util-linux/0099-lscpu-avoid-EBUSY-on-cpuinfo_max_freq.patch

From e561e4740d8dd5419e5fb23ab186ae43fd572736 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Wed, 10 Jan 2024 12:08:17 +0100
Subject: lscpu: avoid EBUSY on cpuinfo_max_freq

Addresses: https://issues.redhat.com/browse/RHEL-13741
---
 include/path.h    |  4 ++++
 lib/path.c        | 20 ++++++++++++++++++++
 sys-utils/lscpu.c | 18 ++++++++++++------
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/include/path.h b/include/path.h
index 4be01095c..965bdd047 100644
--- a/include/path.h
+++ b/include/path.h
@@ -19,8 +19,12 @@ extern void path_read_str(char *result, size_t len, const char *path, ...)
 			__attribute__ ((__format__ (__printf__, 3, 4)));
 extern int path_write_str(const char *str, const char *path, ...)
 			 __attribute__ ((__format__ (__printf__, 2, 3)));
+
+extern int __path_read_s32(int *result, const char *path, ...)
+			__attribute__ ((__format__ (__printf__, 2, 3)));
 extern int path_read_s32(const char *path, ...)
 			__attribute__ ((__format__ (__printf__, 1, 2)));
+
 extern uint64_t path_read_u64(const char *path, ...)
 			__attribute__ ((__format__ (__printf__, 1, 2)));
 
diff --git a/lib/path.c b/lib/path.c
index e8cfa557a..7217c9089 100644
--- a/lib/path.c
+++ b/lib/path.c
@@ -145,6 +145,26 @@ path_read_str(char *result, size_t len, const char *path, ...)
 		result[len - 1] = '\0';
 }
 
+/* like path_read_s32() but do not print any error message */
+int __path_read_s32(int *result, const char *path, ...)
+{
+	FILE *f;
+	va_list ap;
+	int rc;
+
+	va_start(ap, path);
+	f = path_vfopen("r" UL_CLOEXECSTR, 0, path, ap);
+	va_end(ap);
+
+	if (!f)
+		return -1;
+
+	rc = fscanf(f, "%d", result);
+	fclose(f);
+
+	return rc == 1 ? 0 : -1;
+}
+
 int
 path_read_s32(const char *path, ...)
 {
diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 01f8fba35..ed5543901 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -1176,28 +1176,34 @@ static void
 read_max_mhz(struct lscpu_desc *desc, int idx)
 {
 	int num = real_cpu_num(desc, idx);
+	int mhz = 0;
 
 	if (!path_exist(_PATH_SYS_CPU "/cpu%d/cpufreq/cpuinfo_max_freq", num))
 		return;
+	if (__path_read_s32(&mhz, _PATH_SYS_CPU
+				"/cpu%d/cpufreq/cpuinfo_max_freq", num) != 0)
+		return;
+
 	if (!desc->maxmhz)
 		desc->maxmhz = xcalloc(desc->ncpuspos, sizeof(char *));
-	xasprintf(&(desc->maxmhz[idx]), "%.4f",
-		  (float)path_read_s32(_PATH_SYS_CPU
-				       "/cpu%d/cpufreq/cpuinfo_max_freq", num) / 1000);
+	xasprintf(&(desc->maxmhz[idx]), "%.4f", (float) mhz / 1000);
 }
 
 static void
 read_min_mhz(struct lscpu_desc *desc, int idx)
 {
 	int num = real_cpu_num(desc, idx);
+	int mhz = 0;
 
 	if (!path_exist(_PATH_SYS_CPU "/cpu%d/cpufreq/cpuinfo_min_freq", num))
 		return;
+	if (__path_read_s32(&mhz, _PATH_SYS_CPU
+				"/cpu%d/cpufreq/cpuinfo_min_freq", num) != 0)
+		return;
+
 	if (!desc->minmhz)
 		desc->minmhz = xcalloc(desc->ncpuspos, sizeof(char *));
-	xasprintf(&(desc->minmhz[idx]), "%.4f",
-		  (float)path_read_s32(_PATH_SYS_CPU
-				       "/cpu%d/cpufreq/cpuinfo_min_freq", num) / 1000);
+	xasprintf(&(desc->minmhz[idx]), "%.4f", (float) mhz / 1000);
 }
 
 static int
-- 
2.43.0