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23 October 2021, 00:29:24 UTC
Revision f2b3d8566d81deaca31f4e3163def0bea7746e11 authored by James Morse on 24 January 2019, 16:32:55 UTC, committed by Will Deacon on 01 February 2019, 14:09:50 UTC 
arm64: kprobe: Always blacklist the KVM world-switch code
 
On systems with VHE the kernel and KVM's world-switch code run at the
same exception level. Code that is only used on a VHE system does not
need to be annotated as __hyp_text as it can reside anywhere in the
 kernel text.

__hyp_text was also used to prevent kprobes from patching breakpoint
instructions into this region, as this code runs at a different
exception level. While this is no longer true with VHE, KVM still
switches VBAR_EL1, meaning a kprobe's breakpoint executed in the
world-switch code will cause a hyp-panic.

Move the __hyp_text check in the kprobes blacklist so it applies on
VHE systems too, to cover the common code and guest enter/exit
assembly.

Fixes: 888b3c8720e0 ("arm64: Treat all entry code as non-kprobe-able")
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 8ea2359
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Tip revision: f2b3d8566d81deaca31f4e3163def0bea7746e11 authored by James Morse on 24 January 2019, 16:32:55 UTC
arm64: kprobe: Always blacklist the KVM world-switch code
Tip revision: f2b3d85
mutex-debug.h 
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Mutexes: blocking mutual exclusion locks
 *
 * started by Ingo Molnar:
 *
 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 *
 * This file contains mutex debugging related internal declarations,
 * prototypes and inline functions, for the CONFIG_DEBUG_MUTEXES case.
 * More details are in kernel/mutex-debug.c.
 */

/*
 * This must be called with lock->wait_lock held.
 */
extern void debug_mutex_lock_common(struct mutex *lock,
				    struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
				    struct mutex_waiter *waiter);
extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
extern void debug_mutex_add_waiter(struct mutex *lock,
				   struct mutex_waiter *waiter,
				   struct task_struct *task);
extern void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
				struct task_struct *task);
extern void debug_mutex_unlock(struct mutex *lock);
extern void debug_mutex_init(struct mutex *lock, const char *name,
			     struct lock_class_key *key);
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