File s390-tools-sles15sp4-zdump-fix-dev-mem-reading.patch of Package s390-tools.30980

From 455ad953a91be08229837b10c3ee63c9615a4001 Mon Sep 17 00:00:00 2001
From: Alexander Egorenkov <egorenar@linux.ibm.com>
Date: Fri, 28 Jan 2022 15:12:01 +0100
Subject: [PATCH] zdump: Fix /dev/mem reading
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This commit makes zgetdump work with /dev/mem again.
zg_seek() should not attempt to verify the given offset for devices before
issuing lseek() because special devices like /dev/mem report 0 in
stat.sb_size.

$ zgetdump -i /dev/mem
zgetdump: Trying to seek past file end "/dev/mem"

Fixes: 11e78cada516 ("zdump: catch attempts to seek past end of file in zg_seek()")
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zdump/zg.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/zdump/zg.c b/zdump/zg.c
index 8f41793..082167f 100644
--- a/zdump/zg.c
+++ b/zdump/zg.c
@@ -280,7 +280,7 @@ off_t zg_seek(struct zg_fh *zg_fh, off_t off, enum zg_check check)
 {
 	off_t rc;
 
-	if (off >= zg_fh->sb.st_size)
+	if (S_ISREG(zg_fh->sb.st_mode) && off >= zg_fh->sb.st_size)
 		ERR_EXIT("Trying to seek past file end \"%s\"", zg_fh->path);
 
 	rc = lseek(zg_fh->fh, off, SEEK_SET);
-- 
2.35.3