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Commit 81ae6e6b authored by James Morse's avatar James Morse Committed by Greg Kroah-Hartman
Browse files

ACPI / APEI: Switch estatus pool to use vmalloc memory 



[ Upstream commit 0ac234be1a9497498e57d958f4251f5257b116b4 ]

The ghes code is careful to parse and round firmware's advertised
memory requirements for CPER records, up to a maximum of 64K.
However when ghes_estatus_pool_expand() does its work, it splits
the requested size into PAGE_SIZE granules.

This means if firmware generates 5K of CPER records, and correctly
describes this in the table, __process_error() will silently fail as it
is unable to allocate more than PAGE_SIZE.

Switch the estatus pool to vmalloc() memory. On x86 vmalloc() memory
may fault and be fixed up by vmalloc_fault(). To prevent this call
vmalloc_sync_all() before an NMI handler could discover the memory.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 07575de0

drivers/acpi/apei/ghes.c

+15 −15
Original line number Diff line number Diff line
@@ -170,40 +170,40 @@ static int ghes_estatus_pool_init(void) 
	return 0;

}



static void ghes_estatus_pool_free_chunk_page(struct gen_pool *pool,

static void ghes_estatus_pool_free_chunk(struct gen_pool *pool,

					      struct gen_pool_chunk *chunk,

					      void *data)

{

	free_page(chunk->start_addr);

	vfree((void *)chunk->start_addr);

}



static void ghes_estatus_pool_exit(void)

{

	gen_pool_for_each_chunk(ghes_estatus_pool,

				ghes_estatus_pool_free_chunk_page, NULL);

				ghes_estatus_pool_free_chunk, NULL);

	gen_pool_destroy(ghes_estatus_pool);

}



static int ghes_estatus_pool_expand(unsigned long len)

{

	unsigned long i, pages, size, addr;

	int ret;

	unsigned long size, addr;



	ghes_estatus_pool_size_request += PAGE_ALIGN(len);

	size = gen_pool_size(ghes_estatus_pool);

	if (size >= ghes_estatus_pool_size_request)

		return 0;

	pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE;

	for (i = 0; i < pages; i++) {

		addr = __get_free_page(GFP_KERNEL);



	addr = (unsigned long)vmalloc(PAGE_ALIGN(len));

	if (!addr)

		return -ENOMEM;

		ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1);

		if (ret)

			return ret;

	}



	return 0;

	/*

	 * New allocation must be visible in all pgd before it can be found by

	 * an NMI allocating from the pool.

	 */

	vmalloc_sync_all();



	return gen_pool_add(ghes_estatus_pool, addr, PAGE_ALIGN(len), -1);

}



static int map_gen_v2(struct ghes *ghes)