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Re: [PATCH] Clear *VAL in regcache_raw_read_unsigned
- From: Pedro Alves <palves at redhat dot com>
- To: Yao Qi <qiyaoltc at gmail dot com>
- Cc: gdb-patches at sourceware dot org
- Date: Thu, 11 Feb 2016 12:46:19 +0000
- Subject: Re: [PATCH] Clear *VAL in regcache_raw_read_unsigned
- Authentication-results: sourceware.org; auth=none
- References: <1455029644-6197-1-git-send-email-yao dot qi at linaro dot org> <86egckqztq dot fsf at gmail dot com> <56BB6ADB dot 6070909 at redhat dot com> <86a8n8qxyp dot fsf at gmail dot com> <56BB7512 dot 2030507 at redhat dot com> <8660xvr1wr dot fsf at gmail dot com>
On 02/11/2016 10:12 AM, Yao Qi wrote:> Pedro Alves <palves@redhat.com> writes:
>
>> The issue you noticed exposed that regcache_raw_read_unsigned function
>> is broken for memcpy'ing a 32-bit value into a 64-bit variable, and I think
>> your patch papered over the problem for little endian, only.
>
> regcache_raw_read_unsigned has two orthogonal issues, one is VAL isn't
> cleared, and the other one is the endianness issue. My "Clear *VAL"
> patch fixes the former, and I didn't realize the latter then.
I guess you could see it that way, though the way I imagine fixing this
handles both issues as one.
> diff --git a/gdb/gdbserver/regcache.c b/gdb/gdbserver/regcache.c
> index 2af8e24..d69ed5b 100644
> --- a/gdb/gdbserver/regcache.c
> +++ b/gdb/gdbserver/regcache.c
> @@ -21,6 +21,8 @@
> #include "gdbthread.h"
> #include "tdesc.h"
> #include "rsp-low.h"
> +#include <endian.h>
> +
> #ifndef IN_PROCESS_AGENT
>
> struct regcache *
> @@ -441,7 +443,27 @@ regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
> (int) sizeof (ULONGEST));
>
> *val = 0;
> - collect_register (regcache, regnum, val);
> +
> + if (__BYTE_ORDER == __LITTLE_ENDIAN)
> + {
> + /* Little-endian values always sit at the left end of the buffer. */
> + collect_register (regcache, regnum, val);
> + }
> + else if (__BYTE_ORDER == __BIG_ENDIAN)
> + {
> + /* Big-endian values sit at the right end of the buffer. In case of
> + registers whose sizes are smaller than sizeof (long), we must use a
> + padding to access them correctly. */
> + int size = register_size (regcache->tdesc, regnum);
> +
> + if (size < sizeof (ULONGEST))
> + {
> + collect_register (regcache, regnum,
> + (char *) val + sizeof (ULONGEST) - size);
> + }
> + else
> + collect_register (regcache, regnum, val);
> + }
I was thinking we'd just use properly sized types, and the let the
compiler do the zero extension:
uint8_t u8;
uint16_t u16;
uint32_t u32;
uint64_t u64;
switch (size)
{
case 1:
collect_register (regcache, regnum, &u8);
*val = u8;
break;
case 2:
collect_register (regcache, regnum, &u16);
*val = u16;
break;
case 4:
collect_register (regcache, regnum, &u32);
*val = u32;
break;
case 8:
collect_register (regcache, regnum, &u64);
*val = u64;
break;
}
This should work in either endianess, and the '*val = 0' is no longer
necessary either.
Or maybe better, just byte the bullet and make gdbserver use
extract_unsigned_integer, like gdb.
The problem with that is that gdbserver can't currently use 'enum bfd_endian',
which IIRC, was already an issue in the get-next-pcs stuff. I've attached a
patch series that handles that by moving bfd_endian to a separate header.
I've pushed it to the users/palves/gdbserver-extract-unsigned-integer branch
as well.
If you agree with this, I'll run the bfd_endian patch by the binutils folks.
