Testing with a gcc-7 snapshot produced an internal compiler error for this file: drivers/tty/nozomi.c: In function 'receive_flow_control': drivers/tty/nozomi.c:919:12: internal compiler error: in get_substring_ranges_for_loc, at input.c:1388 static int receive_flow_control(struct nozomi *dc) I've reported this at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78569 but also noticed that the code line contains a stack overflow, as it prints a string into a slightly shorter fixed-length 'tmp' variable. A lot of the code here is unnecessary and can be expressed in a simpler way, relying on the fact that removing the 'DEBUG' macro will also get rid of all pr_debug() calls. This change should not change any of the output but avoids both the stack overflow and the gcc crash. The stack overflow will not happen unless a module load parameter is also set to enable the debug messages. Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- drivers/tty/nozomi.c | 47 ++++++++++++----------------------------------- 1 file changed, 12 insertions(+), 35 deletions(-) diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c index e2020a691058..39b3723a32a6 100644 --- a/drivers/tty/nozomi.c +++ b/drivers/tty/nozomi.c @@ -63,44 +63,23 @@ #define VERSION_STRING DRIVER_DESC " 2.1d" -/* Macros definitions */ - /* Default debug printout level */ #define NOZOMI_DEBUG_LEVEL 0x00 - -#define P_BUF_SIZE 128 -#define NFO(_err_flag_, args...) \ -do { \ - char tmp[P_BUF_SIZE]; \ - snprintf(tmp, sizeof(tmp), ##args); \ - printk(_err_flag_ "[%d] %s(): %s\n", __LINE__, \ - __func__, tmp); \ -} while (0) - -#define DBG1(args...) D_(0x01, ##args) -#define DBG2(args...) D_(0x02, ##args) -#define DBG3(args...) D_(0x04, ##args) -#define DBG4(args...) D_(0x08, ##args) -#define DBG5(args...) D_(0x10, ##args) -#define DBG6(args...) D_(0x20, ##args) -#define DBG7(args...) D_(0x40, ##args) -#define DBG8(args...) D_(0x80, ##args) - -#ifdef DEBUG -/* Do we need this settable at runtime? */ static int debug = NOZOMI_DEBUG_LEVEL; +module_param(debug, int, S_IRUGO | S_IWUSR); -#define D(lvl, args...) do \ - {if (lvl & debug) NFO(KERN_DEBUG, ##args); } \ - while (0) -#define D_(lvl, args...) D(lvl, ##args) - -/* These printouts are always printed */ +/* Macros definitions */ +#define DBG_(lvl, fmt, args...) \ +do { \ + if (lvl & debug) \ + pr_debug("[%d] %s(): " fmt "\n", \ + __LINE__, __func__, ##args); \ +} while (0) -#else -static int debug; -#define D_(lvl, args...) -#endif +#define DBG1(args...) DBG_(0x01, ##args) +#define DBG2(args...) DBG_(0x02, ##args) +#define DBG3(args...) DBG_(0x04, ##args) +#define DBG4(args...) DBG_(0x08, ##args) /* TODO: rewrite to optimize macros... */ @@ -1943,7 +1922,5 @@ static __exit void nozomi_exit(void) module_init(nozomi_init); module_exit(nozomi_exit); -module_param(debug, int, S_IRUGO | S_IWUSR); - MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION(DRIVER_DESC); -- 2.9.0 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
