rngd: fix --debug to also filter syslog() calls

Debug logs were only controlled by --debug flag while in --foreground mode.
In --daemon mode (the default for us) /var/log/message got stuffed with
details of entropy pool refilling, which is useless in production, and
hamful when log rotation then gets rid of the more useful logs.

This change makes the two modes consistently only produce debug logs when
--debug is specified.

(From OE-Core rev: 914526868656fd279b13ba8e4d721d27cb2a8792)

Signed-off-by: Yann Dirson <yann@blade-group.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 47 insertions, 0 deletions

diff --git a/meta/recipes-support/rng-tools/rng-tools/0001-rngd-fix-debug-to-also-filter-syslog-calls.patch b/meta/recipes-support/rng-tools/rng-tools/0001-rngd-fix-debug-to-also-filter-syslog-calls.patch
new file mode 100644
index 0000000000..0733378668
--- /dev/null
+++ b/meta/recipes-support/rng-tools/rng-tools/0001-rngd-fix-debug-to-also-filter-syslog-calls.patch
@@ -0,0 +1,46 @@
+From 213a869e8315ead2c739acfcbde712358a842dee Mon Sep 17 00:00:00 2001
+From: Yann Dirson <yann@blade-group.com>
+Date: Fri, 9 Oct 2020 15:12:26 +0200
+Subject: [PATCH] rngd: fix --debug to also filter syslog() calls
+
+Debug logs were only controlled by --debug flag while in --foreground
+mode.  In --daemon mode /var/log/message got stuffed with details of
+entropy pool refilling, which is useless in production, and hamful
+when log rotation then gets rid of the more useful logs.  This is
+especially true for embedded systems.
+
+This change makes the two modes consistently only produce debug logs when
+--debug is specified.
+
+Upstream-Status: Backport [213a869e8315ead2c739acfcbde712358a842dee]
+
+Signed-off-by: Yann Dirson <yann@blade-group.com>
+---
+ rngd.h | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/rngd.h b/rngd.h
+index 901b6f1..a79ea0f 100644
+--- a/rngd.h
++++ b/rngd.h
+@@ -166,13 +166,13 @@ extern bool quiet;
+ #define message(priority,fmt,args...) do { \
+        if (quiet) \
+                break;\
++       if (arguments->debug == false && LOG_PRI(priority) == LOG_DEBUG) \
++               break;\
+        if (am_daemon) { \
+                syslog((priority), fmt, ##args); \
+        } else if (!msg_squash) { \
+-               if ((LOG_PRI(priority) != LOG_DEBUG) || (arguments->debug == true)) {\
+-                       fprintf(stderr, fmt, ##args); \
+-                       fflush(stderr); \
+-               } \
++               fprintf(stderr, fmt, ##args); \
++               fflush(stderr); \
+        } \
+ } while (0)
+ 
+-- 
+2.28.0
+
diff --git a/meta/recipes-support/rng-tools/rng-tools_6.10.bb b/meta/recipes-support/rng-tools/rng-tools_6.10.bb
index 3f9720e406..40ec5ad671 100644
--- a/meta/recipes-support/rng-tools/rng-tools_6.10.bb
+++ b/meta/recipes-support/rng-tools/rng-tools_6.10.bb
@@ -12,6 +12,7 @@ SRC_URI = "\
     git://github.com/nhorman/rng-tools.git \
     file://a4b6d9ce64f132e463b9091d0536913ddaf11516.patch \
     file://dab16a5fd4efde8ef569b358e19b1fcbc7d0d938.patch \
+    file://0001-rngd-fix-debug-to-also-filter-syslog-calls.patch \
     file://init \
     file://default \
     file://rngd.service \