Thanks,
Pedro Alves
>From dd4a4f86240eac1262c760b6109b42242e007923 Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Thu, 11 Feb 2016 11:35:04 +0000
Subject: [PATCH 1/3] Move 'enum bfd_endian' to a non-generated header
Because:
- GDB uses enum bfd_endian extensively.
- gdbserver does not build/link-with bfd.
- We'd like to share more code between gdb and gdbserver.
It'd make our lives easier if we could just use bfd_endian in
gdbserver as well.
The problem is that bfd_endian is defined in a header that only exists
if bfd is built/configured.
Thus this moves bfd_endian to a separate header, so gdbserver can
include it.
bfd/ChangeLog:
2016-02-11 Pedro Alves <palves@redhat.com>
* bfd-in.h: Include bfd-types.h
* bfd-in2.h: Regenerate.
* targets.c (enum bfd_endian): Moved to include/bfd-types.h.
include/ChangeLog:
2016-02-11 Pedro Alves <palves@redhat.com>
* bfd-types.h: New file.
---
bfd/bfd-in.h | 1 +
bfd/bfd-in2.h | 3 +--
bfd/targets.c | 2 --
include/bfd-types.h | 26 ++++++++++++++++++++++++++
4 files changed, 28 insertions(+), 4 deletions(-)
create mode 100644 include/bfd-types.h
diff --git a/bfd/bfd-in.h b/bfd/bfd-in.h
index 5df2bab..277ca5f 100644
--- a/bfd/bfd-in.h
+++ b/bfd/bfd-in.h
@@ -35,6 +35,7 @@ extern "C" {
#include "ansidecl.h"
#include "symcat.h"
#include <sys/stat.h>
+#include "bfd-types.h"
#if defined (__STDC__) || defined (ALMOST_STDC) || defined (HAVE_STRINGIZE)
#ifndef SABER
diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index fb4858c..0d6b40f 100644
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@@ -42,6 +42,7 @@ extern "C" {
#include "ansidecl.h"
#include "symcat.h"
#include <sys/stat.h>
+#include "bfd-types.h"
#if defined (__STDC__) || defined (ALMOST_STDC) || defined (HAVE_STRINGIZE)
#ifndef SABER
@@ -7124,8 +7125,6 @@ enum bfd_flavour
bfd_target_sym_flavour
};
-enum bfd_endian { BFD_ENDIAN_BIG, BFD_ENDIAN_LITTLE, BFD_ENDIAN_UNKNOWN };
-
/* Forward declaration. */
typedef struct bfd_link_info _bfd_link_info;
diff --git a/bfd/targets.c b/bfd/targets.c
index 50f3712..a2ee6ee 100644
--- a/bfd/targets.c
+++ b/bfd/targets.c
@@ -171,8 +171,6 @@ DESCRIPTION
. bfd_target_sym_flavour
.};
.
-.enum bfd_endian { BFD_ENDIAN_BIG, BFD_ENDIAN_LITTLE, BFD_ENDIAN_UNKNOWN };
-.
.{* Forward declaration. *}
.typedef struct bfd_link_info _bfd_link_info;
.
diff --git a/include/bfd-types.h b/include/bfd-types.h
new file mode 100644
index 0000000..816fac4
--- /dev/null
+++ b/include/bfd-types.h
@@ -0,0 +1,26 @@
+/* bfd core types that do not depend on configuration.
+
+ Copyright (C) 1990-2016 Free Software Foundation, Inc.
+
+ This file is part of BFD, the Binary File Descriptor library.
+
+ This program 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.
