Re: [PATCH RFC 07/11] dyndbg: use READ_ONCE()/WRITE_ONCE() to access descriptor flags
flat view
From: "Gary Guo" <gary@garyguo.net>
Date: 2026-10-11 13:16:29
Also in:
driver-core, linux-kselftest, lkml, rust-for-linux
On Sun Oct 11, 2026 at 1:52 PM BST, Thomas Weißschuh wrote:
The descriptor flags are accessed concurrently. Use READ_ONCE()/WRITE_ONCE() to keep their contents consistent. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> --- I am not entirely sure about this. We are only using single bits, so torn reads/writes should not matter. But LKMM has no guidance on this as far as I can see. Also for Rust this seems to be necessary.
Code should assume plain writes to be atomic. Concurrently accessed data should use READ_ONCE/WRITE_ONCE so you're right on this one. I think this patch should be merged with the bitfield definition change, though. Best, Gary
quoted hunk ↗ jump to hunk
--- include/linux/dynamic_debug.h | 6 +++--- lib/dynamic_debug.c | 24 +++++++++++++----------- 2 files changed, 16 insertions(+), 14 deletions(-)