On Tue, Apr 20, 2021 at 10:12:10PM +0100, Sudip Mukherjee wrote: > From: Romain Naour <romain.naour@xxxxxxxxx> > > >From [1] > "GCC 10 (PR 91233) won't silently allow registers that are not > architecturally available to be present in the clobber list anymore, > resulting in build failure for mips*r6 targets in form of: > ... > .../sysdep.h:146:2: error: the register ‘lo’ cannot be clobbered in ‘asm’ for the current target > 146 | __asm__ volatile ( \ > | ^~~~~~~ > > This is because base R6 ISA doesn't define hi and lo registers w/o DSP > extension. This patch provides the alternative clobber list for r6 targets > that won't include those registers." > > Since kernel 5.4 and mips support for generic vDSO [2], the kernel fail to > build for mips r6 cpus with gcc 10 for the same reason as glibc. > > [1] https://sourceware.org/git/?p=glibc.git;a=commit;h=020b2a97bb15f807c0482f0faee2184ed05bcad8 > [2] '24640f233b46 ("mips: Add support for generic vDSO")' > > Signed-off-by: Romain Naour <romain.naour@xxxxxxxxx> > Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> > --- > > v4: [sudip] added macro VDSO_SYSCALL_CLOBBERS and fix checkpatch errors with commit message. > v3 Avoid duplicate code (Maciej W. Rozycki) > v2 use MIPS_ISA_REV instead of __mips_isa_rev (Alexander Lobakin) > > I have reused the original patch by Romain and have retained his s-o-b > and author name as he is the original author of this patch. I have just > added the macro. Build tested with gcc-10.3.1 and gcc-9.3.0. > > arch/mips/include/asm/vdso/gettimeofday.h | 26 ++++++++++++++++++----- > 1 file changed, 21 insertions(+), 5 deletions(-) applied to mips-next. Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]
