Messages in this thread | | | From | "Michael Kerrisk (man-pages)" <> | Date | Thu, 12 Jun 2014 20:49:18 +0200 | Subject | Re: [PATCH v2] ptrace: Clarify PTRACE_GETREGSET/PTRACE_SETREGSET, documentation in uapi header |
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On Thu, Jun 12, 2014 at 8:05 PM, Oleg Nesterov <oleg@redhat.com> wrote: > On 06/12, Anshuman Khandual wrote: >> >> > --- a/include/uapi/linux/ptrace.h >> > +++ b/include/uapi/linux/ptrace.h >> > @@ -39,12 +39,17 @@ >> > * payload are exactly the same layout. >> > * >> > * This interface usage is as follows: >> > - * struct iovec iov = { buf, len}; >> > + * struct iovec iov = { buf, len }; >> > * >> > * ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov); >> > * >> > - * On the successful completion, iov.len will be updated by the kernel, >> > - * specifying how much the kernel has written/read to/from the user's iov.buf. >> > + * On entry, iov describes the buffer's address and length. The buffer's length >> > + * must be a multiple of the size of a single register in the register set. The >> > + * kernel never reads or writes more than iov.len, and caps the buffer length to >> > + * the register set's size. In other words, the kernel reads or writes >> > + * min(iov.len, regset size). > > I think this should be self-obvious ;) otherwise why do we need to pass > the length of the buffer? > > But of course I won't argue with the additional documentation, perhaps you > can re-send this patch to akpm? Usually ptrace changes are routed via -mm > tree. > > But if we update the kernel header, then probably it would be more important > to update the man-page. To me the description of GETREGSET looks good, but > probably it could also mention that buflen should be multiple of regsize (as > you did above). Add Michael.
Can someone send a patch, then?
Cheers,
Michael
-- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
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