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Add SVR4 psABI specific parser for AUXV entries

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NetBSD and OpenBSD always use an int to store the type as
defined in the SVR4 psABI specifications rather than long
as assumed by the default parser.

Define svr4_auxv_parse() that shares code with default_auxv_parse().

Remove obsd_auxv_parse() and switch OpenBSD to svr4_auxv_parse().
Remove not fully accurate comment from obsd-tdep.c.

Use svr4_auxv_parse() on NetBSD.

gdb/ChangeLog:

	* auxv.h (svr4_auxv_parse): New.
	* auxv.c (default_auxv_parse): Split into default_auxv_parse
	and generic_auxv_parse.
	(svr4_auxv_parse): Add.
	* obsd-tdep.c: Include "auxv.h".
	(obsd_auxv_parse): Remove.
	(obsd_init_abi): Remove comment.
	(obsd_init_abi): Change set_gdbarch_auxv_parse passed argument
	from `obsd_auxv_parse' to `svr4_auxv_parse'.
	* nbsd-tdep.c: Include "auxv.h".
	(nbsd_init_abi): Call set_gdbarch_auxv_parse.
This commit is contained in:
Kamil Rytarowski 2020-04-08 04:01:10 +02:00
parent ae4b1d73f9
commit 206c98a650
5 changed files with 80 additions and 44 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
gdb/ChangeLog
View file

@ -1,3 +1,17 @@
2020-04-09 Kamil Rytarowski <n54@gmx.com>
* auxv.h (svr4_auxv_parse): New.
* auxv.c (default_auxv_parse): Split into default_auxv_parse
and generic_auxv_parse.
(svr4_auxv_parse): Add.
* obsd-tdep.c: Include "auxv.h".
(obsd_auxv_parse): Remove.
(obsd_init_abi): Remove comment.
(obsd_init_abi): Change set_gdbarch_auxv_parse passed argument
from `obsd_auxv_parse' to `svr4_auxv_parse'.
* nbsd-tdep.c: Include "auxv.h".
(nbsd_init_abi): Call set_gdbarch_auxv_parse.
2020-04-08 Tom Tromey <tromey@adacore.com>
* nat/windows-nat.h (last_wait_event): Don't declare.

61
gdb/auxv.c
View file

@ -248,34 +248,65 @@ memory_xfer_auxv (struct target_ops *ops,
return procfs_xfer_auxv (readbuf, writebuf, offset, len, xfered_len);
}
/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return 0 if *READPTR is already at the end of the buffer.
Return -1 if there is insufficient buffer for a whole entry.
Return 1 if an entry was read into *TYPEP and *VALP. */
int
default_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
/* This function compared to other auxv_parse functions: it takes the size of
the auxv type field as a parameter. */
static int
generic_auxv_parse (struct gdbarch *gdbarch, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp,
int sizeof_auxv_type)
{
const int sizeof_auxv_field = gdbarch_ptr_bit (target_gdbarch ())
/ TARGET_CHAR_BIT;
const enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
const int sizeof_auxv_val = TYPE_LENGTH (ptr_type);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte *ptr = *readptr;
if (endptr == ptr)
return 0;
if (endptr - ptr < sizeof_auxv_field * 2)
if (endptr - ptr < 2 * sizeof_auxv_val)
return -1;
*typep = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order);
ptr += sizeof_auxv_field;
*valp = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order);
ptr += sizeof_auxv_field;
*typep = extract_unsigned_integer (ptr, sizeof_auxv_type, byte_order);
/* Even if the auxv type takes less space than an auxv value, there is
padding after the type such that the value is aligned on a multiple of
its size (and this is why we advance by `sizeof_auxv_val` and not
`sizeof_auxv_type`). */
ptr += sizeof_auxv_val;
*valp = extract_unsigned_integer (ptr, sizeof_auxv_val, byte_order);
ptr += sizeof_auxv_val;
*readptr = ptr;
return 1;
}
/* See auxv.h. */
int
default_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
{
struct gdbarch *gdbarch = target_gdbarch ();
struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
const int sizeof_auxv_type = TYPE_LENGTH (ptr_type);
return generic_auxv_parse (gdbarch, readptr, endptr, typep, valp,
sizeof_auxv_type);
}
/* See auxv.h. */
int
svr4_auxv_parse (struct gdbarch *gdbarch, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
{
struct type *int_type = builtin_type (gdbarch)->builtin_int;
const int sizeof_auxv_type = TYPE_LENGTH (int_type);
return generic_auxv_parse (gdbarch, readptr, endptr, typep, valp,
sizeof_auxv_type);
}
/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return 0 if *READPTR is already at the end of the buffer.
Return -1 if there is insufficient buffer for a whole entry.

