diff options
author | Christophe Lyon <christophe.lyon@st.com> | 2013-01-18 15:08:04 +0100 |
---|---|---|
committer | Waldemar Brodkorb <wbrodkorb@conet.de> | 2018-08-10 16:01:58 +0200 |
commit | 5ec586eb37f61e57f19ac60b58af61f167ca054a (patch) | |
tree | 6c72d03d43e76a33eb5d6360d9bdb2573a048c42 /ldso/ldso/arm/dl-sysdep.h | |
parent | f88bb681ba22d77a19abfb4c1617c826298ed473 (diff) |
rtld: Add FDPIC code for arm
Add FDPIC dynamic relocations support, similar to what other FDPIC
targets do.
Lazy binding is implemented in a folllow-up patch.
Disable the SEND* macros because they involve relocations to
access constant strings that are unsupported by the existing
arm version.
Define DL_START, START, ARCH_NEEDS_BOOTSTRAP_RELOCS,
DL_CHECK_LIB_TYPE similarly to what other FDPIC targets do.
Define raise() because _dl_find_hash references __aeabi_uidivmod,
which uses __aeabi_idiv0 which in turn references raise.
* include/elf.h (R_ARM_FUNCDESC): Define.
(R_ARM_FUNCDESC_VALUE): Define.
* ldso/include/dl-string.h (SEND_STDERR, SEND_ADDRESS_STDERR)
(SEND_NUMBER_STDERR): Define empty for __FDPIC__.
* ldso/ldso/arm/dl-inlines.h: New file.
* ldso/ldso/arm/dl-startup.h (PERFORM_BOOTSTRAP_RELOC): Fix type
of load_addr. Fix handling of R_ARM_RELATIVE, add support for
R_ARM_FUNCDESC_VALUE.
(DL_START, START): Define for __FDPIC__.
(raise): Define.
* ldso/ldso/arm/dl-sysdep.h (ARCH_NEEDS_BOOTSTRAP_RELOCS): Define.
(DL_CHECK_LIB_TYPE): Define.
(elf_machine_type_class): Take into account FDPIC related
relocations.
(elf_machine_load_address): Support __FDPIC__.
(elf_machine_relative): Likewise.
* ldso/ldso/arm/elfinterp.c (_dl_linux_resolver): Dummy support
for __FDPIC__, implemented in a later patch.
(_dl_do_reloc): Fix reloc_adr computation for __FDPIC__, fix
handling of local symbols. Fix handling of R_ARM_RELATIVE, add
support for R_ARM_FUNCDESC_VALUE, R_ARM_FUNCDESC.
* ldso/ldso/arm/resolve.S: Make _dl_linux_resolve hidden.
* ldso/ldso/fdpic/dl-inlines.h (htab_delete): Declare.
* libc/sysdeps/linux/arm/bits/elf-fdpic.h: New file, similar to bfin's.
* libc/sysdeps/linux/arm/crtreloc.c: Likewise.
* libc/sysdeps/linux/arm/find_exidx.c (__dl_addr_in_loadaddr) Define.
(find_exidx_callback): Support __FDPIC__.
