[igt-dev] [RFC PATCH i-g-t 6/6] lib/core: Use whitelist with kmsg filter

[Petri Latvala]

dmesg messages of level >=warn don't result in an IGT_LOG_WARN if they
match a whitelist regexp now.

The whitelist is not configureable without rebuilding, and it's not
even possible to use a different whitelist for different drivers;
launching the kmsg monitor happens way before opening the driver (if
any).

Signed-off-by: Petri Latvala <petri.latvala at intel.com>
---
 lib/igt_core.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/igt_core.c b/lib/igt_core.c
index 5c93432d..d4495c3f 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -55,6 +55,7 @@
 #include <limits.h>
 #include <locale.h>
 #include <uwildmat/uwildmat.h>
+#include <regex.h>
 #ifdef HAVE_GLIB
 #include <glib.h>
 #endif
@@ -581,6 +582,16 @@ static void oom_adjust_for_doom(void)
 
 }
 
+const char IGT_DMESG_WHITELIST[] =
+	"IRQ [0-9]+: no longer affine to CPU[0-9]+"
+	"|IRQ fixup: irq [0-9]+ move in progress, old vector [0-9]+"
+	"|Setting dangerous option [a-z_]+ - tainting kernel"
+	"|Suspending console\\(s\\) \\(use no_console_suspend to debug\\)"
+	"|cache: parent cpu[0-9]+ should not be sleeping"
+	"|hpet[0-9]+: lost [0-9]+ rtc interrupts"
+	"|usb usb[0-9]+: root hub lost power or was reset"
+	;
+
 static void *kmsg_capture(void *arg)
 {
 	/*
@@ -593,6 +604,13 @@ static void *kmsg_capture(void *arg)
 	char *line = NULL;
 	size_t line_len = 0;
 	ssize_t read;
+	regex_t re;
+
+	if (regcomp(&re, IGT_DMESG_WHITELIST, REG_EXTENDED | REG_NOSUB) != 0) {
+		igt_warn("Cannot compile dmesg whitelist regexp\n");
+		fclose(kmsg_file);
+		return NULL;
+	}
 
 	while ((read = getline(&line, &line_len, kmsg_file))) {
 		int s;
@@ -613,7 +631,8 @@ static void *kmsg_capture(void *arg)
 			   &seq, &ts_usec, &continuation);
 
 		if (s == 4) {
-			if ((flags & 0x7) <= 4)
+			if ((flags & 0x7) <= 4 &&
+			    regexec(&re, line, (size_t)0, NULL, 0))
 				level = IGT_LOG_WARN;
 			else
 				level = IGT_LOG_DEBUG;
-- 
2.14.1