+
+ This program 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, write to the Free Software
+ Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#ifndef BFD_TYPES_H
+#define BFD_TYPES_H
+
+enum bfd_endian { BFD_ENDIAN_BIG, BFD_ENDIAN_LITTLE, BFD_ENDIAN_UNKNOWN };
+
+#endif
--
1.9.3
>From ca47aa93d4a13e676e771041eb7372ff2cdb1487 Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Thu, 11 Feb 2016 11:35:05 +0000
Subject: [PATCH 2/3] Move store/extract ... integer routines to gdb/common/
In preparation for gdbserver using them as well.
gdb/ChangeLog:
2016-02-11 Pedro Alves <palves@redhat.com>
* Makefile.in (SFILES): Add common/gdb-byteswap.c.
(HFILES_NO_SRCDIR): Add common/gdb-byteswap.h.
(COMMON_OBS): Add common/gdb-byteswap.o.
(gdb-byteswap.o): New rule.
* common/common-types.h: Include bfd-types.h.
* common/gdb-byteswap.c: New file.
* common/gdb-byteswap.h: New file.
* defs.h (extract_signed_integer, extract_unsigned_integer)
(extract_long_unsigned_integer, extract_typed_address)
(store_signed_integer, store_unsigned_integer): Moved to
common/gdb-byteswap.h.
* findvar.c (extract_signed_integer, extract_unsigned_integer)
(extract_long_unsigned_integer, extract_typed_address)
(store_signed_integer, store_unsigned_integer): Moved to
common/gdb-byteswap.c.
---
gdb/Makefile.in | 11 ++-
gdb/common/common-types.h | 4 +
gdb/common/gdb-byteswap.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++
gdb/common/gdb-byteswap.h | 49 +++++++++++
gdb/defs.h | 17 +---
gdb/findvar.c | 189 -------------------------------------------
6 files changed, 265 insertions(+), 206 deletions(-)
create mode 100644 gdb/common/gdb-byteswap.c
create mode 100644 gdb/common/gdb-byteswap.h
diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index ec2af52..d63d8aa 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -896,6 +896,7 @@ SFILES = ada-exp.y ada-lang.c ada-typeprint.c ada-valprint.c ada-tasks.c \
target/waitstatus.c common/print-utils.c common/rsp-low.c \
common/errors.c common/common-debug.c common/common-exceptions.c \
common/btrace-common.c common/fileio.c common/common-regcache.c \
+ common/gdb-byteswap.c \
$(SUBDIR_GCC_COMPILE_SRCS)
LINTFILES = $(SFILES) $(YYFILES) $(CONFIG_SRCS) init.c
@@ -988,7 +989,9 @@ common/common-exceptions.h target/target.h common/symbol.h \
common/common-regcache.h fbsd-tdep.h nat/linux-personality.h \
common/fileio.h nat/x86-linux.h nat/x86-linux-dregs.h nat/amd64-linux-siginfo.h\
nat/linux-namespaces.h arch/arm.h common/gdb_sys_time.h arch/aarch64-insn.h \
-tid-parse.h
+tid-parse.h \
+common/gdb-byteswap.h
+
# Header files that already have srcdir in them, or which are in objdir.
@@ -1087,7 +1090,7 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $(YYOBJ) \
format.o registry.o btrace.o record-btrace.o waitstatus.o \
print-utils.o rsp-low.o errors.o common-debug.o debug.o \
common-exceptions.o btrace-common.o fileio.o \
- common-regcache.o \
+ common-regcache.o gdb-byteswap.o \
$(SUBDIR_GCC_COMPILE_OBS)
TSOBS = inflow.o
@@ -2275,6 +2278,10 @@ common-regcache.o: ${srcdir}/common/common-regcache.c
$(COMPILE) $(srcdir)/common/common-regcache.c
$(POSTCOMPILE)
+gdb-byteswap.o: ${srcdir}/common/gdb-byteswap.c
+ $(COMPILE) $(srcdir)/common/gdb-byteswap.c
+ $(POSTCOMPILE)
+
#
# gdb/target/ dependencies
#
diff --git a/gdb/common/common-types.h b/gdb/common/common-types.h
index efeb0db..760f477 100644
--- a/gdb/common/common-types.h
+++ b/gdb/common/common-types.h
@@ -20,6 +20,10 @@
#ifndef COMMON_TYPES_H
#define COMMON_TYPES_H
+/* This header is always available, even when BFD is not
+ configured. */
+#include "bfd-types.h"
+
#ifdef GDBSERVER
/* * A byte from the program being debugged. */
diff --git a/gdb/common/gdb-byteswap.c b/gdb/common/gdb-byteswap.c
new file mode 100644
index 0000000..ed2c8f5
--- /dev/null
+++ b/gdb/common/gdb-byteswap.c
@@ -0,0 +1,201 @@
+/* Basic byte-swapping routines, for GDB, the GNU debugger.
