep.c (windows_xfer_shared_library): Use
> > pe_text_section_offset function instead of possibly wrong
> > 0x1000 constant for .text sextion offset.
>
> Looks good - OK to commit after the following minor corrections
> have been applied. For the record, I have tested this patch on
> x86-windows against AdaCore's GDB testsuite, no regression.
>
> Thank you!
>
> > +/* Get the index of the named section in our own full arrayi.
>
> Small typo at the end if "array".
>
> > +get_pe_section_index (const char *section_name,
> > + struct read_pe_section_data *sections,
> > + int nb_sections)
> > +{
> > + int i;
> > + for (i = 0; i < nb_sections; i++)
>
> Missing empty line after variable declarations...
>
> > + DLL_NAME is the internal name of the DLL file,
> > + OBJFILE is the objfile struct of DLL_NAME. */
> > +
> > +
> > +static int
> > +add_pe_forwarded_sym (const char *sym_name, const char
*forward_dll_name,
>
> Can you delete the second empty line?
>
> > + char * last_point = strrchr (dll_name, '.');
>
> No space between '*' and 'last_point'.
>
> > + otherix++;
> > + section_data = xrealloc (section_data, otherix
> > + * sizeof (struct read_pe_section_data));
> > + name = xstrdup (sec_name);
> > + section_data[otherix - 1].section_name = name;
> > + make_cleanup (xfree, name);
> > + section_data[otherix - 1].rva_start = vaddr;
> > + section_data[otherix - 1].rva_end = vaddr + vsize;
> > + section_data[otherix - 1].vma_offset = 0;
> > + if (characteristics & IMAGE_SCN_CNT_CODE)
> > + section_data[otherix - 1].ms_type = mst_text;
> > + else if (characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA)
> > + section_data[otherix - 1].ms_type = mst_data;
> > + else if (characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA)
> > + section_data[otherix - 1].ms_type = mst_bss;
> > + else
> > + section_data[otherix - 1].ms_type = mst_unknown;
>
> A possible suggestion: It seems simpler to increment otherix
> at the end rather than at the beginning, and thus have:
>
> section_data = xrealloc (section_data, (otherix + 1) [...]);
> [...]
> section_data[otherix].rva_end = vaddr + vsize;
> section_data[otherix].vma_offset = 0;
> [...]
> otherix++;
>
> > + /* First handle forward cases. */
> > + if ((func_rva >= export_rva)
> > + && (func_rva < export_rva + export_size))
>
> You don't need the extra parentheses...
>
> --
> Joel

[-- Attachment #2: fix-dll-offset-v9.patch --]
[-- Type: application/octet-stream, Size: 26474 bytes --]

2012-12-13 Pierre Muller <muller@sourceware.org>

* coff-pe-read.h (pe_text_section_offset): Declare new function.
* coff-pe-read.c (debug_coff_pe_read): New static variable.
(struct read_pe_section_data): Add section_name field.
(IMAGE_SCN_CNT_CODE): New macro, if not already defined.
(IMAGE_SCN_CNT_INITIALIZED_DATA): Ditto.
(IMAGE_SCN_CNT_UNINITIALIZED_DATA): Ditto.
(get_pe_section_index): New function.
(struct pe_sections_info): New type.
(get_section_vmas): Use new struct pe_sections_info.
(add_pe_exported_sym): Handle unnamed exported function.
(add_pe_forwarded_sym): New function.
(read_pe_truncate_name): Truncate at last dot.
(pe_as16): New function.
(read_pe_exported_syms): Use ordinal of function to
retrieve correct RVA address of function and handle
forwarded symbol.
(pe_text_section_offset): New function.
(show_debug_coff_pe_read): New function.
(_initialize_coff_pe_read): New function adding
'set/show debug coff_pe_read' commands.

* windows-tdep.c (windows_xfer_shared_library): Use
pe_text_section_offset function instead of possibly wrong
0x1000 constant for .text sextion offset.

