Adding upstream version 4.19.249.upstream/4.19.249

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

1 files changed, 510 insertions, 0 deletions

diff --git a/arch/sh/kernel/signal_32.c b/arch/sh/kernel/signal_32.c
new file mode 100644
index 000000000..c46c0020f
--- /dev/null
+++ b/arch/sh/kernel/signal_32.c
@@ -0,0 +1,510 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/arch/sh/kernel/signal.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
+ *
+ *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
+ *
+ */
+#include <linux/sched.h>
+#include <linux/sched/task_stack.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/stddef.h>
+#include <linux/tty.h>
+#include <linux/elf.h>
+#include <linux/personality.h>
+#include <linux/binfmts.h>
+#include <linux/io.h>
+#include <linux/tracehook.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+#include <asm/syscalls.h>
+#include <asm/fpu.h>
+
+struct fdpic_func_descriptor {
+	unsigned long	text;
+	unsigned long	GOT;
+};
+
+/*
+ * The following define adds a 64 byte gap between the signal
+ * stack frame and previous contents of the stack.  This allows
+ * frame unwinding in a function epilogue but only if a frame
+ * pointer is used in the function.  This is necessary because
+ * current gcc compilers (<4.3) do not generate unwind info on
+ * SH for function epilogues.
+ */
+#define UNWINDGUARD 64
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+
+#define MOVW(n)	 (0x9300|((n)-2))	/* Move mem word at PC+n to R3 */
+#if defined(CONFIG_CPU_SH2)
+#define TRAP_NOARG 0xc320		/* Syscall w/no args (NR in R3) */
+#else
+#define TRAP_NOARG 0xc310		/* Syscall w/no args (NR in R3) */
+#endif
+#define OR_R0_R0 0x200b			/* or r0,r0 (insert to avoid hardware bug) */
+
+struct sigframe
+{
+	struct sigcontext sc;
+	unsigned long extramask[_NSIG_WORDS-1];
+	u16 retcode[8];
+};
+
+struct rt_sigframe
+{
+	struct siginfo info;
+	struct ucontext uc;
+	u16 retcode[8];
+};
+
+#ifdef CONFIG_SH_FPU
+static inline int restore_sigcontext_fpu(struct sigcontext __user *sc)
+{
+	struct task_struct *tsk = current;
+
+	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
+		return 0;
+
+	set_used_math();
+	return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0],
+				sizeof(long)*(16*2+2));
+}
+
+static inline int save_sigcontext_fpu(struct sigcontext __user *sc,
+				      struct pt_regs *regs)
+{
+	struct task_struct *tsk = current;
+
+	if (!(boot_cpu_data.flags & CPU_HAS_FPU))
+		return 0;
+
+	if (!used_math())
+		return __put_user(0, &sc->sc_ownedfp);
+
+	if (__put_user(1, &sc->sc_ownedfp))
+		return -EFAULT;
+
+	/* This will cause a "finit" to be triggered by the next
+	   attempted FPU operation by the 'current' process.
+	   */
+	clear_used_math();
+
+	unlazy_fpu(tsk, regs);
+	return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu,
+			      sizeof(long)*(16*2+2));
+}
+#endif /* CONFIG_SH_FPU */
+
+static int
+restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p)
+{
+	unsigned int err = 0;
+
+#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
+			COPY(regs[1]);
+	COPY(regs[2]);	COPY(regs[3]);
+	COPY(regs[4]);	COPY(regs[5]);
+	COPY(regs[6]);	COPY(regs[7]);
+	COPY(regs[8]);	COPY(regs[9]);
+	COPY(regs[10]);	COPY(regs[11]);
+	COPY(regs[12]);	COPY(regs[13]);
+	COPY(regs[14]);	COPY(regs[15]);
+	COPY(gbr);	COPY(mach);
+	COPY(macl);	COPY(pr);
+	COPY(sr);	COPY(pc);
+#undef COPY
+
+#ifdef CONFIG_SH_FPU
+	if (boot_cpu_data.flags & CPU_HAS_FPU) {
+		int owned_fp;
+		struct task_struct *tsk = current;
+
+		regs->sr |= SR_FD; /* Release FPU */
+		clear_fpu(tsk, regs);
+		clear_used_math();
+		err |= __get_user (owned_fp, &sc->sc_ownedfp);
+		if (owned_fp)
+			err |= restore_sigcontext_fpu(sc);
+	}
+#endif
+
+	regs->tra = -1;		/* disable syscall checks */
+	err |= __get_user(*r0_p, &sc->sc_regs[0]);
+	return err;
+}
+
+asmlinkage int sys_sigreturn(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15];
+	sigset_t set;
+	int r0;
+
+        /* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+
+	if (__get_user(set.sig[0], &frame->sc.oldmask)
+	    || (_NSIG_WORDS > 1
+		&& __copy_from_user(&set.sig[1], &frame->extramask,
+				    sizeof(frame->extramask))))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(regs, &frame->sc, &r0))
+		goto badframe;
+	return r0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+asmlinkage int sys_rt_sigreturn(void)
+{
+	struct pt_regs *regs = current_pt_regs();
+	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15];
+	sigset_t set;
+	int r0;
+
+	/* Always make any pending restarted system calls return -EINTR */
+	current->restart_block.fn = do_no_restart_syscall;
+
+	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+		goto badframe;
+
+	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+		goto badframe;
+
+	set_current_blocked(&set);
+
+	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
+		goto badframe;
+
+	if (restore_altstack(&frame->uc.uc_stack))
+		goto badframe;
+
+	return r0;
+
+badframe:
+	force_sig(SIGSEGV, current);
+	return 0;
+}
+
+/*
+ * Set up a signal frame.
