[PATCH 02/11] ARM: VDSO: remove cntvct_ok global variable

Thomas Weißschuh thomas.weissschuh at linutronix.de
Tue Aug 26 16:17:05 AEST 2025


From: Rasmus Villemoes <linux at rasmusvillemoes.dk>

The cntvct_ok variable has not had any external user since commit
c7a18100bdff ("lib/vdso: Avoid highres update if clocksource is not
VDSO capable").

It also only has one user in vdso.c, once during init, so rather than
having the caller of patch_vdso() initialize cntvct_ok, just call
cntvct_functional() directly and avoid the global variable entirely.

Signed-off-by: Rasmus Villemoes <linux at rasmusvillemoes.dk>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino at arm.com>
---
 arch/arm/include/asm/vdso/vsyscall.h |  2 --
 arch/arm/kernel/vdso.c               | 10 +++-------
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
index 4e7226ad02ec4dcf88203c9046e1b320a10e7373..ff1c729af05f03ac5db86c28276db2e4a31c775c 100644
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -7,8 +7,6 @@
 #include <vdso/datapage.h>
 #include <asm/cacheflush.h>
 
-extern bool cntvct_ok;
-
 static __always_inline
 void __arch_sync_vdso_time_data(struct vdso_time_data *vdata)
 {
diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c
index 325448ffbba0c29895ea5d97e60d6f51e552cb2e..e38a30477f3d70939f6d57c79fad52eed73c49b4 100644
--- a/arch/arm/kernel/vdso.c
+++ b/arch/arm/kernel/vdso.c
@@ -54,11 +54,9 @@ struct elfinfo {
 	char		*dynstr;	/* ptr to .dynstr section */
 };
 
-/* Cached result of boot-time check for whether the arch timer exists,
- * and if so, whether the virtual counter is useable.
+/* Boot-time check for whether the arch timer exists, and if so,
+ * whether the virtual counter is usable.
  */
-bool cntvct_ok __ro_after_init;
-
 static bool __init cntvct_functional(void)
 {
 	struct device_node *np;
@@ -159,7 +157,7 @@ static void __init patch_vdso(void *ehdr)
 	 * want programs to incur the slight additional overhead of
 	 * dispatching through the VDSO only to fall back to syscalls.
 	 */
-	if (!cntvct_ok) {
+	if (!cntvct_functional()) {
 		vdso_nullpatch_one(&einfo, "__vdso_gettimeofday");
 		vdso_nullpatch_one(&einfo, "__vdso_clock_gettime");
 		vdso_nullpatch_one(&einfo, "__vdso_clock_gettime64");
@@ -197,8 +195,6 @@ static int __init vdso_init(void)
 	vdso_total_pages = VDSO_NR_PAGES; /* for the data/vvar pages */
 	vdso_total_pages += text_pages;
 
-	cntvct_ok = cntvct_functional();
-
 	patch_vdso(vdso_start);
 
 	return 0;

-- 
2.50.1



More information about the Linuxppc-dev mailing list