Merge tag 'io_uring-5.13-2021-05-14' of git://git.kernel.dk/linux-block
[linux-2.6-microblaze.git] / arch / powerpc / kernel / signal_64.c
index 78ae4bb..dca6648 100644 (file)
@@ -172,7 +172,6 @@ static long notrace __unsafe_setup_sigcontext(struct sigcontext __user *sc,
        }
 #endif /* CONFIG_VSX */
        unsafe_put_user(&sc->gp_regs, &sc->regs, efault_out);
-       WARN_ON(!FULL_REGS(regs));
        unsafe_copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE, efault_out);
        unsafe_put_user(msr, &sc->gp_regs[PT_MSR], efault_out);
        unsafe_put_user(softe, &sc->gp_regs[PT_SOFTE], efault_out);
@@ -309,7 +308,6 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 
        err |= __put_user(&sc->gp_regs, &sc->regs);
        err |= __put_user(&tm_sc->gp_regs, &tm_sc->regs);
-       WARN_ON(!FULL_REGS(regs));
        err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
        err |= __copy_to_user(&sc->gp_regs,
                              &tsk->thread.ckpt_regs, GP_REGS_SIZE);
@@ -327,14 +325,16 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 /*
  * Restore the sigcontext from the signal frame.
  */
-
-static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
-                             struct sigcontext __user *sc)
+#define unsafe_restore_sigcontext(tsk, set, sig, sc, label) do {       \
+       if (__unsafe_restore_sigcontext(tsk, set, sig, sc))             \
+               goto label;                                             \
+} while (0)
+static long notrace __unsafe_restore_sigcontext(struct task_struct *tsk, sigset_t *set,
+                                               int sig, struct sigcontext __user *sc)
 {
 #ifdef CONFIG_ALTIVEC
        elf_vrreg_t __user *v_regs;
 #endif
-       unsigned long err = 0;
        unsigned long save_r13 = 0;
        unsigned long msr;
        struct pt_regs *regs = tsk->thread.regs;
@@ -349,27 +349,27 @@ static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
                save_r13 = regs->gpr[13];
 
        /* copy the GPRs */
-       err |= __copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr));
-       err |= __get_user(regs->nip, &sc->gp_regs[PT_NIP]);
+       unsafe_copy_from_user(regs->gpr, sc->gp_regs, sizeof(regs->gpr), efault_out);
+       unsafe_get_user(regs->nip, &sc->gp_regs[PT_NIP], efault_out);
        /* get MSR separately, transfer the LE bit if doing signal return */
-       err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
+       unsafe_get_user(msr, &sc->gp_regs[PT_MSR], efault_out);
        if (sig)
                regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);
-       err |= __get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3]);
-       err |= __get_user(regs->ctr, &sc->gp_regs[PT_CTR]);
-       err |= __get_user(regs->link, &sc->gp_regs[PT_LNK]);
-       err |= __get_user(regs->xer, &sc->gp_regs[PT_XER]);
-       err |= __get_user(regs->ccr, &sc->gp_regs[PT_CCR]);
+       unsafe_get_user(regs->orig_gpr3, &sc->gp_regs[PT_ORIG_R3], efault_out);
+       unsafe_get_user(regs->ctr, &sc->gp_regs[PT_CTR], efault_out);
+       unsafe_get_user(regs->link, &sc->gp_regs[PT_LNK], efault_out);
+       unsafe_get_user(regs->xer, &sc->gp_regs[PT_XER], efault_out);
+       unsafe_get_user(regs->ccr, &sc->gp_regs[PT_CCR], efault_out);
        /* Don't allow userspace to set SOFTE */
        set_trap_norestart(regs);
-       err |= __get_user(regs->dar, &sc->gp_regs[PT_DAR]);
-       err |= __get_user(regs->dsisr, &sc->gp_regs[PT_DSISR]);
-       err |= __get_user(regs->result, &sc->gp_regs[PT_RESULT]);
+       unsafe_get_user(regs->dar, &sc->gp_regs[PT_DAR], efault_out);
+       unsafe_get_user(regs->dsisr, &sc->gp_regs[PT_DSISR], efault_out);
+       unsafe_get_user(regs->result, &sc->gp_regs[PT_RESULT], efault_out);
 
        if (!sig)
                regs->gpr[13] = save_r13;
        if (set != NULL)
-               err |=  __get_user(set->sig[0], &sc->oldmask);
+               unsafe_get_user(set->sig[0], &sc->oldmask, efault_out);
 
