This patch is a reimplementation of [1], which was submitted back in
2015. Copyright issue has been sorted [2] last year. It proposed a new
section (.gnu.xhash) and related dynamic tag (GT_GNU_XHASH). The new
section would be virtually identical to the existing .gnu.hash except
for the translation table (xlat) which would contain correct MIPS
.dynsym indexes corresponding to the hashvals in chains. This is because
MIPS ABI imposes a different ordering of the dynsyms than the one
expected by the .gnu.hash section. Another addition would be a leading
word at the beggining of the section, which would contain the number of
entries in the translation table.
In this patch, the new section name and dynamic tag are changed to
reflect the fact that the section should be treated as MIPS specific
(.MIPS.xhash and DT_MIPS_XHASH).
This patch addresses the alignment issue reported in [3] which is caused
by the leading word of the .MIPS.xhash section. Leading word is now
removed in the corresponding binutils patch, and the number of entries
in the translation table is computed using DT_MIPS_SYMTABNO dynamic tag.
Since the MIPS specific dl-lookup.c file was removed following the
initial patch submission, I opted for the definition of three new macros
in the generic ldsodefs.h. ELF_MACHINE_GNU_HASH_ADDRIDX defines the
index of the dynamic tag in the l_info array. ELF_MACHINE_HASH_SYMIDX is
used to calculate the index of a symbol in GNU hash. On MIPS, it is
defined to look up the symbol index in the translation table.
ELF_MACHINE_XHASH_SETUP is defined for MIPS only. It initializes the
.MIPS.xhash pointer in the link_map_machine struct.
The other major change is bumping the highest EI_ABIVERSION value for
MIPS to suggest that the dynamic linker now supports GNU hash.
The patch was tested by running the glibc testsuite for the three MIPS
ABIs (o32, n32 and n64) and for x86_64-linux-gnu.
[1] https://sourceware.org/ml/binutils/2015-10/msg00057.html
[2] https://sourceware.org/ml/binutils/2018-03/msg00025.html
[3] https://sourceware.org/ml/binutils/2016-01/msg00006.html
* elf/dl-addr.c (determine_info): Calculate the symbol index
using the newly defined ELF_MACHINE_HASH_SYMIDX macro.
* elf/dl-lookup.c (do_lookup_x): Ditto.
(_dl_setup_hash): Initialize MIPS xhash translation table.
* elf/elf.h (SHT_MIPS_XHASH): New define.
(DT_MIPS_XHASH): New define.
* sysdeps/generic/ldsodefs.h (ELF_MACHINE_GNU_HASH_ADDRIDX): New
define.
(ELF_MACHINE_HASH_SYMIDX): Ditto.
(ELF_MACHINE_XHASH_SETUP): Ditto.
* sysdeps/mips/ldsodefs.h (ELF_MACHINE_GNU_HASH_ADDRIDX): New
define.
(ELF_MACHINE_HASH_SYMIDX): Ditto.
(ELF_MACHINE_XHASH_SETUP): Ditto.
* sysdeps/mips/linkmap.h (struct link_map_machine): New member.
* sysdeps/unix/sysv/linux/mips/ldsodefs.h: Increment valid ABI
version.
* sysdeps/unix/sysv/linux/mips/libc-abis: New ABI version.
STO_AARCH64_VARIANT_PCS is a non-visibility st_other flag for marking
symbols that reference functions that may follow a variant PCS with
different register usage convention from the base PCS.
DT_AARCH64_VARIANT_PCS is a dynamic tag that marks ELF modules that
have R_*_JUMP_SLOT relocations for symbols marked with
STO_AARCH64_VARIANT_PCS (i.e. have variant PCS calls via a PLT).
* elf/elf.h (STO_AARCH64_VARIANT_PCS): Define.
(DT_AARCH64_VARIANT_PCS): Define.
This patch adds the new NT_ARM_PACA_KEYS and NT_ARM_PACG_KEYS from
Linux 5.1 to glibc's elf.h.
Tested for x86_64.
* elf/elf.h (NT_ARM_PACA_KEYS): New macro.
(NT_ARM_PACG_KEYS): Likewise.
This patch adds some defines relate to machine flag and section information,
which is used by elfutils elflint check. A C-SKY typo is also fixed with
this patch.
* elf/elf.h (EF_CSKY_ABIMASK, EF_CSKY_OTHER, EF_CSKY_PROCESSOR)
(EF_CSKY_ABIV1, EF_CSKY_ABIV2, SHT_CSKY_ATTRIBUTES): New defines.
This patch adds NT_MIPS_DSP and NT_MIPS_FP_MODE from Linux 4.19 to
elf.h.
Tested for x86_64.
* elf/elf.h (NT_MIPS_DSP): New macro.
(NT_MIPS_FP_MODE): Likewise.
