selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/tools/include/nolibc/compiler.h b/tools/include/nolibc/compiler.h
new file mode 100644
index 000000000..f2d7a81d0
--- /dev/null
+++ b/tools/include/nolibc/compiler.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
+/*
+ * NOLIBC compiler support header
+ * Copyright (C) 2023 Thomas Weißschuh <linux@weissschuh.net>
+ */
+#ifndef _NOLIBC_COMPILER_H
+#define _NOLIBC_COMPILER_H
+
+#if defined(__has_attribute)
+#  define __nolibc_has_attribute(attr) __has_attribute(attr)
+#else
+#  define __nolibc_has_attribute(attr) 0
+#endif
+
+#if defined(__has_feature)
+#  define __nolibc_has_feature(feature) __has_feature(feature)
+#else
+#  define __nolibc_has_feature(feature) 0
+#endif
+
+#define __nolibc_aligned(alignment) __attribute__((aligned(alignment)))
+#define __nolibc_aligned_as(type) __nolibc_aligned(__alignof__(type))
+
+#if __nolibc_has_attribute(naked)
+#  define __nolibc_entrypoint __attribute__((naked))
+#  define __nolibc_entrypoint_epilogue()
+#else
+#  define __nolibc_entrypoint __attribute__((optimize("Os", "omit-frame-pointer")))
+#  define __nolibc_entrypoint_epilogue() __builtin_unreachable()
+#endif /* __nolibc_has_attribute(naked) */
+
+#if defined(__SSP__) || defined(__SSP_STRONG__) || defined(__SSP_ALL__) || defined(__SSP_EXPLICIT__)
+
+#define _NOLIBC_STACKPROTECTOR
+
+#endif /* defined(__SSP__) ... */
+
+#if __nolibc_has_attribute(no_stack_protector)
+#  define __nolibc_no_stack_protector __attribute__((no_stack_protector))
+#else
+#  define __nolibc_no_stack_protector __attribute__((__optimize__("-fno-stack-protector")))
+#endif /* __nolibc_has_attribute(no_stack_protector) */
+
+#if __nolibc_has_attribute(__fallthrough__)
+#  define __nolibc_fallthrough do { } while (0); __attribute__((__fallthrough__))
+#else
+#  define __nolibc_fallthrough do { } while (0)
+#endif /* __nolibc_has_attribute(fallthrough) */
+
+#if defined(__STDC_VERSION__)
+#  define __nolibc_stdc_version __STDC_VERSION__
+#else
+#  define __nolibc_stdc_version 0
+#endif
+
+#define __nolibc_version(_major, _minor, _patch) ((_major) * 10000 + (_minor) * 100 + (_patch))
+
+#ifdef __GNUC__
+#  define __nolibc_gnuc_version \
+		__nolibc_version(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__)
+#else
+#  define __nolibc_gnuc_version 0
+#endif /* __GNUC__ */
+
+#ifdef __clang__
+#  define __nolibc_clang_version \
+		__nolibc_version(__clang_major__, __clang_minor__, __clang_patchlevel__)
+#else
+#  define __nolibc_clang_version 0
+#endif /* __clang__ */
+
+#if __nolibc_stdc_version >= 201112L || \
+	__nolibc_gnuc_version >= __nolibc_version(4, 6, 0) || \
+	__nolibc_clang_version >= __nolibc_version(3, 0, 0)
+#  define __nolibc_static_assert(_t) _Static_assert(_t, "")
+#else
+#  define __nolibc_static_assert(_t)
+#endif
+
+/* Make the optimizer believe the variable can be manipulated arbitrarily. */
+#define _NOLIBC_OPTIMIZER_HIDE_VAR(var)	__asm__ ("" : "+r" (var))
+
+#if __nolibc_has_feature(undefined_behavior_sanitizer)
+#  if defined(__clang__)
+#    define __nolibc_no_sanitize_undefined __attribute__((no_sanitize("function")))
+#  else
+#    define __nolibc_no_sanitize_undefined __attribute__((no_sanitize_undefined))
+#  endif
+#else
+#  define __nolibc_no_sanitize_undefined
+#endif
+
+#endif /* _NOLIBC_COMPILER_H */