diff options
Diffstat (limited to 'src/libdw/memory-access.h')
| -rw-r--r-- | src/libdw/memory-access.h | 215 |
1 files changed, 86 insertions, 129 deletions
diff --git a/src/libdw/memory-access.h b/src/libdw/memory-access.h index b7799e92..a53f7912 100644 --- a/src/libdw/memory-access.h +++ b/src/libdw/memory-access.h @@ -1,52 +1,31 @@ /* Unaligned memory access functionality. - Copyright (C) 2000-2010 Red Hat, Inc. - This file is part of Red Hat elfutils. + Copyright (C) 2000-2014 Red Hat, Inc. + This file is part of elfutils. Written by Ulrich Drepper <drepper@redhat.com>, 2001. - Red Hat elfutils 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; version 2 of the License. + This file is free software; you can redistribute it and/or modify + it under the terms of either - Red Hat elfutils is distributed in the hope that it will be useful, but + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at + your option) any later version + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at + your option) any later version + + or both in parallel, as here. + + 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 Red Hat elfutils; if not, write to the Free Software Foundation, - Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA. - - In addition, as a special exception, Red Hat, Inc. gives You the - additional right to link the code of Red Hat elfutils with code licensed - under any Open Source Initiative certified open source license - (http://www.opensource.org/licenses/index.php) which requires the - distribution of source code with any binary distribution and to - distribute linked combinations of the two. Non-GPL Code permitted under - this exception must only link to the code of Red Hat elfutils through - those well defined interfaces identified in the file named EXCEPTION - found in the source code files (the "Approved Interfaces"). The files - of Non-GPL Code may instantiate templates or use macros or inline - functions from the Approved Interfaces without causing the resulting - work to be covered by the GNU General Public License. Only Red Hat, - Inc. may make changes or additions to the list of Approved Interfaces. - Red Hat's grant of this exception is conditioned upon your not adding - any new exceptions. If you wish to add a new Approved Interface or - exception, please contact Red Hat. You must obey the GNU General Public - License in all respects for all of the Red Hat elfutils code and other - code used in conjunction with Red Hat elfutils except the Non-GPL Code - covered by this exception. If you modify this file, you may extend this - exception to your version of the file, but you are not obligated to do - so. If you do not wish to provide this exception without modification, - you must delete this exception statement from your version and license - this file solely under the GPL without exception. - - Red Hat elfutils is an included package of the Open Invention Network. - An included package of the Open Invention Network is a package for which - Open Invention Network licensees cross-license their patents. No patent - license is granted, either expressly or impliedly, by designation as an - included package. Should you wish to participate in the Open Invention - Network licensing program, please visit www.openinventionnetwork.com - <http://www.openinventionnetwork.com>. */ + You should have received copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see <http://www.gnu.org/licenses/>. */ #ifndef _MEMORY_ACCESS_H #define _MEMORY_ACCESS_H 1 @@ -58,90 +37,76 @@ /* Number decoding macros. See 7.6 Variable Length Data. */ -#define get_uleb128_step(var, addr, nth, break) \ - __b = *(addr)++; \ - var |= (uintmax_t) (__b & 0x7f) << (nth * 7); \ - if (likely ((__b & 0x80) == 0)) \ - break +#define len_leb128(var) ((8 * sizeof (var) + 6) / 7) -#define get_uleb128(var, addr) \ - do { \ - unsigned char __b; \ - var = 0; \ - get_uleb128_step (var, addr, 0, break); \ - var = __libdw_get_uleb128 (var, 1, &(addr)); \ - } while (0) +static inline size_t +__libdw_max_len_leb128 (const unsigned char *addr, const unsigned char *end) +{ + const size_t type_len = len_leb128 (uint64_t); + const size_t pointer_len = likely (addr < end) ? end - addr : 0; + return likely (type_len <= pointer_len) ? type_len : pointer_len; +} -#define get_uleb128_rest_return(var, i, addrp) \ +#define get_uleb128_step(var, addr, nth) \ do { \ - for (; i < 10; ++i) \ - { \ - get_uleb128_step (var, *addrp, i, return var); \ - } \ - /* Other implementations set VALUE to UINT_MAX in this \ - case. So we better do this as well. */ \ - return UINT64_MAX; \ + unsigned char __b = *(addr)++; \ + (var) |= (typeof (var)) (__b & 0x7f) << ((nth) * 7); \ + if (likely ((__b & 0x80) == 0)) \ + return (var); \ } while (0) -/* The signed case is similar, but we sign-extend the result. */ +static inline uint64_t +__libdw_get_uleb128 (const unsigned char **addrp, const unsigned char *end) +{ + uint64_t acc = 0; + + /* Unroll the first step to help the compiler optimize + for the common single-byte case. */ + get_uleb128_step (acc, *addrp, 0); + + const size_t max = __libdw_max_len_leb128 (*addrp - 1, end); + for (size_t i = 1; i < max; ++i) + get_uleb128_step (acc, *addrp, i); + /* Other implementations set VALUE to UINT_MAX in this + case. So we better do this as well. */ + return UINT64_MAX; +} -#define get_sleb128_step(var, addr, nth, break) \ - __b = *(addr)++; \ - _v |= (uint64_t) (__b & 0x7f) << (nth * 7); \ - if (likely ((__b & 0x80) == 0)) \ - { \ - var = (_v << (64 - (nth * 7) - 7)) >> (64 - (nth * 7) - 7); \ - break; \ - } \ - else do {} while (0) +/* Note, addr needs to me smaller than end. */ +#define get_uleb128(var, addr, end) ((var) = __libdw_get_uleb128 (&(addr), end)) -#define get_sleb128(var, addr) \ - do { \ - unsigned char __b; \ - int64_t _v = 0; \ - get_sleb128_step (var, addr, 0, break); \ - var = __libdw_get_sleb128 (_v, 1, &(addr)); \ - } while (0) +/* The signed case is similar, but we sign-extend the result. */ -#define get_sleb128_rest_return(var, i, addrp) \ +#define get_sleb128_step(var, addr, nth) \ do { \ - for (; i < 9; ++i) \ + unsigned char __b = *(addr)++; \ + if (likely ((__b & 0x80) == 0)) \ { \ - get_sleb128_step (var, *addrp, i, return var); \ + struct { signed int i:7; } __s = { .i = __b }; \ + (var) |= (typeof (var)) __s.i * ((typeof (var)) 1 << ((nth) * 7)); \ + return (var); \ } \ - __b = *(*addrp)++; \ - if (likely ((__b & 0x80) == 0)) \ - return var | ((uint64_t) __b << 63); \ - else \ - /* Other implementations set VALUE to INT_MAX in this \ - case. So we better do this as well. */ \ - return INT64_MAX; \ + (var) |= (typeof (var)) (__b & 0x7f) << ((nth) * 7); \ } while (0) -#ifdef IS_LIBDW -extern uint64_t __libdw_get_uleb128 (uint64_t acc, unsigned int i, - const unsigned char **addrp) - internal_function attribute_hidden; -extern int64_t __libdw_get_sleb128 (int64_t acc, unsigned int i, - const unsigned char **addrp) - internal_function attribute_hidden; -#else -static inline uint64_t -__attribute__ ((unused)) -__libdw_get_uleb128 (uint64_t acc, unsigned int i, const unsigned char **addrp) -{ - unsigned char __b; - get_uleb128_rest_return (acc, i, addrp); -} static inline int64_t -__attribute__ ((unused)) -__libdw_get_sleb128 (int64_t acc, unsigned int i, const unsigned char **addrp) +__libdw_get_sleb128 (const unsigned char **addrp, const unsigned char *end) { - unsigned char __b; - int64_t _v = acc; - get_sleb128_rest_return (acc, i, addrp); + int64_t acc = 0; + + /* Unroll the first step to help the compiler optimize + for the common single-byte case. */ + get_sleb128_step (acc, *addrp, 0); + + const size_t max = __libdw_max_len_leb128 (*addrp - 1, end); + for (size_t i = 1; i < max; ++i) + get_sleb128_step (acc, *addrp, i); + /* Other implementations set VALUE to INT_MAX in this + case. So we better do this as well. */ + return INT64_MAX; } -#endif + +#define get_sleb128(var, addr, end) ((var) = __libdw_get_sleb128 (&(addr), end)) /* We use simple memory access functions in case the hardware allows it. @@ -168,6 +133,8 @@ __libdw_get_sleb128 (int64_t acc, unsigned int i, const unsigned char **addrp) ? (int32_t) bswap_32 (*((const int32_t *) (Addr))) \ : *((const int32_t *) (Addr))) +# define read_8ubyte_unaligned_noncvt(Addr) \ + *((const uint64_t *) (Addr)) # define read_8ubyte_unaligned(Dbg, Addr) \ (unlikely ((Dbg)->other_byte_order) \ ? bswap_64 (*((const uint64_t *) (Addr))) \ @@ -244,6 +211,12 @@ read_4sbyte_unaligned_1 (bool other_byte_order, const void *p) } static inline uint64_t +read_8ubyte_unaligned_noncvt (const void *p) +{ + const union unaligned *up = p; + return up->u8; +} +static inline uint64_t read_8ubyte_unaligned_1 (bool other_byte_order, const void *p) { const union unaligned *up = p; @@ -263,17 +236,6 @@ read_8sbyte_unaligned_1 (bool other_byte_order, const void *p) #endif /* allow unaligned */ -#define read_ubyte_unaligned(Nbytes, Dbg, Addr) \ - ((Nbytes) == 2 ? read_2ubyte_unaligned (Dbg, Addr) \ - : (Nbytes) == 4 ? read_4ubyte_unaligned (Dbg, Addr) \ - : read_8ubyte_unaligned (Dbg, Addr)) - -#define read_sbyte_unaligned(Nbytes, Dbg, Addr) \ - ((Nbytes) == 2 ? read_2sbyte_unaligned (Dbg, Addr) \ - : (Nbytes) == 4 ? read_4sbyte_unaligned (Dbg, Addr) \ - : read_8sbyte_unaligned (Dbg, Addr)) - - #define read_2ubyte_unaligned_inc(Dbg, Addr) \ ({ uint16_t t_ = read_2ubyte_unaligned (Dbg, Addr); \ Addr = (__typeof (Addr)) (((uintptr_t) (Addr)) + 2); \ @@ -302,14 +264,9 @@ read_8sbyte_unaligned_1 (bool other_byte_order, const void *p) t_; }) -#define read_ubyte_unaligned_inc(Nbytes, Dbg, Addr) \ - ((Nbytes) == 2 ? read_2ubyte_unaligned_inc (Dbg, Addr) \ - : (Nbytes) == 4 ? read_4ubyte_unaligned_inc (Dbg, Addr) \ - : read_8ubyte_unaligned_inc (Dbg, Addr)) - -#define read_sbyte_unaligned_inc(Nbytes, Dbg, Addr) \ - ((Nbytes) == 2 ? read_2sbyte_unaligned_inc (Dbg, Addr) \ - : (Nbytes) == 4 ? read_4sbyte_unaligned_inc (Dbg, Addr) \ - : read_8sbyte_unaligned_inc (Dbg, Addr)) +#define read_addr_unaligned_inc(Nbytes, Dbg, Addr) \ + (assert ((Nbytes) == 4 || (Nbytes) == 8), \ + ((Nbytes) == 4 ? read_4ubyte_unaligned_inc (Dbg, Addr) \ + : read_8ubyte_unaligned_inc (Dbg, Addr))) #endif /* memory-access.h */ |