Reviewed-by: Alistair Popple <apopple@xxxxxxxxxx> On Wednesday, 19 January 2022 9:15:31 PM AEDT Muhammad Usama Anjum wrote: > The defination of swap() is used from kernel's internal header when this > test is built in source tree. The build fails when this test is built > out of source tree as defination of swap() isn't found. Selftests > shouldn't depend on kernel's internal header files. They can only depend > on uapi header files. Add the defination of swap() to fix the build > error: > > gcc -Wall -I/linux_mainline2/build/usr/include -no-pie userfaultfd.c -lrt -lpthread -o /linux_mainline2/build/kselftest/vm/userfaultfd > userfaultfd.c: In function â??userfaultfd_stressâ??: > userfaultfd.c:1530:3: warning: implicit declaration of function â??swapâ??; did you mean â??swabâ??? [-Wimplicit-function-declaration] > 1530 | swap(area_src, area_dst); > | ^~~~ > | swab > /usr/bin/ld: /tmp/cclUUH7V.o: in function `userfaultfd_stress': > userfaultfd.c:(.text+0x4d64): undefined reference to `swap' > /usr/bin/ld: userfaultfd.c:(.text+0x4d82): undefined reference to `swap' > collect2: error: ld returned 1 exit status > > Fixes: 2c769ed7137a ("tools/testing/selftests/vm/userfaultfd.c: use swap() to make code cleaner") > Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx> > --- > tools/testing/selftests/vm/userfaultfd.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c > index d3fd24f9fae8..d2480ab93037 100644 > --- a/tools/testing/selftests/vm/userfaultfd.c > +++ b/tools/testing/selftests/vm/userfaultfd.c > @@ -119,6 +119,9 @@ struct uffd_stats { > ~(unsigned long)(sizeof(unsigned long long) \ > - 1))) > > +#define swap(a, b) \ > + do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) > + > const char *examples = > "# Run anonymous memory test on 100MiB region with 99999 bounces:\n" > "./userfaultfd anon 100 99999\n\n" >