From 70b439e46effd782097f640c0b64f5f8b0e79913 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Tue, 7 Jul 2026 17:38:27 +0200 Subject: [PATCH] selftests: riscv: Bypass libc in inactive vector ptrace test The ptrace_v_not_enabled test expects the child to reach its ebreak before it has used the vector extension. That is not guaranteed when using fork(), because libc may run child atfork handlers before returning to the test code. In those cases PTRACE_GETREGSET for NT_RISCV_VECTOR then succeeds instead of returning ENODATA for inactive vector state. Use the raw clone syscall with SIGCHLD to keep fork-like semantics while bypassing libc's fork wrapper and atfork handler chain. Cc: Andy Chiu Assisted-by: Claude:claude-sonnet-4-6 Signed-off-by: Andrew Jones Link: https://patch.msgid.link/20260707153827.175245-1-andrew.jones@oss.qualcomm.com Signed-off-by: Paul Walmsley --- tools/testing/selftests/riscv/vector/validate_v_ptrace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/riscv/vector/validate_v_ptrace.c b/tools/testing/selftests/riscv/vector/validate_v_ptrace.c index 74b6f6bcf067..b038e2175c80 100644 --- a/tools/testing/selftests/riscv/vector/validate_v_ptrace.c +++ b/tools/testing/selftests/riscv/vector/validate_v_ptrace.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only #include +#include #include #include #include @@ -25,9 +26,9 @@ TEST(ptrace_v_not_enabled) SKIP(return, "Vector not supported"); chld_lock = 1; - pid = fork(); + pid = (pid_t)syscall(SYS_clone, SIGCHLD, 0, NULL, 0, NULL); ASSERT_LE(0, pid) - TH_LOG("fork: %m"); + TH_LOG("clone: %m"); if (pid == 0) { while (chld_lock == 1)