Messages in this thread | | | From | Roland McGrath <> | Subject | Re: [patch v3 2/2] ptrace: Add support for generic PTRACE_GETREGSET/PTRACE_SETREGSET | Date | Thu, 11 Feb 2010 19:56:06 -0800 (PST) |
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Note that this patch and the xstate user_regset patch are entirely independent. They can me merged in any order or one without the other.
> +/* > + * Generic ptrace interface that exports the architecture specific regsets > + * using the corresponding NT_* types (which are also used in the core dump).
There is a special case here, which I think already works as we intend it to, but which should be clarified in the comment about this API. The NT_PRSTATUS note type in a core dump contains a full 'struct elf_prstatus'. But the user_regset for NT_PRSTATUS contains just the elf_gregset_t that is the pr_reg field of 'struct elf_prstatus'.
For all the other user_regset flavors, the user_regset layout and the ELF core dump note payload are exactly the same layout, as your comment implies.
> +static int ptrace_regset(struct task_struct *task, int req, unsigned int type, > + struct iovec *kiov) > +{ > + const struct user_regset_view *view = task_user_regset_view(task); > + const struct user_regset *regset = find_regset(view, type); > + int regset_no; > + > + if (!regset || (kiov->iov_len % regset->size) != 0) > + return -EIO;
My inclination would be to diagnose these more specifically. For a bad size, give -EINVAL. For an unknown regset type, give maybe -EINVAL or maybe -ENODEV. (-ENODEV is what you get for a known NT_* type that has a user_regset implemented in the kernel, but that the particular hardware we're running on doesn't support. So perhaps you don't want to overload that for a wholly unrecognized NT_* type.)
Otherwise, looks good to me. ACK contingent on Oleg's ACK.
Thanks, Roland
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