1 files changed, 228 insertions, 71 deletions

diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index 457e97aa2945..aa17e62f3754 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -1,56 +1,177 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Common signal handling code for both 32 and 64 bits
  *
- *    Copyright (c) 2007 Benjamin Herrenschmidt, IBM Coproration
+ *    Copyright (c) 2007 Benjamin Herrenschmidt, IBM Corporation
  *    Extracted from signal_32.c and signal_64.c
- *
- * This file is subject to the terms and conditions of the GNU General
- * Public License.  See the file README.legal in the main directory of
- * this archive for more details.
  */
 
-#include <linux/tracehook.h>
+#include <linux/resume_user_mode.h>
 #include <linux/signal.h>
 #include <linux/uprobes.h>
 #include <linux/key.h>
 #include <linux/context_tracking.h>
+#include <linux/livepatch.h>
+#include <linux/syscalls.h>
 #include <asm/hw_breakpoint.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
+#include <asm/switch_to.h>
 #include <asm/unistd.h>
 #include <asm/debug.h>
 #include <asm/tm.h>
 
 #include "signal.h"
 
+#ifdef CONFIG_VSX
+unsigned long copy_fpr_to_user(void __user *to,
+			       struct task_struct *task)
+{
+	u64 buf[ELF_NFPREG];
+	int i;
+
+	/* save FPR copy to local buffer then write to the thread_struct */
+	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
+		buf[i] = task->thread.TS_FPR(i);
+	buf[i] = task->thread.fp_state.fpscr;
+	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
+}
+
+unsigned long copy_fpr_from_user(struct task_struct *task,
+				 void __user *from)
+{
+	u64 buf[ELF_NFPREG];
+	int i;
+
+	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
+		return 1;
+	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
+		task->thread.TS_FPR(i) = buf[i];
+	task->thread.fp_state.fpscr = buf[i];
+
+	return 0;
+}
+
+unsigned long copy_vsx_to_user(void __user *to,
+			       struct task_struct *task)
+{
+	u64 buf[ELF_NVSRHALFREG];
+	int i;
+
+	/* save FPR copy to local buffer then write to the thread_struct */
+	for (i = 0; i < ELF_NVSRHALFREG; i++)
+		buf[i] = task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET];
+	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
+}
+
+unsigned long copy_vsx_from_user(struct task_struct *task,
+				 void __user *from)
+{
+	u64 buf[ELF_NVSRHALFREG];
+	int i;
+
+	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
+		return 1;
+	for (i = 0; i < ELF_NVSRHALFREG ; i++)
+		task->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
+	return 0;
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+unsigned long copy_ckfpr_to_user(void __user *to,
+				  struct task_struct *task)
+{
+	u64 buf[ELF_NFPREG];
+	int i;
+
+	/* save FPR copy to local buffer then write to the thread_struct */
+	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
+		buf[i] = task->thread.TS_CKFPR(i);
+	buf[i] = task->thread.ckfp_state.fpscr;
+	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
+}
+
+unsigned long copy_ckfpr_from_user(struct task_struct *task,
+					  void __user *from)
+{
+	u64 buf[ELF_NFPREG];
+	int i;
+
+	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
+		return 1;
+	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
+		task->thread.TS_CKFPR(i) = buf[i];
+	task->thread.ckfp_state.fpscr = buf[i];
+
+	return 0;
+}
+
+unsigned long copy_ckvsx_to_user(void __user *to,
+				  struct task_struct *task)
+{
+	u64 buf[ELF_NVSRHALFREG];
+	int i;
+
+	/* save FPR copy to local buffer then write to the thread_struct */
+	for (i = 0; i < ELF_NVSRHALFREG; i++)
+		buf[i] = task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET];
+	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
+}
+
+unsigned long copy_ckvsx_from_user(struct task_struct *task,
+					  void __user *from)
+{
+	u64 buf[ELF_NVSRHALFREG];
+	int i;
+
+	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
+		return 1;
+	for (i = 0; i < ELF_NVSRHALFREG ; i++)
+		task->thread.ckfp_state.fpr[i][TS_VSRLOWOFFSET] = buf[i];
+	return 0;
+}
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+#endif
+
 /* Log an error when sending an unhandled signal to a process. Controlled
  * through debug.exception-trace sysctl.
  */
 
 int show_unhandled_signals = 1;
 
