From 7d1460c991ac45cccbf9ba3d8aa137029c2bf312 Mon Sep 17 00:00:00 2001 From: Volodymyr Babchuk Date: Thu, 20 Jun 2019 15:50:21 +0000 Subject: [PATCH] xen/arm: optee: fix compilation with GCC 4.8 GCC 4.8 is unable to see that variables guest_pg, guest_data and xen_data will be always initialized before access, so we need to initialize them earlier. Suggested-by: Stefano Stabellini Signed-off-by: Volodymyr Babchuk Acked-by: Julien Grall --- xen/arch/arm/tee/optee.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/xen/arch/arm/tee/optee.c b/xen/arch/arm/tee/optee.c index 28d34360fc..61029855d4 100644 --- a/xen/arch/arm/tee/optee.c +++ b/xen/arch/arm/tee/optee.c @@ -707,6 +707,19 @@ static int translate_noncontig(struct optee_domain *ctx, gfn = gaddr_to_gfn(param->u.tmem.buf_ptr & ~(OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1)); + /* + * We are initializing guest_pg, guest_data and xen_data with NULL + * to make GCC 4.8 happy, as it can't infer that those variables + * will be initialized with correct values in the loop below. + * + * This silences old GCC, but can lead to NULL dereference, in + * case of programmer's mistake. To minimize chance of this, we + * are initializing those variables there, instead of doing this + * at beginning of the function. + */ + guest_pg = NULL; + xen_data = NULL; + guest_data = NULL; while ( pg_count ) { struct page_info *page; -- 2.30.2