Commit Graph

7 Commits

Author SHA1 Message Date
Florian Weimer
3a0ecccb59 ld.so: Do not export free/calloc/malloc/realloc functions [BZ #25486]
Exporting functions and relying on symbol interposition from libc.so
makes the choice of implementation dependent on DT_NEEDED order, which
is not what some compiler drivers expect.

This commit replaces one magic mechanism (symbol interposition) with
another one (preprocessor-/compiler-based redirection).  This makes
the hand-over from the minimal malloc to the full malloc more
explicit.

Removing the ABI symbols is backwards-compatible because libc.so is
always in scope, and the dynamic loader will find the malloc-related
symbols there since commit f0b2132b35
("ld.so: Support moving versioned symbols between sonames
[BZ #24741]").

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2020-02-15 11:01:23 +01:00
Florian Weimer
2449ae7b2d ld.so: Introduce struct dl_exception
This commit separates allocating and raising exceptions.  This
simplifies catching and re-raising them because it is no longer
necessary to make a temporary, on-stack copy of the exception message.
2017-08-10 16:54:57 +02:00
Florian Weimer
2d6ab5df3b Document and fix --enable-bind-now [BZ #21015] 2017-03-02 14:44:28 +01:00
Florian Weimer
b04beebf07 ld.so: Remove __libc_memalign
It is no longer needed since commit 6c444ad6e9
(elf: Do not use memalign for TCB/TLS blocks allocation [BZ #17730]).
Applications do not link against ld.so and will use the definition in
libc.so, so there is no ABI impact.
2016-11-30 16:23:58 +01:00
Florian Weimer
9e78f6f6e7 Implement _dl_catch_error, _dl_signal_error in libc.so [BZ #16628]
This change moves the main implementation of _dl_catch_error,
_dl_signal_error to libc.so, where TLS variables can be used
directly.  This removes a writable function pointer from the
rtld_global variable.

For use during initial relocation, minimal implementations of these
functions are provided in ld.so.  These are eventually interposed
by the libc.so implementations.  This is implemented by compiling
elf/dl-error-skeleton.c twice, via elf/dl-error.c and
elf/dl-error-minimal.c.

As a side effect of this change, the static version of dl-error.c
no longer includes support for the
_dl_signal_cerror/_dl_receive_error mechanism because it is only
used in ld.so.
2016-11-30 15:59:57 +01:00
H.J. Lu
d3d9c95aef Support PLT and GOT references in local PIC check
Linker in binutils 2.26 and newer generate GOT references instead
PLT references when -z now is passed to linker.  We need to extend
scripts/localplt.awk to allow PLT or GOT references.

	[BZ #19007]
	* scripts/localplt.awk: Also allow GOT references.
	* sysdeps/unix/sysv/linux/i386/localplt.data: Mark
	_Unwind_Find_FDE, calloc, memalign, realloc and __libc_memalign
	with "+ REL R_386_GLOB_DAT".
	* sysdeps/x86_64/localplt.data: Mark calloc, memalign, realloc
	and __libc_memalign with "+ RELA R_X86_64_GLOB_DAT".
2015-10-14 06:00:02 -07:00
H.J. Lu
9637d8a253 Extend local PLT reference check
On x86, linker in binutils 2.26 and newer consolidates R_*_JUMP_SLOT with
R_*_GLOB_DAT relocation against the same symbol.  This patch extends
local PLT reference check to support alternate relocations.

	[BZ #18078]
	* scripts/check-localplt.awk: Support alternate relocations.
	* scripts/localplt.awk: Also check relocations in DT_RELA/DT_REL
	sections.
	* sysdeps/unix/sysv/linux/i386/localplt.data: Mark free and
	malloc entries with + REL R_386_GLOB_DAT.
	* sysdeps/x86_64/localplt.data: New file.
2015-07-29 11:58:06 -07:00