Re: [PATCH] mips: mm: Allocate tlb_vpn array atomically

[Thomas Bogendoerfer]

On Tue, Mar 10, 2026 at 11:40:24AM +0100, Stefan Wiehler wrote:
> Found by DEBUG_ATOMIC_SLEEP:
> 
>   BUG: sleeping function called from invalid context at /include/linux/sched/mm.h:306
>   in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 0, name: swapper/1
>   preempt_count: 1, expected: 0
>   RCU nest depth: 0, expected: 0
>   no locks held by swapper/1/0.
>   irq event stamp: 0
>   hardirqs last  enabled at (0): [<0000000000000000>] 0x0
>   hardirqs last disabled at (0): [<ffffffff801477fc>] copy_process+0x75c/0x1b68
>   softirqs last  enabled at (0): [<ffffffff801477fc>] copy_process+0x75c/0x1b68
>   softirqs last disabled at (0): [<0000000000000000>] 0x0
>   CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.119-d79e757675ec-fct #1
>   Stack : 800000000290bad8 0000000000000000 0000000000000008 800000000290bae8
>           800000000290bae8 800000000290bc78 0000000000000000 0000000000000000
>           ffffffff80c80000 0000000000000001 ffffffff80d8dee8 ffffffff810d09c0
>           784bb2a7ec10647d 0000000000000010 ffffffff80a6fd60 8000000001d8a9c0
>           0000000000000000 0000000000000000 ffffffff80d90000 0000000000000000
>           ffffffff80c9e0e8 0000000007ffffff 0000000000000cc0 0000000000000400
>           ffffffffffffffff 0000000000000001 0000000000000002 ffffffffc0149ed8
>           fffffffffffffffe 8000000002908000 800000000290bae0 ffffffff80a81b74
>           ffffffff80129fb0 0000000000000000 0000000000000000 0000000000000000
>           0000000000000000 0000000000000000 ffffffff80129fd0 0000000000000000
>           ...
>   Call Trace:
>   [<ffffffff80129fd0>] show_stack+0x60/0x158
>   [<ffffffff80a7f894>] dump_stack_lvl+0x88/0xbc
>   [<ffffffff8018d3c8>] __might_resched+0x268/0x288
>   [<ffffffff803648b0>] __kmem_cache_alloc_node+0x2e0/0x330
>   [<ffffffff80302788>] __kmalloc+0x58/0xd0
>   [<ffffffff80a81b74>] r4k_tlb_uniquify+0x7c/0x428
>   [<ffffffff80143e8c>] tlb_init+0x7c/0x110
>   [<ffffffff8012bdb4>] per_cpu_trap_init+0x16c/0x1d0
>   [<ffffffff80133258>] start_secondary+0x28/0x128
> 
> Fixes: 231ac951faba ("MIPS: mm: kmalloc tlb_vpn array to avoid stack overflow")
> Signed-off-by: Stefan Wiehler <stefan.wiehler@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
>  arch/mips/mm/tlb-r4k.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

applied to mips-fixes

Thomas.

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