From: Roland McGrath Date: Mon, 7 Jan 2013 22:53:37 +0000 (-0800) Subject: dwfl_link_map_report: Handle unaligned auxv data. X-Git-Tag: elfutils-0.156~57 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3999ce14663c26bcddc2cf4d4bb9b61c7ad29ac3;p=thirdparty%2Felfutils.git dwfl_link_map_report: Handle unaligned auxv data. Signed-off-by: Roland McGrath --- diff --git a/libdw/ChangeLog b/libdw/ChangeLog index 24f4bb488..3cf303249 100644 --- a/libdw/ChangeLog +++ b/libdw/ChangeLog @@ -1,3 +1,9 @@ +2013-01-07 Roland McGrath + + * memory-access.h + [ALLOW_UNALIGNED] (read_8ubyte_unaligned_noncvt): New macro. + [!ALLOW_UNALIGNED] (read_8ubyte_unaligned_noncvt): New inline function. + 2012-12-18 Mark Wielaard * dwarf_begin_elf.c (valid_p): Call Dwarf_Sig8_Hash_free if invalid. diff --git a/libdw/memory-access.h b/libdw/memory-access.h index 5773e5c9b..16471990d 100644 --- a/libdw/memory-access.h +++ b/libdw/memory-access.h @@ -1,5 +1,5 @@ /* Unaligned memory access functionality. - Copyright (C) 2000-2010 Red Hat, Inc. + Copyright (C) 2000-2013 Red Hat, Inc. This file is part of elfutils. Written by Ulrich Drepper , 2001. @@ -147,6 +147,8 @@ __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))) \ @@ -222,6 +224,12 @@ read_4sbyte_unaligned_1 (bool other_byte_order, const void *p) return up->s4; } +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) { diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index 896ae3900..62973368a 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,9 @@ +2013-01-07 Roland McGrath + + * link_map.c (auxv_format_probe): Handle unaligned 64-bit data, but + still assume the data is at least 32-bit aligned anyway. + (dwfl_link_map_report): Handle unaligned auxv data. + 2012-12-11 Mark Wielaard * linux-kernel-modules.c (report_kernel): Only free fname if diff --git a/libdwfl/link_map.c b/libdwfl/link_map.c index 8543ed6d6..00913fe23 100644 --- a/libdwfl/link_map.c +++ b/libdwfl/link_map.c @@ -1,5 +1,5 @@ /* Report modules by examining dynamic linker data structures. - Copyright (C) 2008-2010 Red Hat, Inc. + Copyright (C) 2008-2013 Red Hat, Inc. This file is part of elfutils. This file is free software; you can redistribute it and/or modify @@ -28,6 +28,7 @@ #include #include "libdwflP.h" +#include "../libdw/memory-access.h" #include #include @@ -66,15 +67,22 @@ auxv_format_probe (const void *auxv, size_t size, inline bool check64 (size_t i) { - if (u->a64[i].a_type == BE64 (PROBE_TYPE) - && u->a64[i].a_un.a_val == BE64 (PROBE_VAL64)) + /* The AUXV pointer might not even be naturally aligned for 64-bit + data, because note payloads in a core file are not aligned. + But we assume the data is 32-bit aligned. */ + + uint64_t type = read_8ubyte_unaligned_noncvt (&u->a64[i].a_type); + uint64_t val = read_8ubyte_unaligned_noncvt (&u->a64[i].a_un.a_val); + + if (type == BE64 (PROBE_TYPE) + && val == BE64 (PROBE_VAL64)) { *elfdata = ELFDATA2MSB; return true; } - if (u->a64[i].a_type == LE64 (PROBE_TYPE) - && u->a64[i].a_un.a_val == LE64 (PROBE_VAL64)) + if (type == LE64 (PROBE_TYPE) + && val == LE64 (PROBE_VAL64)) { *elfdata = ELFDATA2LSB; return true; @@ -618,29 +626,32 @@ dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size, GElf_Xword phent = 0; GElf_Xword phnum = 0; -#define AUXV_SCAN(NN, BL) do \ - { \ - const Elf##NN##_auxv_t *av = auxv; \ - for (size_t i = 0; i < auxv_size / sizeof av[0]; ++i) \ - { \ - Elf##NN##_Addr val = BL##NN (av[i].a_un.a_val); \ - if (av[i].a_type == BL##NN (AT_ENTRY)) \ - entry = val; \ - else if (av[i].a_type == BL##NN (AT_PHDR)) \ - phdr = val; \ - else if (av[i].a_type == BL##NN (AT_PHNUM)) \ - phnum = val; \ - else if (av[i].a_type == BL##NN (AT_PHENT)) \ - phent = val; \ - else if (av[i].a_type == BL##NN (AT_PAGESZ)) \ - { \ - if (val > 1 \ - && (dwfl->segment_align == 0 \ - || val < dwfl->segment_align)) \ - dwfl->segment_align = val; \ - } \ - } \ - } \ +#define READ_AUXV32(ptr) read_4ubyte_unaligned_noncvt (ptr) +#define READ_AUXV64(ptr) read_8ubyte_unaligned_noncvt (ptr) +#define AUXV_SCAN(NN, BL) do \ + { \ + const Elf##NN##_auxv_t *av = auxv; \ + for (size_t i = 0; i < auxv_size / sizeof av[0]; ++i) \ + { \ + uint##NN##_t type = READ_AUXV##NN (&av[i].a_type); \ + uint##NN##_t val = BL##NN (READ_AUXV##NN (&av[i].a_un.a_val)); \ + if (type == BL##NN (AT_ENTRY)) \ + entry = val; \ + else if (type == BL##NN (AT_PHDR)) \ + phdr = val; \ + else if (type == BL##NN (AT_PHNUM)) \ + phnum = val; \ + else if (type == BL##NN (AT_PHENT)) \ + phent = val; \ + else if (type == BL##NN (AT_PAGESZ)) \ + { \ + if (val > 1 \ + && (dwfl->segment_align == 0 \ + || val < dwfl->segment_align)) \ + dwfl->segment_align = val; \ + } \ + } \ + } \ while (0) if (elfclass == ELFCLASS32)