To prepare for supporting boot-time page size selection, refactor code to remove assumptions about PAGE_SIZE being compile-time constant. Code intended to be equivalent when compile-time page size is active.

Updated BUILD_BUG_ON() to test against limit.

Refactored "struct optee_shm_arg_entry" to use a flexible array member for "map", since its length depends on PAGE_SIZE.

Signed-off-by: Ryan Roberts ryan.roberts@arm.com ---

***NOTE*** Any confused maintainers may want to read the cover note here for context: https://lore.kernel.org/all/20241014105514.3206191-1-ryan.roberts@arm.com/

drivers/tee/optee/call.c | 7 +++++-- drivers/tee/optee/smc_abi.c | 2 +- 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c index 16eb953e14bb6..41bd7ace6606e 100644 --- a/drivers/tee/optee/call.c +++ b/drivers/tee/optee/call.c @@ -36,7 +36,7 @@ struct optee_shm_arg_entry { struct list_head list_node; struct tee_shm *shm; - DECLARE_BITMAP(map, MAX_ARG_COUNT_PER_ENTRY); + unsigned long map[]; };

void optee_cq_init(struct optee_call_queue *cq, int thread_count) @@ -271,6 +271,7 @@ struct optee_msg_arg *optee_get_msg_arg(struct tee_context *ctx, struct optee_shm_arg_entry *entry; struct optee_msg_arg *ma; size_t args_per_entry; + size_t entry_sz; u_long bit; u_int offs; void *res; @@ -293,7 +294,9 @@ struct optee_msg_arg *optee_get_msg_arg(struct tee_context *ctx, /* * No entry was found, let's allocate a new. */ - entry = kzalloc(sizeof(*entry), GFP_KERNEL); + entry_sz = struct_size(entry, map, + BITS_TO_LONGS(MAX_ARG_COUNT_PER_ENTRY)); + entry = kzalloc(entry_sz, GFP_KERNEL); if (!entry) { res = ERR_PTR(-ENOMEM); goto out; diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index 844285d4f03c1..005689380d848 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -418,7 +418,7 @@ static void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages, * code heavily relies on this assumption, so it is better be * safe than sorry. */ - BUILD_BUG_ON(PAGE_SIZE < OPTEE_MSG_NONCONTIG_PAGE_SIZE); + BUILD_BUG_ON(PAGE_SIZE_MIN < OPTEE_MSG_NONCONTIG_PAGE_SIZE);

pages_data = (void *)dst; /*