Re: [PATCH] acpi: osl: Replace GFP_ATOMIC with GFP_KERNEL in acpi_os_execute
From: Jia-Ju Bai
Date: Thu Feb 08 2018 - 08:42:41 EST
On 2018/2/8 18:20, Rafael J. Wysocki wrote:
On Thursday, February 8, 2018 11:13:10 AM CET Chris Wilson wrote:
Quoting Rafael J. Wysocki (2018-02-08 09:51:41)
On Thursday, January 25, 2018 11:13:41 AM CET Jia-Ju Bai wrote:
After checking all possible call chains to acpi_os_execute here,
my tool finds that acpi_os_execute is never called in atomic context.
And acpi_os_execute calls acpi_debugger_create_thread
which calls mutex_lock,
thus it proves again that acpi_os_execute can
call functions which may sleep.
Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.
This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
---
drivers/acpi/osl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index 3bb46cb..8ee605e 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -1066,7 +1066,7 @@ acpi_status acpi_os_execute(acpi_execute_type type,
* having a static work_struct.
*/
- dpc = kzalloc(sizeof(struct acpi_os_dpc), GFP_ATOMIC);
+ dpc = kzalloc(sizeof(struct acpi_os_dpc), GFP_KERNEL);
if (!dpc)
return AE_NO_MEMORY;
Applied, thanks!
Hmm, not this patch per se, but
https://intel-gfx-ci.01.org/tree/next/next-20180207/fi-bxt-dsi/dmesg0.log
[ 111.378236] BUG: sleeping function called from invalid context at mm/slab.h:420
[ 111.378259] in_atomic(): 1, irqs_disabled(): 1, pid: 1701, name: gem_exec_flush
[ 111.378275] INFO: lockdep is turned off.
[ 111.378277] irq event stamp: 0
[ 111.378280] hardirqs last enabled at (0): [< (null)>] (null)
[ 111.378286] hardirqs last disabled at (0): [<00000000a01fa473>] copy_process.part.7+0x2f1/0x1db0
[ 111.378290] softirqs last enabled at (0): [<00000000a01fa473>] copy_process.part.7+0x2f1/0x1db0
[ 111.378292] softirqs last disabled at (0): [< (null)>] (null)
[ 111.378293] Preemption disabled at:
[ 111.378298] [<ffffffffa18f14f6>] __mutex_lock+0x56/0x9b0
[ 111.378311] CPU: 1 PID: 1701 Comm: gem_exec_flush Tainted: G U W 4.15.0-next-20180207-g5d1c98967100-next-20180207 #1
[ 111.378313] Hardware name: Intel Corp. Broxton P/Apollolake RVP1A, BIOS APLKRVPA.X64.0150.B11.1608081044 08/08/2016
[ 111.378314] Call Trace:
[ 111.378318] <IRQ>
[ 111.378323] dump_stack+0x5f/0x86
[ 111.378328] ___might_sleep+0x1d9/0x240
[ 111.378334] ? acpi_os_execute+0x2d/0x130
[ 111.378338] kmem_cache_alloc_trace+0x1ae/0x2b0
[ 111.378344] ? acpi_ev_asynch_enable_gpe+0x2d/0x2d
[ 111.378347] acpi_os_execute+0x2d/0x130
[ 111.378351] acpi_ev_gpe_dispatch+0xd7/0x120
[ 111.378355] acpi_ev_gpe_detect+0x156/0x195
[ 111.378362] acpi_ev_sci_xrupt_handler+0x16/0x28
[ 111.378365] acpi_irq+0xd/0x30
[ 111.378369] __handle_irq_event_percpu+0x3c/0x340
[ 111.378374] handle_irq_event_percpu+0x1b/0x50
[ 111.378378] handle_irq_event+0x2f/0x50
[ 111.378381] handle_fasteoi_irq+0x93/0x150
[ 111.378386] handle_irq+0x11/0x20
[ 111.378390] do_IRQ+0x5e/0x120
[ 111.378395] common_interrupt+0xbb/0xbb
[ 111.378397] </IRQ>
does tell us that acpi_os_execute() is called in irq context.
Well, right, thanks!
I overlooked this instance, so dropping the patch.
Sorry for my false positive.
My tool missed that acpi_ev_sci_xrupt_handler() is an interrupt handler,
sorry.
Thank Chris for testing my patch.
Best wishes,
Jia-Ju Bai