* [PATCH v2 0/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context
@ 2022-02-08 18:04 Fabio M. De Francesco
2022-02-08 18:04 ` [PATCH v2 1/2] staging: r8188eu: Use sizeof dereferenced pointer in kzalloc() Fabio M. De Francesco
2022-02-08 18:04 ` [PATCH v2 2/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Fabio M. De Francesco
0 siblings, 2 replies; 5+ messages in thread
From: Fabio M. De Francesco @ 2022-02-08 18:04 UTC (permalink / raw)
To: Larry Finger, Phillip Potter, Greg Kroah-Hartman, linux-staging,
linux-kernel
Cc: Fabio M. De Francesco
Use the GFP_ATOMIC flag of kzalloc() in two memory allocation in rtw_set_key().
This function is not allowed to sleep because it executes in atomic context. With
the GFP_ATOMIC type flag, the allocation is high priority and cannot sleep.
This issue is detected by Smatch which emits the following warning:
drivers/staging/r8188eu/core/rtw_mlme.c:1603 rtw_set_key() warn: sleeping in atomic context
Before the above-mentioned changes, checkpatch.pl reports the following issues:
CHECK: Prefer kzalloc(sizeof(*pcmd)...) over kzalloc(sizeof(struct cmd_obj)...)
+ pcmd = kzalloc(sizeof(struct cmd_obj), GFP_ATOMIC);
CHECK: Prefer kzalloc(sizeof(*psetkeyparm)...) over kzalloc(sizeof(struct setkey_parm)...)
+ psetkeyparm = kzalloc(sizeof(struct setkey_parm), GFP_ATOMIC).
According to the above "CHECK[S]", use the preferred style in the two kzalloc().
Changes from v1: Split one patch into two according to a requirement by
Greg Kroah-Hartman.
Fabio M. De Francesco (2):
staging: r8188eu: Use size of dereferenced pointers in kzalloc()
staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context
drivers/staging/r8188eu/core/rtw_mlme.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--
2.34.1
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v2 1/2] staging: r8188eu: Use sizeof dereferenced pointer in kzalloc()
2022-02-08 18:04 [PATCH v2 0/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Fabio M. De Francesco
@ 2022-02-08 18:04 ` Fabio M. De Francesco
2022-02-08 18:04 ` [PATCH v2 2/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Fabio M. De Francesco
1 sibling, 0 replies; 5+ messages in thread
From: Fabio M. De Francesco @ 2022-02-08 18:04 UTC (permalink / raw)
To: Larry Finger, Phillip Potter, Greg Kroah-Hartman, linux-staging,
linux-kernel
Cc: Fabio M. De Francesco
checkpatch.pl emits the following warning:
CHECK: Prefer kzalloc(sizeof(*pcmd)...) over kzalloc(sizeof(struct cmd_obj)...)
+ pcmd = kzalloc(sizeof(struct cmd_obj), GFP_KERNEL);
CHECK: Prefer kzalloc(sizeof(*psetkeyparm)...) over kzalloc(sizeof(struct setkey_parm)...)
+ psetkeyparm = kzalloc(sizeof(struct setkey_parm), GFP_KERNEL).
According to the above "CHECK[S]", use the preferred style in the two kzalloc()
of rtw_set_key().
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
---
drivers/staging/r8188eu/core/rtw_mlme.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/r8188eu/core/rtw_mlme.c b/drivers/staging/r8188eu/core/rtw_mlme.c
index 038bddc361c3..f5b2df72e0f4 100644
--- a/drivers/staging/r8188eu/core/rtw_mlme.c
+++ b/drivers/staging/r8188eu/core/rtw_mlme.c
@@ -1600,12 +1600,12 @@ int rtw_set_key(struct adapter *adapter, struct security_priv *psecuritypriv, in
struct mlme_priv *pmlmepriv = &adapter->mlmepriv;
int res = _SUCCESS;
- pcmd = kzalloc(sizeof(struct cmd_obj), GFP_KERNEL);
+ pcmd = kzalloc(sizeof(*pcmd), GFP_KERNEL);
if (!pcmd) {
res = _FAIL; /* try again */
goto exit;
}
- psetkeyparm = kzalloc(sizeof(struct setkey_parm), GFP_KERNEL);
+ psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_KERNEL);
if (!psetkeyparm) {
kfree(pcmd);
res = _FAIL;
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH v2 2/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context
2022-02-08 18:04 [PATCH v2 0/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Fabio M. De Francesco
2022-02-08 18:04 ` [PATCH v2 1/2] staging: r8188eu: Use sizeof dereferenced pointer in kzalloc() Fabio M. De Francesco
@ 2022-02-08 18:04 ` Fabio M. De Francesco
2022-02-15 16:10 ` Greg Kroah-Hartman
1 sibling, 1 reply; 5+ messages in thread
From: Fabio M. De Francesco @ 2022-02-08 18:04 UTC (permalink / raw)
To: Larry Finger, Phillip Potter, Greg Kroah-Hartman, linux-staging,
linux-kernel
Cc: Fabio M. De Francesco
Use the GFP_ATOMIC flag of kzalloc() with two memory allocation in rtw_set_key()
because it is not allowed to sleep while it executes in atomic context.
