Hi Dave, It seems that your series conflicts with one of patches of my ILP32: https://patchwork.kernel.org/patch/9599015/ Now I try to rebase ilp32 on your patchset, and maybe will have some questions. The first question is below. If you have comments on my series - please share it. Yury On Thu, Jun 15, 2017 at 03:03:39PM +0100, Dave Martin wrote: > Currently, rt_sigreturn does very limited checking on the > sigcontext coming from userspace. > > Future additions to the sigcontext data will increase the potential > for surprises. Also, it is not clear whether the sigcontext > extension records are supposed to occur in a particular order. > > To allow the parsing code to be extended more easily, this patch > factors out the sigcontext parsing into a separate function, and > adds extra checks to validate the well-formedness of the sigcontext > structure. > > Signed-off-by: Dave Martin <Dave.Martin@xxxxxxx> > +static int parse_user_sigframe(struct user_ctxs *user, > + struct rt_sigframe __user *sf) You parse sigcontext here in fact. At least you take the pointer to the sigcontext from rt_sigframe, and never refer it anymore. rt_sigframe is different for lp64 and ilp32, but sigcontext is the same. So if you'll rename the function to parse_user_sigcontext, and will pass sigcontext to it directly, I will reuse it in ilp32 code. > +{ > + struct sigcontext __user *const sc = &sf->uc.uc_mcontext; > + struct _aarch64_ctx __user *head = > + (struct _aarch64_ctx __user *)&sc->__reserved; > + size_t offset = 0; > + > + user->fpsimd = NULL; > + > + while (1) { > + int err; > + u32 magic, size; > + > + head = (struct _aarch64_ctx __user *)&sc->__reserved[offset]; > + if (!IS_ALIGNED((unsigned long)head, 16)) > + goto invalid; > + > + err = 0; > + __get_user_error(magic, &head->magic, err); > + __get_user_error(size, &head->size, err); > + if (err) > + return err; > + > + switch (magic) { > + case 0: > + if (size) > + goto invalid; > + > + goto done; > + > + case FPSIMD_MAGIC: > + if (user->fpsimd) > + goto invalid; > + > + if (offset > sizeof(sc->__reserved) - > + sizeof(*user->fpsimd) || > + size < sizeof(*user->fpsimd)) > + goto invalid; > + > + user->fpsimd = (struct fpsimd_context __user *)head; > + break; > + > + case ESR_MAGIC: > + /* ignore */ > + break; > + > + default: > + goto invalid; > + } > + > + if (size < sizeof(*head)) > + goto invalid; > + > + if (size > sizeof(sc->__reserved) - (sizeof(*head) + offset)) > + goto invalid; > + > + offset += size; > + } > + > +done: > + if (!user->fpsimd) > + goto invalid; > + > + return 0; > + > +invalid: > + return -EINVAL; > +} > + > static int restore_sigframe(struct pt_regs *regs, > struct rt_sigframe __user *sf) > { > sigset_t set; > int i, err; > - void *aux = sf->uc.uc_mcontext.__reserved; > + struct user_ctxs user; > > err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); > if (err == 0) > @@ -125,12 +200,11 @@ static int restore_sigframe(struct pt_regs *regs, > regs->syscallno = ~0UL; > > err |= !valid_user_regs(®s->user_regs, current); > + if (err == 0) > + err = parse_user_sigframe(&user, sf); > > - if (err == 0) { > - struct fpsimd_context *fpsimd_ctx = > - container_of(aux, struct fpsimd_context, head); > - err |= restore_fpsimd_context(fpsimd_ctx); > - } > + if (err == 0) > + err = restore_fpsimd_context(user.fpsimd); > > return err; > } > -- > 2.1.4 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