+ */
+
+static int
+setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
+		 unsigned long mask)
+{
+	int err = 0;
+
+#define COPY(x)		err |= __put_user(regs->x, &sc->sc_##x)
+	COPY(regs[0]);	COPY(regs[1]);
+	COPY(regs[2]);	COPY(regs[3]);
+	COPY(regs[4]);	COPY(regs[5]);
+	COPY(regs[6]);	COPY(regs[7]);
+	COPY(regs[8]);	COPY(regs[9]);
+	COPY(regs[10]);	COPY(regs[11]);
+	COPY(regs[12]);	COPY(regs[13]);
+	COPY(regs[14]);	COPY(regs[15]);
+	COPY(gbr);	COPY(mach);
+	COPY(macl);	COPY(pr);
+	COPY(sr);	COPY(pc);
+#undef COPY
+
+#ifdef CONFIG_SH_FPU
+	err |= save_sigcontext_fpu(sc, regs);
+#endif
+
+	/* non-iBCS2 extensions.. */
+	err |= __put_user(mask, &sc->oldmask);
+
+	return err;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
+{
+	if (ka->sa.sa_flags & SA_ONSTACK) {
+		if (sas_ss_flags(sp) == 0)
+			sp = current->sas_ss_sp + current->sas_ss_size;
+	}
+
+	return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul);
+}
+
+/* These symbols are defined with the addresses in the vsyscall page.
+   See vsyscall-trapa.S.  */
+extern void __kernel_sigreturn(void);
+extern void __kernel_rt_sigreturn(void);
+
+static int setup_frame(struct ksignal *ksig, sigset_t *set,
+		       struct pt_regs *regs)
+{
+	struct sigframe __user *frame;
+	int err = 0, sig = ksig->sig;
+
+	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		return -EFAULT;
+
+	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
+
+	if (_NSIG_WORDS > 1)
+		err |= __copy_to_user(frame->extramask, &set->sig[1],
+				      sizeof(frame->extramask));
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+		regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
+#ifdef CONFIG_VSYSCALL
+	} else if (likely(current->mm->context.vdso)) {
+		regs->pr = VDSO_SYM(&__kernel_sigreturn);
+#endif
+	} else {
+		/* Generate return code (system call to sigreturn) */
+		err |= __put_user(MOVW(7), &frame->retcode[0]);
+		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
+		err |= __put_user((__NR_sigreturn), &frame->retcode[7]);
+		regs->pr = (unsigned long) frame->retcode;
+		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
+	}
+
+	if (err)
+		return -EFAULT;
+
+	/* Set up registers for signal handler */
+	regs->regs[15] = (unsigned long) frame;
+	regs->regs[4] = sig; /* Arg for signal handler */
+	regs->regs[5] = 0;
+	regs->regs[6] = (unsigned long) &frame->sc;
+
+	if (current->personality & FDPIC_FUNCPTRS) {
+		struct fdpic_func_descriptor __user *funcptr =
+			(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
+
+		err |= __get_user(regs->pc, &funcptr->text);
+		err |= __get_user(regs->regs[12], &funcptr->GOT);
+	} else
+		regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
+
+	if (err)
+		return -EFAULT;
+
+	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
+		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
+
+	return 0;
+}
+
+static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+			  struct pt_regs *regs)
+{
+	struct rt_sigframe __user *frame;
+	int err = 0, sig = ksig->sig;
+
+	frame = get_sigframe(&ksig->ka, regs->regs[15], sizeof(*frame));
+
+	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+		return -EFAULT;
+
+	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
+
+	/* Create the ucontext.  */
+	err |= __put_user(0, &frame->uc.uc_flags);
+	err |= __put_user(NULL, &frame->uc.uc_link);
+	err |= __save_altstack(&frame->uc.uc_stack, regs->regs[15]);
+	err |= setup_sigcontext(&frame->uc.uc_mcontext,
+			        regs, set->sig[0]);
+	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+
+	/* Set up to return from userspace.  If provided, use a stub
+	   already in userspace.  */
+	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
+		regs->pr = (unsigned long) ksig->ka.sa.sa_restorer;
+#ifdef CONFIG_VSYSCALL
+	} else if (likely(current->mm->context.vdso)) {
+		regs->pr = VDSO_SYM(&__kernel_rt_sigreturn);
+#endif
+	} else {
+		/* Generate return code (system call to rt_sigreturn) */
+		err |= __put_user(MOVW(7), &frame->retcode[0]);
