On 5.11.18 г. 23:42 ч., Rosen Penev wrote: > On Mon, Nov 5, 2018 at 1:31 PM Nikolay Borisov <nborisov@xxxxxxxx> wrote: >> >> >> >> On 5.11.18 г. 21:06 ч., Rosen Penev wrote: >>> Replaced bswap with _ variants. While it's a glibc extension, all of the >>> popular libc implementations (glibc, uClibc, musl, BIONIC) seem to support >>> it. >>> >>> Added static inline to two functions to match little endian variants. This >>> fixes a linking error experienced when compiling. >> >> On what platform did you experience the linking error? > MIPS 24kc. OpenWrt specifically. Here's a link with the compile log > (near the end): > https://circleci.com/gh/openwrt/packages/77?utm_campaign=workflow-failed&utm_medium=email&utm_source=notification > > The LTO errors I believe are due to GCC 7.3.0 being broken (fixed in 7.3.1). > > This patch fixes both issues. I'm still unsure why bswap32 is not > being included but the _ variant works. >> >>> >>> Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx> (Some explanation below but the patch is ok) Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx> >>> --- >>> kernel-lib/bitops.h | 8 ++++---- >>> 1 file changed, 4 insertions(+), 4 deletions(-) >>> >>> diff --git a/kernel-lib/bitops.h b/kernel-lib/bitops.h >>> index b1fd6f5..2c51a26 100644 >>> --- a/kernel-lib/bitops.h >>> +++ b/kernel-lib/bitops.h >>> @@ -178,9 +178,9 @@ static inline unsigned long find_next_zero_bit(const unsigned long *addr, >>> static inline unsigned long ext2_swab(const unsigned long y) >>> { >>> #if BITS_PER_LONG == 64 >>> - return (unsigned long) bswap64((u64) y); >>> + return (unsigned long) bswap_64((u64) y); >>> #elif BITS_PER_LONG == 32 >>> - return (unsigned long) bswap32((u32) y); >>> + return (unsigned long) bswap_32((u32) y); Alternatively those bswaps* could be replaced by __builtin_bswap32/64 which come directly from the compiler. Looking at: https://git.musl-libc.org/cgit/musl/tree/include/byteswap.h It seems musl only defines bswap_* variants. glibc also seems to define only _ variants as per: https://sourceware.org/git/?p=glibc.git;a=blob;f=string/byteswap.h;h=a45b3e20ed5d0849bc3939b80272bd3d6d43dc31;hb=HEAD And indeed http://man7.org/linux/man-pages/man3/bswap.3.html documents the functions as having _ suffix so this was a mistake on my part. Your solution is correct (and now I have no explanation where did bswap64 definition come from so that it didn't fail for me). >>> #else >>> #error BITS_PER_LONG not defined >>> #endif >>> @@ -218,14 +218,14 @@ static inline unsigned long _find_next_bit_le(const unsigned long *addr1, >>> return min(start + __ffs(ext2_swab(tmp)), nbits); >>> } >>> >>> -unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, >>> +static inline unsigned long find_next_zero_bit_le(const void *addr, unsigned long size, >>> unsigned long offset) >>> { >>> return _find_next_bit_le(addr, NULL, size, offset, ~0UL); >>> } >>> >>> >>> -unsigned long find_next_bit_le(const void *addr, unsigned long size, >>> +static inline unsigned long find_next_bit_le(const void *addr, unsigned long size, >>> unsigned long offset) >>> { >>> return _find_next_bit_le(addr, NULL, size, offset, 0UL); >>> >
