Wean mtrace away from the malloc hooks and move them into the debug
DSO. Split the API away from the implementation so that we can add
the API to libc.so as well as libc_malloc_debug.so, with the libc
implementations being empty.
Update localplt data since memalign no longer has any callers after
this change.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
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>
Given my patch
<https://gcc.gnu.org/ml/gcc-patches/2017-08/msg00965.html> for the
ICEs building a glibc string function test for SH, the testsuite can
build completely for SH with GCC 7 and mainline. However, there is a
test failure that does not appear for GCC 6: check-localplt fails
because of an abort PLT reference in libc.so.
Given the lack of a trap insn pattern for SH, it seems unavoidable
that the compiler might sometimes generate abort calls, and such abort
calls (generated from __builtin_trap when there is no trap insn
pattern) will be unaffected by the normal mapping to __GI_abort for
calls within glibc. Thus, this patch allows (but does not require) an
abort PLT reference in libc.so for SH.
Tested for sh4-linux-gnu with build-many-glibcs.py (GCC 7, with my
patch applied).
* sysdeps/unix/sysv/linux/sh/localplt.data: Allow abort in
libc.so.
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.
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.
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.
This patch adds a localplt.data file for sh so that test passes. The
architecture-specific entries are for _Unwind_Find_FDE, _exit and
__errno_location.
Tested for sh3 and sh4.
* sysdeps/unix/sysv/linux/sh/localplt.data: New file.
Siddhesh Poyarekar
Florian Weimer
Joseph Myers