This patch adds two new constants from Linux 4.18 to elf.h,
NT_VMCOREDD and AT_MINSIGSTKSZ.
Tested for x86_64.
* elf/elf.c (NT_VMCOREDD): New macro.
(AT_MINSIGSTKSZ): Likewise.
The BPF ELF format has new relocation types R_BPF_64_64 and R_BPF_64_32.
The existing R_BPF_MAP_FD was an extension that never got implemented.
Remove it, because the constant conflicts with the official R_BPF_64_64.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
As requested in bug 20079, this patch adds SHT_X86_64_UNWIND (a
standard value from the x86_64 ABI) to elf.h.
Tested for x86_64.
[BZ #20079]
* elf/elf.h (SHT_X86_64_UNWIND): New macro.
Linux 4.15 adds NT_S390_RI_CB to linux/elf.h (and NT_ARM_SVE, which we
already have in glibc). This shows up that various other ELF note
values from linux/elf.h are missing from glibc's elf.h.
This patch adds the missing values that are relevant to glibc
architectures. As elf.h is a general description of the ELF format,
not necessarily limited to glibc configurations, there's an argument
for having the remaining NT_* values that Linux uses for non-glibc
architectures in glibc's elf.h as well, but this patch does not add
them.
Adding the NT_PRFPREG name is bug 14890. That bug also requests
making the NT_FPREGSET name obsolete. Given that elf.h is not just
for Linux but can describe ELF for other operating systems, I don't
think that a change of name in the Linux kernel is sufficient
justification for declaring the other name obsolete; there can be
multiple names for the same note value, even with incompatible
semantics, if those reflect variants of the ELF format in actual use.
For example, FreeBSD appears still to have the name NT_FPREGSET
<https://github.com/freebsd/freebsd/blob/master/sys/sys/elf_common.h>
(note: I haven't checked whether the FreeBSD kernel actually generates
such notes or whether this is actually an other-OS definition present
in FreeBSD's header).
[BZ #14890]
* elf/elf.h (NT_PRFPREG): New macro.
(NT_S390_VXRS_LOW): Likewise.
(NT_S390_VXRS_HIGH): Likewise.
(NT_S390_GS_CB): Likewise.
(NT_S390_GS_BC): Likewise.
(NT_S390_RI_CB): Likewise.
The RISC-V port defines ELF flags that enforce compatibility between
various objects. This adds the shared support necessary for these
flags.
2018-01-25 Palmer Dabbelt <palmer@sifive.com>
* elf/cache.c (print_entry): Add FLAG_RISCV_FLOAT_ABI_SOFT and
FLAG_RISCV_FLOAT_ABI_DOUBLE.
* elf/elf.h (EF_RISCV_RVC): New define.
(EF_RISCV_FLOAT_ABI): Likewise.
(EF_RISCV_FLOAT_ABI_SOFT): Likewise.
(EF_RISCV_FLOAT_ABI_SINGLE): Likewise.
(EF_RISCV_FLOAT_ABI_DOUBLE): Likewise.
(EF_RISCV_FLOAT_ABI_QUAD): Likewise.
* sysdeps/generic/ldconfig.h (FLAG_RISCV_FLOAT_ABI_SOFT): New
define.
(FLAG_RISCV_FLOAT_ABI_DOUBLE): Likewise.
This patch synchronizes DF_1_* flags with binutils
and ensures that all DF_1_* flags defined in binutil's
include/elf/common.h are also defined glibc's elf/elf.h.
This is a user visible change since elf/elf.h is installed
by default as /usr/include/elf.h.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
ELFv2 functions with localentry:0 are those with a single entry point,
ie. global entry == local entry, that have no requirement on r2 or
r12 and guarantee r2 is unchanged on return. Such an external
function can be called via the PLT without saving r2 or restoring it
on return, avoiding a common load-hit-store for small functions.
This patch implements the ld.so changes necessary for this
optimization. ld.so needs to check that an optimized plt call
sequence is in fact calling a function implemented with localentry:0,
end emit a fatal error otherwise.
The elf/testobj6.c change is to stop "error while loading shared
libraries: expected localentry:0 `preload'" when running
elf/preloadtest, which we'd get otherwise.
* elf/elf.h (PPC64_OPT_LOCALENTRY): Define.
* sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Add
refsym and sym parameters. Adjust callers.
* sysdeps/aarch64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/hppa/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/m68k/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/microblaze/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/mips/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/nios2/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_fixup_plt):
Likewise.
* sysdeps/s390/s390-32/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/s390/s390-64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sh/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/tile/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.c (_dl_error_localentry): New.
(_dl_reloc_overflow): Increase buffser size. Formatting.
* sysdeps/powerpc/powerpc64/dl-machine.h (ppc64_local_entry_offset):
Delete reloc param, add refsym and sym. Check optimized plt
call stubs for localentry:0 functions. Adjust callers.
