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lib/test_bpf: Call page_address() on page acquired with GFP_KERNEL flag 

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' and label 'err_free_page'.

  [1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Link: https://lore.kernel.org/bpf/20230623151644.GA434468@sumitra.com
This commit is contained in:
Sumitra Sharma 2023-06-23 08:16:44 -07:00 committed by Daniel Borkmann
parent 3a8a670eee
commit da1a055d01
1 changed files with 1 additions and 11 deletions
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12
lib/test_bpf.c
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@ -14381,25 +14381,15 @@ 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);
}
return skb;
err_free_page:
__free_page(page);
err_kfree_skb:
kfree_skb(skb);
return NULL;