+unsigned long get_min_sigframe_size(void)
+{
+	if (IS_ENABLED(CONFIG_PPC64))
+		return get_min_sigframe_size_64();
+	else
+		return get_min_sigframe_size_32();
+}
+
+#ifdef CONFIG_COMPAT
+unsigned long get_min_sigframe_size_compat(void)
+{
+	return get_min_sigframe_size_32();
+}
+#endif
+
 /*
  * Allocate space for the signal frame
  */
-void __user * get_sigframe(struct k_sigaction *ka, unsigned long sp,
-			   size_t frame_size, int is_32)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk);
+
+void __user *get_sigframe(struct ksignal *ksig, struct task_struct *tsk,
+			  size_t frame_size, int is_32)
 {
         unsigned long oldsp, newsp;
+	unsigned long sp = get_tm_stackpointer(tsk);
 
         /* Default to using normal stack */
-        oldsp = get_clean_sp(sp, is_32);
-
-	/* Check for alt stack */
-	if ((ka->sa.sa_flags & SA_ONSTACK) &&
-	    current->sas_ss_size && !on_sig_stack(oldsp))
-		oldsp = (current->sas_ss_sp + current->sas_ss_size);
-
-	/* Get aligned frame */
+	if (is_32)
+		oldsp = sp & 0x0ffffffffUL;
+	else
+		oldsp = sp;
+	oldsp = sigsp(oldsp, ksig);
 	newsp = (oldsp - frame_size) & ~0xFUL;
 
-	/* Check access */
-	if (!access_ok(VERIFY_WRITE, (void __user *)newsp, oldsp - newsp))
-		return NULL;
-
         return (void __user *)newsp;
 }
 
@@ -61,12 +182,21 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
 	int restart = 1;
 
 	/* syscall ? */
-	if (TRAP(regs) != 0x0C00)
+	if (!trap_is_syscall(regs))
+		return;
+
+	if (trap_norestart(regs))
 		return;
 
 	/* error signalled ? */
-	if (!(regs->ccr & 0x10000000))
+	if (trap_is_scv(regs)) {
+		/* 32-bit compat mode sign extend? */
+		if (!IS_ERR_VALUE(ret))
+			return;
+		ret = -ret;
+	} else if (!(regs->ccr & 0x10000000)) {
 		return;
+	}
 
 	switch (ret) {
 	case ERESTART_RESTARTBLOCK:
@@ -96,88 +226,90 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
 			regs->gpr[0] = __NR_restart_syscall;
 		else
 			regs->gpr[3] = regs->orig_gpr3;
-		regs->nip -= 4;
+		regs_add_return_ip(regs, -4);
 		regs->result = 0;
 	} else {
-		regs->result = -EINTR;
-		regs->gpr[3] = EINTR;
-		regs->ccr |= 0x10000000;
+		if (trap_is_scv(regs)) {
+			regs->result = -EINTR;
+			regs->gpr[3] = -EINTR;
+		} else {
+			regs->result = -EINTR;
+			regs->gpr[3] = EINTR;
+			regs->ccr |= 0x10000000;
+		}
 	}
 }
 
-static int do_signal(struct pt_regs *regs)
+static void do_signal(struct task_struct *tsk)
 {
 	sigset_t *oldset = sigmask_to_save();
-	siginfo_t info;
-	int signr;
-	struct k_sigaction ka;
+	struct ksignal ksig = { .sig = 0 };
 	int ret;
-	int is32 = is_32bit_task();
 
-	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
+	BUG_ON(tsk != current);
+
+	get_signal(&ksig);
 
 	/* Is there any syscall restart business here ? */
-	check_syscall_restart(regs, &ka, signr > 0);
+	check_syscall_restart(tsk->thread.regs, &ksig.ka, ksig.sig > 0);
 
-	if (signr <= 0) {
+	if (ksig.sig <= 0) {
 		/* No signal to deliver -- put the saved sigmask back */
 		restore_saved_sigmask();
-		regs->trap = 0;
-		return 0;               /* no signals delivered */
+		set_trap_norestart(tsk->thread.regs);
+		return;               /* no signals delivered */
 	}
 
-#ifndef CONFIG_PPC_ADV_DEBUG_REGS
         /*
 	 * Reenable the DABR before delivering the signal to
 	 * user space. The DABR will have been cleared if it
 	 * triggered inside the kernel.
 	 */
-	if (current->thread.hw_brk.address &&
-		current->thread.hw_brk.type)
-		set_breakpoint(&current->thread.hw_brk);
-#endif
+	if (!IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
+		int i;
+
+		for (i = 0; i < nr_wp_slots(); i++) {
+			if (tsk->thread.hw_brk[i].address && tsk->thread.hw_brk[i].type)
+				__set_breakpoint(i, &tsk->thread.hw_brk[i]);
+		}
+	}
+
 	/* Re-enable the breakpoints for the signal stack */
-	thread_change_pc(current, regs);
+	thread_change_pc(tsk, tsk->thread.regs);
+
+	rseq_signal_deliver(&ksig, tsk->thread.regs);
 