(elf_machine_fixup_plt, elf_machine_plt_conflict): Add refsym
and sym parameters. Adjust callers.
(_dl_reloc_overflow): Move attribute.
(_dl_error_localentry): Declare.
* elf/dl-runtime.c (_dl_fixup): Save original sym. Pass
refsym and sym to elf_machine_fixup_plt.
* elf/testobj6.c (preload): Call printf.
Add support to getauxval() for new types to get L1, L2, L3 cache sizes,
cache line sizes, and cache associativities. The new types for
getauxval() were added in the stream for Linux kernel v4.11 in commit
98a5f361b8625c6f4841d6ba013bbf0e80d08147.
* elf/elf.h (AT_L1I_CACHESIZE, AT_L1I_CACHEGEOMETRY, AT_L1D_CACHESIZE,
AT_L1D_CACHEGEOMETRY, AT_L2_CACHESIZE, AT_L2_CACHEGEOMETRY,
AT_L3_CACHESIZE, AT_L3_CACHEGEOMETRY): New. Add auxvec
identifiers from kernel arch/powerpc/include/uapi/asm/auxvec.h.
The EM_BPF number has been officially assigned, though it
has not yet been posted to the gabi webpage yet.
* elf/elf.h (EM_BPF): New.
(EM_NUM): Update.
(R_BPF_NONE, R_BPF_MAP_FD): New.
The following new 386 and X86_64 were added to binutils. They are
non-dynamic relocations, so don't need direct handling in glibc.
But other programs, like elfutils, use the glibc elf.h definitions
for the names and numbers when inspecting ET_REL files.
R_386_GOT32X was proposed in
https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I
X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX were proposed in
https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0
There also used to be R_X86_64_PC32_BND and R_X86_64_PLT32_BND
but those already got deprecated in
https://groups.google.com/d/msg/x86-64-abi/-hdQyMixt8Y/XFDOvioG85cJ
* elf/elf.h (R_386_GOT32X): New.
(R_386_NUM): Update.
(R_X86_64_GOTPCRELX: New.
(R_X86_64_REX_GOTPCRELX): New.
(R_X86_64_NUM): Update.
The following new 386 and X86_64 were added to binutils. They are
non-dynamic relocations, so don't need direct handling in glibc.
But other programs, like elfutils, use the glibc elf.h definitions
for the names and numbers when inspecting ET_REL files.
R_386_GOT32X was proposed in
https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I
X86_64_GOTPCRELX and R_X86_64_REX_GOTPCRELX were proposed in
https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0
There also used to be R_X86_64_PC32_BND and R_X86_64_PLT32_BND
but those already got deprecated in
https://groups.google.com/d/msg/x86-64-abi/-hdQyMixt8Y/XFDOvioG85cJ
* elf/elf.h (R_386_GOT32X): New.
(R_386_NUM): Update.
(R_X86_64_GOTPCRELX: New.
(R_X86_64_REX_GOTPCRELX): New.
(R_X86_64_NUM): Update.
This tag allows debugging of MIPS position independent executables
and provides access to shared library information.
* elf/elf.h (DT_MIPS_RLD_MAP_REL): New macro.
(DT_MIPS_NUM): Update.
* sysdeps/mips/dl-machine.h (ELF_MACHINE_DEBUG_SETUP): Handle
DT_MIPS_RLD_MAP_REL.
Any use of SHF_EXCLUDE in code that tries to check it against sh_flags
will trigger undefined behaviour because it is defined as a 31 bit shift
against an signed integer. Fix by explicitly using an unsigned int.
This patch is glibc support for a PowerPC TLS optimization, inspired
by Alexandre Oliva's TLS optimization for other processors,
http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
In essence, this optimization uses a zero module id in the tls_index
GOT entry to indicate that a TLS variable is allocated space in the
static TLS area. A special plt call linker stub for __tls_get_addr
checks for such a tls_index and if found, returns the offset
immediately. The linker communicates the fact that the special
__tls_get_addr stub is used by setting a bit in the dynamic tag
DT_PPC64_OPT/DT_PPC_OPT. glibc communicates to the linker that this
optimization is available by the presence of __tls_get_addr_opt.
tst-tlsmod2.so is built with -Wl,--no-tls-get-addr-optimize for
tst-tls-dlinfo, which otherwise would fail since it tests that no
static tls is allocated. The ld option --no-tls-get-addr-optimize has
been available since binutils-2.20 so doesn't need a configure test.
* NEWS: Advertise TLS optimization.
* elf/elf.h (R_PPC_TLSGD, R_PPC_TLSLD, DT_PPC_OPT, PPC_OPT_TLS): Define.
(DT_PPC_NUM): Increment.
* elf/dynamic-link.h (HAVE_STATIC_TLS): Define.
(CHECK_STATIC_TLS): Use here.
* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela): Optimize
TLS descriptors.
* sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela): Likewise.
* sysdeps/powerpc/dl-tls.c: New file.
* sysdeps/powerpc/Versions: Add __tls_get_addr_opt.
* sysdeps/powerpc/tst-tlsopt-powerpc.c: New tls test.
* sysdeps/unix/sysv/linux/powerpc/Makefile: Add new test.
Build tst-tlsmod2.so with --no-tls-get-addr-optimize.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist: Update.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist: Likewise.
The latest version of the binutils ELF header defines a new set of
dynamic relocations for ILP32 and renames some to make the naming
more uniform.
ChangeLog:
2014-11-21 Will Newton <will.newton@linaro.org>
Andrew Pinski <andrew.pinski@caviumnetworks.com>
* elf/elf.h (R_AARCH64_P32_ABS32, R_AARCH64_P32_COPY,
R_AARCH64_P32_GLOB_DAT, R_AARCH64_P32_JUMP_SLOT,
R_AARCH64_P32_RELATIVE, R_AARCH64_P32_TLS_DTPMOD,
R_AARCH64_P32_TLS_DTPREL, R_AARCH64_P32_TLS_TPREL,
R_AARCH64_P32_TLSDESC, R_AARCH64_P32_IRELATIVE): Define.
(R_AARCH64_TLS_DTPMOD64): Rename to ..
(R_AARCH64_TLS_DTPMOD): This.
(R_AARCH64_TLS_DTPREL64): Rename to ...
(R_AARCH64_TLS_DTPREL): This.
(R_AARCH64_TLS_TPREL64): Rename to ...
(R_AARCH64_TLS_TPREL): This.
* sysdeps/aarch64/dl-machine.h (elf_machine_type_class): Update
R_AARCH64_TLS_DTPMOD64, R_AARCH64_TLS_DTPREL64, and
R_AARCH64_TLS_TPREL64.
(elf_machine_rela): Likewise.
This is a follow-on to the previous patch to support the ELFv2 ABI in the
dynamic loader, split off into its own patch since it is just an optional
optimization.
In the ELFv2 ABI, most functions define both a global and a local entry
point; the local entry requires r2 to be already set up by the caller
to point to the callee's TOC; while the global entry does not require
the caller to know about the callee's TOC, but it needs to set up r12
to the callee's entry point address.
Now, when setting up a PLT slot, the dynamic linker will usually need
to enter the target function's global entry point. However, if the
linker can prove that the target function is in the same DSO as the
PLT slot itself, and the whole DSO only uses a single TOC (which the
linker will let ld.so know via a DT_PPC64_OPT entry), then it is
possible to actually enter the local entry point address into the
PLT slot, for a slight improvement in performance.
Note that this uncovered a problem on the first call via _dl_runtime_resolve,
because that routine neglected to restore the caller's TOC before calling
the target function for the first time, since it assumed that function
would always reload its own TOC anyway ...
This patch adds support for the ELFv2 ABI feature to remove function
descriptors. See this GCC patch for in-depth discussion:
http://gcc.gnu.org/ml/gcc-patches/2013-11/msg01141.html
This mostly involves two types of changes: updating assembler source
files to the new logic, and updating the dynamic loader.
After the refactoring in the previous patch, most of the assembler source
changes can be handled simply by providing ELFv2 versions of the
macros in sysdep.h. One somewhat non-obvious change is in __GI__setjmp:
this used to "fall through" to the immediately following __setjmp ENTRY
point. This is no longer safe in the ELFv2 since ENTRY defines both
a global and a local entry point, and you cannot simply fall through
to a global entry point as it requires r12 to be set up.
Also, makecontext needs to be updated to set up registers according to
the new ABI for calling into the context's start routine.
The dynamic linker changes mostly consist of removing special code
to handle function descriptors. We also need to support the new PLT
and glink format used by the the ELFv2 linker, see:
https://sourceware.org/ml/binutils/2013-10/msg00376.html
In addition, the dynamic linker now verifies that the dynamic libraries
it loads match its own ABI.
The hack in VDSO_IFUNC_RET to "synthesize" a function descriptor
for vDSO routines is also no longer necessary for ELFv2.
This patch updates glibc in accordance with the binutils patch checked in here:
https://sourceware.org/ml/binutils/2013-10/msg00372.html
This changes the various R_PPC64_..._HI and _HA relocations to report
32-bit overflows. The motivation is that existing uses of @h / @ha
are to build up 32-bit offsets (for the "medium model" TOC access
that GCC now defaults to), and we'd really like to see failures at
link / load time rather than silent truncations.
For those rare cases where a modifier is needed to build up a 64-bit
constant, new relocations _HIGH / _HIGHA are supported.
The patch also fixes a bug in overflow checking for the R_PPC64_ADDR30
and R_PPC64_ADDR32 relocations.
