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Revert "Use the dynamic table instead of __rela?_iplt_* to find the linker's IRELATIVE relocs." 

This reverts commit 65bdf655c4.

Reason for revert: checking the failure of avd/avd_boot_test
Bug: 197781964
Change-Id: I70eb03b45cdfbd87ef6edb03b74ad6d1970dc08c
This commit is contained in:
ycheo 2021-08-21 19:29:22 +00:00 committed by Ram Muthiah
parent 65bdf655c4
commit e5570c5dfe
1 changed files with 9 additions and 51 deletions
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60
linker/linker_main.cpp
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@ -39,7 +39,6 @@
#include "linker_globals.h"
#include "linker_phdr.h"
#include "linker_relocate.h"
#include "linker_relocs.h"
#include "linker_tls.h"
#include "linker_utils.h"
@ -597,66 +596,25 @@ static void set_bss_vma_name(soinfo* si) {
}
}
// TODO: There is a similar ifunc resolver calling loop in libc_init_static.cpp, but that version
// uses weak symbols, which don't work in the linker prior to its relocation. This version also
// supports a load bias. When we stop supporting the gold linker in the NDK, then maybe we can use
// non-weak definitions and merge the two loops.
#if defined(USE_RELA)
using RelType = ElfW(Rela);
#else
using RelType = ElfW(Rel);
#endif
extern __LIBC_HIDDEN__ ElfW(Rela) __rela_iplt_start[], __rela_iplt_end[];
extern __LIBC_HIDDEN__ ElfW(Ehdr) __ehdr_start;
static void find_irelative_relocs(RelType **begin, RelType **end) {
// Find the IRELATIVE relocations using the DT_JMPREL and DT_PLTRELSZ dynamic
// tags. In theory this could include more than just IRELATIVE relocations,
// but in practice the linker doesn't dynamically link against any other
// binaries, so we shouldn't expect to see anything else.
auto* ehdr = reinterpret_cast<char*>(&__ehdr_start);
auto* phdr = reinterpret_cast<ElfW(Phdr)*>(ehdr + __ehdr_start.e_phoff);
for (size_t i = 0; i != __ehdr_start.e_phnum; ++i) {
if (phdr[i].p_type != PT_DYNAMIC) {
continue;
}
auto *dyn = reinterpret_cast<ElfW(Dyn)*>(ehdr + phdr[i].p_vaddr);
ElfW(Addr) jmprel = 0, pltrelsz = 0;
for (size_t j = 0, size = phdr[i].p_filesz / sizeof(ElfW(Dyn)); j != size; ++j) {
if (dyn[j].d_tag == DT_JMPREL) {
jmprel = dyn[j].d_un.d_ptr;
} else if (dyn[j].d_tag == DT_PLTRELSZ) {
pltrelsz = dyn[j].d_un.d_ptr;
}
}
if (jmprel && pltrelsz) {
*begin = reinterpret_cast<RelType*>(ehdr + jmprel);
*end = reinterpret_cast<RelType*>(ehdr + jmprel + pltrelsz);
} else {
*begin = *end = nullptr;
}
}
}
#if defined(USE_RELA)
static void call_ifunc_resolvers(ElfW(Addr) load_bias) {
ElfW(Rela)* begin;
ElfW(Rela)* end;
find_irelative_relocs(&begin, &end);
for (ElfW(Rela) *r = begin; r != end; ++r) {
if (ELFW(R_TYPE)(r->r_info) != R_GENERIC_IRELATIVE) {
continue;
}
for (ElfW(Rela) *r = __rela_iplt_start; r != __rela_iplt_end; ++r) {
ElfW(Addr)* offset = reinterpret_cast<ElfW(Addr)*>(r->r_offset + load_bias);
ElfW(Addr) resolver = r->r_addend + load_bias;
*offset = __bionic_call_ifunc_resolver(resolver);
}
}
#else
extern __LIBC_HIDDEN__ ElfW(Rel) __rel_iplt_start[], __rel_iplt_end[];
static void call_ifunc_resolvers(ElfW(Addr) load_bias) {
ElfW(Rel)* begin;
ElfW(Rel)* end;
find_irelative_relocs(&begin, &end);
for (ElfW(Rel) *r = begin; r != end; ++r) {
if (ELFW(R_TYPE)(r->r_info) != R_GENERIC_IRELATIVE) {
continue;
}
for (ElfW(Rel) *r = __rel_iplt_start; r != __rel_iplt_end; ++r) {
ElfW(Addr)* offset = reinterpret_cast<ElfW(Addr)*>(r->r_offset + load_bias);
ElfW(Addr) resolver = *offset + load_bias;
*offset = __bionic_call_ifunc_resolver(resolver);