On 5/28/24 5:19 AM, Jason A. Donenfeld wrote: > +/** > + * type vdso_kernel_ulong - unsigned long type that matches kernel's unsigned long s/type/typedef/ (for first "type" only) > + * > + * Data shared between userspace and the kernel must operate the same way in both 64-bit code and in > + * 32-bit compat code, over the same potentially 64-bit kernel. This type represents the size of an > + * unsigned long as used by kernel code. This isn't necessarily the same as an unsigned long as used > + * by userspace, however. > + * > + * +-------------------+-------------------+------------------+-------------------+ > + * | 32-bit userspace | 32-bit userspace | 64-bit userspace | 64-bit userspace | > + * | unsigned long | vdso_kernel_ulong | unsigned long | vdso_kernel_ulong | > + * +---------------+-------------------+-------------------+------------------+-------------------+ > + * | 32-bit kernel | ✓ same size | ✓ same size | > + * | unsigned long | | | > + * +---------------+-------------------+-------------------+------------------+-------------------+ > + * | 64-bit kernel | ✘ different size! | ✓ same size | ✓ same size | ✓ same size | > + * | unsigned long | | | | | > + * +---------------+-------------------+-------------------+------------------+-------------------+ > + */ > +#ifdef CONFIG_64BIT > +typedef u64 vdso_kernel_ulong; > +#else > +typedef u32 vdso_kernel_ulong; > +#endif -- #Randy https://people.kernel.org/tglx/notes-about-netiquette https://subspace.kernel.org/etiquette.html
