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| author | Ilya Leoshkevich <iii@linux.ibm.com> | 2018-08-10 09:07:44 +0200 |
|---|---|---|
| committer | Stefan Liebler <stli@linux.ibm.com> | 2018-08-10 09:07:44 +0200 |
| commit | 71c01af52fdf643abe3946f934693a55887a8ead (patch) | |
| tree | 3ffe528dc1f7a56facab84d857f458f42d208655 /sysdeps/unix/sysv/linux/s390/s390-64 | |
| parent | 8d997d2253e742546db2b27c8ee56edbbe4c906c (diff) | |
| download | glibc-71c01af52fdf643abe3946f934693a55887a8ead.tar.gz | |
S390: Implement 64-bit __fentry__
* Since __fentry__ is almost the same as _mcount, reuse the code by
#including it twice with different #defines around.
* Remove LA usages - they are needed in 31-bit mode to clear the top
bit, but in 64-bit they appear to do nothing.
* Add CFI rule for the nonstandard return register. This rule applies
to the current function (binutils generates a new CIE - see
gas/dw2gencfi.c:select_cie_for_fde()), so it is not necessary to put
__fentry__ into a new file.
* Fix CFI offset for %r14.
* Add CFI rule for %r0.
* Fix unwound value of %r15 being off by 244 bytes.
* Unwinding in __fentry__@plt does not work, no plan to fix it - it
would require asking linker to generate CFI for return address in
%r0. From functional perspective keeping it broken is fine, since
the callee did not have a chance to do anything yet. From
convenience perspective it would be possible to enhance GDB in the
future to treat __fentry__@plt in a special way.
* Fix whitespace.
* Fix offsets in comments, which were copied from 32-bit code.
* 32-bit version will not be implemented, since it's not compatible
with the corresponding PLT stubs: they assume %r12 points to GOT,
which is not the case for gcc-emitted __fentry__ stub, which runs
before the prolog.
This patch adds the runtime support in glibc for the -mfentry
gcc feature introduced in [1] and [2].
[1] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00784.html
[2] https://gcc.gnu.org/ml/gcc-patches/2018-07/msg00912.html
ChangeLog:
* sysdeps/s390/s390-64/Versions (__fentry__): Add.
* sysdeps/s390/s390-64/s390x-mcount.S: Move the common
code to s390x-mcount.h and #include it.
* sysdeps/s390/s390-64/s390x-mcount.h: New file.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist
(__fentry__): Add.
Diffstat (limited to 'sysdeps/unix/sysv/linux/s390/s390-64')
| -rw-r--r-- | sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist index 3b5465558b..04a539ff02 100644 --- a/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist +++ b/sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist @@ -1907,6 +1907,7 @@ GLIBC_2.28 thrd_current F GLIBC_2.28 thrd_equal F GLIBC_2.28 thrd_sleep F GLIBC_2.28 thrd_yield F +GLIBC_2.29 __fentry__ F GLIBC_2.3 __ctype_b_loc F GLIBC_2.3 __ctype_tolower_loc F GLIBC_2.3 __ctype_toupper_loc F |