[patch V2 21/26] timekeeping: Add auxiliary clock support to __timekeeping_inject_offset()
From: Thomas Gleixner <hidden>
Date: 2025-05-19 08:33:41
Also in:
lkml
Redirect the relative offset adjustment to the auxiliary clock offset instead of modifying CLOCK_REALTIME, which has no meaning in context of these clocks. Signed-off-by: Thomas Gleixner <redacted> --- kernel/time/timekeeping.c | 34 ++++++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 8 deletions(-) ---
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c@@ -1448,16 +1448,34 @@ static int __timekeeping_inject_offset(s timekeeping_forward_now(tks); - /* Make sure the proposed value is valid */ - tmp = timespec64_add(tk_xtime(tks), *ts); - if (timespec64_compare(&tks->wall_to_monotonic, ts) > 0 || - !timespec64_valid_settod(&tmp)) { - timekeeping_restore_shadow(tkd); - return -EINVAL; + if (!IS_ENABLED(CONFIG_POSIX_AUX_CLOCKS) || tks->id == TIMEKEEPER_CORE) { + /* Make sure the proposed value is valid */ + tmp = timespec64_add(tk_xtime(tks), *ts); + if (timespec64_compare(&tks->wall_to_monotonic, ts) > 0 || + !timespec64_valid_settod(&tmp)) { + timekeeping_restore_shadow(tkd); + return -EINVAL; + } + + tk_xtime_add(tks, ts); + tk_set_wall_to_mono(tks, timespec64_sub(tks->wall_to_monotonic, *ts)); + } else { + struct tk_read_base *tkr_mono = &tks->tkr_mono; + ktime_t now, offs; + + /* Get the current time */ + now = ktime_add_ns(tkr_mono->base, timekeeping_get_ns(tkr_mono)); + /* Add the relative offset change */ + offs = ktime_add(tks->offs_aux, timespec64_to_ktime(*ts)); + + /* Prevent that the resulting time becomes negative */ + if (ktime_add(now, offs) < 0) { + timekeeping_restore_shadow(tkd); + return -EINVAL; + } + tks->offs_aux = offs; } - tk_xtime_add(tks, ts); - tk_set_wall_to_mono(tks, timespec64_sub(tks->wall_to_monotonic, *ts)); timekeeping_update_from_shadow(tkd, TK_UPDATE_ALL); return 0; }