Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 257 insertions, 0 deletions

diff --git a/arch/hexagon/kernel/signal.c b/arch/hexagon/kernel/signal.c
new file mode 100644
index 000000000..94cc7ff52
--- /dev/null
+++ b/arch/hexagon/kernel/signal.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Signal support for Hexagon processor
+ *
+ * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/linkage.h>
+#include <linux/syscalls.h>
+#include <linux/tracehook.h>
+#include <linux/sched/task_stack.h>
+
+#include <asm/registers.h>
+#include <asm/thread_info.h>
+#include <asm/unistd.h>
+#include <linux/uaccess.h>
+#include <asm/ucontext.h>
+#include <asm/cacheflush.h>
+#include <asm/signal.h>
+#include <asm/vdso.h>
+
+struct rt_sigframe {
+	unsigned long tramp[2];
+	struct siginfo info;
+	struct ucontext uc;
+};
+
+static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
+			  size_t frame_size)
+{
+	unsigned long sp = sigsp(regs->r29, ksig);
+
+	return (void __user *)((sp - frame_size) & ~(sizeof(long long) - 1));
+}
+
+static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
+{
+	unsigned long tmp;
+	int err = 0;
+
+	err |= copy_to_user(&sc->sc_regs.r0, &regs->r00,
+			    32*sizeof(unsigned long));
+
+	err |= __put_user(regs->sa0, &sc->sc_regs.sa0);
+	err |= __put_user(regs->lc0, &sc->sc_regs.lc0);
+	err |= __put_user(regs->sa1, &sc->sc_regs.sa1);
+	err |= __put_user(regs->lc1, &sc->sc_regs.lc1);
+	err |= __put_user(regs->m0, &sc->sc_regs.m0);
+	err |= __put_user(regs->m1, &sc->sc_regs.m1);
+	err |= __put_user(regs->usr, &sc->sc_regs.usr);
+	err |= __put_user(regs->preds, &sc->sc_regs.p3_0);
+	err |= __put_user(regs->gp, &sc->sc_regs.gp);
+	err |= __put_user(regs->ugp, &sc->sc_regs.ugp);
+#if CONFIG_HEXAGON_ARCH_VERSION >= 4
+	err |= __put_user(regs->cs0, &sc->sc_regs.cs0);
+	err |= __put_user(regs->cs1, &sc->sc_regs.cs1);
+#endif
+	tmp = pt_elr(regs); err |= __put_user(tmp, &sc->sc_regs.pc);
+	tmp = pt_cause(regs); err |= __put_user(tmp, &sc->sc_regs.cause);
+	tmp = pt_badva(regs); err |= __put_user(tmp, &sc->sc_regs.badva);
+
+	return err;
+}
+
+static int restore_sigcontext(struct pt_regs *regs,
+			      struct sigcontext __user *sc)
+{
+	unsigned long tmp;
+	int err = 0;
+
+	err |= copy_from_user(&regs->r00, &sc->sc_regs.r0,
+			      32 * sizeof(unsigned long));
+
+	err |= __get_user(regs->sa0, &sc->sc_regs.sa0);
+	err |= __get_user(regs->lc0, &sc->sc_regs.lc0);
+	err |= __get_user(regs->sa1, &sc->sc_regs.sa1);
+	err |= __get_user(regs->lc1, &sc->sc_regs.lc1);
+	err |= __get_user(regs->m0, &sc->sc_regs.m0);
+	err |= __get_user(regs->m1, &sc->sc_regs.m1);
+	err |= __get_user(regs->usr, &sc->sc_regs.usr);
+	err |= __get_user(regs->preds, &sc->sc_regs.p3_0);
+	err |= __get_user(regs->gp, &sc->sc_regs.gp);
+	err |= __get_user(regs->ugp, &sc->sc_regs.ugp);
+#if CONFIG_HEXAGON_ARCH_VERSION >= 4
+	err |= __get_user(regs->cs0, &sc->sc_regs.cs0);
+	err |= __get_user(regs->cs1, &sc->sc_regs.cs1);
+#endif
+	err |= __get_user(tmp, &sc->sc_regs.pc); pt_set_elr(regs, tmp);
+
+	return err;
+}
+
+/*
+ * Setup signal stack frame with siginfo structure
+ */
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+			  struct pt_regs *regs)
+{
+	int err = 0;
+	struct rt_sigframe __user *frame;
+	struct hexagon_vdso *vdso = current->mm->context.vdso;
+
+	frame = get_sigframe(ksig, regs, sizeof(struct rt_sigframe));
+
+	if (!access_ok(frame, sizeof(struct rt_sigframe)))
+		return -EFAULT;
+
+	if (copy_siginfo_to_user(&frame->info, &ksig->info))
+		return -EFAULT;
+
+	/* The on-stack signal trampoline is no longer executed;
+	 * however, the libgcc signal frame unwinding code checks for
+	 * the presence of these two numeric magic values.
