forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
321 lines
8.0 KiB
321 lines
8.0 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd. |
|
* Chen Liqin <[email protected]> |
|
* Lennox Wu <[email protected]> |
|
* Copyright (C) 2012 Regents of the University of California |
|
*/ |
|
|
|
#include <linux/signal.h> |
|
#include <linux/uaccess.h> |
|
#include <linux/syscalls.h> |
|
#include <linux/tracehook.h> |
|
#include <linux/linkage.h> |
|
|
|
#include <asm/ucontext.h> |
|
#include <asm/vdso.h> |
|
#include <asm/switch_to.h> |
|
#include <asm/csr.h> |
|
|
|
extern u32 __user_rt_sigreturn[2]; |
|
|
|
#define DEBUG_SIG 0 |
|
|
|
struct rt_sigframe { |
|
struct siginfo info; |
|
struct ucontext uc; |
|
#ifndef CONFIG_MMU |
|
u32 sigreturn_code[2]; |
|
#endif |
|
}; |
|
|
|
#ifdef CONFIG_FPU |
|
static long restore_fp_state(struct pt_regs *regs, |
|
union __riscv_fp_state __user *sc_fpregs) |
|
{ |
|
long err; |
|
struct __riscv_d_ext_state __user *state = &sc_fpregs->d; |
|
size_t i; |
|
|
|
err = __copy_from_user(¤t->thread.fstate, state, sizeof(*state)); |
|
if (unlikely(err)) |
|
return err; |
|
|
|
fstate_restore(current, regs); |
|
|
|
/* We support no other extension state at this time. */ |
|
for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) { |
|
u32 value; |
|
|
|
err = __get_user(value, &sc_fpregs->q.reserved[i]); |
|
if (unlikely(err)) |
|
break; |
|
if (value != 0) |
|
return -EINVAL; |
|
} |
|
|
|
return err; |
|
} |
|
|
|
static long save_fp_state(struct pt_regs *regs, |
|
union __riscv_fp_state __user *sc_fpregs) |
|
{ |
|
long err; |
|
struct __riscv_d_ext_state __user *state = &sc_fpregs->d; |
|
size_t i; |
|
|
|
fstate_save(current, regs); |
|
err = __copy_to_user(state, ¤t->thread.fstate, sizeof(*state)); |
|
if (unlikely(err)) |
|
return err; |
|
|
|
/* We support no other extension state at this time. */ |
|
for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) { |
|
err = __put_user(0, &sc_fpregs->q.reserved[i]); |
|
if (unlikely(err)) |
|
break; |
|
} |
|
|
|
return err; |
|
} |
|
#else |
|
#define save_fp_state(task, regs) (0) |
|
#define restore_fp_state(task, regs) (0) |
|
#endif |
|
|
|
static long restore_sigcontext(struct pt_regs *regs, |
|
struct sigcontext __user *sc) |
|
{ |
|
long err; |
|
/* sc_regs is structured the same as the start of pt_regs */ |
|
err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs)); |
|
/* Restore the floating-point state. */ |
|
if (has_fpu()) |
|
err |= restore_fp_state(regs, &sc->sc_fpregs); |
|
return err; |
|
} |
|
|
|
SYSCALL_DEFINE0(rt_sigreturn) |
|
{ |
|
struct pt_regs *regs = current_pt_regs(); |
|
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->sp; |
|
|
|
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)) |
|
goto badframe; |
|
|
|
if (restore_altstack(&frame->uc.uc_stack)) |
|
goto badframe; |
|
|
|
return regs->a0; |
|
|
|
badframe: |
|
task = current; |
|
if (show_unhandled_signals) { |
|
pr_info_ratelimited( |
|
"%s[%d]: bad frame in %s: frame=%p pc=%p sp=%p\n", |
|
task->comm, task_pid_nr(task), __func__, |
|
frame, (void *)regs->epc, (void *)regs->sp); |
|
} |
|
force_sig(SIGSEGV); |
|
return 0; |
|
} |
|
|
|
static long setup_sigcontext(struct rt_sigframe __user *frame, |
|
struct pt_regs *regs) |
|
{ |
|
struct sigcontext __user *sc = &frame->uc.uc_mcontext; |
|
long err; |
|
/* sc_regs is structured the same as the start of pt_regs */ |
|
err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs)); |
|
/* Save the floating-point state. */ |
|
if (has_fpu()) |
|
err |= save_fp_state(regs, &sc->sc_fpregs); |
|
return err; |
|
} |
|
|
|
static inline void __user *get_sigframe(struct ksignal *ksig, |
|
