[PATCH 6.1 208/312] mips: mm: Allocate tlb_vpn array atomically

Greg Kroah-Hartman
2026-04-08T18:15:46Z

From: Stefan Wiehler <stefan.wiehler@nokia.com>

commit 01cc50ea5167bb14117257ec084637abe9e5f691 upstream.

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@nokia.com>
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/mips/mm/tlb-r4k.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -528,7 +528,7 @@ static void __ref r4k_tlb_uniquify(void)

tlb_vpn_size = tlbsize * sizeof(*tlb_vpns);
tlb_vpns = (use_slab ?
- kmalloc(tlb_vpn_size, GFP_KERNEL) :
+ kmalloc(tlb_vpn_size, GFP_ATOMIC) :
memblock_alloc_raw(tlb_vpn_size, sizeof(*tlb_vpns)));
if (WARN_ON(!tlb_vpns))
return; /* Pray local_flush_tlb_all() is good enough. */