Index: coff-pe-read.h
===================================================================
RCS file: /cvs/src/src/gdb/coff-pe-read.h,v
retrieving revision 1.11
diff -u -p -r1.11 coff-pe-read.h
--- coff-pe-read.h 4 Jan 2012 08:17:00 -0000 1.11
+++ coff-pe-read.h 13 Dec 2012 10:41:57 -0000
@@ -23,9 +23,14 @@
#define COFF_PE_READ_H

struct objfile;
+struct bfd;

/* Read the export table and convert it to minimal symbol table
entries */
extern void read_pe_exported_syms (struct objfile *objfile);

+/* Extract from ABFD the offset of the .text section.
+ Returns default value 0x1000 if information is not found. */
+extern CORE_ADDR pe_text_section_offset (struct bfd *abfd);
+
#endif /* !defined (COFF_PE_READ_H) */
Index: coff-pe-read.c
===================================================================
RCS file: /cvs/src/src/gdb/coff-pe-read.c,v
retrieving revision 1.18
diff -u -p -r1.18 coff-pe-read.c
--- coff-pe-read.c 7 Nov 2012 20:10:13 -0000 1.18
+++ coff-pe-read.c 13 Dec 2012 10:41:57 -0000
@@ -28,12 +28,23 @@
#include "bfd.h"
#include "gdbtypes.h"

+#include "command.h"
+#include "gdbcmd.h"
#include "symtab.h"
#include "symfile.h"
#include "objfiles.h"
+#include "common/common-utils.h"
+
+#include <ctype.h>

/* Internal section information */

+/* Coff PE read debugging flag:
+ default value is 0,
+ value 1 outputs problems encountered while parsing PE file,
+ value above 1 also lists all generated minimal symbols. */
+static unsigned int debug_coff_pe_read;
+
struct read_pe_section_data
{
CORE_ADDR vma_offset; /* Offset to loaded address of section. */
@@ -41,8 +52,18 @@ struct read_pe_section_data
unsigned long rva_end; /* End offset within the pe. */
enum minimal_symbol_type ms_type; /* Type to assign symbols in
section. */
+ char *section_name; /* Recorded section name. */
};

+#ifndef IMAGE_SCN_CNT_CODE
+# define IMAGE_SCN_CNT_CODE 0x20
+#endif
+#ifndef IMAGE_SCN_CNT_INITIALIZED_DATA
+# define IMAGE_SCN_CNT_INITIALIZED_DATA 0x40
+#endif
+#ifndef IMAGE_SCN_CNT_UNINITIALIZED_DATA
+# define IMAGE_SCN_CNT_UNINITIALIZED_DATA 0x80
+#endif
#define PE_SECTION_INDEX_TEXT 0
#define PE_SECTION_INDEX_DATA 1
#define PE_SECTION_INDEX_BSS 2
@@ -77,13 +98,41 @@ read_pe_section_index (const char *secti
}
}

+/* Get the index of the named section in our own full arrayi.
+ text, data and bss in that order. Return PE_SECTION_INDEX_INVALID
+ if passed an unrecognised section name. */
+
+static int
+get_pe_section_index (const char *section_name,
+ struct read_pe_section_data *sections,
+ int nb_sections)
+{
+ int i;
+
+ for (i = 0; i < nb_sections; i++)
+ if (strcmp (sections[i].section_name, section_name) == 0)
+ return i;
+ return PE_SECTION_INDEX_INVALID;
+}
+
+/* Structure used by get_section_vmas function below
+ to access section_data array and the size of the array
+ stored in nb_sections field. */
+struct pe_sections_info
+{
+ int nb_sections;
+ struct read_pe_section_data *sections;
+};
+
/* Record the virtual memory address of a section. */

static void
get_section_vmas (bfd *abfd, asection *sectp, void *context)
{
- struct read_pe_section_data *sections = context;
- int sectix = read_pe_section_index (sectp->name);
+ struct pe_sections_info *data = context;
+ struct read_pe_section_data *sections = data->sections;
+ int sectix = get_pe_section_index (sectp->name, sections,
+ data->nb_sections);

