On 05/15/2018 04:13 AM, Peter Xu wrote:
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; \
Double-underscore names are reserved for the compiler's use, not ours.
Better would be naming this:
static bool print_once_;
with a trailing underscore, or at most a single leading underscore.
+ bool __ret_print_once = !__print_once; \
Same comment for this variable.
+ \
+ 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;
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
