On 2025-01-02, Petr Mladek <pmladek@xxxxxxxx> wrote: > On Mon 2024-12-30 14:26:43, Rob Herring wrote: >> On Thu, Dec 19, 2024 at 08:17:21PM +0106, John Ogness wrote: >> > On 2024-12-19, Petr Mladek <pmladek@xxxxxxxx> wrote: >> > > I do not want to revert everything now just because of theoretical >> > > problems. >> > >> > What would you revert? This has always been an issue for printk(). >> > >> > > Well, it would be nice to document the lock dependency in >> > > Documentation/core-api/printk-formats.rst >> > >> > Yes. If any locking is involved at all, such specifiers should be >> > documented as not safe in NMI context or within printk_cpu_sync >> > blocks. >> >> For the folks that don't read documentation, should we bail out on >> in_nmi() for these as well? > > I like this idea. Perhaps also include a check using the upcoming is_printk_cpu_sync_owner() [0] as well. John Ogness [0] https://git.kernel.org/pub/scm/linux/kernel/git/printk/linux.git/commit/?h=for-6.14-cpu_sync-fixup&id=0161e2d6950fe66cf6ac1c10d945bae971f33667