With the GFP_ATOMIC type flag, the allocation is high priority and thus it
cannot sleep.
This issue is detected by Smatch which emits the following warning:
"drivers/staging/r8188eu/core/rtw_mlme.c:1603 rtw_set_key() warn: sleeping in atomic context".
Fixes: 79f712ea994d ("staging: r8188eu: Remove wrappers for kalloc() and kzalloc()")
Fixes: 15865124feed ("staging: r8188eu: introduce new core dir for RTL8188eu driver")
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
---
drivers/staging/r8188eu/core/rtw_mlme.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/r8188eu/core/rtw_mlme.c b/drivers/staging/r8188eu/core/rtw_mlme.c
index f5b2df72e0f4..860835e29b79 100644
--- a/drivers/staging/r8188eu/core/rtw_mlme.c
+++ b/drivers/staging/r8188eu/core/rtw_mlme.c
@@ -1600,12 +1600,12 @@ int rtw_set_key(struct adapter *adapter, struct security_priv *psecuritypriv, in
struct mlme_priv *pmlmepriv = &adapter->mlmepriv;
int res = _SUCCESS;
- pcmd = kzalloc(sizeof(*pcmd), GFP_KERNEL);
+ pcmd = kzalloc(sizeof(*pcmd), GFP_ATOMIC);
if (!pcmd) {
res = _FAIL; /* try again */
goto exit;
}
- psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_KERNEL);
+ psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_ATOMIC);
if (!psetkeyparm) {
kfree(pcmd);
res = _FAIL;
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v2 2/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context
2022-02-08 18:04 ` [PATCH v2 2/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Fabio M. De Francesco
@ 2022-02-15 16:10 ` Greg Kroah-Hartman
2022-02-17 9:32 ` Fabio M. De Francesco
0 siblings, 1 reply; 5+ messages in thread
From: Greg Kroah-Hartman @ 2022-02-15 16:10 UTC (permalink / raw)
To: Fabio M. De Francesco
Cc: Larry Finger, Phillip Potter, linux-staging, linux-kernel
On Tue, Feb 08, 2022 at 07:04:26PM +0100, Fabio M. De Francesco wrote:
> Use the GFP_ATOMIC flag of kzalloc() with two memory allocation in rtw_set_key()
> because it is not allowed to sleep while it executes in atomic context.
>
> With the GFP_ATOMIC type flag, the allocation is high priority and thus it
> cannot sleep.
>
> This issue is detected by Smatch which emits the following warning:
>
> "drivers/staging/r8188eu/core/rtw_mlme.c:1603 rtw_set_key() warn: sleeping in atomic context".