if (sectix != PE_SECTION_INDEX_INVALID)
{
@@ -95,58 +144,147 @@ get_section_vmas (bfd *abfd, asection *s
}
}
\f
-/* Create a minimal symbol entry for an exported symbol. */
+/* Create a minimal symbol entry for an exported symbol.
+ SYM_NAME contains the exported name or NULL if exported by ordinal,
+ FUNC_RVA contains the Relative Virtual Address of the symbol,
+ ORDINAL is the ordinal index value of the symbol,
+ SECTION_DATA contains information about the section in which the
+ symbol is declared,
+ DLL_NAME is the internal name of the DLL file,
+ OBJFILE is the objfile struct of DLL_NAME. */

static void
-add_pe_exported_sym (char *sym_name,
+add_pe_exported_sym (const char *sym_name,
unsigned long func_rva,
+ int ordinal,
const struct read_pe_section_data *section_data,
const char *dll_name, struct objfile *objfile)
{
+ char *qualified_name, *bare_name;
/* Add the stored offset to get the loaded address of the symbol. */
-
CORE_ADDR vma = func_rva + section_data->vma_offset;
-
- char *qualified_name = 0;
int dll_name_len = strlen (dll_name);

/* Generate a (hopefully unique) qualified name using the first part
of the dll name, e.g. KERNEL32!AddAtomA. This matches the style
used by windbg from the "Microsoft Debugging Tools for Windows". */

- qualified_name = xmalloc (dll_name_len + strlen (sym_name) + 2);
+ if (sym_name == NULL || *sym_name == '\0')
+ bare_name = xstrprintf ("#%d", ordinal);
+ else
+ bare_name = xstrdup (sym_name);
+
+ qualified_name = xstrprintf ("%s!%s", dll_name, bare_name);

- strncpy (qualified_name, dll_name, dll_name_len);
- qualified_name[dll_name_len] = '!';
- strcpy (qualified_name + dll_name_len + 1, sym_name);
+ if ((section_data->ms_type == mst_unknown) && debug_coff_pe_read)
+ fprintf_unfiltered (gdb_stdlog , _("Unknown section type for \"%s\""
+ " for entry \"%s\" in dll \"%s\"\n"),
+ section_data->section_name, sym_name, dll_name);

- prim_record_minimal_symbol (qualified_name,
- vma, section_data->ms_type, objfile);
+ prim_record_minimal_symbol (qualified_name, vma,
+ section_data->ms_type, objfile);

