On 17/07/2024 13:11, Dev Jain wrote:
On 7/17/24 17:27, Ryan Roberts wrote:
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@arm.com/ 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@arm.com
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.
The testcases already assume that high addresses must be empty. Yes, FORCE_52BIT is the only way something could already be mapped at high addresses, but in that case the test fails trivially.
agreed.
+ 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__`?
Ah yes, I just checked and that is true. I shall post v2 in some time, shall wait if any more comments are there.
With this fixup:
Reviewed-by: Ryan Roberts ryan.roberts@arm.com
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