Sumitra Sharma wrote: > generate_test_data() acquires a page with alloc_page(GFP_KERNEL). > The GFP_KERNEL is typical for kernel-internal allocations. > The caller requires ZONE_NORMAL or a lower zone for direct access. > > Therefore the page cannot come from ZONE_HIGHMEM. Thus there's > no need to map it with kmap(). > > Also, the kmap() is being deprecated in favor of > kmap_local_page() [1]. > > Hence, use a plain page_address() directly. > > Since the page passed to the page_address() is not from the highmem > zone, the page_address() function will always return a valid kernel > virtual address and will not return NULL. Hence, remove the check > 'if (!ptr)'. > > Remove the unused variable 'ptr'. > > [1]: https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny > @intel.com/ Odd line break here which makes looking at this reference harder. > > Suggested-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx> > Signed-off-by: Sumitra Sharma <sumitraartsy@xxxxxxxxx> The code looks good though. Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> > --- > > - Link to v1: https://lore.kernel.org/bpf/20230613073020.GA359792@xxxxxxxxxxx/T/ > - Link to v2: https://lore.kernel.org/lkml/3564297.R56niFO833@suse/T/ > > Changes in v3: > Noted by: Fabio M. De Francesco<fmdefrancesco@xxxxxxxxx> > - Remove the check 'if (!ptr)'. > - Remove the unused variable 'ptr'. > - Change the commit message. > > Changes in v2: > Noted by: Fabio M. De Francesco<fmdefrancesco@xxxxxxxxx> > - Remove the kmap() call and call page_address() instead. > - Change the commit subject and message. > > > lib/test_bpf.c | 8 +------- > 1 file changed, 1 insertion(+), 7 deletions(-) > > diff --git a/lib/test_bpf.c b/lib/test_bpf.c > index ade9ac672adb..448bc1b0b8b5 100644 > --- a/lib/test_bpf.c > +++ b/lib/test_bpf.c > @@ -14381,18 +14381,12 @@ static void *generate_test_data(struct bpf_test *test, int sub) > * single fragment to the skb, filled with > * test->frag_data. > */ > - void *ptr; > - > page = alloc_page(GFP_KERNEL); > > if (!page) > goto err_kfree_skb; > > - ptr = kmap(page); > - if (!ptr) > - goto err_free_page; > - memcpy(ptr, test->frag_data, MAX_DATA); > - kunmap(page); > + memcpy(page_address(page), test->frag_data, MAX_DATA); > skb_add_rx_frag(skb, 0, page, 0, MAX_DATA, MAX_DATA); > } > > -- > 2.25.1 >
