From be45e63f79ecfea8373f18f50330838d77553a6b Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 8 May 2025 14:26:42 +0100 Subject: [PATCH] kselftest/arm64: tpidr2: Adjust to new clone() behaviour In order to fix an ABI problem, we recently changed the way that a clone() syscall manipulates TPIDR2 and PSTATE.ZA. Historically the child would inherit the parent's TPIDR2 value unless CLONE_SETTLS was set, and now the child will inherit the parent's TPIDR2 value unless CLONE_VM is set. Update the tpidr2 test for the new behaviour. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Daniel Kiss Cc: Marc Zyngier Cc: Mark Brown Cc: Richard Sandiford Cc: Sander De Smalen Cc: Tamas Petz Cc: Will Deacon Cc: Yury Khrustalev Link: https://lore.kernel.org/r/20250508132644.1395904-23-mark.rutland@arm.com Signed-off-by: Will Deacon --- tools/testing/selftests/arm64/abi/tpidr2.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/arm64/abi/tpidr2.c b/tools/testing/selftests/arm64/abi/tpidr2.c index 285c47dd42f63..eb19dcc37a755 100644 --- a/tools/testing/selftests/arm64/abi/tpidr2.c +++ b/tools/testing/selftests/arm64/abi/tpidr2.c @@ -169,8 +169,10 @@ static int sys_clone(unsigned long clone_flags, unsigned long newsp, child_tidptr); } +#define __STACK_SIZE (8 * 1024 * 1024) + /* - * If we clone with CLONE_SETTLS then the value in the parent should + * If we clone with CLONE_VM then the value in the parent should * be unchanged and the child should start with zero and be able to * set its own value. */ @@ -179,11 +181,19 @@ static int write_clone_read(void) int parent_tid, child_tid; pid_t parent, waiting; int ret, status; + void *stack; parent = getpid(); set_tpidr2(parent); - ret = sys_clone(CLONE_SETTLS, 0, &parent_tid, 0, &child_tid); + stack = malloc(__STACK_SIZE); + if (!stack) { + putstr("# malloc() failed\n"); + return 0; + } + + ret = sys_clone(CLONE_VM, (unsigned long)stack + __STACK_SIZE, + &parent_tid, 0, &child_tid); if (ret == -1) { putstr("# clone() failed\n"); putnum(errno); -- 2.39.5