// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/kernel.h>
#include <linux/signal.h>
+#include <linux/uaccess.h>
#include <linux/syscalls.h>
-#include <linux/errno.h>
-#include <linux/wait.h>
-#include <linux/ptrace.h>
-#include <linux/unistd.h>
-#include <linux/stddef.h>
-#include <linux/highuid.h>
-#include <linux/personality.h>
-#include <linux/tty.h>
-#include <linux/binfmts.h>
#include <linux/tracehook.h>
-#include <linux/freezer.h>
-#include <linux/uaccess.h>
-#include <asm/setup.h>
-#include <asm/pgtable.h>
#include <asm/traps.h>
#include <asm/ucontext.h>
#include <asm/vdso.h>
#ifdef CONFIG_CPU_HAS_FPU
#include <abi/fpu.h>
-
-static int restore_fpu_state(struct sigcontext *sc)
+static int restore_fpu_state(struct sigcontext __user *sc)
{
int err = 0;
struct user_fp user_fp;
- err = copy_from_user(&user_fp, &sc->sc_user_fp, sizeof(user_fp));
+ err = __copy_from_user(&user_fp, &sc->sc_user_fp, sizeof(user_fp));
restore_from_user_fp(&user_fp);
return err;
}
-static int save_fpu_state(struct sigcontext *sc)
+static int save_fpu_state(struct sigcontext __user *sc)
{
struct user_fp user_fp;
save_to_user_fp(&user_fp);
- return copy_to_user(&sc->sc_user_fp, &user_fp, sizeof(user_fp));
+ return __copy_to_user(&sc->sc_user_fp, &user_fp, sizeof(user_fp));
}
#else
-static inline int restore_fpu_state(struct sigcontext *sc) { return 0; }
-static inline int save_fpu_state(struct sigcontext *sc) { return 0; }
+#define restore_fpu_state(sigcontext) (0)
+#define save_fpu_state(sigcontext) (0)
#endif
struct rt_sigframe {
- int sig;
- struct siginfo *pinfo;
- void *puc;
struct siginfo info;
struct ucontext uc;
};
-static int
-restore_sigframe(struct pt_regs *regs,
- struct sigcontext *sc, int *pr2)
+static long restore_sigcontext(struct pt_regs *regs,
+ struct sigcontext __user *sc)
{
int err = 0;
- /* Always make any pending restarted system calls return -EINTR */
- current_thread_info()->task->restart_block.fn = do_no_restart_syscall;
-
- err |= copy_from_user(regs, &sc->sc_pt_regs, sizeof(struct pt_regs));
+ /* sc_pt_regs is structured the same as the start of pt_regs */
+ err |= __copy_from_user(regs, &sc->sc_pt_regs, sizeof(struct pt_regs));
+ /* Restore the floating-point state. */
err |= restore_fpu_state(sc);
- *pr2 = regs->a0;
return err;
}
-asmlinkage int
-do_rt_sigreturn(void)
+SYSCALL_DEFINE0(rt_sigreturn)
{
- sigset_t set;
- int a0;
struct pt_regs *regs = current_pt_regs();
- struct rt_sigframe *frame = (struct rt_sigframe *)(regs->usp);
+ struct rt_sigframe __user *frame;
+ struct task_struct *task;
+ sigset_t set;
+
+ /* Always make any pending restarted system calls return -EINTR */
+ current->restart_block.fn = do_no_restart_syscall;
+
+ frame = (struct rt_sigframe __user *)regs->usp;
if (!access_ok(frame, sizeof(*frame)))
goto badframe;
+
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
- sigdelsetmask(&set, (sigmask(SIGKILL) | sigmask(SIGSTOP)));
- spin_lock_irq(¤t->sighand->siglock);
- current->blocked = set;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
+ set_current_blocked(&set);
+
+ if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+ goto badframe;
- if (restore_sigframe(regs, &frame->uc.uc_mcontext, &a0))
+ if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
- return a0;
+ return regs->a0;
badframe:
- force_sig(SIGSEGV, current);
+ task = current;
+ force_sig(SIGSEGV, task);
return 0;
}
-static int setup_sigframe(struct sigcontext *sc, struct pt_regs *regs)
+static int setup_sigcontext(struct rt_sigframe __user *frame,
+ struct pt_regs *regs)
{
+ struct sigcontext __user *sc = &frame->uc.uc_mcontext;
int err = 0;
- err |= copy_to_user(&sc->sc_pt_regs, regs, sizeof(struct pt_regs));
+ err |= __copy_to_user(&sc->sc_pt_regs, regs, sizeof(struct pt_regs));
err |= save_fpu_state(sc);
return err;
}
-static inline void *
-get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
+static inline void __user *get_sigframe(struct ksignal *ksig,
+ struct pt_regs *regs, size_t framesize)
{
- unsigned long usp;
+ unsigned long sp;
+ /* Default to using normal stack */
+ sp = regs->usp;
- /* Default to using normal stack. */
- usp = regs->usp;
+ /*
+ * If we are on the alternate signal stack and would overflow it, don't.
