MIPS: Factor o32 specific code into signal_o32.c

The commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
caused building a 64 bit kernel with support for n32 and not o32
to produce a build error:

arch/mips/kernel/signal32.c:415:11: error: ‘vdso_image_o32’ undeclared here (not in a function)
  .vdso  = &vdso_image_o32,

Fix this by moving the o32 specific code into signal_o32.c and
updating the Makefile accordingly.

Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: Alex Smith <alex@alex-smith.me.uk>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13690/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 285 insertions, 0 deletions

diff --git a/arch/mips/kernel/signal_o32.c b/arch/mips/kernel/signal_o32.c
new file mode 100644
index 000000000000..5e169fc5ca5c
--- /dev/null
+++ b/arch/mips/kernel/signal_o32.c
@@ -0,0 +1,285 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1991, 1992  Linus Torvalds
+ * Copyright (C) 1994 - 2000, 2006  Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2016, Imagination Technologies Ltd.
+ */
+#include <linux/compiler.h>
+#include <linux/errno.h>
+#include <linux/signal.h>
+#include <linux/uaccess.h>
+
+#include <asm/abi.h>
+#include <asm/compat-signal.h>
+#include <asm/dsp.h>
+#include <asm/sim.h>
+#include <asm/unistd.h>
+
+#include "signal-common.h"
+
+/*
+ * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
+ */
+#define __NR_O32_restart_syscall	4253
+
+struct sigframe32 {
+	u32 sf_ass[4];		/* argument save space for o32 */
+	u32 sf_pad[2];		/* Was: signal trampoline */
+	struct sigcontext32 sf_sc;
+	compat_sigset_t sf_mask;
+};
+
+struct ucontext32 {
+	u32		    uc_flags;
+	s32		    uc_link;
+	compat_stack_t      uc_stack;
+	struct sigcontext32 uc_mcontext;
+	compat_sigset_t	    uc_sigmask;	  /* mask last for extensibility */
+};
+
+struct rt_sigframe32 {
+	u32 rs_ass[4];			/* argument save space for o32 */
+	u32 rs_pad[2];			/* Was: signal trampoline */
+	compat_siginfo_t rs_info;
+	struct ucontext32 rs_uc;
+};
+
+static int setup_sigcontext32(struct pt_regs *regs,
+			      struct sigcontext32 __user *sc)
+{
+	int err = 0;
+	int i;
+
+	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
+
+	err |= __put_user(0, &sc->sc_regs[0]);
+	for (i = 1; i < 32; i++)
+		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);
+
+	err |= __put_user(regs->hi, &sc->sc_mdhi);
+	err |= __put_user(regs->lo, &sc->sc_mdlo);
+	if (cpu_has_dsp) {
+		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
+		err |= __put_user(mfhi1(), &sc->sc_hi1);
+		err |= __put_user(mflo1(), &sc->sc_lo1);
+		err |= __put_user(mfhi2(), &sc->sc_hi2);
+		err |= __put_user(mflo2(), &sc->sc_lo2);
+		err |= __put_user(mfhi3(), &sc->sc_hi3);
+		err |= __put_user(mflo3(), &sc->sc_lo3);
+	}
+
+	/*
+	 * Save FPU state to signal context.  Signal handler
+	 * will "inherit" current FPU state.
+	 */
+	err |= protected_save_fp_context(sc);
+
+	return err;
+}
+
+static int restore_sigcontext32(struct pt_regs *regs,
+				struct sigcontext32 __user *sc)
+{
+	int err = 0;
+	s32 treg;
+	int i;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
+	err |= __get_user(regs->hi, &sc->sc_mdhi);
+	err |= __get_user(regs->lo, &sc->sc_mdlo);
+	if (cpu_has_dsp) {
+		err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
+		err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
+		err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
+		err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
+		err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
+		err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
+		err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
+	}
+
+	for (i = 1; i < 32; i++)
+		err |= __get_user(regs->regs[i], &sc->sc_regs[i]);
+
+	return err ?: protected_restore_fp_context(sc);
+}
+
+static int setup_frame_32(void *sig_return, struct ksignal *ksig,
+			  struct pt_regs *regs, sigset_t *set)
+{
+	struct sigframe32 __user *frame;
+	int err = 0;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+		return -EFAULT;
+
+	err |= setup_sigcontext32(regs, &frame->sf_sc);
+	err |= __copy_conv_sigset_to_user(&frame->sf_mask, set);
+
+	if (err)
+		return -EFAULT;
+
+	/*
+	 * Arguments to signal handler:
+	 *
+	 *   a0 = signal number
+	 *   a1 = 0 (should be cause)
+	 *   a2 = pointer to struct sigcontext
+	 *
+	 * $25 and c0_epc point to the signal handler, $29 points to the
+	 * struct sigframe.
+	 */
+	regs->regs[ 4] = ksig->sig;
+	regs->regs[ 5] = 0;
+	regs->regs[ 6] = (unsigned long) &frame->sf_sc;
+	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;
+}
+
+asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
+{
+	struct rt_sigframe32 __user *frame;
+	sigset_t set;
+	int sig;
+
+	frame = (struct rt_sigframe32 __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_sigcontext32(&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_32(void *sig_return, struct ksignal *ksig,
+			     struct pt_regs *regs, sigset_t *set)
+{
+	struct rt_sigframe32 __user *frame;
+	int err = 0;
+
+	frame = get_sigframe(ksig, regs, sizeof(*frame));
+	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
+		return -EFAULT;
+
+	/* Convert (siginfo_t -> compat_siginfo_t) and copy to user. */
+	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_sigcontext32(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_sigframe32.
+	 */
+	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;
+}
+
+/*
+ * o32 compatibility on 64-bit kernels, without DSP ASE
+ */
+struct mips_abi mips_abi_32 = {
+	.setup_frame	= setup_frame_32,
+	.setup_rt_frame = setup_rt_frame_32,
+	.restart	= __NR_O32_restart_syscall,
+
+	.off_sc_fpregs = offsetof(struct sigcontext32, sc_fpregs),
+	.off_sc_fpc_csr = offsetof(struct sigcontext32, sc_fpc_csr),
+	.off_sc_used_math = offsetof(struct sigcontext32, sc_used_math),
+
+	.vdso		= &vdso_image_o32,
+};
+
+
+asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs)
+{
+	struct sigframe32 __user *frame;
+	sigset_t blocked;
+	int sig;
+
+	frame = (struct sigframe32 __user *) regs.regs[29];
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+	if (__copy_conv_sigset_from_user(&blocked, &frame->sf_mask))
+		goto badframe;
+
+	set_current_blocked(&blocked);
+
+	sig = restore_sigcontext32(&regs, &frame->sf_sc);
+	if (sig < 0)
+		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
+
+	/*
+	 * 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);
+}