17
gdb/auxv.h
View file

@ -25,12 +25,27 @@
/* See "include/elf/common.h" for the definition of valid AT_* values. */
/* The default implementation of to_auxv_parse, used by the target
stack. */
stack.
Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return 0 if *READPTR is already at the end of the buffer.
Return -1 if there is insufficient buffer for a whole entry.
Return 1 if an entry was read into *TYPEP and *VALP. */
extern int default_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep,
CORE_ADDR *valp);
/* The SVR4 psABI implementation of to_auxv_parse, that uses an int to
store the type rather than long as assumed by the default parser.
Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return 0 if *READPTR is already at the end of the buffer.
Return -1 if there is insufficient buffer for a whole entry.
Return 1 if an entry was read into *TYPEP and *VALP. */
extern int svr4_auxv_parse (struct gdbarch *gdbarch, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep,
CORE_ADDR *valp);
/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return 0 if *READPTR is already at the end of the buffer.
Return -1 if there is insufficient buffer for a whole entry.

2
gdb/nbsd-tdep.c
View file

@ -20,6 +20,7 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "auxv.h"
#include "solib-svr4.h"
#include "nbsd-tdep.h"
#include "gdbarch.h"
@ -362,4 +363,5 @@ nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
set_gdbarch_gdb_signal_from_target (gdbarch, nbsd_gdb_signal_from_target);
set_gdbarch_gdb_signal_to_target (gdbarch, nbsd_gdb_signal_to_target);
set_gdbarch_skip_solib_resolver (gdbarch, nbsd_skip_solib_resolver);
set_gdbarch_auxv_parse (gdbarch, svr4_auxv_parse);
}

30
gdb/obsd-tdep.c
View file

@ -18,6 +18,7 @@
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "auxv.h"
#include "frame.h"
#include "symtab.h"
#include "objfiles.h"
@ -289,32 +290,6 @@ obsd_gdb_signal_to_target (struct gdbarch *gdbarch,
return -1;
}
static int
obsd_auxv_parse (struct gdbarch *gdbarch, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
{
struct type *int_type = builtin_type (gdbarch)->builtin_int;
struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
const int sizeof_auxv_type = TYPE_LENGTH (int_type);
const int sizeof_auxv_val = TYPE_LENGTH (ptr_type);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte *ptr = *readptr;
if (endptr == ptr)
return 0;
if (endptr - ptr < 2 * sizeof_auxv_val)
return -1;
*typep = extract_unsigned_integer (ptr, sizeof_auxv_type, byte_order);
ptr += sizeof_auxv_val; /* Alignment. */
*valp = extract_unsigned_integer (ptr, sizeof_auxv_val, byte_order);
ptr += sizeof_auxv_val;
*readptr = ptr;
return 1;
}
void
obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
@ -323,6 +298,5 @@ obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
set_gdbarch_gdb_signal_to_target (gdbarch,
obsd_gdb_signal_to_target);
/* Unlike Linux, OpenBSD actually follows the ELF standard. */
set_gdbarch_auxv_parse (gdbarch, obsd_auxv_parse);
set_gdbarch_auxv_parse (gdbarch, svr4_auxv_parse);
}