        /*
         * Force reload of FP/VEC.
@@ -379,29 +379,27 @@ static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
        regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
 
 #ifdef CONFIG_ALTIVEC
-       err |= __get_user(v_regs, &sc->v_regs);
-       if (err)
-               return err;
+       unsafe_get_user(v_regs, &sc->v_regs, efault_out);
        if (v_regs && !access_ok(v_regs, 34 * sizeof(vector128)))
                return -EFAULT;
        /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
        if (v_regs != NULL && (msr & MSR_VEC) != 0) {
-               err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
-                                       33 * sizeof(vector128));
+               unsafe_copy_from_user(&tsk->thread.vr_state, v_regs,
+                                     33 * sizeof(vector128), efault_out);
                tsk->thread.used_vr = true;
        } else if (tsk->thread.used_vr) {
                memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
        }
        /* Always get VRSAVE back */
        if (v_regs != NULL)
-               err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
+               unsafe_get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33], efault_out);
        else
                tsk->thread.vrsave = 0;
        if (cpu_has_feature(CPU_FTR_ALTIVEC))
                mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
 #endif /* CONFIG_ALTIVEC */
        /* restore floating point */
-       err |= copy_fpr_from_user(tsk, &sc->fp_regs);
+       unsafe_copy_fpr_from_user(tsk, &sc->fp_regs, efault_out);
 #ifdef CONFIG_VSX
        /*
         * Get additional VSX data. Update v_regs to point after the
@@ -410,14 +408,17 @@ static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
         */
        v_regs += ELF_NVRREG;
        if ((msr & MSR_VSX) != 0) {
-               err |= copy_vsx_from_user(tsk, v_regs);
+               unsafe_copy_vsx_from_user(tsk, v_regs, efault_out);
                tsk->thread.used_vsr = true;
        } else {
                for (i = 0; i < 32 ; i++)
                        tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
        }
 #endif
-       return err;
+       return 0;
+
+efault_out:
+       return -EFAULT;
 }
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -705,11 +706,17 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx,
         * We kill the task with a SIGSEGV in this situation.
         */
 
-       if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
+       if (__get_user_sigset(&set, &new_ctx->uc_sigmask))
                do_exit(SIGSEGV);
        set_current_blocked(&set);
-       if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
+
+       if (!user_read_access_begin(new_ctx, ctx_size))
+               return -EFAULT;
+       if (__unsafe_restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext)) {
+               user_read_access_end();
                do_exit(SIGSEGV);
+       }
+       user_read_access_end();
 
        /* This returns like rt_sigreturn */
        set_thread_flag(TIF_RESTOREALL);
@@ -738,7 +745,7 @@ SYSCALL_DEFINE0(rt_sigreturn)
        if (!access_ok(uc, sizeof(*uc)))
                goto badframe;
 
-       if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
+       if (__get_user_sigset(&set, &uc->uc_sigmask))
                goto badframe;
        set_current_blocked(&set);
 
@@ -812,8 +819,13 @@ SYSCALL_DEFINE0(rt_sigreturn)
                 * causing a TM bad thing.
                 */
                current->thread.regs->msr &= ~MSR_TS_MASK;
-               if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
+               if (!user_read_access_begin(&uc->uc_mcontext, sizeof(uc->uc_mcontext)))
                        goto badframe;
+
+               unsafe_restore_sigcontext(current, NULL, 1, &uc->uc_mcontext,
+                                         badframe_block);
+
+               user_read_access_end();
        }
 
        if (restore_altstack(&uc->uc_stack))
@@ -822,6 +834,8 @@ SYSCALL_DEFINE0(rt_sigreturn)
        set_thread_flag(TIF_RESTOREALL);
        return 0;
 
