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/*
* Copyright (C) 2015 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#pragma once
#include <string.h>
#include "linker.h"
#include "linker_sleb128.h"
const size_t RELOCATION_GROUPED_BY_INFO_FLAG = 1;
const size_t RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG = 2;
const size_t RELOCATION_GROUPED_BY_ADDEND_FLAG = 4;
const size_t RELOCATION_GROUP_HAS_ADDEND_FLAG = 8;
#if defined(USE_RELA)
typedef ElfW(Rela) rel_t;
#else
typedef ElfW(Rel) rel_t;
#endif
template <typename F>
inline bool for_all_packed_relocs(sleb128_decoder decoder, F&& callback) {
const size_t num_relocs = decoder.pop_front();
rel_t reloc = {
.r_offset = decoder.pop_front(),
};
for (size_t idx = 0; idx < num_relocs; ) {
const size_t group_size = decoder.pop_front();
const size_t group_flags = decoder.pop_front();
size_t group_r_offset_delta = 0;
if (group_flags & RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG) {
group_r_offset_delta = decoder.pop_front();
}
if (group_flags & RELOCATION_GROUPED_BY_INFO_FLAG) {
reloc.r_info = decoder.pop_front();
}
#if defined(USE_RELA)
const size_t group_flags_reloc = group_flags & (RELOCATION_GROUP_HAS_ADDEND_FLAG |
RELOCATION_GROUPED_BY_ADDEND_FLAG);
if (group_flags_reloc == RELOCATION_GROUP_HAS_ADDEND_FLAG) {
// Each relocation has an addend. This is the default situation with lld's current encoder.
} else if (group_flags_reloc == (RELOCATION_GROUP_HAS_ADDEND_FLAG |
RELOCATION_GROUPED_BY_ADDEND_FLAG)) {
reloc.r_addend += decoder.pop_front();
} else {
reloc.r_addend = 0;
}
#else
if (__predict_false(group_flags & RELOCATION_GROUP_HAS_ADDEND_FLAG)) {
// This platform does not support rela, and yet we have it encoded in android_rel section.
async_safe_fatal("unexpected r_addend in android.rel section");
}
#endif
for (size_t i = 0; i < group_size; ++i) {
if (group_flags & RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG) {
reloc.r_offset += group_r_offset_delta;
} else {
reloc.r_offset += decoder.pop_front();
}
if ((group_flags & RELOCATION_GROUPED_BY_INFO_FLAG) == 0) {
reloc.r_info = decoder.pop_front();
}
#if defined(USE_RELA)
if (group_flags_reloc == RELOCATION_GROUP_HAS_ADDEND_FLAG) {
reloc.r_addend += decoder.pop_front();
}
#endif
if (!callback(reloc)) {
return false;
}
}
idx += group_size;
}
return true;
}