+ /* Enter the plain name as well, which might not be unique. */
+ prim_record_minimal_symbol (bare_name, vma, section_data->ms_type, objfile);
+ if (debug_coff_pe_read > 1)
+ fprintf_unfiltered (gdb_stdlog, _("Adding exported symbol \"%s\""
+ " in dll \"%s\"\n"), sym_name, dll_name);
xfree (qualified_name);
+ xfree (bare_name);
+}
+
+/* Create a minimal symbol entry for an exported forward symbol.
+ Return 1 if the forwarded function was found 0 otherwise.
+ SYM_NAME contains the exported name or NULL if exported by ordinal,
+ FORWARD_DLL_NAME is the name of the DLL in which the target symobl resides,
+ FORWARD_FUNC_NAME is the name of the target symbol in that DLL,
+ ORDINAL is the ordinal index value of the symbol,
+ DLL_NAME is the internal name of the DLL file,
+ OBJFILE is the objfile struct of DLL_NAME. */
+
+static int
+add_pe_forwarded_sym (const char *sym_name, const char *forward_dll_name,
+ const char *forward_func_name, int ordinal,
+ const char *dll_name, struct objfile *objfile)
+{
+ CORE_ADDR vma;
+ struct objfile *forward_objfile;
+ struct minimal_symbol *msymbol;
+ short section;
+ enum minimal_symbol_type msymtype;
+ int dll_name_len = strlen (dll_name);
+ char *qualified_name, *bare_name;
+ int forward_dll_name_len = strlen (forward_dll_name);
+ int forward_func_name_len = strlen (forward_func_name);
+ int forward_len = forward_dll_name_len + forward_func_name_len + 2;
+ char *forward_qualified_name = alloca (forward_len);
+
+ xsnprintf (forward_qualified_name, forward_len, "%s!%s", forward_dll_name,
+ forward_func_name);
+
+
+ msymbol = lookup_minimal_symbol_and_objfile (forward_qualified_name,
+ &forward_objfile);
+
+ if (!msymbol)
+ {
+ int i;
+
+ for (i = 0; i < forward_dll_name_len; i++)
+ forward_qualified_name[i] = tolower (forward_qualified_name[i]);
+ msymbol = lookup_minimal_symbol_and_objfile (forward_qualified_name,
+ &forward_objfile);
+ }
+
+ if (!msymbol)
+ {
+ if (debug_coff_pe_read)
+ fprintf_unfiltered (gdb_stdlog, _("Unable to find function \"%s\" in"
+ " dll \"%s\", forward of \"%s\" in dll \"%s\"\n"),
+ forward_func_name, forward_dll_name, sym_name,
+ dll_name);
+ return 0;
+ }
+
+ if (debug_coff_pe_read > 1)
+ fprintf_unfiltered (gdb_stdlog, _("Adding forwarded exported symbol"
+ " \"%s\" in dll \"%s\", pointing to \"%s\"\n"),
+ sym_name, dll_name, forward_qualified_name);
+
+ vma = SYMBOL_VALUE_ADDRESS (msymbol);
+ section = SYMBOL_SECTION (msymbol);
+ msymtype = MSYMBOL_TYPE (msymbol);
+
+ /* Generate a (hopefully unique) qualified name using the first part
+ of the dll name, e.g. KERNEL32!AddAtomA. This matches the style
+ used by windbg from the "Microsoft Debugging Tools for Windows". */
+
+ if (sym_name == NULL || *sym_name == '\0')
+ bare_name = xstrprintf ("#%d", ordinal);
+ else
+ bare_name = xstrdup (sym_name);
+
+ qualified_name = xstrprintf ("%s!%s", dll_name, bare_name);
+
+ prim_record_minimal_symbol (qualified_name, vma, msymtype, objfile);

/* Enter the plain name as well, which might not be unique. */
- prim_record_minimal_symbol (sym_name, vma,
- section_data->ms_type, objfile);
+ prim_record_minimal_symbol (bare_name, vma, msymtype, objfile);
+ xfree (qualified_name);
+ xfree (bare_name);
+
+ return 1;
}

-/* Truncate a dll_name at the first dot character. */
+/* Truncate a dll_name at the last dot character. */

static void
read_pe_truncate_name (char *dll_name)
{
- while (*dll_name)
- {
- if ((*dll_name) == '.')
- {
- *dll_name = '\0'; /* truncates and causes loop exit. */
- }
+ char *last_point = strrchr (dll_name, '.');

- else
- {
- ++dll_name;
- }
- }
+ if (last_point != NULL)
+ *last_point = '\0';
}
\f
/* Low-level support functions, direct from the ld module pe-dll.c. */
@@ -171,6 +309,14 @@ pe_get32 (bfd *abfd, int where)
}

static unsigned int
+pe_as16 (void *ptr)
+{
+ unsigned char *b = ptr;
+
+ return b[0] + (b[1] << 8);
+}
+
+static unsigned int
pe_as32 (void *ptr)
{
unsigned char *b = ptr;
@@ -186,35 +332,53 @@ void
read_pe_exported_syms (struct objfile *objfile)
{
bfd *dll = objfile->obfd;
+ unsigned long nbnormal, nbforward;
unsigned long pe_header_offset, opthdr_ofs, num_entries, i;
+ unsigned long export_opthdrrva, export_opthdrsize;
unsigned long export_rva, export_size, nsections, secptr, expptr;
unsigned long exp_funcbase;
unsigned char *expdata, *erva;
unsigned long name_rvas, ordinals, nexp, ordbase;
- char *dll_name;
+ char *dll_name = (char *) dll->filename;
+ int otherix = PE_SECTION_TABLE_SIZE;
+ int exportix = -1;
int is_pe64 = 0;
int is_pe32 = 0;

