Hi Breno, (Sorry, sending this again as I forgot to use reply-all in my previous email.)
On Tue, Aug 11, 2026 at 1:46 AM Breno Leitao <[email protected]> wrote: > > put_chars() runs from the hvc console write path with preemption > disabled, so it asks alloc_buf() for GFP_ATOMIC. Only the data buffer > gets it: the struct port_buffer itself keeps the GFP_KERNEL default, so > the allocation can enter direct reclaim and sleep. A write to /dev/kmsg > on a CONFIG_DEBUG_ATOMIC_SLEEP kernel splats: > > BUG: sleeping function called from invalid context at > ./include/linux/sched/mm.h:320 > in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: > virtme-ng-init > preempt_count: 1, expected: 0 > Preemption disabled at: > [<ffffffff813fd90d>] vprintk_emit+0x17d/0x510 > Call Trace: > <TASK> > dump_stack_lvl+0x69/0xa0 > __might_resched+0x37a/0x4d0 > __kmalloc_cache_noprof+0x94/0x5f0 > put_chars+0x209/0x3e0 > hvc_console_print+0x234/0x640 > console_flush_all+0x4fc/0x950 > console_unlock+0xbf/0x1b0 > vprintk_emit+0x312/0x510 > devkmsg_emit+0xba/0x110 > devkmsg_write+0x21b/0x2e0 > vfs_write+0x4dc/0x9d0 > ksys_write+0x108/0x1e0 > do_syscall_64+0xfa/0x460 > </TASK> > > Pass gfp on to that allocation too. > > Fixes: fc220d6be3c7 ("virtio_console: refactor __send_to_port() buffer > ownership") > Signed-off-by: Breno Leitao <[email protected]> Looks good to me. Thanks for fixing the part I missed. Acked-by: Sungho Bae <[email protected]> -- Thanks, Sungho
