BUG() and BUG_ON() are generally used to test a condition that should never happen. If it does, it is a bug.
Linux always enables them, but doing so in U-Boot causes image size problems on some platforms. Introduce CONFIG_ENABLE_BUG_CHECKS to make them no-op by default. Platforms without image size constraint are free to enable this option to catch bugs easily.
Likewise, silence WARN_ON() unless this option is enabled.
Suggested-by: Tom Rini trini@konsulko.com Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---
Changes in v2: - Newly added
include/linux/bug.h | 9 ++++++++- lib/Kconfig | 7 +++++++ 2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/include/linux/bug.h b/include/linux/bug.h index f07bb71..ac1c7de 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -6,17 +6,24 @@ #include <linux/compiler.h> #include <linux/printk.h>
+#ifdef CONFIG_ENABLE_BUG_CHECKS #define BUG() do { \ printk("BUG at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \ panic("BUG!"); \ } while (0) +#define __WARN() \ + printk("WARNING at %s:%d/%s()!\n", __FILE__, __LINE__, __func__) +#else +#define BUG() +#define __WARN() +#endif
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
#define WARN_ON(condition) ({ \ int __ret_warn_on = !!(condition); \ if (unlikely(__ret_warn_on)) \ - printk("WARNING at %s:%d/%s()!\n", __FILE__, __LINE__, __func__); \ + __WARN(); \ unlikely(__ret_warn_on); \ })
diff --git a/lib/Kconfig b/lib/Kconfig index 00ac650..36b1b3b 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -45,6 +45,13 @@ config USE_TINY_PRINTF
The supported format specifiers are %c, %s, %u/%d and %x.
+config ENABLE_BUG_CHECKS + bool "Enable BUG/BUG_ON() checks and WARN_ON() logs" + help + BUG() and BUG_ON() are no-op by default. This option enables + them to print noisy messages, then reboot or halt the system. + It also enables WARN_ON() messages. + config PANIC_HANG bool "Do not reset the system on fatal error" help