[alsa-devel] [PATCH] ASoC: Intel: sst: fix kmalloc call with wrong flags

[Alex Levin]

When calling kmalloc with GFP_KERNEL in case CONFIG_SLOB is unset,
kmem_cache_alloc_trace is called.

In case CONFIG_TRACING is set, kmem_cache_alloc_trace will ball
slab_alloc, which will call slab_pre_alloc_hook which might_sleep_if.

The context in which it is called in this case, the
intel_sst_interrupt_mrfld, calling a sleeping kmalloc generates a BUG():

Fixes: 972b0d456e64 ("ASoC: Intel: remove GFP_ATOMIC, use GFP_KERNEL")

[   20.250671] BUG: sleeping function called from invalid context at mm/slab.h:422
[   20.250683] in_atomic(): 1, irqs_disabled(): 1, pid: 1791, name: Chrome_IOThread
[   20.250690] CPU: 0 PID: 1791 Comm: Chrome_IOThread Tainted: G        W         4.19.43 #61
[   20.250693] Hardware name: GOOGLE Kefka, BIOS Google_Kefka.7287.337.0 03/02/2017
[   20.250697] Call Trace:
[   20.250704]  <IRQ>
[   20.250716]  dump_stack+0x7e/0xc3
[   20.250725]  ___might_sleep+0x12a/0x140
[   20.250731]  kmem_cache_alloc_trace+0x53/0x1c5
[   20.250736]  ? update_cfs_rq_load_avg+0x17e/0x1aa
[   20.250740]  ? cpu_load_update+0x6c/0xc2
[   20.250746]  sst_create_ipc_msg+0x2d/0x88
[   20.250752]  intel_sst_interrupt_mrfld+0x12a/0x22c
[   20.250758]  __handle_irq_event_percpu+0x133/0x228
[   20.250764]  handle_irq_event_percpu+0x35/0x7a
[   20.250768]  handle_irq_event+0x36/0x55
[   20.250773]  handle_fasteoi_irq+0xab/0x16c
[   20.250779]  handle_irq+0xd9/0x11e
[   20.250785]  do_IRQ+0x54/0xe0
[   20.250791]  common_interrupt+0xf/0xf
[   20.250795]  </IRQ>
[   20.250800] RIP: 0010:__lru_cache_add+0x4e/0xad
[   20.250806] Code: 00 01 48 c7 c7 b8 df 01 00 65 48 03 3c 25 28 f1 00 00 48 8b 48 08 48 89 ca 48 ff ca f6 c1 01 48 0f 44 d0 f0 ff 42 34 0f b6 0f <89> ca fe c2 88 17 48 89 44 cf 08 80 fa 0f 74 0e 48 8b 08 66 85 c9
[   20.250809] RSP: 0000:ffffa568810bfd98 EFLAGS: 00000202 ORIG_RAX: ffffffffffffffd6
[   20.250814] RAX: ffffd3b904eb1940 RBX: ffffd3b904eb1940 RCX: 0000000000000004
[   20.250817] RDX: ffffd3b904eb1940 RSI: ffffa10ee5c47450 RDI: ffffa10efba1dfb8
[   20.250821] RBP: ffffa568810bfda8 R08: ffffa10ef9c741c1 R09: dead000000000100
[   20.250824] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa10ee8d52a40
[   20.250827] R13: ffffa10ee8d52000 R14: ffffa10ee5c47450 R15: 800000013ac65067
[   20.250835]  lru_cache_add_active_or_unevictable+0x4e/0xb8
[   20.250841]  handle_mm_fault+0xd98/0x10c4
[   20.250848]  __do_page_fault+0x235/0x42d
[   20.250853]  ? page_fault+0x8/0x30
[   20.250858]  do_page_fault+0x3d/0x17a
[   20.250862]  ? page_fault+0x8/0x30
[   20.250866]  page_fault+0x1e/0x30
[   20.250872] RIP: 0033:0x7962fdea9304
[   20.250875] Code: 0f 11 4c 17 f0 c3 48 3b 15 f1 26 31 00 0f 83 e2 00 00 00 48 39 f7 72 0f 74 12 4c 8d 0c 16 4c 39 cf 0f 82 63 01 00 00 48 89 d1 <f3> a4 c3 80 fa 08 73 12 80 fa 04 73 1e 80 fa 01 77 26 72 05 0f b6
[   20.250879] RSP: 002b:00007962f4db5468 EFLAGS: 00010206
[   20.250883] RAX: 00003c8cc9d47008 RBX: 0000000000000000 RCX: 0000000000001b48
[   20.250886] RDX: 0000000000002b40 RSI: 00003c8cc9551000 RDI: 00003c8cc9d48000
[   20.250890] RBP: 00007962f4db5820 R08: 0000000000000000 R09: 00003c8cc9552b48
[   20.250893] R10: 0000562dd1064d30 R11: 00003c8cc825b908 R12: 00003c8cc966d3c0
[   20.250896] R13: 00003c8cc9e280c0 R14: 0000000000000000 R15: 0000000000000000

Signed-off-by: Alex Levin <levinale at chromium.org>
---

 sound/soc/intel/atom/sst/sst_pvt.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/intel/atom/sst/sst_pvt.c b/sound/soc/intel/atom/sst/sst_pvt.c
index 00a37a09dc9b..dba0ca07ebf9 100644
--- a/sound/soc/intel/atom/sst/sst_pvt.c
+++ b/sound/soc/intel/atom/sst/sst_pvt.c
@@ -166,11 +166,11 @@ int sst_create_ipc_msg(struct ipc_post **arg, bool large)
 {
 	struct ipc_post *msg;
 
-	msg = kzalloc(sizeof(*msg), GFP_KERNEL);
+	msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
 	if (!msg)
 		return -ENOMEM;
 	if (large) {
-		msg->mailbox_data = kzalloc(SST_MAILBOX_SIZE, GFP_KERNEL);
+		msg->mailbox_data = kzalloc(SST_MAILBOX_SIZE, GFP_ATOMIC);
 		if (!msg->mailbox_data) {
 			kfree(msg);
 			return -ENOMEM;
-- 
2.22.0.rc2.383.gf4fbbf30c2-goog