From 4276cfe2fa6fba6dc71a2cc3c0c2a5cc194ce542 Mon Sep 17 00:00:00 2001 From: Andre Przywara Date: Wed, 7 Oct 2020 11:09:42 +0100 Subject: [PATCH] fdt: Fix coverity complaint about 32-bit multiplication Coverity raised an eyebrow over our GICR frame size calculation: ======== CID 362942: Integer handling issues (OVERFLOW_BEFORE_WIDEN) Potentially overflowing expression "nr_cores * gicr_frame_size" with type "unsigned int" (32 bits, unsigned) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type "uint64_t" (64 bits, unsigned). ======== Even with a GICv4 (256KB frame size) we need 16384 cores to overflow 32-bit, so it's not a practical issue. But it's also easy to fix, so let's just do that: cast gicr_frame_size to an unsigned 64-bit integer, so that the multiplication is done in the 64-bit realm. Change-Id: Iad10e19b9e58d5fbf9d13205fbcef0aac5ae48af Signed-off-by: Andre Przywara --- common/fdt_fixup.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/common/fdt_fixup.c b/common/fdt_fixup.c index a1604e74f..e88a55008 100644 --- a/common/fdt_fixup.c +++ b/common/fdt_fixup.c @@ -425,7 +425,8 @@ int fdt_adjust_gic_redist(void *dtb, unsigned int nr_cores, redist_size_32 = cpu_to_fdt32(nr_cores * gicr_frame_size); val = &redist_size_32; } else { - redist_size_64 = cpu_to_fdt64(nr_cores * gicr_frame_size); + redist_size_64 = cpu_to_fdt64(nr_cores * + (uint64_t)gicr_frame_size); val = &redist_size_64; }