On 2022/6/4 5:03, Andrii Nakryiko wrote:

On Mon, May 30, 2022 at 2:03 PM Daniel Borkmann [off-list ref] wrote:

quoted

On 5/30/22 11:28 AM, Pu Lehui wrote:

quoted

The members of bpf_prog_info, which are line_info, jited_line_info,
jited_ksyms and jited_func_lens, store u64 address pointed to the
corresponding memory regions. Memory addresses are conceptually
unsigned, (unsigned long) casting makes more sense, so let's make
a change for conceptual uniformity.

Signed-off-by: Pu Lehui <pulehui@huawei.com>
---
   tools/lib/bpf/bpf_prog_linfo.c | 9 +++++----
   1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/lib/bpf/bpf_prog_linfo.c b/tools/lib/bpf/bpf_prog_linfo.c
index 5c503096ef43..7beb060d0671 100644
--- a/tools/lib/bpf/bpf_prog_linfo.c
+++ b/tools/lib/bpf/bpf_prog_linfo.c

@@ -127,7 +127,8 @@ struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info)
       prog_linfo->raw_linfo = malloc(data_sz);
       if (!prog_linfo->raw_linfo)
               goto err_free;
-     memcpy(prog_linfo->raw_linfo, (void *)(long)info->line_info, data_sz);
+     memcpy(prog_linfo->raw_linfo, (void *)(unsigned long)info->line_info,
+            data_sz);

Took in patch 1-3, lgtm, thanks! My question around the cleanups in patch 4-6 ...
there are various other such cases e.g. in libbpf, perhaps makes sense to clean all
of them up at once and not just the 4 locations in here.

if (void *)(long) pattern is wrong, then I guess the best replacement
should be (void *)(uintptr_t) ?

I also think that (void *)(uintptr_t) would be the best replacement. I 
applied the changes to kernel/bpf and samples/bpf, and it worked fine. 
But in selftests/bpf, the following similar error occur at compile time:

progs/test_cls_redirect.c:504:11: error: cast to 'uint8_t *' (aka 
'unsigned char *') from smaller integer type 'uintptr_t' (aka 'unsigned 
int') [-Werror,-Wint-to-pointer-cast]
	.head = (uint8_t *)(uintptr_t)skb->data,

I take clang to compile with the front and back end separation, like 
samples/bpf, and it works. It seems that the all-in-one clang has 
problems handling the uintptr_t.

quoted

Thanks,
Daniel

.