38 lines
1.5 KiB
Diff
38 lines
1.5 KiB
Diff
From 640af90afaf13bef5a99a458ed8e862359588d8f Mon Sep 17 00:00:00 2001
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From: Kailash Sethuraman <hsaliak@gmail.com>
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Date: Thu, 13 Jan 2022 13:52:46 -0500
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Subject: [PATCH] Fixes #4395 by correctly checking for EPIPE.
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kmsg is a unique device, which can recover from EPIPE errors.
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The original code checked for this, but checked the return value for the libc
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read call, which always returns -1 and sets the appropriate errno.
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This meant that when an EPIPE error actually happened, the fd was infinitely retried. The 'for loop' was broken out of, but the readikmsg() function is repeatedly called.
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Note: there is an additional bug here. The readikmsg function needs better error checking on the fd. I suspect that this was rarely an issue because /dev/kmsg goes truly invalid when the system is actually shutting down.
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The fix here is to check the return value as well as the errno.
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Conflict:NA
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Reference:https://github.com/rsyslog/rsyslog/commit/feb6420148c351072a190990622b58124fd44506
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---
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contrib/imkmsg/kmsg.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/contrib/imkmsg/kmsg.c b/contrib/imkmsg/kmsg.c
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index beb4076..5a3f45e 100644
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--- a/contrib/imkmsg/kmsg.c
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+++ b/contrib/imkmsg/kmsg.c
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@@ -214,7 +214,7 @@ readkmsg(void)
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if (i > 0) {
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/* successful read of message of nonzero length */
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pRcv[i] = '\0';
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- } else if (i == -EPIPE) {
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+ } else if (i < 0 && errno == EPIPE) {
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imkmsgLogIntMsg(LOG_WARNING,
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"imkmsg: some messages in circular buffer got overwritten");
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continue;
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--
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2.33.0
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