Hi Michael, Thanks for all the comments! I'll fix most of it when I post a new version of the manpage, but I have a few general questions. On 12/09/2015 03:08 AM, Michael Kerrisk (man-pages) wrote: >> >> +is the protection or storage key to assign to the memory. > > Why "protection or storage key" here? This phrasing seems a > little ambiguous to me, given that we also have a 'prot' > argument. I think it would be clearer just to say > "protection key". But maybe I'm missing something. x86 calls it a "protection key" while powerpc calls it a "storage key". They're called "protection keys" consistently inside the kernel. Should we just stick to one name in the manpages? > * A general overview of why this functionality is useful. Any preference on a central spot to do the general overview? Does it go in one of the manpages I'm already modifying, or a new one? > * A note on which architectures support/will support > this functionality. x86 only for now. We might get powerpc support down the road somewhere. > * Explanation of what a protection domain is. A protection domain is a unique view of memory and is represented by the value in the PKRU register. > * Explanation of how a process (thread?) changes its > protection domain. Changing protection domains is done by pkey_set() system call, or by using the WRPKRU instruction. The system call is preferred and less error-prone since it enforces that a protection is allocated before its access protection can be modified. > * Explanation of the relationship between page permission > bits (PROT_READ/PROT_WRITE/PROTE_EXEC) and > PKEY_DISABLE_ACCESS and PKEY_DISABLE_WRITE. > It's still not clear to me. Do the PKEY_* bits > override the PROT_* bits. Or, something else? Protection keys add access restrictions in addition to existing page permissions. They can only take away access; they never grant additional access. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>