On 17/07/2024 12:10, Dev Jain wrote: > Post my improvement of the test: > https://lore.kernel.org/all/20240522070435.773918-3-dev.jain@xxxxxxx/ > The test begins to fail on 4k and 16k pages, on non-LPA2 systems. To > reduce noise in the CI systems, let us skip the test when higher address > space is not implemented. > > Signed-off-by: Dev Jain <dev.jain@xxxxxxx> > --- > The patch applies on linux-next. > > tools/testing/selftests/mm/va_high_addr_switch.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/mm/va_high_addr_switch.c b/tools/testing/selftests/mm/va_high_addr_switch.c > index fa7eabfaf841..c6040e1d6e53 100644 > --- a/tools/testing/selftests/mm/va_high_addr_switch.c > +++ b/tools/testing/selftests/mm/va_high_addr_switch.c > @@ -293,6 +293,18 @@ static int run_test(struct testcase *test, int count) > return ret; > } > > +/* Check if userspace VA > 48 bits */ > +static int high_address_present(void) > +{ > + void *ptr = mmap((void *)(1UL << 50), 1, PROT_READ | PROT_WRITE, > + MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); I think there is (very unlikely) possibility that something is already mapped at this address so it will be replaced due to MAP_FIXED. That could break the test. But the only way something could be already mapped is if ARM64_FORCE_52BIT is set and in that case, the test will fail anyway, right? So I think this is fine. > + if (ptr == MAP_FAILED) > + return 0; > + > + munmap(ptr, 1); > + return 1; > +} I'm guessing this will cause a function-not-used warning on arches other than arm64? Perhaps wrap it in `#ifdef __aarch64__`? Thanks, Ryan > + > static int supported_arch(void) > { > #if defined(__powerpc64__) > @@ -300,7 +312,7 @@ static int supported_arch(void) > #elif defined(__x86_64__) > return 1; > #elif defined(__aarch64__) > - return 1; > + return high_address_present(); > #else > return 0; > #endif
