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-rw-r--r--arch/sh/kernel/signal_32.c510
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 0000000000..a6bfc6f374
--- /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/resume_user_mode.h>
+#include <asm/ucontext.h>
+#include <linux/uaccess.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;
+ unsigned int sr = regs->sr & ~SR_USER_MASK;
+
+#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
+
+ regs->sr = (regs->sr & SR_USER_MASK) | sr;
+
+#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(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);
+ 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(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);
+ 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(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(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 | _TIF_NOTIFY_SIGNAL))
+ do_signal(regs, save_r0);
+
+ if (thread_info_flags & _TIF_NOTIFY_RESUME)
+ resume_user_mode_work(regs);
+}
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