+
+ Copyright (C) 1986-2016 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program 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.
+
+ This program 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 "common-defs.h"
+#include "gdb-byteswap.h"
+#include "host-defs.h"
+
+/* See gdb-byteswap.h. */
+
+LONGEST
+extract_signed_integer (const gdb_byte *addr, int len,
+ enum bfd_endian byte_order)
+{
+ LONGEST retval;
+ const unsigned char *p;
+ const unsigned char *startaddr = addr;
+ const unsigned char *endaddr = startaddr + len;
+
+ if (len > (int) sizeof (LONGEST))
+ error (_("\
+That operation is not available on integers of more than %d bytes."),
+ (int) sizeof (LONGEST));
+
+ /* Start at the most significant end of the integer, and work towards
+ the least significant. */
+ if (byte_order == BFD_ENDIAN_BIG)
+ {
+ p = startaddr;
+ /* Do the sign extension once at the start. */
+ retval = ((LONGEST) * p ^ 0x80) - 0x80;
+ for (++p; p < endaddr; ++p)
+ retval = (retval << 8) | *p;
+ }
+ else
+ {
+ p = endaddr - 1;
+ /* Do the sign extension once at the start. */
+ retval = ((LONGEST) * p ^ 0x80) - 0x80;
+ for (--p; p >= startaddr; --p)
+ retval = (retval << 8) | *p;
+ }
+ return retval;
+}
+
+/* See gdb-byteswap.h. */
+
+ULONGEST
+extract_unsigned_integer (const gdb_byte *addr, int len,
+ enum bfd_endian byte_order)
+{
+ ULONGEST retval;
+ const unsigned char *p;
+ const unsigned char *startaddr = addr;
+ const unsigned char *endaddr = startaddr + len;
+
+ if (len > (int) sizeof (ULONGEST))
+ error (_("\
+That operation is not available on integers of more than %d bytes."),
+ (int) sizeof (ULONGEST));
+
+ /* Start at the most significant end of the integer, and work towards
+ the least significant. */
+ retval = 0;
+ if (byte_order == BFD_ENDIAN_BIG)
+ {
+ for (p = startaddr; p < endaddr; ++p)
+ retval = (retval << 8) | *p;
+ }
+ else
+ {
+ for (p = endaddr - 1; p >= startaddr; --p)
+ retval = (retval << 8) | *p;
+ }
+ return retval;
+}
+
+/* See gdb_byteswap.h. */
+
+int
+extract_long_unsigned_integer (const gdb_byte *addr, int orig_len,
+ enum bfd_endian byte_order, LONGEST *pval)
+{
+ const gdb_byte *p;
+ const gdb_byte *first_addr;
+ int len;
+
+ len = orig_len;
+ if (byte_order == BFD_ENDIAN_BIG)
+ {
+ for (p = addr;
+ len > (int) sizeof (LONGEST) && p < addr + orig_len;
+ p++)
+ {
+ if (*p == 0)
+ len--;
+ else
+ break;
+ }
+ first_addr = p;
+ }
+ else
+ {
+ first_addr = addr;
+ for (p = addr + orig_len - 1;
+ len > (int) sizeof (LONGEST) && p >= addr;
+ p--)
+ {
+ if (*p == 0)
+ len--;
+ else
+ break;
+ }
+ }
+
+ if (len <= (int) sizeof (LONGEST))
+ {
+ *pval = (LONGEST) extract_unsigned_integer (first_addr,
+ sizeof (LONGEST),
+ byte_order);
+ return 1;
+ }
+
+ return 0;
+}
+
+
+/* See gdb-byteswap.h. */
+
+void
+store_signed_integer (gdb_byte *addr, int len,
+ enum bfd_endian byte_order, LONGEST val)
+{
+ gdb_byte *p;
+ gdb_byte *startaddr = addr;
+ gdb_byte *endaddr = startaddr + len;
+