>
> Fixes: 79f712ea994d ("staging: r8188eu: Remove wrappers for kalloc() and kzalloc()")
> Fixes: 15865124feed ("staging: r8188eu: introduce new core dir for RTL8188eu driver")
> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
> ---
> drivers/staging/r8188eu/core/rtw_mlme.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/staging/r8188eu/core/rtw_mlme.c b/drivers/staging/r8188eu/core/rtw_mlme.c
> index f5b2df72e0f4..860835e29b79 100644
> --- a/drivers/staging/r8188eu/core/rtw_mlme.c
> +++ b/drivers/staging/r8188eu/core/rtw_mlme.c
> @@ -1600,12 +1600,12 @@ int rtw_set_key(struct adapter *adapter, struct security_priv *psecuritypriv, in
> struct mlme_priv *pmlmepriv = &adapter->mlmepriv;
> int res = _SUCCESS;
>
> - pcmd = kzalloc(sizeof(*pcmd), GFP_KERNEL);
> + pcmd = kzalloc(sizeof(*pcmd), GFP_ATOMIC);
> if (!pcmd) {
> res = _FAIL; /* try again */
> goto exit;
> }
> - psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_KERNEL);
> + psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_ATOMIC);
> if (!psetkeyparm) {
> kfree(pcmd);
> res = _FAIL;
> --
> 2.34.1
What code path is calling this in atomic context?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH v2 2/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context
2022-02-15 16:10 ` Greg Kroah-Hartman
@ 2022-02-17 9:32 ` Fabio M. De Francesco
0 siblings, 0 replies; 5+ messages in thread
From: Fabio M. De Francesco @ 2022-02-17 9:32 UTC (permalink / raw)
To: Greg Kroah-Hartman
Cc: Larry Finger, Phillip Potter, linux-staging, linux-kernel
On marted? 15 febbraio 2022 17:10:12 CET Greg Kroah-Hartman wrote:
> On Tue, Feb 08, 2022 at 07:04:26PM +0100, Fabio M. De Francesco wrote:
> > Use the GFP_ATOMIC flag of kzalloc() with two memory allocation in rtw_set_key()
> > because it is not allowed to sleep while it executes in atomic context.
> >
> > With the GFP_ATOMIC type flag, the allocation is high priority and thus it
> > cannot sleep.
> >
> > This issue is detected by Smatch which emits the following warning:
> >
> > "drivers/staging/r8188eu/core/rtw_mlme.c:1603 rtw_set_key() warn: sleeping in atomic context".
> >
> > Fixes: 79f712ea994d ("staging: r8188eu: Remove wrappers for kalloc() and kzalloc()")
> > Fixes: 15865124feed ("staging: r8188eu: introduce new core dir for RTL8188eu driver")
> > Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
> > ---
> > drivers/staging/r8188eu/core/rtw_mlme.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/core/rtw_mlme.c b/drivers/staging/r8188eu/core/rtw_mlme.c
> > index f5b2df72e0f4..860835e29b79 100644
> > --- a/drivers/staging/r8188eu/core/rtw_mlme.c
> > +++ b/drivers/staging/r8188eu/core/rtw_mlme.c
> > @@ -1600,12 +1600,12 @@ int rtw_set_key(struct adapter *adapter, struct security_priv *psecuritypriv, in
> > struct mlme_priv *pmlmepriv = &adapter->mlmepriv;
> > int res = _SUCCESS;
> >
> > - pcmd = kzalloc(sizeof(*pcmd), GFP_KERNEL);
> > + pcmd = kzalloc(sizeof(*pcmd), GFP_ATOMIC);
> > if (!pcmd) {
> > res = _FAIL; /* try again */
> > goto exit;
> > }
> > - psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_KERNEL);
> > + psetkeyparm = kzalloc(sizeof(*psetkeyparm), GFP_ATOMIC);
> > if (!psetkeyparm) {
> > kfree(pcmd);
> > res = _FAIL;
> > --
> > 2.34.1
>
> What code path is calling this in atomic context?
>
> thanks,
>
> greg k-h
>
I blindly trusted Smatch and didn't check properly :(
Now I'm pretty sure that all(?) the code paths that lead to those kzalloc() do
not call rtw_set_key() in atomic context.
The only calls chain that seemed to call rtw_set_key() in atomic context was
rtw_set_key() <- ips_leave() <- _rtw_pwr_wakeup() <- rtw_set_802_11_disassociate()
but Smatch (and I) missed that, immediately before calling ips_leave(), an 'if'
condition makes _rtw_pwr_wakeup() exit and return to rtw_set_802_11_disassociate().
Therefore, please drop this patch.
Thanks,
Fabio M. De Francesco
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-02-17 9:32 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2022-02-08 18:04 [PATCH v2 0/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Fabio M. De Francesco
2022-02-08 18:04 ` [PATCH v2 1/2] staging: r8188eu: Use sizeof dereferenced pointer in kzalloc() Fabio M. De Francesco
2022-02-08 18:04 ` [PATCH v2 2/2] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context Fabio M. De Francesco
2022-02-15 16:10 ` Greg Kroah-Hartman
2022-02-17 9:32 ` Fabio M. De Francesco
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