/* Array elements are for text, data and bss in that order
- Initialization with start_rva > end_rva guarantees that
+ Initialization with RVA_START > RVA_END guarantees that
unused sections won't be matched. */
- struct read_pe_section_data section_data[PE_SECTION_TABLE_SIZE]
- = { {0, 1, 0, mst_text},
- {0, 1, 0, mst_data},
- {0, 1, 0, mst_bss}
- };
+ struct read_pe_section_data *section_data;
+ struct pe_sections_info pe_sections_info;

- struct cleanup *back_to = 0;
+ struct cleanup *back_to = make_cleanup (null_cleanup, 0);

char const *target = bfd_get_target (objfile->obfd);

+ section_data = xzalloc (PE_SECTION_TABLE_SIZE
+ * sizeof (struct read_pe_section_data));
+
+ make_cleanup (free_current_contents, &section_data);
+
+ for (i=0; i < PE_SECTION_TABLE_SIZE; i++)
+ {
+ section_data[i].vma_offset = 0;
+ section_data[i].rva_start = 1;
+ section_data[i].rva_end = 0;
+ };
+ section_data[PE_SECTION_INDEX_TEXT].ms_type = mst_text;
+ section_data[PE_SECTION_INDEX_TEXT].section_name = ".text";
+ section_data[PE_SECTION_INDEX_DATA].ms_type = mst_data;
+ section_data[PE_SECTION_INDEX_DATA].section_name = ".data";
+ section_data[PE_SECTION_INDEX_BSS].ms_type = mst_bss;
+ section_data[PE_SECTION_INDEX_BSS].section_name = ".bss";
+
is_pe64 = (strcmp (target, "pe-x86-64") == 0
|| strcmp (target, "pei-x86-64") == 0);
is_pe32 = (strcmp (target, "pe-i386") == 0
|| strcmp (target, "pei-i386") == 0
|| strcmp (target, "pe-arm-wince-little") == 0
|| strcmp (target, "pei-arm-wince-little") == 0);
-
if (!is_pe32 && !is_pe64)
{
/* This is not a recognized PE format file. Abort now, because
@@ -235,21 +399,21 @@ read_pe_exported_syms (struct objfile *o
{
return;
}
-
if (is_pe64)
{
- export_rva = pe_get32 (dll, opthdr_ofs + 112);
- export_size = pe_get32 (dll, opthdr_ofs + 116);
+ export_opthdrrva = pe_get32 (dll, opthdr_ofs + 112);
+ export_opthdrsize = pe_get32 (dll, opthdr_ofs + 116);
}
else
{
- export_rva = pe_get32 (dll, opthdr_ofs + 96);
- export_size = pe_get32 (dll, opthdr_ofs + 100);
+ export_opthdrrva = pe_get32 (dll, opthdr_ofs + 96);
+ export_opthdrsize = pe_get32 (dll, opthdr_ofs + 100);
}
nsections = pe_get16 (dll, pe_header_offset + 4 + 2);
secptr = (pe_header_offset + 4 + 20 +
pe_get16 (dll, pe_header_offset + 4 + 16));
expptr = 0;
+ export_size = 0;

/* Get the rva and size of the export section. */
for (i = 0; i < nsections; i++)
@@ -261,17 +425,31 @@ read_pe_exported_syms (struct objfile *o
unsigned long fptr = pe_get32 (dll, secptr1 + 20);

bfd_seek (dll, (file_ptr) secptr1, SEEK_SET);
- bfd_bread (sname, (bfd_size_type) 8, dll);
+ bfd_bread (sname, (bfd_size_type) sizeof (sname), dll);

- if (vaddr <= export_rva && vaddr + vsize > export_rva)
+ if ((strcmp (sname, ".edata") == 0)
+ || (vaddr <= export_opthdrrva && export_opthdrrva < vaddr + vsize))
{
- expptr = fptr + (export_rva - vaddr);
- if (export_rva + export_size > vaddr + vsize)
- export_size = vsize - (export_rva - vaddr);
+ if (strcmp (sname, ".edata") != 0)
+ {
+ if (debug_coff_pe_read)
+ fprintf_unfiltered (gdb_stdlog, _("Export RVA for dll "
+ "\"%s\" is in section \"%s\"\n"),
+ dll_name, sname);
+ }
+ else if (export_opthdrrva != vaddr && debug_coff_pe_read)
+ fprintf_unfiltered (gdb_stdlog, _("Wrong value of export RVA"
+ " for dll \"%s\": 0x%lx instead of 0x%lx\n"),
+ dll_name, export_opthdrrva, vaddr);
+ expptr = fptr + (export_opthdrrva - vaddr);
+ exportix = i;
break;
}
}