+badframe_block:
+       user_read_access_end();
 badframe:
        signal_fault(current, regs, "rt_sigreturn", uc);
 
@@ -840,45 +854,53 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
        unsigned long msr = regs->msr;
 
        frame = get_sigframe(ksig, tsk, sizeof(*frame), 0);
-       if (!access_ok(frame, sizeof(*frame)))
-               goto badframe;
 
-       err |= __put_user(&frame->info, &frame->pinfo);
-       err |= __put_user(&frame->uc, &frame->puc);
-       err |= copy_siginfo_to_user(&frame->info, &ksig->info);
-       if (err)
+       /*
+        * This only applies when calling unsafe_setup_sigcontext() and must be
+        * called before opening the uaccess window.
+        */
+       if (!MSR_TM_ACTIVE(msr))
+               prepare_setup_sigcontext(tsk);
+
+       if (!user_write_access_begin(frame, sizeof(*frame)))
                goto badframe;
 
+       unsafe_put_user(&frame->info, &frame->pinfo, badframe_block);
+       unsafe_put_user(&frame->uc, &frame->puc, badframe_block);
+
        /* Create the ucontext.  */
-       err |= __put_user(0, &frame->uc.uc_flags);
-       err |= __save_altstack(&frame->uc.uc_stack, regs->gpr[1]);
+       unsafe_put_user(0, &frame->uc.uc_flags, badframe_block);
+       unsafe_save_altstack(&frame->uc.uc_stack, regs->gpr[1], badframe_block);
 
        if (MSR_TM_ACTIVE(msr)) {
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
                /* The ucontext_t passed to userland points to the second
                 * ucontext_t (for transactional state) with its uc_link ptr.
                 */
-               err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
+               unsafe_put_user(&frame->uc_transact, &frame->uc.uc_link, badframe_block);
+
+               user_write_access_end();
+
                err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
                                            &frame->uc_transact.uc_mcontext,
                                            tsk, ksig->sig, NULL,
                                            (unsigned long)ksig->ka.sa.sa_handler,
                                            msr);
+
+               if (!user_write_access_begin(&frame->uc.uc_sigmask,
+                                            sizeof(frame->uc.uc_sigmask)))
+                       goto badframe;
+
 #endif
        } else {
-               err |= __put_user(0, &frame->uc.uc_link);
-               prepare_setup_sigcontext(tsk);
-               if (!user_write_access_begin(&frame->uc.uc_mcontext,
-                                            sizeof(frame->uc.uc_mcontext)))
-                       return -EFAULT;
-               err |= __unsafe_setup_sigcontext(&frame->uc.uc_mcontext, tsk,
-                                               ksig->sig, NULL,
-                                               (unsigned long)ksig->ka.sa.sa_handler, 1);
-               user_write_access_end();
+               unsafe_put_user(0, &frame->uc.uc_link, badframe_block);
+               unsafe_setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
+                                       NULL, (unsigned long)ksig->ka.sa.sa_handler,
+                                       1, badframe_block);
        }
-       err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-       if (err)
-               goto badframe;
+
+       unsafe_copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set), badframe_block);
+       user_write_access_end();
 
        /* Make sure signal handler doesn't get spurious FP exceptions */
        tsk->thread.fp_state.fpscr = 0;
@@ -893,6 +915,11 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
                regs->nip = (unsigned long) &frame->tramp[0];
        }
 
+
+       /* Save the siginfo outside of the unsafe block. */
+       if (copy_siginfo_to_user(&frame->info, &ksig->info))
+               goto badframe;
+
        /* Allocate a dummy caller frame for the signal handler. */
        newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
        err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);
@@ -932,6 +959,8 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
 
        return 0;
 
+badframe_block:
+       user_write_access_end();
 badframe:
        signal_fault(current, regs, "handle_rt_signal64", frame);