After checking all possible call chains to firmware_map_add_hotplug(),
my tool finds that this function is never called in atomic context,
namely never in an interrupt handler or holding a spinlock.
I manually check the code, and find that
this function is only called by add_memory_resource() that calls
mem_hotplug_begin(), and mem_hotplug_begin() calls mutex_lock() that
can sleep, so it indicates that firmware_map_add_hotplug()
can call function which can 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.
And I also manually audit the result.
Signed-off-by: Jia-Ju Bai <[email protected]>
---
drivers/firmware/memmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/firmware/memmap.c b/drivers/firmware/memmap.c
index 5de3ed2..598eb05 100644
--- a/drivers/firmware/memmap.c
+++ b/drivers/firmware/memmap.c
@@ -297,7 +297,7 @@ int __meminit firmware_map_add_hotplug(u64 start, u64 end, const char *type)
entry = firmware_map_find_entry_bootmem(start, end - 1, type);
if (!entry) {
- entry = kzalloc(sizeof(struct firmware_map_entry), GFP_ATOMIC);
+ entry = kzalloc(sizeof(struct firmware_map_entry), GFP_KERNEL);
if (!entry)
return -ENOMEM;
} else {
--
1.7.9.5