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| author |   Kees Cook <keescook@chromium.org> | 2018-01-10 12:53:20 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2018-01-15 12:07:46 -0800 |
| commit | 4229a470175be14e1d2648713be8a5e8e8fbea02 (patch) | |
| tree | 9800d572b0046b2226f1b853f15c3055e304078e /include/linux/stddef.h | |
| parent | lkdtm/usercopy: Adjust test to include an offset to check reporting (diff) | |
| download | wireguard-linux-4229a470175be14e1d2648713be8a5e8e8fbea02.tar.xz wireguard-linux-4229a470175be14e1d2648713be8a5e8e8fbea02.zip | |
stddef.h: Introduce sizeof_field()
The size of fields within a structure is needed in a few places in the
kernel already, and will be needed for the usercopy whitelisting when
declaring whitelist regions within structures. This creates a dedicated
macro and redefines offsetofend() to use it.
Existing usage, ignoring the 1200+ lustre assert uses:
$ git grep -E 'sizeof\(\(\((struct )?[a-zA-Z_]+ \*\)0\)->' | \
grep -v staging/lustre | wc -l
65
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'include/linux/stddef.h')
| -rw-r--r-- | include/linux/stddef.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/include/linux/stddef.h b/include/linux/stddef.h index 2181719fd907..998a4ba28eba 100644 --- a/include/linux/stddef.h +++ b/include/linux/stddef.h @@ -20,12 +20,20 @@ enum { #endif /** + * sizeof_field(TYPE, MEMBER) + * + * @TYPE: The structure containing the field of interest + * @MEMBER: The field to return the size of + */ +#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER)) + +/** * offsetofend(TYPE, MEMBER) * * @TYPE: The type of the structure * @MEMBER: The member within the structure to get the end offset of */ #define offsetofend(TYPE, MEMBER) \ - (offsetof(TYPE, MEMBER) + sizeof(((TYPE *)0)->MEMBER)) + (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER)) #endif |