+ /* Start at the least significant end of the integer, and work towards
+ the most significant. */
+ if (byte_order == BFD_ENDIAN_BIG)
+ {
+ for (p = endaddr - 1; p >= startaddr; --p)
+ {
+ *p = val & 0xff;
+ val >>= 8;
+ }
+ }
+ else
+ {
+ for (p = startaddr; p < endaddr; ++p)
+ {
+ *p = val & 0xff;
+ val >>= 8;
+ }
+ }
+}
+
+/* See gdb-byteswap.h. */
+
+void
+store_unsigned_integer (gdb_byte *addr, int len,
+ enum bfd_endian byte_order, ULONGEST val)
+{
+ unsigned char *p;
+ unsigned char *startaddr = (unsigned char *) addr;
+ unsigned char *endaddr = startaddr + len;
+
+ /* Start at the least significant end of the integer, and work towards
+ the most significant. */
+ if (byte_order == BFD_ENDIAN_BIG)
+ {
+ for (p = endaddr - 1; p >= startaddr; --p)
+ {
+ *p = val & 0xff;
+ val >>= 8;
+ }
+ }
+ else
+ {
+ for (p = startaddr; p < endaddr; ++p)
+ {
+ *p = val & 0xff;
+ val >>= 8;
+ }
+ }
+}
diff --git a/gdb/common/gdb-byteswap.h b/gdb/common/gdb-byteswap.h
new file mode 100644
index 0000000..9cf1d22
--- /dev/null
+++ b/gdb/common/gdb-byteswap.h
@@ -0,0 +1,49 @@
+/* Basic byte-swapping routines, for GDB, the GNU debugger.
+
+ Copyright (C) 2009-2016 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ This program 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.
+
+ This program 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/>. */
+
+#ifndef GDB_BYTESWAP_H
+#define GDB_BYTESWAP_H 1
+
+/* All 'extract' functions return a host-format integer from a
+ target-format integer at ADDR which is LEN bytes long. */
+
+extern LONGEST extract_signed_integer (const gdb_byte *, int,
+ enum bfd_endian);
+
+extern ULONGEST extract_unsigned_integer (const gdb_byte *, int,
+ enum bfd_endian);
+
+/* Sometimes a long long unsigned integer can be extracted as a
+ LONGEST value. This is done so that we can print these values
+ better. If this integer can be converted to a LONGEST, this
+ function returns 1 and sets *PVAL. Otherwise it returns 0. */
+
+extern int extract_long_unsigned_integer (const gdb_byte *, int,
+ enum bfd_endian, LONGEST *);
+
+/* All 'store' functions accept a host-format integer and store a
+ target-format integer at ADDR which is LEN bytes long. */
+
+extern void store_signed_integer (gdb_byte *, int,
+ enum bfd_endian, LONGEST);
+
+extern void store_unsigned_integer (gdb_byte *, int,
+ enum bfd_endian, ULONGEST);
+
+#endif
diff --git a/gdb/defs.h b/gdb/defs.h
index f6ffeac..1e7fd10 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -594,26 +594,13 @@ extern double atof (const char *); /* X3.159-1989 4.10.1.1 */
enum { MAX_REGISTER_SIZE = 64 };
-/* In findvar.c. */
-
-extern LONGEST extract_signed_integer (const gdb_byte *, int,
- enum bfd_endian);
-
-extern ULONGEST extract_unsigned_integer (const gdb_byte *, int,
- enum bfd_endian);
+#include "gdb-byteswap.h"
-extern int extract_long_unsigned_integer (const gdb_byte *, int,
- enum bfd_endian, LONGEST *);
+/* In findvar.c. */
