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elf: Properly handle zero DT_RELA/DT_REL values 

With DT_RELR, there may be no relocations in DT_RELA/DT_REL and their
entry values are zero.  Don't relocate DT_RELA/DT_REL and update the
combined relocation start address if their entry values are zero.
This commit is contained in:
H.J. Lu 2022-01-04 05:47:21 -08:00
parent e895cff59a
commit 60196d2ef2
2 changed files with 23 additions and 7 deletions
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6
elf/dynamic-link.h
View File

@ -84,7 +84,9 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
__typeof (((ElfW(Dyn) *) 0)->d_un.d_val) nrelative; int lazy; } \
ranges[2] = { { 0, 0, 0, 0 }, { 0, 0, 0, 0 } }; \
\
if ((map)->l_info[DT_##RELOC]) \
/* With DT_RELR, DT_RELA/DT_REL can have zero value. */ \
if ((map)->l_info[DT_##RELOC] != NULL \
&& (map)->l_info[DT_##RELOC]->d_un.d_ptr != 0) \
{ \
ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \
ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \
@ -98,6 +100,8 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[],
ElfW(Addr) start = D_PTR ((map), l_info[DT_JMPREL]); \
ElfW(Addr) size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \
\
if (ranges[0].start == 0) \
ranges[0].start = start; \
if (ranges[0].start + ranges[0].size == (start + size)) \
ranges[0].size -= size; \
if (!(do_lazy) \

24
elf/get-dynamic-info.h
View File

@ -75,24 +75,36 @@ elf_get_dynamic_info (struct link_map *l, bool bootstrap,
# define ADJUST_DYN_INFO(tag) \
do \
if (info[tag] != NULL) \
info[tag]->d_un.d_ptr += l_addr; \
{ \
if (info[tag] != NULL) \
info[tag]->d_un.d_ptr += l_addr; \
} \
while (0)
ADJUST_DYN_INFO (DT_HASH);
ADJUST_DYN_INFO (DT_PLTGOT);
ADJUST_DYN_INFO (DT_STRTAB);
ADJUST_DYN_INFO (DT_SYMTAB);
ADJUST_DYN_INFO (DT_RELR);
ADJUST_DYN_INFO (DT_JMPREL);
ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM));
ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH));
# undef ADJUST_DYN_INFO
/* DT_RELA/DT_REL are mandatory. But they may have zero value if
there is DT_RELR. Don't relocate them if they are zero. */
# define ADJUST_DYN_INFO(tag) \
do \
if (info[tag] != NULL && info[tag]->d_un.d_ptr != 0) \
info[tag]->d_un.d_ptr += l_addr; \
while (0)
# if ! ELF_MACHINE_NO_RELA
ADJUST_DYN_INFO (DT_RELA);
# endif
# if ! ELF_MACHINE_NO_REL
ADJUST_DYN_INFO (DT_REL);
# endif
ADJUST_DYN_INFO (DT_RELR);
ADJUST_DYN_INFO (DT_JMPREL);
ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM));
ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH));
# undef ADJUST_DYN_INFO
}
if (info[DT_PLTREL] != NULL)