mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Avi Weiss <thnkslprpt@gmail.com>
To: jstultz@google.com, tglx@kernel.org
Cc: sboyd@kernel.org, mlichvar@redhat.com,
	linux-kernel@vger.kernel.org, Avi Weiss <thnkslprpt@gmail.com>
Subject: [PATCH] timekeeping: Refresh auxiliary base before offset validation
Date: Tue,  3 Nov 2026 11:06:05 +0200	[thread overview]
Message-ID: <20261103090605.1292660-1-thnkslprpt@gmail.com> (raw)

timekeeping_forward_now() can advance an auxiliary timekeeper across a
second boundary without refreshing tkr_mono.base. The negative-time
check in __timekeeping_inject_offset() then uses the stale base and
rejects valid ADJ_SETOFFSET adjustments with -EINVAL.

Refresh the derived timekeeper data before calculating the current
auxiliary time, as aux_clock_set() already does.

On 7.4-rc1, a valid negative adjustment fails at the first second
rollover. The patched kernel accepts all 12 tested rollover adjustments
and continues to reject invalid negative offsets.

Fixes: 2c8aea59c206 ("timekeeping: Add auxiliary clock support to __timekeeping_inject_offset()")
Signed-off-by: Avi Weiss <thnkslprpt@gmail.com>
---
 kernel/time/timekeeping.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index dcf47f1ffdcf..6d55cecf86ee 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1775,6 +1775,7 @@ static int __timekeeping_inject_offset(struct tk_data *tkd, const struct timespe
 		struct tk_read_base *tkr_mono = &tks->tkr_mono;
 		ktime_t now, offs;
 
+		tk_update_ktime_data(tks);
 		/* Get the current time */
 		now = ktime_add_ns(tkr_mono->base, timekeeping_get_ns(tkr_mono));
 		/* Add the relative offset change */

base-commit: 6628e7d4c6b25c8d18f1345e3a20d21829aae7e4
-- 
2.53.0


                 reply	other threads:[~2026-11-03  9:06 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20261103090605.1292660-1-thnkslprpt@gmail.com \
    --to=thnkslprpt@gmail.com \
    --cc=jstultz@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mlichvar@redhat.com \
    --cc=sboyd@kernel.org \
    --cc=tglx@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®