+	 */
+	err |= __put_user(0x7800d166, &frame->tramp[0]);
+	err |= __put_user(0x5400c004, &frame->tramp[1]);
+	err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+	err |= __save_altstack(&frame->uc.uc_stack, user_stack_pointer(regs));
+	if (err)
+		return -EFAULT;
+
+	/* Load r0/r1 pair with signumber/siginfo pointer... */
+	regs->r0100 = ((unsigned long long)((unsigned long)&frame->info) << 32)
+		| (unsigned long long)ksig->sig;
+	regs->r02 = (unsigned long) &frame->uc;
+	regs->r31 = (unsigned long) vdso->rt_signal_trampoline;
+	pt_psp(regs) = (unsigned long) frame;
+	pt_set_elr(regs, (unsigned long)ksig->ka.sa.sa_handler);
+
+	return 0;
+}
+
+/*
+ * Setup invocation of signal handler
+ */
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+{
+	int ret;
+
+	/*
+	 * If we're handling a signal that aborted a system call,
+	 * set up the error return value before adding the signal
+	 * frame to the stack.
+	 */
+
+	if (regs->syscall_nr >= 0) {
+		switch (regs->r00) {
+		case -ERESTART_RESTARTBLOCK:
+		case -ERESTARTNOHAND:
+			regs->r00 = -EINTR;
+			break;
+		case -ERESTARTSYS:
+			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+				regs->r00 = -EINTR;
+				break;
+			}
+			fallthrough;
+		case -ERESTARTNOINTR:
+			regs->r06 = regs->syscall_nr;
+			pt_set_elr(regs, pt_elr(regs) - 4);
+			regs->r00 = regs->restart_r0;
+			break;
+		default:
+			break;
+		}
+	}
+
+	/*
+	 * Set up the stack frame; not doing the SA_SIGINFO thing.  We
+	 * only set up the rt_frame flavor.
+	 */
+	/* If there was an error on setup, no signal was delivered. */
+	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
+
+	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+}
+
+/*
+ * Called from return-from-event code.
+ */
+void do_signal(struct pt_regs *regs)
+{
+	struct ksignal ksig;
+
+	if (!user_mode(regs))
+		return;
+
+	if (get_signal(&ksig)) {
+		handle_signal(&ksig, regs);
+		return;
+	}
+
+	/*
+	 * No (more) signals; if we came from a system call, handle the restart.
+	 */
+
+	if (regs->syscall_nr >= 0) {
+		switch (regs->r00) {
+		case -ERESTARTNOHAND:
+		case -ERESTARTSYS:
+		case -ERESTARTNOINTR:
+			regs->r06 = regs->syscall_nr;
+			break;
+		case -ERESTART_RESTARTBLOCK:
+			regs->r06 = __NR_restart_syscall;
+			break;
+		default:
+			goto no_restart;
+		}
+		pt_set_elr(regs, pt_elr(regs) - 4);
+		regs->r00 = regs->restart_r0;
+	}
+
+no_restart:
+	/* If there's no signal to deliver, put the saved sigmask back */
+	restore_saved_sigmask();
+}
+
+/*
+ * Architecture-specific wrappers for signal-related system calls
+ */
+
+asmlinkage int sys_rt_sigreturn(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe __user *frame;
+	sigset_t blocked;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	frame = (struct rt_sigframe __user *)pt_psp(regs);
+	if (!access_ok(frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
+		goto badframe;
+
+	set_current_blocked(&blocked);
+
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+		goto badframe;
+
+	/* Restore the user's stack as well */
+	pt_psp(regs) = regs->r29;
+
+	regs->syscall_nr = -1;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return regs->r00;
+
+badframe:
+	force_sig(SIGSEGV);
+	return 0;
+}