[RFC PATCH 5/5] selftests/powerpc: Remove powerpc special cases from stack expansion test

From: Michael Ellerman
Date: Fri Jul 03 2020 - 10:12:50 EST


Now that the powerpc code behaves the same as other architectures we
can drop the special cases we had.

Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
---
.../powerpc/mm/stack_expansion_ldst.c | 41 +++----------------
1 file changed, 5 insertions(+), 36 deletions(-)

diff --git a/tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c b/tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c
index 95c3f3de16a1..ed9143990888 100644
--- a/tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c
+++ b/tools/testing/selftests/powerpc/mm/stack_expansion_ldst.c
@@ -56,13 +56,7 @@ int consume_stack(unsigned long target_sp, unsigned long stack_high, int delta,
#else
asm volatile ("mov %%rsp, %[sp]" : [sp] "=r" (stack_top_sp));
#endif
-
- // Kludge, delta < 0 indicates relative to SP
- if (delta < 0)
- target = stack_top_sp + delta;
- else
- target = stack_high - delta + 1;
-
+ target = stack_high - delta + 1;
volatile char *p = (char *)target;

if (type == STORE)
@@ -162,41 +156,16 @@ static int test_one(unsigned int stack_used, int delta, enum access_type type)

static void test_one_type(enum access_type type, unsigned long page_size, unsigned long rlim_cur)
{
- assert(test_one(DEFAULT_SIZE, 512 * _KB, type) == 0);
+ unsigned long delta;

- // powerpc has a special case to allow up to 1MB
- assert(test_one(DEFAULT_SIZE, 1 * _MB, type) == 0);
-
-#ifdef __powerpc__
- // This fails on powerpc because it's > 1MB and is not a stdu &
- // not close to r1
- assert(test_one(DEFAULT_SIZE, 1 * _MB + 8, type) != 0);
-#else
- assert(test_one(DEFAULT_SIZE, 1 * _MB + 8, type) == 0);
-#endif
-
-#ifdef __powerpc__
- // Accessing way past the stack pointer is not allowed on powerpc
- assert(test_one(DEFAULT_SIZE, rlim_cur, type) != 0);
-#else
// We should be able to access anywhere within the rlimit
+ for (delta = page_size; delta <= rlim_cur; delta += page_size)
+ assert(test_one(DEFAULT_SIZE, delta, type) == 0);
+
assert(test_one(DEFAULT_SIZE, rlim_cur, type) == 0);
-#endif

// But if we go past the rlimit it should fail
assert(test_one(DEFAULT_SIZE, rlim_cur + 1, type) != 0);
-
- // Above 1MB powerpc only allows accesses within 4096 bytes of
- // r1 for accesses that aren't stdu
- assert(test_one(1 * _MB + page_size - 128, -4096, type) == 0);
-#ifdef __powerpc__
- assert(test_one(1 * _MB + page_size - 128, -4097, type) != 0);
-#else
- assert(test_one(1 * _MB + page_size - 128, -4097, type) == 0);
-#endif
-
- // By consuming 2MB of stack we test the stdu case
- assert(test_one(2 * _MB + page_size - 128, -4096, type) == 0);
}

static int test(void)
--
2.25.1