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

[Stefan Roese]

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;
 }
 
-- 
2.21.0