+ export_rva = export_opthdrrva;
+ export_size = export_opthdrsize;
+
if (export_size == 0)
{
/* Empty export table. */
@@ -285,10 +463,11 @@ read_pe_exported_syms (struct objfile *o
unsigned long secptr1 = secptr + 40 * i;
unsigned long vsize = pe_get32 (dll, secptr1 + 8);
unsigned long vaddr = pe_get32 (dll, secptr1 + 12);
+ unsigned long characteristics = pe_get32 (dll, secptr1 + 36);
char sec_name[9];
int sectix;

- sec_name[8] = '\0';
+ memset (sec_name, 0, sizeof (sec_name));
bfd_seek (dll, (file_ptr) secptr1 + 0, SEEK_SET);
bfd_bread (sec_name, (bfd_size_type) 8, dll);

@@ -299,10 +478,32 @@ read_pe_exported_syms (struct objfile *o
section_data[sectix].rva_start = vaddr;
section_data[sectix].rva_end = vaddr + vsize;
}
+ else
+ {
+ char *name;
+
+ section_data = xrealloc (section_data, (otherix + 1)
+ * sizeof (struct read_pe_section_data));
+ name = xstrdup (sec_name);
+ section_data[otherix].section_name = name;
+ make_cleanup (xfree, name);
+ section_data[otherix].rva_start = vaddr;
+ section_data[otherix].rva_end = vaddr + vsize;
+ section_data[otherix].vma_offset = 0;
+ if (characteristics & IMAGE_SCN_CNT_CODE)
+ section_data[otherix].ms_type = mst_text;
+ else if (characteristics & IMAGE_SCN_CNT_INITIALIZED_DATA)
+ section_data[otherix].ms_type = mst_data;
+ else if (characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA)
+ section_data[otherix].ms_type = mst_bss;
+ else
+ section_data[otherix].ms_type = mst_unknown;
+ otherix++;
+ }
}

expdata = (unsigned char *) xmalloc (export_size);
- back_to = make_cleanup (xfree, expdata);
+ make_cleanup (xfree, expdata);

bfd_seek (dll, (file_ptr) expptr, SEEK_SET);
bfd_bread (expdata, (bfd_size_type) export_size, dll);
@@ -317,12 +518,15 @@ read_pe_exported_syms (struct objfile *o
/* Use internal dll name instead of full pathname. */
dll_name = pe_as32 (expdata + 12) + erva;

- bfd_map_over_sections (dll, get_section_vmas, section_data);
+ pe_sections_info.nb_sections = otherix;
+ pe_sections_info.sections = section_data;
+
+ bfd_map_over_sections (dll, get_section_vmas, &pe_sections_info);

/* Adjust the vma_offsets in case this PE got relocated. This
assumes that *all* sections share the same relocation offset
as the text section. */
- for (i = 0; i < PE_SECTION_TABLE_SIZE; i++)
+ for (i = 0; i < otherix; i++)
{
section_data[i].vma_offset
+= ANOFFSET (objfile->section_offsets, SECT_OFF_TEXT (objfile));
@@ -332,31 +536,184 @@ read_pe_exported_syms (struct objfile *o
lower case for convenience on Windows. */
read_pe_truncate_name (dll_name);

+ if (debug_coff_pe_read)
+ fprintf_unfiltered (gdb_stdlog, _("DLL \"%s\" has %ld export entries,"
+ " base=%ld\n"), dll_name, nexp, ordbase);
+ nbforward = 0;
+ nbnormal = 0;
/* Iterate through the list of symbols. */
for (i = 0; i < nexp; i++)
{
/* Pointer to the names vector. */
unsigned long name_rva = pe_as32 (erva + name_rvas + i * 4);
+ /* Retrieve ordinal value. */
+
+ unsigned long ordinal = pe_as16 (erva + ordinals + i * 2);
+

