Commit 65ca73f9 authored by Ilya Leoshkevich's avatar Ilya Leoshkevich Committed by Andrew Morton
Browse files

s390/mm: define KMSAN metadata for vmalloc and modules 

The pages for the KMSAN metadata associated with most kernel mappings are
taken from memblock by the common code.  However, vmalloc and module
metadata needs to be defined by the architectures.

Be a little bit more careful than x86: allocate exactly MODULES_LEN for
the module shadow and origins, and then take 2/3 of vmalloc for the
vmalloc shadow and origins.  This ensures that users passing small
vmalloc= values on the command line do not cause module metadata
collisions.

Link: https://lkml.kernel.org/r/20240621113706.315500-32-iii@linux.ibm.com


Signed-off-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: default avatarAlexander Potapenko <glider@google.com>
Acked-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Acked-by: default avatarHeiko Carstens <hca@linux.ibm.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: 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 1b301f5f

arch/s390/boot/startup.c

+7 −0
Original line number Diff line number Diff line
@@ -304,11 +304,18 @@ static unsigned long setup_kernel_memory_layout(unsigned long kernel_size) 
	MODULES_END = round_down(kernel_start, _SEGMENT_SIZE);

	MODULES_VADDR = MODULES_END - MODULES_LEN;

	VMALLOC_END = MODULES_VADDR;

	if (IS_ENABLED(CONFIG_KMSAN))

		VMALLOC_END -= MODULES_LEN * 2;



	/* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */

	vsize = (VMALLOC_END - FIXMAP_SIZE) / 2;

	vsize = round_down(vsize, _SEGMENT_SIZE);

	vmalloc_size = min(vmalloc_size, vsize);

	if (IS_ENABLED(CONFIG_KMSAN)) {

		/* take 2/3 of vmalloc area for KMSAN shadow and origins */

		vmalloc_size = round_down(vmalloc_size / 3, _SEGMENT_SIZE);

		VMALLOC_END -= vmalloc_size * 2;

	}

	VMALLOC_START = VMALLOC_END - vmalloc_size;



	__memcpy_real_area = round_down(VMALLOC_START - MEMCPY_REAL_SIZE, PAGE_SIZE);

arch/s390/include/asm/pgtable.h

+12 −0
Original line number Diff line number Diff line
@@ -107,6 +107,18 @@ static inline int is_module_addr(void *addr) 
	return 1;

}



#ifdef CONFIG_KMSAN

#define KMSAN_VMALLOC_SIZE (VMALLOC_END - VMALLOC_START)

#define KMSAN_VMALLOC_SHADOW_START VMALLOC_END

#define KMSAN_VMALLOC_SHADOW_END (KMSAN_VMALLOC_SHADOW_START + KMSAN_VMALLOC_SIZE)

#define KMSAN_VMALLOC_ORIGIN_START KMSAN_VMALLOC_SHADOW_END

#define KMSAN_VMALLOC_ORIGIN_END (KMSAN_VMALLOC_ORIGIN_START + KMSAN_VMALLOC_SIZE)

#define KMSAN_MODULES_SHADOW_START KMSAN_VMALLOC_ORIGIN_END

#define KMSAN_MODULES_SHADOW_END (KMSAN_MODULES_SHADOW_START + MODULES_LEN)

#define KMSAN_MODULES_ORIGIN_START KMSAN_MODULES_SHADOW_END

#define KMSAN_MODULES_ORIGIN_END (KMSAN_MODULES_ORIGIN_START + MODULES_LEN)

#endif



#ifdef CONFIG_RANDOMIZE_BASE

#define KASLR_LEN	(1UL << 31)

#else