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| author |   Kumar Kartikeya Dwivedi <memxor@gmail.com> | 2021-07-02 16:48:22 +0530 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2021-07-07 20:01:45 -0700 |
| commit | cb0f80039fb7ec9981a74d22019daaa85ff51a3d (patch) | |
| tree | 4a723ac4dfa94fb5af8474bb084e9f997559d805 /include/linux/typecheck.h | |
| parent | net: core: Split out code to run generic XDP prog (diff) | |
| download | wireguard-linux-cb0f80039fb7ec9981a74d22019daaa85ff51a3d.tar.xz wireguard-linux-cb0f80039fb7ec9981a74d22019daaa85ff51a3d.zip | |
bitops: Add non-atomic bitops for pointers
cpumap needs to set, clear, and test the lowest bit in skb pointer in
various places. To make these checks less noisy, add pointer friendly
bitop macros that also do some typechecking to sanitize the argument.
These wrap the non-atomic bitops __set_bit, __clear_bit, and test_bit
but for pointer arguments. Pointer's address has to be passed in and it
is treated as an unsigned long *, since width and representation of
pointer and unsigned long match on targets Linux supports. They are
prefixed with double underscore to indicate lack of atomicity.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210702111825.491065-3-memxor@gmail.com
Diffstat (limited to 'include/linux/typecheck.h')
| -rw-r--r-- | include/linux/typecheck.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/typecheck.h b/include/linux/typecheck.h index 20d310331eb5..46b15e2aaefb 100644 --- a/include/linux/typecheck.h +++ b/include/linux/typecheck.h @@ -22,4 +22,13 @@ (void)__tmp; \ }) +/* + * Check at compile time that something is a pointer type. + */ +#define typecheck_pointer(x) \ +({ typeof(x) __dummy; \ + (void)sizeof(*__dummy); \ + 1; \ +}) + #endif /* TYPECHECK_H_INCLUDED */ |