On Tue, Aug 12, 2025 at 10:13:43PM +0800, Qianfeng Rong wrote: > > 在 2025/8/12 21:48, Dan Carpenter 写道: > > On Tue, Aug 12, 2025 at 09:32:18PM +0800, Qianfeng Rong wrote: > > > Remove array_size() calls and replace vmalloc() with vmalloc_array() to > > > simplify the code. > > > > > > Signed-off-by: Qianfeng Rong <rongqianfeng@xxxxxxxx> > > > --- > > > drivers/net/wireless/marvell/mwifiex/cfg80211.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c > > > index 3498743d5ec0..fb4183ff02a9 100644 > > > --- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c > > > +++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c > > > @@ -4673,8 +4673,8 @@ int mwifiex_init_channel_scan_gap(struct mwifiex_adapter *adapter) > > > * additional active scan request for hidden SSIDs on passive channels. > > > */ > > > adapter->num_in_chan_stats = 2 * (n_channels_bg + n_channels_a); > > > - adapter->chan_stats = vmalloc(array_size(sizeof(*adapter->chan_stats), > > > - adapter->num_in_chan_stats)); > > > + adapter->chan_stats = vmalloc_array(adapter->num_in_chan_stats, > > > + sizeof(*adapter->chan_stats)); > > n_channels_bg is 14 > > n_channels_a is either 0 or 31 depending on if we're using BAND_A. > > sizeof(*adapter->chan_stats) is 10. > > > > So we're either allocating 280 or 900 bytes, which is quite small. We > > should just use kmalloc_array() instead of vmalloc_array(). > Switching to kmalloc_array() requires changing vfree() to kfree(), > but I couldn't locate the memory release code. It's not hard to locate with a bit of looking. ;) > This modification > likely requires deep familiarity with the codebase. Also, for > variable-sized allocations, kvmalloc_array() is preferable, but > requires kvfree() for proper memory release. Don't use kvmalloc_array(). The rules are: 1) small amounts of memory: kmalloc() 2) possibly large ammounts of memory up to 2GB: kvmalloc() 3) definitely large ammounts of memory or larger than 2GB: vmalloc() There are also places where the memory needs to be contiguous and for those situations kvmalloc() and vmalloc() can't be used. Here we're allocating less than a PAGE so the appropriate thing is kmalloc_array(). I'm looking at this some more and these statistics are updated in mwifiex_update_chan_statistics() and not necessarily all of them are updated. But they're used in mwifiex_cfg80211_dump_survey() when potentially the memory is still uninitialized. I really think we should zero this memory, so lets allocate it with kcalloc(). regards, dan carpenter
