Now the ARM port implements pointer encryption for jmpbufs, gdb needs
a SystemTap probe point in longjmp to determine the target PC of
a call to longjmp. This patch implements the probe point in longjmp
and a similar probe point in setjmp.
In order to have all the appropriate registers available to pass to the
probe this reorders the layout of jmpbuf, putting the sp and lr registers
at the start rather than the end, allowing them to be read and
written sequentially.
Tested on armv7, no new failures in the glibc testsuite and confirmed
that this fixes the gdb.base/longjmp.exp failures in the gdb testsuite.
ChangeLog:
2014-02-25 Will Newton <will.newton@linaro.org>
* sysdeps/arm/__longjmp.S: Include stap-probe.h.
(__longjmp): Restore sp and lr before restoring callee
saved registers. Add longjmp and longjmp_target
SystemTap probe point.
* sysdeps/arm/bits/setjmp.h (__jmp_buf): Update comment.
* sysdeps/arm/include/bits/setjmp.h (__JMP_BUF_SP):
Define to zero to match jmpbuf layout.
* sysdeps/arm/setjmp.S: Include stap-probe.h.
(__sigsetjmp): Save sp and lr before saving callee
saved registers. Add setjmp SystemTap probe point.
I've moved the ARM port from ports to the main sysdeps hierarchy.
Beyond the README update, the move of the files was simply
git mv ports/sysdeps/arm sysdeps/arm
git mv ports/sysdeps/unix/arm sysdeps/unix/arm
git mv ports/sysdeps/unix/sysv/linux/arm sysdeps/unix/sysv/linux/arm
and in addition to the ChangeLog entries here, I put a note at the top
of ports/ChangeLog.arm similar to that at the top of
ChangeLog.powerpc. There is deliberately no NEWS change, as I think
it makes the most sense to put in a general note above all ports
having moved if we can achieve that for 2.20.
Tested that disassembly of installed shared libraries for arm is the
same before and after this patch, except for data (not instructions)
in ld.so (there are assertions in sysdeps/arm/dl-machine.h, and the
path by which that file is found, and so by which it appears in the
assertion message, changes as a result of the move).
* sysdeps/arm: Move directory from ports/sysdeps/arm.
* sysdeps/unix/arm: Move directory from ports/sysdeps/unix/arm.
* sysdeps/unix/sysv/linux/arm: Move directory from
ports/sysdeps/unix/sysv/linux/arm.
* README: Update listing for arm-*-linux-gnueabi.
ports/ChangeLog.arm:
* sysdeps/arm: Move directory to ../sysdeps/arm.
* sysdeps/unix/arm: Move directory to ../sysdeps.arm.
* sysdeps/unix/sysv/linux/arm: Move directory to
../sysdeps/unix/sysv/linux/arm.
