[PATCH v2 2/9] vdso/gettimeofday: Validate system call existence for time() and gettimeofday()
From: Thomas Weißschuh <hidden>
Date: 2026-06-30 07:38:39
Also in:
linux-api, linux-arm-kernel, linux-mips, lkml, sparclinux
Subsystem:
generic vdso library, library code, the rest · Maintainers:
Andy Lutomirski, Thomas Gleixner, Vincenzo Frascino, Andrew Morton, Linus Torvalds
Not all architectures have the system calls for time() and gettimeofday(). When the system call is missing, the vDSO function should also not be present. Validate that. Signed-off-by: Thomas Weißschuh <redacted> --- lib/vdso/gettimeofday.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index e0f289d3d110..b8c1fc85eb74 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c@@ -12,6 +12,8 @@ #include <vdso/time32.h> #include <vdso/time64.h> +#include <uapi/linux/unistd.h> + /* * The generic vDSO implementation requires that gettimeofday.h * provides:
@@ -348,6 +350,10 @@ __cvdso_gettimeofday_data(const struct vdso_time_data *vd, { const struct vdso_clock *vc = vd->clock_data; +#ifndef __NR_gettimeofday + BUILD_BUG(); +#endif + if (likely(tv != NULL)) { struct __kernel_timespec ts;
@@ -382,6 +388,10 @@ __cvdso_time_data(const struct vdso_time_data *vd, __kernel_old_time_t *time) const struct vdso_clock *vc = vd->clock_data; __kernel_old_time_t t; +#ifndef __NR_time + BUILD_BUG(); +#endif + if (vdso_is_timens_clock(vc)) { vd = vdso_timens_data(vd); vc = vd->clock_data;
--
2.55.0