* [PATCH] net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
@ 2018-04-10 13:54 Jia-Ju Bai
2018-04-10 16:57 ` Michael Büsch
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Jia-Ju Bai @ 2018-04-10 13:54 UTC (permalink / raw)
To: Larry.Finger, kvalo
Cc: linux-wireless, b43-dev, netdev, linux-kernel, Jia-Ju Bai
dma_tx_fragment() is never called in atomic context.
dma_tx_fragment() is only called by b43legacy_dma_tx(), which is
only called by b43legacy_tx_work().
b43legacy_tx_work() is only set a parameter of INIT_WORK() in
b43legacy_wireless_init().
Despite never getting called from atomic context,
dma_tx_fragment() calls alloc_skb() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
drivers/net/wireless/broadcom/b43legacy/dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/broadcom/b43legacy/dma.c b/drivers/net/wireless/broadcom/b43legacy/dma.c
index cfa617d..2f0c64c 100644
--- a/drivers/net/wireless/broadcom/b43legacy/dma.c
+++ b/drivers/net/wireless/broadcom/b43legacy/dma.c
@@ -1064,7 +1064,7 @@ static int dma_tx_fragment(struct b43legacy_dmaring *ring,
meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
/* create a bounce buffer in zone_dma on mapping failure. */
if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
- bounce_skb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
+ bounce_skb = alloc_skb(skb->len, GFP_KERNEL | GFP_DMA);
if (!bounce_skb) {
ring->current_slot = old_top_slot;
ring->used_slots = old_used_slots;
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
2018-04-10 13:54 [PATCH] net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment Jia-Ju Bai
@ 2018-04-10 16:57 ` Michael Büsch
2018-04-30 10:27 ` Kalle Valo
[not found] ` <1523368459-32128-1-git-send-email-baijiaju1990-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2 siblings, 0 replies; 6+ messages in thread
From: Michael Büsch @ 2018-04-10 16:57 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: Larry.Finger, kvalo, netdev, linux-wireless, b43-dev, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 2015 bytes --]
On Tue, 10 Apr 2018 21:54:19 +0800
Jia-Ju Bai <baijiaju1990@gmail.com> wrote:
> dma_tx_fragment() is never called in atomic context.
>
> dma_tx_fragment() is only called by b43legacy_dma_tx(), which is
> only called by b43legacy_tx_work().
> b43legacy_tx_work() is only set a parameter of INIT_WORK() in
> b43legacy_wireless_init().
>
> Despite never getting called from atomic context,
> dma_tx_fragment() calls alloc_skb() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
>
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
> drivers/net/wireless/broadcom/b43legacy/dma.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43legacy/dma.c b/drivers/net/wireless/broadcom/b43legacy/dma.c
> index cfa617d..2f0c64c 100644
> --- a/drivers/net/wireless/broadcom/b43legacy/dma.c
> +++ b/drivers/net/wireless/broadcom/b43legacy/dma.c
> @@ -1064,7 +1064,7 @@ static int dma_tx_fragment(struct b43legacy_dmaring *ring,
> meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
> /* create a bounce buffer in zone_dma on mapping failure. */
> if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
> - bounce_skb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
> + bounce_skb = alloc_skb(skb->len, GFP_KERNEL | GFP_DMA);
> if (!bounce_skb) {
> ring->current_slot = old_top_slot;
> ring->used_slots = old_used_slots;
Ack.
I think the GFP_ATOMIC came from the days where we did DMA operations
under spinlock instead of mutex.
The same thing can be done in b43.
Also
setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC)
could be GFP_KERNEL in dma_rx().
This function is called from IRQ thread context.
--
Michael
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^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
@ 2018-04-10 16:57 ` Michael Büsch
0 siblings, 0 replies; 6+ messages in thread
From: Michael Büsch @ 2018-04-10 16:57 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: Larry.Finger, kvalo, netdev, linux-wireless, b43-dev, linux-kernel
On Tue, 10 Apr 2018 21:54:19 +0800
Jia-Ju Bai <baijiaju1990@gmail.com> wrote:
> dma_tx_fragment() is never called in atomic context.
>
> dma_tx_fragment() is only called by b43legacy_dma_tx(), which is
> only called by b43legacy_tx_work().
> b43legacy_tx_work() is only set a parameter of INIT_WORK() in
> b43legacy_wireless_init().
>
> Despite never getting called from atomic context,
> dma_tx_fragment() calls alloc_skb() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
>
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
> drivers/net/wireless/broadcom/b43legacy/dma.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/b43legacy/dma.c b/drivers/net/wireless/broadcom/b43legacy/dma.c
> index cfa617d..2f0c64c 100644
> --- a/drivers/net/wireless/broadcom/b43legacy/dma.c
> +++ b/drivers/net/wireless/broadcom/b43legacy/dma.c
> @@ -1064,7 +1064,7 @@ static int dma_tx_fragment(struct b43legacy_dmaring *ring,
> meta->dmaaddr = map_descbuffer(ring, skb->data, skb->len, 1);
> /* create a bounce buffer in zone_dma on mapping failure. */
> if (b43legacy_dma_mapping_error(ring, meta->dmaaddr, skb->len, 1)) {
> - bounce_skb = alloc_skb(skb->len, GFP_ATOMIC | GFP_DMA);
> + bounce_skb = alloc_skb(skb->len, GFP_KERNEL | GFP_DMA);
> if (!bounce_skb) {
> ring->current_slot = old_top_slot;
> ring->used_slots = old_used_slots;
Ack.