+ * Return an always-bogus address instead so we will die with SIGSEGV.
+ */
+ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
+ return (void __user __force *)(-1UL);
- /* This is the X/Open sanctioned signal stack switching. */
- if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(usp)) {
- if (!on_sig_stack(usp))
- usp = current->sas_ss_sp + current->sas_ss_size;
- }
- return (void *)((usp - frame_size) & -8UL);
+ /* This is the X/Open sanctioned signal stack switching. */
+ sp = sigsp(sp, ksig) - framesize;
+
+ /* Align the stack frame. */
+ sp &= -8UL;
+
+ return (void __user *)sp;
}
static int
{
struct rt_sigframe *frame;
int err = 0;
-
struct csky_vdso *vdso = current->mm->context.vdso;
- frame = get_sigframe(&ksig->ka, regs, sizeof(*frame));
- if (!frame)
- return 1;
+ frame = get_sigframe(ksig, regs, sizeof(*frame));
+ if (!access_ok(frame, sizeof(*frame)))
+ return -EFAULT;
- err |= __put_user(ksig->sig, &frame->sig);
- err |= __put_user(&frame->info, &frame->pinfo);
- err |= __put_user(&frame->uc, &frame->puc);
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
- /* Create the ucontext. */
+ /* Create the ucontext. */
err |= __put_user(0, &frame->uc.uc_flags);
- err |= __put_user(0, &frame->uc.uc_link);
- err |= __put_user((void *)current->sas_ss_sp,
- &frame->uc.uc_stack.ss_sp);
- err |= __put_user(sas_ss_flags(regs->usp),
- &frame->uc.uc_stack.ss_flags);
- err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
- err |= setup_sigframe(&frame->uc.uc_mcontext, regs);
- err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
-
+ err |= __put_user(NULL, &frame->uc.uc_link);
+ err |= __save_altstack(&frame->uc.uc_stack, regs->usp);
+ err |= setup_sigcontext(frame, regs);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
- goto give_sigsegv;
+ return -EFAULT;
- /* Set up registers for signal handler */
- regs->usp = (unsigned long)frame;
- regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
- regs->lr = (unsigned long)vdso->rt_signal_retcode;
+ /* Set up to return from userspace. */
+ regs->lr = (unsigned long)(vdso->rt_signal_retcode);
-adjust_stack:
- regs->a0 = ksig->sig; /* first arg is signo */
- regs->a1 = (unsigned long)(&(frame->info));
- regs->a2 = (unsigned long)(&(frame->uc));
- return err;
+ /*
+ * Set up registers for signal handler.
+ * Registers that we don't modify keep the value they had from
+ * user-space at the time we took the signal.
+ * We always pass siginfo and mcontext, regardless of SA_SIGINFO,
+ * since some things rely on this (e.g. glibc's debug/segfault.c).
+ */
+ regs->pc = (unsigned long)ksig->ka.sa.sa_handler;
+ regs->usp = (unsigned long)frame;
+ regs->a0 = ksig->sig; /* a0: signal number */
+ regs->a1 = (unsigned long)(&(frame->info)); /* a1: siginfo pointer */
+ regs->a2 = (unsigned long)(&(frame->uc)); /* a2: ucontext pointer */
-give_sigsegv:
- if (ksig->sig == SIGSEGV)
- ksig->ka.sa.sa_handler = SIG_DFL;
- force_sig(SIGSEGV, current);
- goto adjust_stack;
+ return 0;
}
-/*
- * OK, we're invoking a handler
- */
-static int
-handle_signal(struct ksignal *ksig, struct pt_regs *regs)
+static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
{
- int ret;
sigset_t *oldset = sigmask_to_save();
+ int ret;
- /*
- * set up the stack frame, regardless of SA_SIGINFO,
- * and pass info anyway.