Signed-off-by: Mickaël Guêné <mickael.guene@st.com>
Signed-off-by: Christophe Lyon <christophe.lyon@st.com>
Diffstat (limited to 'ldso/ldso/arm/dl-sysdep.h')
-rw-r--r-- | ldso/ldso/arm/dl-sysdep.h | 67 |
1 files changed, 61 insertions, 6 deletions
diff --git a/ldso/ldso/arm/dl-sysdep.h b/ldso/ldso/arm/dl-sysdep.h index a47a55213..0f783e1c4 100644 --- a/ldso/ldso/arm/dl-sysdep.h +++ b/ldso/ldso/arm/dl-sysdep.h @@ -10,6 +10,19 @@ /* Define this if the system uses RELOCA. */ #undef ELF_USES_RELOCA #include <elf.h> + +#ifdef __FDPIC__ +/* Need bootstrap relocations */ +#define ARCH_NEEDS_BOOTSTRAP_RELOCS + +#define DL_CHECK_LIB_TYPE(epnt, piclib, _dl_progname, libname) \ +do \ +{ \ + (piclib) = 2; \ +} \ +while (0) +#endif /* __FDPIC__ */ + /* Initialization sequence for the GOT. */ #define INIT_GOT(GOT_BASE,MODULE) \ { \ @@ -63,11 +76,25 @@ unsigned long _dl_linux_resolver(struct elf_resolve * tpnt, int reloc_entry); ELF_RTYPE_CLASS_NOCOPY iff TYPE should not be allowed to resolve to one of the main executable's symbols, as for a COPY reloc. */ + +#ifdef __FDPIC__ +/* Avoid R_ARM_ABS32 to go through the PLT so that R_ARM_TARGET1 + translated to R_ARM_ABS32 doesn't use the PLT: otherwise, this + breaks init_array because functions are referenced through the + PLT. */ +#define elf_machine_type_class(type) \ + ((((type) == R_ARM_JUMP_SLOT || (type) == R_ARM_TLS_DTPMOD32 \ + || (type) == R_ARM_FUNCDESC_VALUE || (type) == R_ARM_FUNCDESC || (type) == R_ARM_ABS32 \ + || (type) == R_ARM_TLS_DTPOFF32 || (type) == R_ARM_TLS_TPOFF32) \ + * ELF_RTYPE_CLASS_PLT) \ + | (((type) == R_ARM_COPY) * ELF_RTYPE_CLASS_COPY)) +#else #define elf_machine_type_class(type) \ ((((type) == R_ARM_JUMP_SLOT || (type) == R_ARM_TLS_DTPMOD32 \ || (type) == R_ARM_TLS_DTPOFF32 || (type) == R_ARM_TLS_TPOFF32) \ * ELF_RTYPE_CLASS_PLT) \ | (((type) == R_ARM_COPY) * ELF_RTYPE_CLASS_COPY)) +#endif /* __FDPIC__ */ /* Return the link-time address of _DYNAMIC. Conveniently, this is the first element of the GOT. We used to use the PIC register to do this @@ -106,10 +133,24 @@ elf_machine_dynamic (void) extern char __dl_start[] __asm__("_dl_start"); +#ifdef __FDPIC__ +/* We must force strings used early in the bootstrap into the data + segment. */ +#undef SEND_EARLY_STDERR +#define SEND_EARLY_STDERR(S) \ + do { /* FIXME: implement */; } while (0) + +#undef INIT_GOT +#include "../fdpic/dl-sysdep.h" +#endif /* __FDPIC__ */ + /* Return the run-time load address of the shared object. */ static __always_inline Elf32_Addr __attribute__ ((unused)) elf_machine_load_address (void) { +#if defined(__FDPIC__) + return 0; +#else Elf32_Addr got_addr = (Elf32_Addr) &__dl_start; Elf32_Addr pcrel_addr; #if defined __OPTIMIZE__ && !defined __thumb__ @@ -128,19 +169,33 @@ elf_machine_load_address (void) : "=r" (pcrel_addr), "=r" (tmp)); #endif return pcrel_addr - got_addr; +#endif } static __always_inline void +#ifdef __FDPIC__ +elf_machine_relative (DL_LOADADDR_TYPE load_off, const Elf32_Addr rel_addr, +#else elf_machine_relative (Elf32_Addr load_off, const Elf32_Addr rel_addr, +#endif Elf32_Word relative_count) { - Elf32_Rel * rpnt = (void *) rel_addr; - --rpnt; - do { - Elf32_Addr *const reloc_addr = (void *) (load_off + (++rpnt)->r_offset); +#if defined(__FDPIC__) + Elf32_Rel *rpnt = (void *) rel_addr; + + do { + unsigned long *reloc_addr = (unsigned long *) DL_RELOC_ADDR(load_off, rpnt->r_offset); - *reloc_addr += load_off; - } while (--relative_count); + *reloc_addr = DL_RELOC_ADDR(load_off, *reloc_addr); + rpnt++; +#else + Elf32_Rel * rpnt = (void *) rel_addr; + --rpnt; + do { + Elf32_Addr *const reloc_addr = (void *) (load_off + (++rpnt)->r_offset); + *reloc_addr += load_off; +#endif + } while(--relative_count); } #endif /* !_ARCH_DL_SYSDEP */ |