| Message ID | 3700190a602a6d30fcbf76e1eea667e29a65c4c9.1590474856.git.greentime.hu@sifive.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | riscv: Add vector ISA support | expand |
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? Oleg.
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));
On 05/27, Greentime Hu wrote: > > 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)); Yes, agreed. Oleg.
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 43d6179508d6..6877105e1b1e 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -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; + + kiov->iov_len = min(kiov->iov_len, (__kernel_size_t) size); if (req == PTRACE_GETREGSET) return copy_regset_to_user(task, view, regset_no, 0,
It uses regset_size() instead of using regset->n and regset->size directly. In this case, it will call the get_size() ported by arch dynamically to support dynamic regset size case. Signed-off-by: Greentime Hu <greentime.hu@sifive.com> --- kernel/ptrace.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)