General purpose registers in mcontext_t structure
are 8 bytes long for both MIPS32/MIPS64.
get/set/make/swap context implementations for MIPS O32
incorrectly assume that general purpose registers
in this structure are 4 bytes long.
This patch is fixing that.
Tested for MIPS O32 LE and BE.
Compared objdump of modified functions for mips n32 and mips n64.
[BZ #21548]
* sysdeps/unix/sysv/linux/mips/getcontext.S: Define MCONTEXT_SZGREG as
8 and use it when copying general purpose registers.
* sysdeps/unix/sysv/linux/mips/makecontext.S: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/Makefile: Include new test for
mips o32.
* sysdeps/unix/sysv/linux/mips/mips32/bug-getcontext-mips-gp.c: Added
new test for mips o32.
* sysdeps/unix/sysv/linux/mips/setcontext.S: Define MCONTEXT_SZGREG as
8 and use it when copying general purpose registers.
* sysdeps/unix/sysv/linux/mips/swapcontext.S: Likewise.
In makecontext the FDE needs to be terminated before the return
trampoline otherwise backtrace called within a context created by
makecontext yields infinite backtrace.
This bug has been present for a long time, stdlib/tst-makecontext did
not fail until recent commit e535ce25. Tested on mips-linux-gnu and
mips64el-linux-gnuabi64 and mips-linux-gnu, no regression.
This fixes stdlib/tst-makecontext on MIPS.
Changelog:
[BZ #19792]
* sysdeps/unix/sysv/linux/mips/makecontext.S (__makecontext):
Terminate FDE before return label.
I've moved the MIPS port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply
git mv ports/sysdeps/mips sysdeps/mips
git mv ports/sysdeps/unix/mips sysdeps/unix/mips
git mv ports/sysdeps/unix/sysv/linux/mips sysdeps/unix/sysv/linux/mips
and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.mips similar to those in other files.
Tested that disassembly of installed shared libraries for mips is the
same before and after this patch (except for ld.so where paths in
assertions are involved, as for arm).
* sysdeps/mips: Move directory from ports/sysdeps/mips.
* sysdeps/unix/mips: Move directory from ports/sysdeps/unix/mips.
* sysdeps/unix/sysv/linux/mips: Move directory from
ports/sysdeps/unix/sysv/linux/mips.
* README: Update listing for mips-*-linux-gnu and
mips64-*-linux-gnu.
* sysdeps/mips: Move directory to ../sysdeps/mips.
* sysdeps/unix/mips: Move directory to ../sysdeps/unix/mips.
* sysdeps/unix/sysv/linux/mips: Move directory to
../sysdeps/unix/sysv/linux/mips.
