I stole the printk_once() macro. I always wanted to be able to print some error directly if there is a buffer to dump, however we can't use error_report() really quite often when there can be any DDOS attack. To avoid that, we can introduce a print-once function for it.
CC: Markus Armbruster <arm...@redhat.com> Signed-off-by: Peter Xu <pet...@redhat.com> --- We can for sure introduce similar functions for the rest of the error_*() functions, it's just an idea to see whether we'd like it in general. --- include/qemu/error-report.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/qemu/error-report.h b/include/qemu/error-report.h index e1c8ae1a52..efebb80e2c 100644 --- a/include/qemu/error-report.h +++ b/include/qemu/error-report.h @@ -44,6 +44,18 @@ void error_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2); void warn_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2); void info_report(const char *fmt, ...) GCC_FMT_ATTR(1, 2); +#define error_report_once(fmt, ...) \ + ({ \ + static bool __print_once; \ + bool __ret_print_once = !__print_once; \ + \ + if (!__print_once) { \ + __print_once = true; \ + error_report(fmt, ##__VA_ARGS__); \ + } \ + unlikely(__ret_print_once); \ + }) + const char *error_get_progname(void); extern bool enable_timestamp_msg; -- 2.17.0