> -----Original Message----- > From: owner-linux-mm@xxxxxxxxx [mailto:owner-linux-mm@xxxxxxxxx] On > Behalf Of Andrew Morton > Sent: Friday, August 21, 2020 8:55 AM > To: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> > Cc: Linux-Next Mailing List <linux-next@xxxxxxxxxxxxxxx>; open list > <linux-kernel@xxxxxxxxxxxxxxx>; linux-mm <linux-mm@xxxxxxxxx>; > lkft-triage@xxxxxxxxxxxxxxxx; Linuxarm <linuxarm@xxxxxxxxxx>; Song Bao Hua > (Barry Song) <song.bao.hua@xxxxxxxxxxxxx>; John Hubbard > <jhubbard@xxxxxxxxxx>; Jan Kara <jack@xxxxxxx>; Jérôme Glisse > <jglisse@xxxxxxxxxx>; Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>; Al > Viro <viro@xxxxxxxxxxxxxxxxxx>; Christoph Hellwig <hch@xxxxxxxxxxxxx>; Dan > Williams <dan.j.williams@xxxxxxxxx>; Dave Chinner <david@xxxxxxxxxxxxx>; > Jason Gunthorpe <jgg@xxxxxxxx>; Jonathan Corbet <corbet@xxxxxxx>; Michal > Hocko <mhocko@xxxxxxxx>; Mike Kravetz <mike.kravetz@xxxxxxxxxx>; > Shuah Khan <shuah@xxxxxxxxxx>; Vlastimil Babka <vbabka@xxxxxxx> > Subject: Re: mm/gup.c:1922:7: error: implicit declaration of function > ‘is_valid_gup_flags’ > > On Thu, 20 Aug 2020 14:59:52 +0530 Naresh Kamboju > <naresh.kamboju@xxxxxxxxxx> wrote: > > > arm and riscv architecture build failed on linux next 20200820 tag. > > > > make -sk KBUILD_BUILD_USER=TuxBuild -C/linux -j16 ARCH=arm > > CROSS_COMPILE=arm-linux-gnueabihf- HOSTCC=gcc CC="sccache > > arm-linux-gnueabihf-gcc" O=build zImage > > > > 348# > > 349../mm/gup.c: In function ‘get_user_pages’: > > 350../mm/gup.c:1922:7: error: implicit declaration of function > > ‘is_valid_gup_flags’ [-Werror=implicit-function-declaration] > > 351 1922 | if (!is_valid_gup_flags(gup_flags)) > > 352 | ^~~~~~~~~~~~~~~~~~ > > 353cc1: some warnings being treated as errors > > > > Yes, thanks. > > From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Subject: > mm-gup-dont-permit-users-to-call-get_user_pages-with-foll_longterm-fix > > fix CONFIG_MMU=n build > > Link: > https://lkml.kernel.org/r/CA+G9fYuNS3k0DVT62twfV746pfNhCSrk5sVMcOcQ1 > PGGnEseyw@xxxxxxxxxxxxxx > Reported-by: Naresh Kamboju <naresh.kamboju@xxxxxxxxxx> > Cc: Barry Song <song.bao.hua@xxxxxxxxxxxxx> > Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Andrew, Thanks for taking care of this build issue. Acked-by: Barry Song <song.bao.hua@xxxxxxxxxxxxx> > --- > > mm/gup.c | 38 +++++++++++++++++++------------------- > 1 file changed, 19 insertions(+), 19 deletions(-) > > --- > a/mm/gup.c~mm-gup-dont-permit-users-to-call-get_user_pages-with-foll_long > term-fix > +++ a/mm/gup.c > @@ -1759,6 +1759,25 @@ static __always_inline long __gup_longte } > #endif /* CONFIG_FS_DAX || CONFIG_CMA */ > > +static bool is_valid_gup_flags(unsigned int gup_flags) { > + /* > + * FOLL_PIN must only be set internally by the pin_user_pages*() APIs, > + * never directly by the caller, so enforce that with an assertion: > + */ > + if (WARN_ON_ONCE(gup_flags & FOLL_PIN)) > + return false; > + /* > + * FOLL_PIN is a prerequisite to FOLL_LONGTERM. Another way of saying > + * that is, FOLL_LONGTERM is a specific case, more restrictive case of > + * FOLL_PIN. > + */ > + if (WARN_ON_ONCE(gup_flags & FOLL_LONGTERM)) > + return false; > + > + return true; > +} > + > #ifdef CONFIG_MMU > static long __get_user_pages_remote(struct mm_struct *mm, > unsigned long start, unsigned long nr_pages, @@ > -1789,25 +1808,6 @@ static long __get_user_pages_remote(stru > gup_flags | FOLL_TOUCH | FOLL_REMOTE); } > > -static bool is_valid_gup_flags(unsigned int gup_flags) -{ > - /* > - * FOLL_PIN must only be set internally by the pin_user_pages*() APIs, > - * never directly by the caller, so enforce that with an assertion: > - */ > - if (WARN_ON_ONCE(gup_flags & FOLL_PIN)) > - return false; > - /* > - * FOLL_PIN is a prerequisite to FOLL_LONGTERM. Another way of saying > - * that is, FOLL_LONGTERM is a specific case, more restrictive case of > - * FOLL_PIN. > - */ > - if (WARN_ON_ONCE(gup_flags & FOLL_LONGTERM)) > - return false; > - > - return true; > -} > - > /** > * get_user_pages_remote() - pin user pages in memory > * @mm: mm_struct of target mm > _ > Best Regards Barry
