WSL2-Linux-Kernel/arch/mips/lib
Paul Burton 690d9163bf
MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7
Some versions of GCC suboptimally generate calls to the __multi3()
intrinsic for MIPS64r6 builds, resulting in link failures due to the
missing function:

    LD      vmlinux.o
    MODPOST vmlinux.o
  kernel/bpf/verifier.o: In function `kmalloc_array':
  include/linux/slab.h:631: undefined reference to `__multi3'
  fs/select.o: In function `kmalloc_array':
  include/linux/slab.h:631: undefined reference to `__multi3'
  ...

We already have a workaround for this in which we provide the
instrinsic, but we do so selectively for GCC 7 only. Unfortunately the
issue occurs with older GCC versions too - it has been observed with
both GCC 5.4.0 & GCC 6.4.0.

MIPSr6 support was introduced in GCC 5, so all major GCC versions prior
to GCC 8 are affected and we extend our workaround accordingly to all
MIPS64r6 builds using GCC versions older than GCC 8.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Fixes: ebabcf17bc ("MIPS: Implement __multi3 for GCC7 MIPS64r6 builds")
Patchwork: https://patchwork.linux-mips.org/patch/20297/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # 4.15+
2018-08-21 12:14:11 -07:00
..
Makefile MIPS: Use generic GCC library routines from lib/ 2018-04-23 16:39:37 +01:00
bitops.c
bswapdi.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bswapsi.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
csum_partial.S MIPS: Export csum functions alongside their definitions 2017-01-03 16:34:50 +01:00
delay.c MIPS: Include asm/delay.h for __{,n,u}delay() 2017-08-29 15:21:54 +02:00
dump_tlb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iomap-pci.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iomap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iomap_copy.c MIPS: Add __ioread64_copy 2017-09-04 13:53:14 +02:00
libgcc.h MIPS: Implement __multi3 for GCC7 MIPS64r6 builds 2018-01-11 14:40:31 +01:00
memcpy.S MIPS: R6: Fix PREF instruction usage by memcpy for MIPS R6 2017-06-29 02:42:24 +02:00
memset.S MIPS: memset.S: Add comments to fault fixup handlers 2018-07-24 17:02:43 -07:00
mips-atomic.c
multi3.c MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7 2018-08-21 12:14:11 -07:00
r3k_dump_tlb.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
strncpy_user.S get rid of unused __strncpy_from_user() instances 2017-05-15 23:40:28 -04:00
strnlen_user.S mips: get rid of unused __strnlen_user() 2017-05-15 23:40:32 -04:00
uncached.c