v4.19.13 snapshot.
diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c
new file mode 100644
index 0000000..8f65aaf
--- /dev/null
+++ b/arch/mips/kernel/signal_n32.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2003 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include <linux/cache.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/ptrace.h>
+#include <linux/unistd.h>
+#include <linux/compat.h>
+#include <linux/bitops.h>
+
+#include <asm/abi.h>
+#include <asm/asm.h>
+#include <asm/cacheflush.h>
+#include <asm/compat-signal.h>
+#include <asm/sim.h>
+#include <linux/uaccess.h>
+#include <asm/ucontext.h>
+#include <asm/fpu.h>
+#include <asm/cpu-features.h>
+#include <asm/war.h>
+
+#include "signal-common.h"
+
+/*
+ * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
+ */
+#define __NR_N32_restart_syscall 6214
+
+extern int setup_sigcontext(struct pt_regs *, struct sigcontext __user *);
+extern int restore_sigcontext(struct pt_regs *, struct sigcontext __user *);
+
+struct ucontextn32 {
+ u32 uc_flags;
+ s32 uc_link;
+ compat_stack_t uc_stack;
+ struct sigcontext uc_mcontext;
+ compat_sigset_t uc_sigmask; /* mask last for extensibility */
+};
+
+struct rt_sigframe_n32 {
+ u32 rs_ass[4]; /* argument save space for o32 */
+ u32 rs_pad[2]; /* Was: signal trampoline */
+ struct compat_siginfo rs_info;
+ struct ucontextn32 rs_uc;
+};
+
+asmlinkage void sysn32_rt_sigreturn(void)
+{
+ struct rt_sigframe_n32 __user *frame;
+ struct pt_regs *regs;
+ sigset_t set;
+ int sig;
+
+ regs = current_pt_regs();
+ frame = (struct rt_sigframe_n32 __user *)regs->regs[29];
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_conv_sigset_from_user(&set, &frame->rs_uc.uc_sigmask))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ sig = restore_sigcontext(regs, &frame->rs_uc.uc_mcontext);
+ if (sig < 0)
+ goto badframe;
+ else if (sig)
+ force_sig(sig, current);
+
+ if (compat_restore_altstack(&frame->rs_uc.uc_stack))
+ goto badframe;
+
+ /*
+ * Don't let your children do this ...
+ */
+ __asm__ __volatile__(
+ "move\t$29, %0\n\t"
+ "j\tsyscall_exit"
+ : /* no outputs */
+ : "r" (regs));
+ /* Unreached */
+
+badframe:
+ force_sig(SIGSEGV, current);
+}
+
+static int setup_rt_frame_n32(void *sig_return, struct ksignal *ksig,
+ struct pt_regs *regs, sigset_t *set)
+{
+ struct rt_sigframe_n32 __user *frame;
+ int err = 0;
+
+ frame = get_sigframe(ksig, regs, sizeof(*frame));
+ if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+ return -EFAULT;
+
+ /* Create siginfo. */
+ err |= copy_siginfo_to_user32(&frame->rs_info, &ksig->info);
+
+ /* Create the ucontext. */
+ err |= __put_user(0, &frame->rs_uc.uc_flags);
+ err |= __put_user(0, &frame->rs_uc.uc_link);
+ err |= __compat_save_altstack(&frame->rs_uc.uc_stack, regs->regs[29]);
+ err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
+ err |= __copy_conv_sigset_to_user(&frame->rs_uc.uc_sigmask, set);
+
+ if (err)
+ return -EFAULT;
+
+ /*
+ * Arguments to signal handler:
+ *
+ * a0 = signal number
+ * a1 = 0 (should be cause)
+ * a2 = pointer to ucontext
+ *
+ * $25 and c0_epc point to the signal handler, $29 points to
+ * the struct rt_sigframe.
+ */
+ regs->regs[ 4] = ksig->sig;
+ regs->regs[ 5] = (unsigned long) &frame->rs_info;
+ regs->regs[ 6] = (unsigned long) &frame->rs_uc;
+ regs->regs[29] = (unsigned long) frame;
+ regs->regs[31] = (unsigned long) sig_return;
+ regs->cp0_epc = regs->regs[25] = (unsigned long) ksig->ka.sa.sa_handler;
+
+ DEBUGP("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%lx\n",
+ current->comm, current->pid,
+ frame, regs->cp0_epc, regs->regs[31]);
+
+ return 0;
+}
+
+struct mips_abi mips_abi_n32 = {
+ .setup_rt_frame = setup_rt_frame_n32,
+ .restart = __NR_N32_restart_syscall,
+
+ .off_sc_fpregs = offsetof(struct sigcontext, sc_fpregs),
+ .off_sc_fpc_csr = offsetof(struct sigcontext, sc_fpc_csr),
+ .off_sc_used_math = offsetof(struct sigcontext, sc_used_math),
+
+ .vdso = &vdso_image_n32,
+};