+		err |= __put_user(TRAP_NOARG, &frame->retcode[1]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[2]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[3]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[4]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[5]);
+		err |= __put_user(OR_R0_R0, &frame->retcode[6]);
+		err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]);
+		regs->pr = (unsigned long) frame->retcode;
+		flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode));
+	}
+
+	if (err)
+		return -EFAULT;
+
+	/* Set up registers for signal handler */
+	regs->regs[15] = (unsigned long) frame;
+	regs->regs[4] = sig; /* Arg for signal handler */
+	regs->regs[5] = (unsigned long) &frame->info;
+	regs->regs[6] = (unsigned long) &frame->uc;
+
+	if (current->personality & FDPIC_FUNCPTRS) {
+		struct fdpic_func_descriptor __user *funcptr =
+			(struct fdpic_func_descriptor __user *)ksig->ka.sa.sa_handler;
+
+		err |= __get_user(regs->pc, &funcptr->text);
+		err |= __get_user(regs->regs[12], &funcptr->GOT);
+	} else
+		regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
+
+	if (err)
+		return -EFAULT;
+
+	pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
+		 current->comm, task_pid_nr(current), frame, regs->pc, regs->pr);
+
+	return 0;
+}
+
+static inline void
+handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs,
+		       struct sigaction *sa)
+{
+	/* If we're not from a syscall, bail out */
+	if (regs->tra < 0)
+		return;
+
+	/* check for system call restart.. */
+	switch (regs->regs[0]) {
+		case -ERESTART_RESTARTBLOCK:
+		case -ERESTARTNOHAND:
+		no_system_call_restart:
+			regs->regs[0] = -EINTR;
+			break;
+
+		case -ERESTARTSYS:
+			if (!(sa->sa_flags & SA_RESTART))
+				goto no_system_call_restart;
+		/* fallthrough */
+		case -ERESTARTNOINTR:
+			regs->regs[0] = save_r0;
+			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
+			break;
+	}
+}
+
+/*
+ * OK, we're invoking a handler
+ */
+static void
+handle_signal(struct ksignal *ksig, struct pt_regs *regs, unsigned int save_r0)
+{
+	sigset_t *oldset = sigmask_to_save();
+	int ret;
+
+	/* Set up the stack frame */
+	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
+		ret = setup_rt_frame(ksig, oldset, regs);
+	else
+		ret = setup_frame(ksig, oldset, regs);
+
+	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
+}
+
+/*
+ * Note that 'init' is a special process: it doesn't get signals it doesn't
+ * want to handle. Thus you cannot kill init even with a SIGKILL even by
+ * mistake.
+ *
+ * Note that we go through the signals twice: once to check the signals that
+ * the kernel can handle, and then we build all the user-level signal handling
+ * stack-frames in one go after that.
+ */
+static void do_signal(struct pt_regs *regs, unsigned int save_r0)
+{
+	struct ksignal ksig;
+
+	/*
+	 * We want the common case to go fast, which
+	 * is why we may in certain cases get here from
+	 * kernel mode. Just return without doing anything
+	 * if so.
+	 */
+	if (!user_mode(regs))
+		return;
+
+	if (get_signal(&ksig)) {
+		handle_syscall_restart(save_r0, regs, &ksig.ka.sa);
+
+		/* Whee!  Actually deliver the signal.  */
+		handle_signal(&ksig, regs, save_r0);
+		return;
+	}
+
+	/* Did we come from a system call? */
+	if (regs->tra >= 0) {
+		/* Restart the system call - no handlers present */
+		if (regs->regs[0] == -ERESTARTNOHAND ||
+		    regs->regs[0] == -ERESTARTSYS ||
+		    regs->regs[0] == -ERESTARTNOINTR) {
+			regs->regs[0] = save_r0;
+			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
+		} else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) {
+			regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
+			regs->regs[3] = __NR_restart_syscall;
+		}
+	}
+
+	/*
+	 * If there's no signal to deliver, we just put the saved sigmask
+	 * back.
+	 */
+	restore_saved_sigmask();
+}
+
+asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0,
+				 unsigned long thread_info_flags)
+{
+	/* deal with pending signal delivery */
+	if (thread_info_flags & _TIF_SIGPENDING)
+		do_signal(regs, save_r0);
+
+	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
+		clear_thread_flag(TIF_NOTIFY_RESUME);
+		tracehook_notify_resume(regs);
+	}
+}