- */
- ret = setup_rt_frame(ksig, oldset, regs);
+ /* Are we from a system call? */
+ if (in_syscall(regs)) {
+ /* Avoid additional syscall restarting via ret_from_exception */
+ forget_syscall(regs);
+
+ /* If so, check system call restarting.. */
+ switch (regs->a0) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ regs->a0 = -EINTR;
+ break;
- if (ret != 0) {
- force_sigsegv(ksig->sig, current);
- return ret;
+ case -ERESTARTSYS:
+ if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
+ regs->a0 = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ regs->a0 = regs->orig_a0;
+ regs->pc -= TRAP0_SIZE;
+ break;
+ }
}
- /* Block the signal if we were successful. */
- spin_lock_irq(¤t->sighand->siglock);
- sigorsets(¤t->blocked, ¤t->blocked, &ksig->ka.sa.sa_mask);
- if (!(ksig->ka.sa.sa_flags & SA_NODEFER))
- sigaddset(¤t->blocked, ksig->sig);
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
+ /* Set up the stack frame */
+ ret = setup_rt_frame(ksig, oldset, regs);
- return 0;
+ signal_setup_done(ret, ksig, 0);
}
-/*
- * 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 retval = 0, continue_addr = 0, restart_addr = 0;
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))
+ if (get_signal(&ksig)) {
+ /* Actually deliver the signal */
+ handle_signal(&ksig, regs);
return;
+ }
- /*
- * If we were from a system call, check for system call restarting...
- */
+ /* Did we come from a system call? */
if (in_syscall(regs)) {
+ /* Avoid additional syscall restarting via ret_from_exception */
forget_syscall(regs);
- continue_addr = regs->pc;
-#if defined(__CSKYABIV2__)
- restart_addr = continue_addr - 4;
-#else
- restart_addr = continue_addr - 2;
-#endif
- retval = regs->a0;
- /*
- * Prepare for system call restart. We do this here so that a
- * debugger will see the already changed.
- */
- switch (retval) {
+ /* Restart the system call - no handlers present */
+ switch (regs->a0) {
case -ERESTARTNOHAND:
case -ERESTARTSYS:
case -ERESTARTNOINTR:
regs->a0 = regs->orig_a0;
- regs->pc = restart_addr;
+ regs->pc -= TRAP0_SIZE;
break;
case -ERESTART_RESTARTBLOCK:
- regs->a0 = -EINTR;
+ regs->a0 = regs->orig_a0;
+ regs_syscallid(regs) = __NR_restart_syscall;
+ regs->pc -= TRAP0_SIZE;
break;
}
}
- if (try_to_freeze())
- goto no_signal;
-
/*
- * Get the signal to deliver. When running under ptrace, at this
- * point the debugger may change all our registers ...
+ * If there is no signal to deliver, we just put the saved
+ * sigmask back.
*/
- if (get_signal(&ksig)) {
- /*
- * Depending on the signal settings we may need to revert the
- * decision to restart the system call. But skip this if a
- * debugger has chosen to restart at a different PC.
- */
- if (regs->pc == restart_addr) {
- if (retval == -ERESTARTNOHAND ||
- (retval == -ERESTARTSYS &&
- !(ksig.ka.sa.sa_flags & SA_RESTART))) {
- regs->a0 = -EINTR;
- regs->pc = continue_addr;
- }
- }
-
- /* Whee! Actually deliver the signal. */
- if (handle_signal(&ksig, regs) == 0) {
- /*
- * A signal was successfully delivered; the saved
- * sigmask will have been stored in the signal frame,
- * and will be restored by sigreturn, so we can simply
- * clear the TIF_RESTORE_SIGMASK flag.
- */
- if (test_thread_flag(TIF_RESTORE_SIGMASK))
- clear_thread_flag(TIF_RESTORE_SIGMASK);
- }
- return;
- }
-
-no_signal:
- if (in_syscall(regs)) {
- forget_syscall(regs);
-
- /*
- * Handle restarting a different system call. As above,
- * if a debugger has chosen to restart at a different PC,
- * ignore the restart.
- */
- if (retval == -ERESTART_RESTARTBLOCK
- && regs->pc == continue_addr) {
-#if defined(__CSKYABIV2__)
- regs->regs[3] = __NR_restart_syscall;
- regs->pc -= 4;
-#else
- regs->regs[9] = __NR_restart_syscall;
- regs->pc -= 2;
-#endif
- }
-
- /*
- * If there's no signal to deliver, we just put the saved
- * sigmask back.
- */
- if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
- clear_thread_flag(TIF_RESTORE_SIGMASK);
- sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL);
- }
- }
+ restore_saved_sigmask();
}
-asmlinkage void
-do_notify_resume(unsigned int thread_flags, struct pt_regs *regs)
+/*
+ * notification of userspace execution resumption
+ * - triggered by the _TIF_WORK_MASK flags
+ */
+asmlinkage void do_notify_resume(struct pt_regs *regs,
+ unsigned long thread_info_flags)
{
- if (thread_flags & _TIF_SIGPENDING)
+ /* Handle pending signal delivery */
+ if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
- if (thread_flags & _TIF_NOTIFY_RESUME) {
+ if (thread_info_flags & _TIF_NOTIFY_RESUME) {
clear_thread_flag(TIF_NOTIFY_RESUME);
tracehook_notify_resume(regs);
}
projects / mirror_ubuntu-hirsute-kernel.git / commitdiff