Re: hppa vDSO and compiler (non-)support

From: Jiri Slaby
Date: Mon Mar 21 2022 - 03:26:53 EST


On 09. 03. 22, 6:48, Jiri Slaby wrote:
Hi,

On 08. 03. 22, 15:51, Helge Deller wrote:
Hi Jiri,

Thanks for testing on parisc!

On 3/8/22 12:06, Jiri Slaby wrote:
since the "parisc: Add vDSO support" commit, I can no longer cross-build a hppa kernel. I see two issues:

1) CROSS32_COMPILE detection doesn't work here, as openSUSE provides hppa-suse-linux-* binaries. It's easy to overcome by "CROSS32_COMPILE=hppa-suse-linux-"

How is it handled for other platforms like s390x?

s390 simply uses CC for vdso32:
cmd_vdso32cc = $(CC) $(c_flags) -c -o $@ $<

Would it make sense to add the detection for SUSE too?

Maybe.

So, could 1) be fixed on the Kconfig side? Or should I (people running SUSE) use "CROSS32_COMPILE=hppa-suse-linux-"?

2) openSUSE doesn't provide any libc for hppa. So gcc doesn't provide libgcc.a and the build of vDSO fails.

libgcc.a comes with the compiler, I don't think you need libc for that.

I was told glibc is needed to build libgcc.a.

2) was fixed on the compiler (SUSE) side. cross-hppa-gcc12-bootstrap was introduced -- note it's known to be a misnomer -- it should have been like s/-bootstrap/-baremetal/.

thanks,
--
js
suse labs