-	if (is32) {
-        	if (ka.sa.sa_flags & SA_SIGINFO)
-			ret = handle_rt_signal32(signr, &ka, &info, oldset,
-					regs);
+	if (is_32bit_task()) {
+        	if (ksig.ka.sa.sa_flags & SA_SIGINFO)
+			ret = handle_rt_signal32(&ksig, oldset, tsk);
 		else
-			ret = handle_signal32(signr, &ka, &info, oldset,
-					regs);
+			ret = handle_signal32(&ksig, oldset, tsk);
 	} else {
-		ret = handle_rt_signal64(signr, &ka, &info, oldset, regs);
+		ret = handle_rt_signal64(&ksig, oldset, tsk);
 	}
 
-	regs->trap = 0;
-	if (ret) {
-		signal_delivered(signr, &info, &ka, regs,
-					 test_thread_flag(TIF_SINGLESTEP));
-	}
-
-	return ret;
+	set_trap_norestart(tsk->thread.regs);
+	signal_setup_done(ret, &ksig, test_thread_flag(TIF_SINGLESTEP));
 }
 
 void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
 {
-	user_exit();
-
 	if (thread_info_flags & _TIF_UPROBE)
 		uprobe_notify_resume(regs);
 
-	if (thread_info_flags & _TIF_SIGPENDING)
-		do_signal(regs);
+	if (thread_info_flags & _TIF_PATCH_PENDING)
+		klp_update_patch_state(current);
 
-	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
-		clear_thread_flag(TIF_NOTIFY_RESUME);
-		tracehook_notify_resume(regs);
+	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) {
+		BUG_ON(regs != current->thread.regs);
+		do_signal(current);
 	}
 
-	user_enter();
+	if (thread_info_flags & _TIF_NOTIFY_RESUME)
+		resume_user_mode_work(regs);
 }
 
-unsigned long get_tm_stackpointer(struct pt_regs *regs)
+static unsigned long get_tm_stackpointer(struct task_struct *tsk)
 {
 	/* When in an active transaction that takes a signal, we need to be
 	 * careful with the stack.  It's possible that the stack has moved back
@@ -193,21 +325,46 @@ unsigned long get_tm_stackpointer(struct pt_regs *regs)
 	 * need to use the stack pointer from the checkpointed state, rather
 	 * than the speculated state.  This ensures that the signal context
 	 * (written tm suspended) will be written below the stack required for
-	 * the rollback.  The transaction is aborted becuase of the treclaim,
+	 * the rollback.  The transaction is aborted because of the treclaim,
 	 * so any memory written between the tbegin and the signal will be
 	 * rolled back anyway.
 	 *
 	 * For signals taken in non-TM or suspended mode, we use the
 	 * normal/non-checkpointed stack pointer.
 	 */
+	struct pt_regs *regs = tsk->thread.regs;
+	unsigned long ret = regs->gpr[1];
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	BUG_ON(tsk != current);
+
 	if (MSR_TM_ACTIVE(regs->msr)) {
-		tm_enable();
-		tm_reclaim(&current->thread, regs->msr, TM_CAUSE_SIGNAL);
+		preempt_disable();
+		tm_reclaim_current(TM_CAUSE_SIGNAL);
 		if (MSR_TM_TRANSACTIONAL(regs->msr))
-			return current->thread.ckpt_regs.gpr[1];
+			ret = tsk->thread.ckpt_regs.gpr[1];
+
+		/*
+		 * If we treclaim, we must clear the current thread's TM bits
+		 * before re-enabling preemption. Otherwise we might be
+		 * preempted and have the live MSR[TS] changed behind our back
+		 * (tm_recheckpoint_new_task() would recheckpoint). Besides, we
+		 * enter the signal handler in non-transactional state.
+		 */
+		regs_set_return_msr(regs, regs->msr & ~MSR_TS_MASK);
+		preempt_enable();
 	}
 #endif
-	return regs->gpr[1];
+	return ret;
+}
+
+static const char fm32[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %08lx lr %08lx\n";
+static const char fm64[] = KERN_INFO "%s[%d]: bad frame in %s: %p nip %016lx lr %016lx\n";
+
+void signal_fault(struct task_struct *tsk, struct pt_regs *regs,
+		  const char *where, void __user *ptr)
+{
+	if (show_unhandled_signals)
+		printk_ratelimited(regs->msr & MSR_64BIT ? fm64 : fm32, tsk->comm,
+				   task_pid_nr(tsk), where, ptr, regs->nip, regs->link);
 }