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

[Stefan Roese]

On 02.04.19 12:30, Michal Simek wrote:
> On 02. 04. 19 11:57, 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>
>> ---
>>   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                            | 2 +-
>>   board/xilinx/zynqmp/zynqmp.c                         | 2 +-
>>   6 files changed, 6 insertions(+), 6 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..7c8c32a1c7 100644
>> --- a/board/xilinx/zynq/board.c
>> +++ b/board/xilinx/zynq/board.c
>> @@ -19,7 +19,7 @@
>>   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_SPL_BUILD) && defined(CONFIG_BOARD_EARLY_INIT_F)
>> diff --git a/board/xilinx/zynqmp/zynqmp.c b/board/xilinx/zynqmp/zynqmp.c
>> index 5e1d2116bc..1c2aa99b97 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) && \
>>
> 
> If you want to do it for all then please remove the same from this file
> 
> http://git.denx.de/?p=u-boot.git;a=commitdiff;h=4490e013ee4f2a4b9b6ca9224221fed2788b6940
> 
> +#if defined(CONFIG_WDT) && !defined(CONFIG_SPL_BUILD)
> +       /* bss is not cleared at time when watchdog_reset() is called */
> +       watchdog_dev = NULL;
> +#endif
> 
> 
> And also from zynq file.
> board/xilinx/zynq/board.c

Thanks for spotting. I'll remove it in v2.

Thanks,
Stefan