timekeeping: Make do_adjtimex() reusable

Split out the actual functionality of adjtimex() and make do_adjtimex() a
wrapper which feeds the core timekeeper into it and handles the result
including audit at the call site.

This allows to reuse the actual functionality for auxiliary clocks.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <jstultz@google.com>
Link: https://lore.kernel.org/all/20250625183758.187322876@linutronix.de

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e893557cd53f51af7a67b9c7c4cd62f52db9ae37..0de61315b40c3ce69c8d3ec8c3bd5c42c3494257 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -2585,17 +2585,18 @@ unsigned long random_get_entropy_fallback(void)
 }
 EXPORT_SYMBOL_GPL(random_get_entropy_fallback);
 
-/**
- * do_adjtimex() - Accessor function to NTP __do_adjtimex function
- * @txc:       Pointer to kernel_timex structure containing NTP parameters
- */
-int do_adjtimex(struct __kernel_timex *txc)
+struct adjtimex_result {
+       struct audit_ntp_data   ad;
+       struct timespec64       delta;
+       bool                    clock_set;
+};
+
+static int __do_adjtimex(struct tk_data *tkd, struct __kernel_timex *txc,
+                        struct adjtimex_result *result)
 {
-       struct tk_data *tkd = &tk_core;
-       struct timespec64 delta, ts;
-       struct audit_ntp_data ad;
-       bool offset_set = false;
-       bool clock_set = false;
+       struct timekeeper *tks = &tkd->shadow_timekeeper;
+       struct timespec64 ts;
+       s32 orig_tai, tai;
        int ret;
 
        /* Validate the data before disabling interrupts */
@@ -2604,56 +2605,65 @@ int do_adjtimex(struct __kernel_timex *txc)
                return ret;
        add_device_randomness(txc, sizeof(*txc));
 
-       audit_ntp_init(&ad);
-
        ktime_get_real_ts64(&ts);
        add_device_randomness(&ts, sizeof(ts));
 
-       scoped_guard (raw_spinlock_irqsave, &tkd->lock) {
-               struct timekeeper *tks = &tkd->shadow_timekeeper;
-               s32 orig_tai, tai;
+       guard(raw_spinlock_irqsave)(&tkd->lock);
 
-               if (!tks->clock_valid)
-                       return -ENODEV;
-
-               if (txc->modes & ADJ_SETOFFSET) {
-                       delta.tv_sec  = txc->time.tv_sec;
-                       delta.tv_nsec = txc->time.tv_usec;
-                       if (!(txc->modes & ADJ_NANO))
-                               delta.tv_nsec *= 1000;
-                       ret = __timekeeping_inject_offset(tkd, &delta);
-                       if (ret)
-                               return ret;
-
-                       offset_set = delta.tv_sec != 0;
-                       clock_set = true;
-               }
+       if (!tks->clock_valid)
+               return -ENODEV;
 
-               orig_tai = tai = tks->tai_offset;
-               ret = ntp_adjtimex(tks->id, txc, &ts, &tai, &ad);
+       if (txc->modes & ADJ_SETOFFSET) {
+               result->delta.tv_sec  = txc->time.tv_sec;
+               result->delta.tv_nsec = txc->time.tv_usec;
+               if (!(txc->modes & ADJ_NANO))
+                       result->delta.tv_nsec *= 1000;
+               ret = __timekeeping_inject_offset(tkd, &result->delta);
+               if (ret)
+                       return ret;
+               result->clock_set = true;
+       }
 
-               if (tai != orig_tai) {
-                       __timekeeping_set_tai_offset(tks, tai);
-                       timekeeping_update_from_shadow(tkd, TK_CLOCK_WAS_SET);
-                       clock_set = true;
-               } else {
-                       tk_update_leap_state_all(&tk_core);
-               }
+       orig_tai = tai = tks->tai_offset;
+       ret = ntp_adjtimex(tks->id, txc, &ts, &tai, &result->ad);
 
-               /* Update the multiplier immediately if frequency was set directly */
-               if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK))
-                       clock_set |= __timekeeping_advance(tkd, TK_ADV_FREQ);
+       if (tai != orig_tai) {
+               __timekeeping_set_tai_offset(tks, tai);
+               timekeeping_update_from_shadow(tkd, TK_CLOCK_WAS_SET);
+               result->clock_set = true;
+       } else {
+               tk_update_leap_state_all(&tk_core);
        }
 
+       /* Update the multiplier immediately if frequency was set directly */
+       if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK))
+               result->clock_set |= __timekeeping_advance(tkd, TK_ADV_FREQ);
+
+       return ret;
+}
+
+/**
+ * do_adjtimex() - Accessor function to NTP __do_adjtimex function
+ * @txc:       Pointer to kernel_timex structure containing NTP parameters
+ */
+int do_adjtimex(struct __kernel_timex *txc)
+{
+       struct adjtimex_result result = { };
+       int ret;
+
+       ret = __do_adjtimex(&tk_core, txc, &result);
+       if (ret < 0)
+               return ret;
+
        if (txc->modes & ADJ_SETOFFSET)
-               audit_tk_injoffset(delta);
+               audit_tk_injoffset(result.delta);
 
-       audit_ntp_log(&ad);
+       audit_ntp_log(&result.ad);
 
-       if (clock_set)
+       if (result.clock_set)
                clock_was_set(CLOCK_SET_WALL);
 
-       ntp_notify_cmos_timer(offset_set);
+       ntp_notify_cmos_timer(result.delta.tv_sec != 0);
 
        return ret;
 }