extern CORE_ADDR extract_typed_address (const gdb_byte *buf,
struct type *type);
-extern void store_signed_integer (gdb_byte *, int,
- enum bfd_endian, LONGEST);
-
-extern void store_unsigned_integer (gdb_byte *, int,
- enum bfd_endian, ULONGEST);
-
extern void store_typed_address (gdb_byte *buf, struct type *type,
CORE_ADDR addr);
diff --git a/gdb/findvar.c b/gdb/findvar.c
index a39d897..70b9249 100644
--- a/gdb/findvar.c
+++ b/gdb/findvar.c
@@ -34,136 +34,6 @@
#include "language.h"
#include "dwarf2loc.h"
-/* Basic byte-swapping routines. All 'extract' functions return a
- host-format integer from a target-format integer at ADDR which is
- LEN bytes long. */
-
-#if TARGET_CHAR_BIT != 8 || HOST_CHAR_BIT != 8
- /* 8 bit characters are a pretty safe assumption these days, so we
- assume it throughout all these swapping routines. If we had to deal with
- 9 bit characters, we would need to make len be in bits and would have
- to re-write these routines... */
-you lose
-#endif
-
-LONGEST
-extract_signed_integer (const gdb_byte *addr, int len,
- enum bfd_endian byte_order)
-{
- LONGEST retval;
- const unsigned char *p;
- const unsigned char *startaddr = addr;
- const unsigned char *endaddr = startaddr + len;
-
- if (len > (int) sizeof (LONGEST))
- error (_("\
-That operation is not available on integers of more than %d bytes."),
- (int) sizeof (LONGEST));
-
- /* Start at the most significant end of the integer, and work towards
- the least significant. */
- if (byte_order == BFD_ENDIAN_BIG)
- {
- p = startaddr;
- /* Do the sign extension once at the start. */
- retval = ((LONGEST) * p ^ 0x80) - 0x80;
- for (++p; p < endaddr; ++p)
- retval = (retval << 8) | *p;
- }
- else
- {
- p = endaddr - 1;
- /* Do the sign extension once at the start. */
- retval = ((LONGEST) * p ^ 0x80) - 0x80;
- for (--p; p >= startaddr; --p)
- retval = (retval << 8) | *p;
- }
- return retval;
-}
-
-ULONGEST
-extract_unsigned_integer (const gdb_byte *addr, int len,
- enum bfd_endian byte_order)
-{
- ULONGEST retval;
- const unsigned char *p;
- const unsigned char *startaddr = addr;
- const unsigned char *endaddr = startaddr + len;
-
- if (len > (int) sizeof (ULONGEST))
- error (_("\
-That operation is not available on integers of more than %d bytes."),
- (int) sizeof (ULONGEST));
-
- /* Start at the most significant end of the integer, and work towards
- the least significant. */
- retval = 0;
- if (byte_order == BFD_ENDIAN_BIG)
- {
- for (p = startaddr; p < endaddr; ++p)
- retval = (retval << 8) | *p;
- }
- else
- {
- for (p = endaddr - 1; p >= startaddr; --p)
- retval = (retval << 8) | *p;
- }
- return retval;
-}
-
-/* Sometimes a long long unsigned integer can be extracted as a
- LONGEST value. This is done so that we can print these values
- better. If this integer can be converted to a LONGEST, this
- function returns 1 and sets *PVAL. Otherwise it returns 0. */
-
-int
-extract_long_unsigned_integer (const gdb_byte *addr, int orig_len,
- enum bfd_endian byte_order, LONGEST *pval)
