From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- lib/kunit/bug.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 lib/kunit/bug.c (limited to 'lib/kunit/bug.c') diff --git a/lib/kunit/bug.c b/lib/kunit/bug.c new file mode 100644 index 000000000..8579235c9 --- /dev/null +++ b/lib/kunit/bug.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit helpers for backtrace suppression + * + * Copyright (C) 2025 Alessandro Carminati + * Copyright (C) 2024 Guenter Roeck + */ + +#include +#include +#include +#include +#include +#include + +#include "hooks-impl.h" + +struct kunit_suppressed_warning { + struct list_head node; + struct task_struct *task; + struct kunit *test; + atomic_t counter; +}; + +static LIST_HEAD(suppressed_warnings); +static DEFINE_SPINLOCK(suppressed_warnings_lock); + +static void kunit_suppress_warning_remove(struct kunit_suppressed_warning *w) +{ + unsigned long flags; + + spin_lock_irqsave(&suppressed_warnings_lock, flags); + list_del_rcu(&w->node); + spin_unlock_irqrestore(&suppressed_warnings_lock, flags); + put_task_struct(w->task); +} + +KUNIT_DEFINE_ACTION_WRAPPER(kunit_suppress_warning_cleanup, + kunit_suppress_warning_remove, + struct kunit_suppressed_warning *); + +bool kunit_has_active_suppress_warning(void) +{ + return __kunit_is_suppressed_warning_impl(false); +} +EXPORT_SYMBOL_GPL(kunit_has_active_suppress_warning); + +struct kunit_suppressed_warning * +kunit_start_suppress_warning(struct kunit *test) +{ + struct kunit_suppressed_warning *w; + unsigned long flags; + int ret; + + if (kunit_has_active_suppress_warning()) { + KUNIT_FAIL(test, "Another suppression block is already active"); + return NULL; + } + + w = kunit_kzalloc(test, sizeof(*w), GFP_KERNEL); + if (!w) { + KUNIT_FAIL(test, "Failed to allocate suppression handle."); + return NULL; + } + + w->task = get_task_struct(current); + w->test = test; + + spin_lock_irqsave(&suppressed_warnings_lock, flags); + list_add_rcu(&w->node, &suppressed_warnings); + spin_unlock_irqrestore(&suppressed_warnings_lock, flags); + + ret = kunit_add_action_or_reset(test, + kunit_suppress_warning_cleanup, w); + if (ret) { + KUNIT_FAIL(test, "Failed to add suppression cleanup action."); + return NULL; + } + + return w; +} +EXPORT_SYMBOL_GPL(kunit_start_suppress_warning); + +void kunit_end_suppress_warning(struct kunit *test, + struct kunit_suppressed_warning *w) +{ + if (!w) + return; + kunit_release_action(test, kunit_suppress_warning_cleanup, w); +} +EXPORT_SYMBOL_GPL(kunit_end_suppress_warning); + +void __kunit_suppress_auto_cleanup(struct kunit_suppressed_warning **wp) +{ + if (*wp) + kunit_end_suppress_warning((*wp)->test, *wp); +} +EXPORT_SYMBOL_GPL(__kunit_suppress_auto_cleanup); + +int kunit_suppressed_warning_count(struct kunit_suppressed_warning *w) +{ + return w ? atomic_read(&w->counter) : 0; +} +EXPORT_SYMBOL_GPL(kunit_suppressed_warning_count); + +bool __kunit_is_suppressed_warning_impl(bool count) +{ + struct kunit_suppressed_warning *w; + + guard(rcu)(); + list_for_each_entry_rcu(w, &suppressed_warnings, node) { + if (w->task == current) { + if (count) + atomic_inc(&w->counter); + return true; + } + } + + return false; +} -- cgit v1.3.1