/* Pointer to the function address vector. */
- unsigned long func_rva = pe_as32 (erva + exp_funcbase + i * 4);
+ /* This is relatived to ordinal value. */
+ unsigned long func_rva = pe_as32 (erva + exp_funcbase +
+ ordinal * 4);

/* Find this symbol's section in our own array. */
int sectix = 0;
+ int section_found = 0;
+
+ /* First handle forward cases. */
+ if (func_rva >= export_rva && func_rva < export_rva + export_size)
+ {
+ char *forward_name = (char *) (erva + func_rva);
+ char *funcname = (char *) (erva + name_rva);
+ char *forward_dll_name = forward_name;
+ char *forward_func_name = forward_name;
+ char *sep = strrchr (forward_name, '.');
+
+ if (sep)
+ {
+ int len = (int) (sep - forward_name);

- for (sectix = 0; sectix < PE_SECTION_TABLE_SIZE; ++sectix)
+ forward_dll_name = alloca (len + 1);
+ strncpy (forward_dll_name, forward_name, len);
+ forward_dll_name[len] = '\0';
+ forward_func_name = ++sep;
+ }
+ if (add_pe_forwarded_sym (funcname, forward_dll_name,
+ forward_func_name, ordinal,
+ dll_name, objfile) != 0)
+ ++nbforward;
+ continue;
+ }
+
+ for (sectix = 0; sectix < otherix; ++sectix)
{
if ((func_rva >= section_data[sectix].rva_start)
&& (func_rva < section_data[sectix].rva_end))
{
+ section_found = 1;
add_pe_exported_sym (erva + name_rva,
- func_rva,
+ func_rva, ordinal,
section_data + sectix, dll_name, objfile);
+ ++nbnormal;
break;
}
}
+ if (!section_found)
+ {
+ char *funcname = (char *) (erva + name_rva);
+
+ if (name_rva == 0)
+ {
+ add_pe_exported_sym (NULL, func_rva, ordinal,
+ section_data, dll_name, objfile);
+ ++nbnormal;
+ }
+ else if (debug_coff_pe_read)
+ fprintf_unfiltered (gdb_stdlog, _("Export name \"%s\" ord. %lu,"
+ " RVA 0x%lx in dll \"%s\" not handled\n"),
+ funcname, ordinal, func_rva, dll_name);
+ }
}