-{
- const gdb_byte *p;
- const gdb_byte *first_addr;
- int len;
-
- len = orig_len;
- if (byte_order == BFD_ENDIAN_BIG)
- {
- for (p = addr;
- len > (int) sizeof (LONGEST) && p < addr + orig_len;
- p++)
- {
- if (*p == 0)
- len--;
- else
- break;
- }
- first_addr = p;
- }
- else
- {
- first_addr = addr;
- for (p = addr + orig_len - 1;
- len > (int) sizeof (LONGEST) && p >= addr;
- p--)
- {
- if (*p == 0)
- len--;
- else
- break;
- }
- }
-
- if (len <= (int) sizeof (LONGEST))
- {
- *pval = (LONGEST) extract_unsigned_integer (first_addr,
- sizeof (LONGEST),
- byte_order);
- return 1;
- }
-
- return 0;
-}
-
-
/* Treat the bytes at BUF as a pointer of type TYPE, and return the
address it represents. */
CORE_ADDR
@@ -178,65 +48,6 @@ extract_typed_address (const gdb_byte *buf, struct type *type)
return gdbarch_pointer_to_address (get_type_arch (type), type, buf);
}
-/* All 'store' functions accept a host-format integer and store a
- target-format integer at ADDR which is LEN bytes long. */
-
-void
-store_signed_integer (gdb_byte *addr, int len,
- enum bfd_endian byte_order, LONGEST val)
-{
- gdb_byte *p;
- gdb_byte *startaddr = addr;
- gdb_byte *endaddr = startaddr + len;
-
- /* Start at the least significant end of the integer, and work towards
- the most significant. */
- if (byte_order == BFD_ENDIAN_BIG)
- {
- for (p = endaddr - 1; p >= startaddr; --p)
- {
- *p = val & 0xff;
- val >>= 8;
- }
- }
- else
- {
- for (p = startaddr; p < endaddr; ++p)
- {
- *p = val & 0xff;
- val >>= 8;
- }
- }
-}
-
-void
-store_unsigned_integer (gdb_byte *addr, int len,
- enum bfd_endian byte_order, ULONGEST val)
-{
- unsigned char *p;
- unsigned char *startaddr = (unsigned char *) addr;
- unsigned char *endaddr = startaddr + len;
-
- /* Start at the least significant end of the integer, and work towards
- the most significant. */
- if (byte_order == BFD_ENDIAN_BIG)
- {
- for (p = endaddr - 1; p >= startaddr; --p)
- {
- *p = val & 0xff;
- val >>= 8;
- }
- }
- else
- {
- for (p = startaddr; p < endaddr; ++p)
- {
- *p = val & 0xff;
- val >>= 8;
- }
- }
-}
-
/* Store the address ADDR as a pointer of type TYPE at BUF, in target
form. */
void
--
1.9.3
>From 04956cf9b84b53728e20f0dae1f561ab26714453 Mon Sep 17 00:00:00 2001
From: Pedro Alves <palves@redhat.com>
Date: Thu, 11 Feb 2016 11:44:35 +0000
Subject: [PATCH 3/3] Fix gdbserver's regcache_raw_read_unsigned on big endian
hosts
The regcache_raw_read_unsigned function is memcpy'ing a 32-bit value
directly into a 64-bit variable, which doesn't work on big endian
targets.
Fix this by memcpy'ing to a buffer, and then using
extract_unsigned_integer, just like gdb's version.
gdb/gdbserver/ChangeLog:
2016-02-11 Pedro Alves <palves@redhat.com>
* Makefile.in (SFILES): Add $(srcdir)/common/gdb-byteswap.c.
(gdb-byteswap.o): New rule.
* regcache.c: Include "gdb-byteswap.h".
(host_bfd_endian): New function.
(regcache_raw_read_unsigned): Use extract_unsigned_integer and
host_bfd_endian.
