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bpf: Add flags arg to bpf_dynptr_read and bpf_dynptr_write APIs

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Commit 13bbbfbea7 ("bpf: Add bpf_dynptr_read and bpf_dynptr_write")
added the bpf_dynptr_write() and bpf_dynptr_read() APIs.

However, it will be needed for some dynptr types to pass in flags as
well (e.g. when writing to a skb, the user may like to invalidate the
hash or recompute the checksum).

This patch adds a "u64 flags" arg to the bpf_dynptr_read() and
bpf_dynptr_write() APIs before their UAPI signature freezes where
we then cannot change them anymore with a 5.19.x released kernel.

Fixes: 13bbbfbea7 ("bpf: Add bpf_dynptr_read and bpf_dynptr_write")
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20220706232547.4016651-1-joannelkoong@gmail.com
This commit is contained in:
Joanne Koong
2022-07-06 16:25:47 -07:00
committed by Daniel Borkmann
parent 0326195f52
commit f8d3da4ef8
5 changed files with 29 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
tools/testing/selftests/bpf/progs/dynptr_fail.c
View File

@@ -140,12 +140,12 @@ int use_after_invalid(void *ctx)
bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(read_data), 0, &ptr);
bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0);
bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
bpf_ringbuf_submit_dynptr(&ptr, 0);
/* this should fail */
bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0);
bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
return 0;
}
@@ -338,7 +338,7 @@ int invalid_helper2(void *ctx)
get_map_val_dynptr(&ptr);
/* this should fail */
bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 8, 0);
bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 8, 0, 0);
return 0;
}
@@ -377,7 +377,7 @@ int invalid_write2(void *ctx)
memcpy((void *)&ptr + 8, &x, sizeof(x));
/* this should fail */
bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0);
bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
bpf_ringbuf_submit_dynptr(&ptr, 0);
@@ -473,7 +473,7 @@ int invalid_read2(void *ctx)
get_map_val_dynptr(&ptr);
/* this should fail */
bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 1, 0);
bpf_dynptr_read(read_data, sizeof(read_data), (void *)&ptr + 1, 0, 0);
return 0;
}

4
tools/testing/selftests/bpf/progs/dynptr_success.c
View File

@@ -43,10 +43,10 @@ int test_read_write(void *ctx)
bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr);
/* Write data into the dynptr */
err = err ?: bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data));
err = bpf_dynptr_write(&ptr, 0, write_data, sizeof(write_data), 0);
/* Read the data that was written into the dynptr */
err = err ?: bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0);
err = err ?: bpf_dynptr_read(read_data, sizeof(read_data), &ptr, 0, 0);
/* Ensure the data we read matches the data we wrote */
for (i = 0; i < sizeof(read_data); i++) {