From: Olaf Hering <olaf@aepfle.de>
Date: Tue, 5 Nov 2024 08:14:04 +0000 (+0100)
Subject: tools/hv: terminate fcopy daemon if read from uio fails
X-Git-Tag: v6.13-rc4~33^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a9640fcdd400463442846677e62b8208b81cb031;p=thirdparty%2Flinux.git

tools/hv: terminate fcopy daemon if read from uio fails

Terminate endless loop in reading fails, to avoid flooding syslog.

This happens if the state of "Guest services" integration service
is changed from "enabled" to "disabled" at runtime in the VM
settings. In this case pread returns EIO.

Also handle an interrupted system call, and continue in this case.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Link: https://lore.kernel.org/r/20241105081437.15689-1-olaf@aepfle.de
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20241105081437.15689-1-olaf@aepfle.de>
---

diff --git a/tools/hv/hv_fcopy_uio_daemon.c b/tools/hv/hv_fcopy_uio_daemon.c
index 12743d7f164f0..0198321d14a29 100644
--- a/tools/hv/hv_fcopy_uio_daemon.c
+++ b/tools/hv/hv_fcopy_uio_daemon.c
@@ -466,8 +466,10 @@ int main(int argc, char *argv[])
 		 */
 		ret = pread(fcopy_fd, &tmp, sizeof(int), 0);
 		if (ret < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
 			syslog(LOG_ERR, "pread failed: %s", strerror(errno));
-			continue;
+			goto close;
 		}
 
 		len = HV_RING_SIZE;