From: Romain Naour romain.naour@gmail.com
commit 1d7ba0165d8206ac073f7ac3b14fc0836b66eae7 upstream.
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%3Ba=commit%3Bh=020b2a97bb15f807c0482... [2] '24640f233b46 ("mips: Add support for generic vDSO")'
Signed-off-by: Romain Naour romain.naour@gmail.com Signed-off-by: Sudip Mukherjee sudipm.mukherjee@gmail.com Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/mips/include/asm/vdso/gettimeofday.h | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-)
--- a/arch/mips/include/asm/vdso/gettimeofday.h +++ b/arch/mips/include/asm/vdso/gettimeofday.h @@ -20,6 +20,12 @@
#define VDSO_HAS_CLOCK_GETRES 1
+#if MIPS_ISA_REV < 6 +#define VDSO_SYSCALL_CLOBBERS "hi", "lo", +#else +#define VDSO_SYSCALL_CLOBBERS +#endif + static __always_inline long gettimeofday_fallback( struct __kernel_old_timeval *_tv, struct timezone *_tz) @@ -35,7 +41,9 @@ static __always_inline long gettimeofday : "=r" (ret), "=r" (error) : "r" (tv), "r" (tz), "r" (nr) : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + "$14", "$15", "$24", "$25", + VDSO_SYSCALL_CLOBBERS + "memory");
return error ? -ret : ret; } @@ -59,7 +67,9 @@ static __always_inline long clock_gettim : "=r" (ret), "=r" (error) : "r" (clkid), "r" (ts), "r" (nr) : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + "$14", "$15", "$24", "$25", + VDSO_SYSCALL_CLOBBERS + "memory");
return error ? -ret : ret; } @@ -83,7 +93,9 @@ static __always_inline int clock_getres_ : "=r" (ret), "=r" (error) : "r" (clkid), "r" (ts), "r" (nr) : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + "$14", "$15", "$24", "$25", + VDSO_SYSCALL_CLOBBERS + "memory");
return error ? -ret : ret; } @@ -105,7 +117,9 @@ static __always_inline long clock_gettim : "=r" (ret), "=r" (error) : "r" (clkid), "r" (ts), "r" (nr) : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + "$14", "$15", "$24", "$25", + VDSO_SYSCALL_CLOBBERS + "memory");
return error ? -ret : ret; } @@ -125,7 +139,9 @@ static __always_inline int clock_getres3 : "=r" (ret), "=r" (error) : "r" (clkid), "r" (ts), "r" (nr) : "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13", - "$14", "$15", "$24", "$25", "hi", "lo", "memory"); + "$14", "$15", "$24", "$25", + VDSO_SYSCALL_CLOBBERS + "memory");
return error ? -ret : ret; }