diff --git a/libpfm-truncation.patch b/libpfm-truncation.patch
new file mode 100644
index 0000000..99170f3
--- /dev/null
+++ b/libpfm-truncation.patch
@@ -0,0 +1,85 @@
+diff --git a/lib/pfmlib_perf_event_pmu.c b/lib/pfmlib_perf_event_pmu.c
+index 86ff824..ca371d8 100644
+--- a/lib/pfmlib_perf_event_pmu.c
++++ b/lib/pfmlib_perf_event_pmu.c
+@@ -344,6 +344,7 @@ gen_tracepoint_table(void)
+ 
+ 	err = 0;
+ 	while((d1 = readdir(dir1)) && err >= 0) {
++		int retlen;
+ 
+ 		if (!strcmp(d1->d_name, "."))
+ 			continue;
+@@ -351,7 +352,10 @@ gen_tracepoint_table(void)
+ 		if (!strcmp(d1->d_name, ".."))
+ 			continue;
+ 
+-		snprintf(d2path, MAXPATHLEN, "%s/%s", debugfs_mnt, d1->d_name);
++		retlen = snprintf(d2path, MAXPATHLEN, "%s/%s", debugfs_mnt, d1->d_name);
++		/* if string truncated do not try to open the corrupted path */
++		if (retlen < 0 || retlen >= MAXPATHLEN)
++			continue;
+ 
+ 		/* fails if d2path is not a directory */
+ 		dir2 = opendir(d2path);
+@@ -398,10 +402,16 @@ gen_tracepoint_table(void)
+ 				continue;
+ 
+ #ifdef HAS_OPENAT
+-                        snprintf(idpath, MAXPATHLEN, "%s/id", d2->d_name);
++			retlen = snprintf(idpath, MAXPATHLEN, "%s/id", d2->d_name);
++			/* if string truncated do not try to open the corrupted path */
++			if (retlen < 0 || retlen >= MAXPATHLEN)
++				continue;
+                         fd = openat(dir2_fd, idpath, O_RDONLY);
+ #else
+-                        snprintf(idpath, MAXPATHLEN, "%s/%s/id", d2path, d2->d_name);
++			retlen = snprintf(idpath, MAXPATHLEN, "%s/%s/id", d2path, d2->d_name);
++			/* if string truncated do not try to open the corrupted path */
++			if (retlen < 0 || retlen >= MAXPATHLEN)
++				continue;
+                         fd = open(idpath, O_RDONLY);
+ #endif
+ 			if (fd == -1)
+diff --git a/perf_examples/syst_count.c b/perf_examples/syst_count.c
+index e0fa42e..7841d01 100644
+--- a/perf_examples/syst_count.c
++++ b/perf_examples/syst_count.c
+@@ -112,12 +112,14 @@ open_cgroup(char *name)
+ {
+         char path[MAX_PATH+1];
+         char mnt[MAX_PATH+1];
+-        int cfd;
++        int cfd, retlen;
+ 
+         if (cgroupfs_find_mountpoint(mnt, MAX_PATH+1))
+                 errx(1, "cannot find cgroup fs mount point");
+ 
+-        snprintf(path, MAX_PATH, "%s/%s", mnt, name);
++        retlen = snprintf(path, MAX_PATH, "%s/%s", mnt, name);
++	if (retlen < 0 || retlen >= MAX_PATH)
++                warn("path truncated %s/%s\n", mnt, name);
+ 
+         cfd = open(path, O_RDONLY);
+         if (cfd == -1)
+diff --git a/perf_examples/syst_smpl.c b/perf_examples/syst_smpl.c
+index 6b70e0e..a8b00df 100755
+--- a/perf_examples/syst_smpl.c
++++ b/perf_examples/syst_smpl.c
+@@ -278,12 +278,14 @@ open_cgroup(char *name)
+ {
+         char path[MAX_PATH+1];
+         char mnt[MAX_PATH+1];
+-        int cfd;
++        int cfd, retlen;
+ 
+         if (cgroupfs_find_mountpoint(mnt, MAX_PATH+1))
+                 errx(1, "cannot find cgroup fs mount point");
+ 
+-        snprintf(path, MAX_PATH, "%s/%s", mnt, name);
++        retlen = snprintf(path, MAX_PATH, "%s/%s", mnt, name);
++	if (retlen < 0 || retlen >= MAX_PATH)
++                warn("path truncated %s/%s\n", mnt, name);
+ 
+         cfd = open(path, O_RDONLY);
+         if (cfd == -1)
diff --git a/libpfm.spec b/libpfm.spec
index eb0ed58..0424a04 100644
--- a/libpfm.spec
+++ b/libpfm.spec
@@ -10,7 +10,7 @@
 
 Name:		libpfm
 Version:	4.9.0
-Release:	3%{?dist}
+Release:	4%{?dist}
 
 Summary:	Library to encode performance events for use by perf tool
 
@@ -18,6 +18,7 @@ Group:		System Environment/Libraries
 License:	MIT
 URL:		http://perfmon2.sourceforge.net/
 Source0:	http://sourceforge.net/projects/perfmon2/files/libpfm4/%{name}-%{version}.tar.gz
+Patch1:		libpfm-truncation.patch
 
 %if %{with python}
 BuildRequires:	python2-devel
@@ -66,6 +67,7 @@ Python bindings for libpfm4 and perf_event_open system call.
 
 %prep
 %setup -q
+%patch1 -p1 -b .trun
 
 %build
 %if %{with python}
@@ -114,6 +116,9 @@ make \
 %endif
 
 %changelog
+* Tue Jan 30 2018 William Cohen <wcohen@redhat.com> - 4.9.0-4
+- Address truncation issues.
+
 * Tue Jan 30 2018 William Cohen <wcohen@redhat.com> - 4.9.0-3
 - Use the RPM build flags. (RHBZ #1540262)