[U-Boot] [PATCH v2] watchdog: Move watchdog_dev to data section (BSS may not be cleared)

[Michal Simek]

On 03. 04. 19 9:12, Stefan Roese wrote:
> This patch moves all instances of static "watchdog_dev" declarations to
> the "data" section. This may be needed, as the BSS may not be cleared
> in the early U-Boot phase, where watchdog_reset() is already beeing
> called. This may result in incorrect pointer access, as the check to
> "!watchdog_dev" in watchdog_reset() may not be true and the function
> may continue to run.
> 
> Signed-off-by: Stefan Roese <sr at denx.de>
> Cc: Heiko Schocher <hs at denx.de>
> Cc: Tom Rini <trini at konsulko.com>
> Cc: Michal Simek <michal.simek at xilinx.com>
> Cc: "Marek Behún" <marek.behun at nic.cz>
> Cc: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
> ---
> v2:
> - Remove now superfluous explicit clearing of watchdog_dev in Xilinx
>   zynq and zynqmp board_early_init_f() as suggested by Michal
> 
>  arch/mips/mach-mt7620/cpu.c                          | 2 +-
>  board/CZ.NIC/turris_mox/turris_mox.c                 | 2 +-
>  board/CZ.NIC/turris_omnia/turris_omnia.c             | 2 +-
>  board/xilinx/microblaze-generic/microblaze-generic.c | 2 +-
>  board/xilinx/zynq/board.c                            | 7 +------
>  board/xilinx/zynqmp/zynqmp.c                         | 7 +------
>  6 files changed, 6 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/mips/mach-mt7620/cpu.c b/arch/mips/mach-mt7620/cpu.c
> index 9e0ca716f7..fe74f26a54 100644
> --- a/arch/mips/mach-mt7620/cpu.c
> +++ b/arch/mips/mach-mt7620/cpu.c
> @@ -70,7 +70,7 @@ int print_cpuinfo(void)
>  }
>  
>  #ifdef CONFIG_WATCHDOG
> -static struct udevice *watchdog_dev;
> +static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
>  
>  /* Called by macro WATCHDOG_RESET */
>  void watchdog_reset(void)
> diff --git a/board/CZ.NIC/turris_mox/turris_mox.c b/board/CZ.NIC/turris_mox/turris_mox.c
> index 65d50a92dd..96cb9c7e5c 100644
> --- a/board/CZ.NIC/turris_mox/turris_mox.c
> +++ b/board/CZ.NIC/turris_mox/turris_mox.c
> @@ -120,7 +120,7 @@ int board_fix_fdt(void *blob)
>  #endif
>  
>  #ifdef CONFIG_WDT_ARMADA_37XX
> -static struct udevice *watchdog_dev;
> +static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
>  
>  void watchdog_reset(void)
>  {
> diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c b/board/CZ.NIC/turris_omnia/turris_omnia.c
> index 1f7650cb36..c7f6479a0c 100644
> --- a/board/CZ.NIC/turris_omnia/turris_omnia.c
> +++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
> @@ -365,7 +365,7 @@ static bool disable_mcu_watchdog(void)
>  #endif
>  
>  #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_WDT_ORION)
> -static struct udevice *watchdog_dev = NULL;
> +static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
>  #endif
>  
>  int board_init(void)
> diff --git a/board/xilinx/microblaze-generic/microblaze-generic.c b/board/xilinx/microblaze-generic/microblaze-generic.c
> index c946ec3208..28c9efa3a2 100644
> --- a/board/xilinx/microblaze-generic/microblaze-generic.c
> +++ b/board/xilinx/microblaze-generic/microblaze-generic.c
> @@ -25,7 +25,7 @@
>  DECLARE_GLOBAL_DATA_PTR;
>  
>  #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_WDT)
> -static struct udevice *watchdog_dev;
> +static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
>  #endif /* !CONFIG_SPL_BUILD && CONFIG_WDT */
>  
>  ulong ram_base;
> diff --git a/board/xilinx/zynq/board.c b/board/xilinx/zynq/board.c
> index b4b84df576..ea26aad16f 100644
> --- a/board/xilinx/zynq/board.c
> +++ b/board/xilinx/zynq/board.c
> @@ -19,17 +19,12 @@
>  DECLARE_GLOBAL_DATA_PTR;
>  
>  #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_WDT)
> -static struct udevice *watchdog_dev;
> +static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
>  #endif
>  
>  #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_BOARD_EARLY_INIT_F)
>  int board_early_init_f(void)
>  {
> -# if defined(CONFIG_WDT)
> -	/* bss is not cleared at time when watchdog_reset() is called */
> -	watchdog_dev = NULL;
> -# endif
> -
>  	return 0;
>  }
>  #endif
> diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
> index 5e1d2116bc..db27247850 100644
> --- a/board/xilinx/zynqmp/zynqmp.c
> +++ b/board/xilinx/zynqmp/zynqmp.c
> @@ -25,7 +25,7 @@
>  DECLARE_GLOBAL_DATA_PTR;
>  
>  #if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_WDT)
> -static struct udevice *watchdog_dev;
> +static struct udevice *watchdog_dev __attribute__((section(".data"))) = NULL;
>  #endif
>  
>  #if defined(CONFIG_FPGA) && defined(CONFIG_FPGA_ZYNQMPPL) && \
> @@ -322,11 +322,6 @@ int board_early_init_f(void)
>  	ret = psu_init();
>  #endif
>  
> -#if defined(CONFIG_WDT) && !defined(CONFIG_SPL_BUILD)
> -	/* bss is not cleared at time when watchdog_reset() is called */
> -	watchdog_dev = NULL;
> -#endif
> -
>  	return ret;
>  }
>  
> 

Tested-by: Michal Simek <michal.simek at xilinx.com> (on zcu100)
Reviewed-by: Michal Simek <michal.simek at xilinx.com>

Thanks,
Michal