From: "Thomas Weißschuh" <thomas.weissschuh@linutronix.de>
To: Anna-Maria Behnsen <anna-maria@linutronix.de>,
Frederic Weisbecker <frederic@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org,
"Thomas Weißschuh" <thomas.weissschuh@linutronix.de>
Subject: [PATCH] timer_list: Don't use %pK through printk
Date: Tue, 11 Mar 2025 10:54:47 +0100 [thread overview]
Message-ID: <20250311-restricted-pointers-timer-v1-1-6626b91e54ab@linutronix.de> (raw)
This reverts
commit f590308536db ("timer debug: Hide kernel addresses via %pK in /proc/timer_list")
SEQ_printf() either uses the real seq_printf() to write implement a virtual
file or vprintk() to print to the kernel log.
In the past %pK was preferable to %p as it would not leak raw pointer
values into the kernel log.
Since commit ad67b74d2469 ("printk: hash addresses printed with %p")
the regular %p has been improved to avoid this issue.
Furthermore, restricted pointers ("%pK") were never meant to be used
through printk(). They can still unintentionally leak raw pointers or
acquire sleeping looks in atomic contexts.
Switch to the regular pointer formatting which is safer, easier to reason
about and sufficient here.
Link: https://lore.kernel.org/lkml/20250113171731-dc10e3c1-da64-4af0-b767-7c7070468023@linutronix.de/
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
---
kernel/time/timer_list.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index 1c311c46da5074c1cb33027c96638e68a606574a..cfbb46cc4e7613a3d7255b67a941dd05387cf68e 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -46,7 +46,7 @@ static void
print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
int idx, u64 now)
{
- SEQ_printf(m, " #%d: <%pK>, %ps", idx, taddr, timer->function);
+ SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, timer->function);
SEQ_printf(m, ", S:%02x", timer->state);
SEQ_printf(m, "\n");
SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
@@ -98,7 +98,7 @@ print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base,
static void
print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
{
- SEQ_printf(m, " .base: %pK\n", base);
+ SEQ_printf(m, " .base: %p\n", base);
SEQ_printf(m, " .index: %d\n", base->index);
SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution);
---
base-commit: 4d872d51bc9d7b899c1f61534e3dbde72613f627
change-id: 20250311-restricted-pointers-timer-f169f21c3838
Best regards,
--
Thomas Weißschuh <thomas.weissschuh@linutronix.de>
next reply other threads:[~2025-03-11 9:54 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-11 9:54 Thomas Weißschuh [this message]
2025-03-13 7:32 ` [tip: timers/core] timer_list: Don't use %pK through printk() tip-bot2 for Thomas Weißschuh
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=20250311-restricted-pointers-timer-v1-1-6626b91e54ab@linutronix.de \
--to=thomas.weissschuh@linutronix.de \
--cc=anna-maria@linutronix.de \
--cc=frederic@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tglx@linutronix.de \
/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®