---
gdb/gdbserver/Makefile.in | 7 ++++++-
gdb/gdbserver/regcache.c | 31 ++++++++++++++++++++++++-------
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in
index 1e874e3..06a6f1b 100644
--- a/gdb/gdbserver/Makefile.in
+++ b/gdb/gdbserver/Makefile.in
@@ -185,7 +185,8 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/inferiors.c $(srcdir)/dll.c \
$(srcdir)/common/btrace-common.c \
$(srcdir)/common/fileio.c $(srcdir)/nat/linux-namespaces.c \
$(srcdir)/arch/arm.c $(srcdir)/common/common-regcache.c \
- $(srcdir)/arch/arm-linux.c $(srcdir)/arch/arm-get-next-pcs.c
+ $(srcdir)/arch/arm-linux.c $(srcdir)/arch/arm-get-next-pcs.c \
+ $(srcdir)/common/gdb-byteswap.c
DEPFILES = @GDBSERVER_DEPFILES@
@@ -200,6 +201,7 @@ OBS = agent.o ax.o inferiors.o regcache.o remote-utils.o server.o signals.o \
common-utils.o ptid.o buffer.o format.o filestuff.o dll.o notif.o \
tdesc.o print-utils.o rsp-low.o errors.o common-debug.o cleanups.o \
common-exceptions.o symbol.o btrace-common.o fileio.o common-regcache.o \
+ gdb-byteswap.o \
$(XML_BUILTIN) $(DEPFILES) $(LIBOBJS)
GDBREPLAY_OBS = gdbreplay.o version.o
GDBSERVER_LIBS = @GDBSERVER_LIBS@
@@ -590,6 +592,9 @@ fileio.o: ../common/fileio.c
common-regcache.o: ../common/common-regcache.c
$(COMPILE) $<
$(POSTCOMPILE)
+gdb-byteswap.o: ../common/gdb-byteswap.c
+ $(COMPILE) $<
+ $(POSTCOMPILE)
# Arch object files rules form ../arch
diff --git a/gdb/gdbserver/regcache.c b/gdb/gdbserver/regcache.c
index 2af8e24..f875b10 100644
--- a/gdb/gdbserver/regcache.c
+++ b/gdb/gdbserver/regcache.c
@@ -21,6 +21,9 @@
#include "gdbthread.h"
#include "tdesc.h"
#include "rsp-low.h"
+#include "bfd-types.h"
+#include "gdb-byteswap.h"
+
#ifndef IN_PROCESS_AGENT
struct regcache *
@@ -424,14 +427,25 @@ collect_register (struct regcache *regcache, int n, void *buf)
register_size (regcache->tdesc, n));
}
+#ifndef IN_PROCESS_AGENT
+
+/* Return host endianness as an enum bfd_endian. */
+
+static enum bfd_endian
+host_bfd_endian (void)
+{
+ return (__BYTE_ORDER == __LITTLE_ENDIAN
+ ? BFD_ENDIAN_LITTLE
+ : BFD_ENDIAN_BIG);
+}
+
enum register_status
regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
ULONGEST *val)
{
int size;
-
- gdb_assert (regcache != NULL);
- gdb_assert (regnum >= 0 && regnum < regcache->tdesc->num_registers);
+ gdb_byte *buf;
+ enum bfd_endian byteorder;
size = register_size (regcache->tdesc, regnum);
@@ -440,14 +454,17 @@ regcache_raw_read_unsigned (struct regcache *regcache, int regnum,
"%d bytes."),
(int) sizeof (ULONGEST));
- *val = 0;
- collect_register (regcache, regnum, val);
+ buf = (gdb_byte *) alloca (size);
+ collect_register (regcache, regnum, buf);
+
+ /* Assume the inferior's byte order is the same as gdbserver's (the
+ host). */
+ byteorder = host_bfd_endian ();
+ *val = extract_unsigned_integer (buf, size, byteorder);
return REG_VALID;
}
-#ifndef IN_PROCESS_AGENT
-
void
collect_register_as_string (struct regcache *regcache, int n, char *buf)
{
--
1.9.3