I think the GFP_ATOMIC came from the days where we did DMA operations
under spinlock instead of mutex.
The same thing can be done in b43.
Also
setup_rx_descbuffer(ring, desc, meta, GFP_ATOMIC)
could be GFP_KERNEL in dma_rx().
This function is called from IRQ thread context.
--
Michael
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
2018-04-10 13:54 [PATCH] net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment Jia-Ju Bai
2018-04-10 16:57 ` Michael Büsch
@ 2018-04-30 10:27 ` Kalle Valo
[not found] ` <1523368459-32128-1-git-send-email-baijiaju1990-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2 siblings, 0 replies; 6+ messages in thread
From: Kalle Valo @ 2018-04-30 10:27 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: Larry.Finger, linux-wireless, b43-dev, netdev, linux-kernel, Jia-Ju Bai
Jia-Ju Bai <baijiaju1990@gmail.com> wrote:
> dma_tx_fragment() is never called in atomic context.
>
> dma_tx_fragment() is only called by b43legacy_dma_tx(), which is
> only called by b43legacy_tx_work().
> b43legacy_tx_work() is only set a parameter of INIT_WORK() in
> b43legacy_wireless_init().
>
> Despite never getting called from atomic context,
> dma_tx_fragment() calls alloc_skb() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
>
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Patch applied to wireless-drivers-next.git, thanks.
6e1d8d1470b2 net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
--
https://patchwork.kernel.org/patch/10333217/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
2018-04-10 13:54 [PATCH] net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment Jia-Ju Bai
@ 2018-04-30 10:27 ` Kalle Valo
2018-04-30 10:27 ` Kalle Valo
[not found] ` <1523368459-32128-1-git-send-email-baijiaju1990-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2 siblings, 0 replies; 6+ messages in thread
From: Kalle Valo @ 2018-04-30 10:27 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: netdev-u79uwXL29TY76Z2rM5mHXA,
linux-wireless-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA, Jia-Ju Bai,
b43-dev-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
Larry.Finger-tQ5ms3gMjBLk1uMJSBkQmQ
Jia-Ju Bai <baijiaju1990-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> dma_tx_fragment() is never called in atomic context.
>
> dma_tx_fragment() is only called by b43legacy_dma_tx(), which is
> only called by b43legacy_tx_work().
> b43legacy_tx_work() is only set a parameter of INIT_WORK() in
> b43legacy_wireless_init().
>
> Despite never getting called from atomic context,
> dma_tx_fragment() calls alloc_skb() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
>
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Patch applied to wireless-drivers-next.git, thanks.
6e1d8d1470b2 net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
--
https://patchwork.kernel.org/patch/10333217/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 6+ messages in thread
* net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
@ 2018-04-30 10:27 ` Kalle Valo
0 siblings, 0 replies; 6+ messages in thread
From: Kalle Valo @ 2018-04-30 10:27 UTC (permalink / raw)
To: Jia-Ju Bai
Cc: netdev-u79uwXL29TY76Z2rM5mHXA,
linux-wireless-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
b43-dev-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
Larry.Finger-tQ5ms3gMjBLk1uMJSBkQmQ
Jia-Ju Bai <baijiaju1990@gmail.com> wrote:
> dma_tx_fragment() is never called in atomic context.
>
> dma_tx_fragment() is only called by b43legacy_dma_tx(), which is
> only called by b43legacy_tx_work().
> b43legacy_tx_work() is only set a parameter of INIT_WORK() in
> b43legacy_wireless_init().
>
> Despite never getting called from atomic context,
> dma_tx_fragment() calls alloc_skb() with GFP_ATOMIC,
> which does not sleep for allocation.
> GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
> which can sleep and improve the possibility of sucessful allocation.
>
> This is found by a static analysis tool named DCNS written by myself.
> And I also manually check it.
>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Patch applied to wireless-drivers-next.git, thanks.
6e1d8d1470b2 net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment
--
https://patchwork.kernel.org/patch/10333217/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-04-30 10:27 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-10 13:54 [PATCH] net: wireless: b43legacy: Replace GFP_ATOMIC with GFP_KERNEL in dma_tx_fragment Jia-Ju Bai
2018-04-10 16:57 ` Michael Büsch
2018-04-10 16:57 ` Michael Büsch
2018-04-30 10:27 ` Kalle Valo
[not found] ` <1523368459-32128-1-git-send-email-baijiaju1990-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2018-04-30 10:27 ` Kalle Valo
2018-04-30 10:27 ` Kalle Valo
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