Messages in this thread | | | From | Greentime Hu <> | Date | Wed, 27 May 2020 14:34:05 +0800 | Subject | Re: [RFC PATCH v4 01/13] ptrace: Use regset_size() for dynamic regset size. |
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Oleg Nesterov <oleg@redhat.com> 於 2020年5月26日 週二 下午10:00寫道: > > On 05/26, Greentime Hu wrote: > > > > @@ -882,13 +882,18 @@ static int ptrace_regset(struct task_struct *task, int req, unsigned int type, > > const struct user_regset_view *view = task_user_regset_view(task); > > const struct user_regset *regset = find_regset(view, type); > > int regset_no; > > + unsigned int size; > > > > - if (!regset || (kiov->iov_len % regset->size) != 0) > > + if (!regset) > > return -EINVAL; > > > > regset_no = regset - view->regsets; > > - kiov->iov_len = min(kiov->iov_len, > > - (__kernel_size_t) (regset->n * regset->size)); > > + size = regset_size(task, regset); > > + > > + if ((kiov->iov_len % size) != 0) > > + return -EINVAL; > > Hmm. this doesn't look right. > > Before this patch we check "iov_len % regset->size", this is not the same > as "iov_len % regset_size()". > > IOW, currently you can read/write, say, only the 1st register, you patch > breaks this? >
Hi Oleg,
Thank you. I misunderstood the meaning of regset->size It seems I only needs to update this line, right? - kiov->iov_len = min(kiov->iov_len, (__kernel_size_t) (regset->n * regset->size)); + kiov->iov_len = min(kiov->iov_len, (__kernel_size_t) regset_size(task, regset));
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