[PATCH v3] staging: r8188eu: Use kzalloc() with GFP_ATOMIC in atomic context

Fabio M. De Francesco
2021-11-01T19:18:53Z

Use the GFP_ATOMIC flag of kzalloc() with two memory allocation in
report_del_sta_event(). This function is called while holding spinlocks,
therefore it is not allowed to sleep. With the GFP_ATOMIC type flag, the
allocation is high priority and must not sleep.

This issue is detected by Smatch which emits the following warning:
"drivers/staging/r8188eu/core/rtw_mlme_ext.c:6848 report_del_sta_event()
warn: sleeping in atomic context".

After the change, the post-commit hook output the following message:
"CHECK: Prefer kzalloc(sizeof(*pcmd_obj)...) over
kzalloc(sizeof(struct cmd_obj)...)".

According to the above "CHECK", use the preferred style in the first
kzalloc().

Fixes: 79f712ea994d ("staging: r8188eu: Remove wrappers for kalloc() and kzalloc()")
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
---

v2->v3: Add the "Fixes:" tag, as requested by Greg Kroah-Hartman.

v1->v2: Fix an error that I introduced with an incorrect copy-paste
of the sizeof() operator.

drivers/staging/r8188eu/core/rtw_mlme_ext.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/r8188eu/core/rtw_mlme_ext.c b/drivers/staging/r8188eu/core/rtw_mlme_ext.c
index 55c3d4a6faeb..315902682292 100644
--- a/drivers/staging/r8188eu/core/rtw_mlme_ext.c
+++ b/drivers/staging/r8188eu/core/rtw_mlme_ext.c
@@ -6845,12 +6845,12 @@ void report_del_sta_event(struct adapter *padapter, unsigned char *MacAddr, unsi
struct mlme_ext_priv *pmlmeext = &padapter->mlmeextpriv;
struct cmd_priv *pcmdpriv = &padapter->cmdpriv;

- pcmd_obj = kzalloc(sizeof(struct cmd_obj), GFP_KERNEL);
+ pcmd_obj = kzalloc(sizeof(*pcmd_obj), GFP_ATOMIC);
if (!pcmd_obj)
return;

cmdsz = (sizeof(struct stadel_event) + sizeof(struct C2HEvent_Header));
- pevtcmd = kzalloc(cmdsz, GFP_KERNEL);
+ pevtcmd = kzalloc(cmdsz, GFP_ATOMIC);
if (!pevtcmd) {
kfree(pcmd_obj);
return;
--
2.33.1