Hi Sven and Heiko,
Apologies if this has been reported/fixed already, I checked the s390
tree but I did not see any changes there nor did I find anything when
searching lore. After commit 1256e70a082a ("s390/ftrace: enable
HAVE_FUNCTION_GRAPH_RETVAL") in -next, I see the following errors when
building Debian's configuration [1], which selects CONFIG_MARCH_Z10=y.
GCC/binutils:
arch/s390/kernel/mcount.S: Assembler messages:
arch/s390/kernel/mcount.S:140: Error: Unrecognized opcode: `aghik'
clang:
arch/s390/kernel/mcount.S:140:2: error: instruction requires: distinct-ops
aghik %r3,%r15,160
^
It seems like there is already some handling for this situation in
mcount.S but my knowledge of s390 assembly is basically non-existent,
hence this report in lieu of a patch. I am more than happy to provide
any additional information or test any patches if necessary.
[1]: https://salsa.debian.org/kernel-team/linux/-/blob/master/debian/config/s390x/config
Cheers,
Nathan
