From: James Morse james.morse@arm.com
[ 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: James Morse james.morse@arm.com Reviewed-by: Borislav Petkov bp@suse.de Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/apei/ghes.c | 30 +++++++++++++++--------------- 1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index bb81cd05f0bc8..d532aa87eef10 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -198,40 +198,40 @@ 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); - if (!addr) - return -ENOMEM; - ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1); - if (ret) - return ret; - }
- return 0; + addr = (unsigned long)vmalloc(PAGE_ALIGN(len)); + if (!addr) + return -ENOMEM; + + /* + * 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 struct ghes *ghes_new(struct acpi_hest_generic *generic)