Commit 2a48c8c9 authored by Ilya Leoshkevich's avatar Ilya Leoshkevich Committed by Andrew Morton
Browse files

s390/kmsan: implement the architecture-specific functions 

arch_kmsan_get_meta_or_null() finds the lowcore shadow by querying the
prefix and calling kmsan_get_metadata() again.

kmsan_virt_addr_valid() delegates to virt_addr_valid().

Link: https://lkml.kernel.org/r/20240621113706.315500-38-iii@linux.ibm.com


Signed-off-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Acked-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarAlexander Potapenko <glider@google.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 7e17eac2

arch/s390/include/asm/kmsan.h

0 → 100644
+59 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

#ifndef _ASM_S390_KMSAN_H

#define _ASM_S390_KMSAN_H



#include <asm/lowcore.h>

#include <asm/page.h>

#include <linux/kmsan.h>

#include <linux/mmzone.h>

#include <linux/stddef.h>



#ifndef MODULE



static inline bool is_lowcore_addr(void *addr)

{

	return addr >= (void *)&S390_lowcore &&

	       addr < (void *)(&S390_lowcore + 1);

}



static inline void *arch_kmsan_get_meta_or_null(void *addr, bool is_origin)

{

	if (is_lowcore_addr(addr)) {

		/*

		 * Different lowcores accessed via S390_lowcore are described

		 * by the same struct page. Resolve the prefix manually in

		 * order to get a distinct struct page.

		 */

		addr += (void *)lowcore_ptr[raw_smp_processor_id()] -

			(void *)&S390_lowcore;

		if (KMSAN_WARN_ON(is_lowcore_addr(addr)))

			return NULL;

		return kmsan_get_metadata(addr, is_origin);

	}

	return NULL;

}



static inline bool kmsan_virt_addr_valid(void *addr)

{

	bool ret;



	/*

	 * pfn_valid() relies on RCU, and may call into the scheduler on exiting

	 * the critical section. However, this would result in recursion with

	 * KMSAN. Therefore, disable preemption here, and re-enable preemption

	 * below while suppressing reschedules to avoid recursion.

	 *

	 * Note, this sacrifices occasionally breaking scheduling guarantees.

	 * Although, a kernel compiled with KMSAN has already given up on any

	 * performance guarantees due to being heavily instrumented.

	 */

	preempt_disable();

	ret = virt_addr_valid(addr);

	preempt_enable_no_resched();



	return ret;

}



#endif /* !MODULE */



#endif /* _ASM_S390_KMSAN_H */