From bf068c7643f23c3f0936e3d1d292cc537acaf3bb Mon Sep 17 00:00:00 2001 From: Ley Foon Tan <ley.foon.tan@intel.com> Date: Wed, 24 Apr 2019 13:21:47 +0800 Subject: [PATCH] arm: socfpga: mailbox: Fix off-by-one error on command length checking A mailbox command contains 1-u32 header + arguments. The "len" variable only contains the length of the arguments, but not the 1-u32 header. Include the length of header when checking the ring buffer space to prevent off-by-one error. Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com> Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com> --- arch/arm/mach-socfpga/mailbox_s10.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-socfpga/mailbox_s10.c b/arch/arm/mach-socfpga/mailbox_s10.c index 3c33223936..4498ab55df 100644 --- a/arch/arm/mach-socfpga/mailbox_s10.c +++ b/arch/arm/mach-socfpga/mailbox_s10.c @@ -55,11 +55,11 @@ static __always_inline int mbox_fill_cmd_circular_buff(u32 header, u32 len, cout = MBOX_READL(MBOX_COUT) % MBOX_CMD_BUFFER_SIZE; /* if command buffer is full or not enough free space - * to fit the data + * to fit the data. Note, len is in u32 unit. */ if (((cin + 1) % MBOX_CMD_BUFFER_SIZE) == cout || ((MBOX_CMD_BUFFER_SIZE - cin + cout - 1) % - MBOX_CMD_BUFFER_SIZE) < len) + MBOX_CMD_BUFFER_SIZE) < (len + 1)) return -ENOMEM; /* write header to circular buffer */ -- 2.39.5