- /* Discard expdata. */
+ if (debug_coff_pe_read)
+ fprintf_unfiltered (gdb_stdlog, _("Finished reading \"%s\", exports %ld,"
+ " forwards %ld, total %ld/%ld.\n"), dll_name, nbnormal,
+ nbforward, nbnormal + nbforward, nexp);
+ /* Discard expdata and section_data. */
do_cleanups (back_to);
}
+
+/* Extract from ABFD the offset of the .text section.
+ This offset is mainly related to the offset within the file.
+ The value was previously expected to be 0x1000 for all files,
+ but some Windows OS core DLLs seem to use 0x10000 section alignement
+ which modified the return value of that function.
+ Still return default 0x1000 value if ABFD is NULL or
+ if '.text' section is not found, but that should not happen... */
+
+#define DEFAULT_COFF_PE_TEXT_SECTION_OFFSET 0x1000
+
+CORE_ADDR
+pe_text_section_offset (struct bfd *abfd)
+
+{
+ unsigned long pe_header_offset, opthdr_ofs, num_entries, i;
+ unsigned long export_rva, export_size, nsections, secptr, expptr;
+ unsigned long exp_funcbase;
+ unsigned char *expdata, *erva;
+ unsigned long name_rvas, ordinals, nexp, ordbase;
+ char *dll_name;
+ int is_pe64 = 0;
+ int is_pe32 = 0;
+ char const *target;
+
+ if (!abfd)
+ return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
+
+ target = bfd_get_target (abfd);
+
+ is_pe64 = (strcmp (target, "pe-x86-64") == 0
+ || strcmp (target, "pei-x86-64") == 0);
+ is_pe32 = (strcmp (target, "pe-i386") == 0
+ || strcmp (target, "pei-i386") == 0
+ || strcmp (target, "pe-arm-wince-little") == 0
+ || strcmp (target, "pei-arm-wince-little") == 0);
+
+ if (!is_pe32 && !is_pe64)
+ {
+ /* This is not a recognized PE format file. Abort now, because
+ the code is untested on anything else. *FIXME* test on
+ further architectures and loosen or remove this test. */
+ return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
+ }
+
+ /* Get pe_header, optional header and numbers of sections. */
+ pe_header_offset = pe_get32 (abfd, 0x3c);
+ opthdr_ofs = pe_header_offset + 4 + 20;
+ nsections = pe_get16 (abfd, pe_header_offset + 4 + 2);
+ secptr = (pe_header_offset + 4 + 20 +
+ pe_get16 (abfd, pe_header_offset + 4 + 16));
+
+ /* Get the rva and size of the export section. */
+ for (i = 0; i < nsections; i++)
+ {
+ char sname[8];
+ unsigned long secptr1 = secptr + 40 * i;
+ unsigned long vaddr = pe_get32 (abfd, secptr1 + 12);
+
+ bfd_seek (abfd, (file_ptr) secptr1, SEEK_SET);
+ bfd_bread (sname, (bfd_size_type) 8, abfd);
+ if (strcmp (sname, ".text") == 0)
+ return vaddr;
+ }
+
+ return DEFAULT_COFF_PE_TEXT_SECTION_OFFSET;
+}
+
+/* Implements "show debug coff_pe_read" command. */
+
+static void
+show_debug_coff_pe_read (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Coff PE read debugging is %s.\n"), value);
+}
+
+/* Provide a prototype to silence -Wmissing-prototypes. */
+
+void _initialize_coff_pe_read (void);
+
+/* Adds "Set/show debug coff_pe_read" commands. */
+
+void
+_initialize_coff_pe_read (void)
+{
+ add_setshow_uinteger_cmd ("coff_pe_read", class_maintenance,
+ &debug_coff_pe_read,
+ _("Set coff PE read debugging."),
+ _("Show coff PE read debugging."),
+ _("When set, debugging messages for coff reading "
+ "of exported symbols are displayed."),
+ NULL, show_debug_coff_pe_read,
+ &setdebuglist, &showdebuglist);
+}
Index: windows-tdep.c
===================================================================
RCS file: /cvs/src/src/gdb/windows-tdep.c,v
retrieving revision 1.17
diff -u -p -r1.17 windows-tdep.c
--- windows-tdep.c 9 Nov 2012 19:58:02 -0000 1.17
+++ windows-tdep.c 13 Dec 2012 10:41:57 -0000
@@ -27,6 +27,10 @@
#include "gdbcmd.h"
#include "gdbthread.h"
#include "objfiles.h"
+#include "symfile.h"
+#include "coff-pe-read.h"
+#include "gdb_bfd.h"
+#include "complaints.h"

struct cmd_list_element *info_w32_cmdlist;

@@ -387,15 +391,21 @@ windows_xfer_shared_library (const char*
struct gdbarch *gdbarch, struct obstack *obstack)
{
char *p;
+ struct bfd * dll;
+ CORE_ADDR text_offset;
+
obstack_grow_str (obstack, "<library name=\"");
p = xml_escape_text (so_name);
obstack_grow_str (obstack, p);
xfree (p);
obstack_grow_str (obstack, "\"><segment address=\"");
- /* The symbols in a dll are offset by 0x1000, which is the
- offset from 0 of the first byte in an image - because of the file
- header and the section alignment. */
- obstack_grow_str (obstack, paddress (gdbarch, load_addr + 0x1000));
+ dll = gdb_bfd_open_maybe_remote (so_name);
+ /* The following calls are OK even if dll is NULL.
+ The default value 0x1000 is returned by pe_text_section_offset
+ in that case. */
+ text_offset = pe_text_section_offset (dll);
+ gdb_bfd_unref (dll);
+ obstack_grow_str (obstack, paddress (gdbarch, load_addr + text_offset));
obstack_grow_str (obstack, "\"/></library>");
}