Always check the return value of lseek.

This is a follow-up to r289845, which only fixed one occurence of CID
1009429.

Coverity CID:	1009429
Reviewed by:	markj
MFC after:	2 weeks
X-MFC-With:	r289845
Sponsored by:	Spectra Logic
Differential Revision:	https://reviews.freebsd.org/D4096

1 files changed, 4 insertions, 6 deletions

diff --git a/sbin/savecore/savecore.c b/sbin/savecore/savecore.c
index b87b95b..0c1e806 100644
--- a/sbin/savecore/savecore.c
+++ b/sbin/savecore/savecore.c
@@ -491,9 +491,8 @@ DoFile(const char *savedir, const char *device)
 	}
 
 	lasthd = mediasize - sectorsize;
-	lseek(fd, lasthd, SEEK_SET);
-	error = read(fd, &kdhl, sizeof kdhl);
-	if (error != sizeof kdhl) {
+	if (lseek(fd, lasthd, SEEK_SET) != lasthd ||
+	    read(fd, &kdhl, sizeof(kdhl)) != sizeof(kdhl)) {
 		syslog(LOG_ERR,
 		    "error reading last dump header at offset %lld in %s: %m",
 		    (long long)lasthd, device);
@@ -569,9 +568,8 @@ DoFile(const char *savedir, const char *device)
 	}
 	dumpsize = dtoh64(kdhl.dumplength);
 	firsthd = lasthd - dumpsize - sizeof kdhf;
-	lseek(fd, firsthd, SEEK_SET);
-	error = read(fd, &kdhf, sizeof kdhf);
-	if (error != sizeof kdhf) {
+	if (lseek(fd, firsthd, SEEK_SET) != firsthd ||
+	    read(fd, &kdhf, sizeof(kdhf)) != sizeof(kdhf)) {
 		syslog(LOG_ERR,
 		    "error reading first dump header at offset %lld in %s: %m",
 		    (long long)firsthd, device);