struct pt_regs *regs, size_t framesize) |
|
{ |
|
unsigned long sp; |
|
/* Default to using normal stack */ |
|
sp = regs->sp; |
|
|
|
/* |
|
* 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. */ |
|
sp = sigsp(sp, ksig) - framesize; |
|
|
|
/* Align the stack frame. */ |
|
sp &= ~0xfUL; |
|
|
|
return (void __user *)sp; |
|
} |
|
|
|
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, |
|
struct pt_regs *regs) |
|
{ |
|
struct rt_sigframe __user *frame; |
|
long err = 0; |
|
|
|
frame = get_sigframe(ksig, regs, 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->sp); |
|
err |= setup_sigcontext(frame, regs); |
|
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
|
if (err) |
|
return -EFAULT; |
|
|
|
/* Set up to return from userspace. */ |
|
#ifdef CONFIG_MMU |
|
regs->ra = (unsigned long)VDSO_SYMBOL( |
|
current->mm->context.vdso, rt_sigreturn); |
|
#else |
|
/* |
|
* For the nommu case we don't have a VDSO. Instead we push two |
|
* instructions to call the rt_sigreturn syscall onto the user stack. |
|
*/ |
|
if (copy_to_user(&frame->sigreturn_code, __user_rt_sigreturn, |
|
sizeof(frame->sigreturn_code))) |
|
return -EFAULT; |
|
regs->ra = (unsigned long)&frame->sigreturn_code; |
|
#endif /* CONFIG_MMU */ |
|
|
|
/* |
|
* 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->epc = (unsigned long)ksig->ka.sa.sa_handler; |
|
regs->sp = (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 */ |
|
|
|
#if DEBUG_SIG |
|
pr_info("SIG deliver (%s:%d): sig=%d pc=%p ra=%p sp=%p\n", |
|
current->comm, task_pid_nr(current), ksig->sig, |
|
(void *)regs->epc, (void *)regs->ra, frame); |
|
#endif |
|
|
|
return 0; |
|
} |
|
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
|
{ |
|
sigset_t *oldset = sigmask_to_save(); |
|
int ret; |
|
|
|
/* Are we from a system call? */ |
|
if (regs->cause == EXC_SYSCALL) { |
|
/* Avoid additional syscall restarting via ret_from_exception */ |
|
regs->cause = -1UL; |
|
/* If so, check system call restarting.. */ |
|
switch (regs->a0) { |
|
case -ERESTART_RESTARTBLOCK: |
|
case -ERESTARTNOHAND: |
|
regs->a0 = -EINTR; |
|
break; |
|
|
|
case -ERESTARTSYS: |
|
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
|
regs->a0 = -EINTR; |
|
break; |
|
} |
|
fallthrough; |
|
case -ERESTARTNOINTR: |
|
regs->a0 = regs->orig_a0; |
|
regs->epc -= 0x4; |
|
break; |
|
} |
|
} |
|
|
|
/* Set up the stack frame */ |
|
ret = setup_rt_frame(ksig, oldset, regs); |
|
|
|
signal_setup_done(ret, ksig, 0); |
|
} |
|
|
|
static void do_signal(struct pt_regs *regs) |
|
{ |
|
struct ksignal ksig; |
|
|
|
if (get_signal(&ksig)) { |
|
/* Actually deliver the signal */ |
|
handle_signal(&ksig, regs); |
|
return; |
|
} |
|
|
|
/* Did we come from a system call? */ |
|
if (regs->cause == EXC_SYSCALL) { |
|
/* Avoid additional syscall restarting via ret_from_exception */ |
|
regs->cause = -1UL; |
|
|
|
/* Restart the system call - no handlers present */ |
|
switch (regs->a0) { |
|
case -ERESTARTNOHAND: |
|
case -ERESTARTSYS: |
|
case -ERESTARTNOINTR: |
|
regs->a0 = regs->orig_a0; |
|
regs->epc -= 0x4; |
|
break; |
|
case -ERESTART_RESTARTBLOCK: |
|
regs->a0 = regs->orig_a0; |
|
regs->a7 = __NR_restart_syscall; |
|
regs->epc -= 0x4; |
|
break; |
|
} |
|
} |
|
|
|
/* |
|
* If there is no signal to deliver, we just put the saved |
|
* sigmask back. |
|
*/ |
|
restore_saved_sigmask(); |
|
} |
|
|
|
/* |
|
* notification of userspace execution resumption |
|
* - triggered by the _TIF_WORK_MASK flags |
|
*/ |
|
asmlinkage __visible void do_notify_resume(struct pt_regs *regs, |
|
unsigned long thread_info_flags) |
|
{ |
|
if (thread_info_flags & _TIF_UPROBE) |
|
uprobe_notify_resume(regs); |
|
|
|
/* Handle pending signal delivery */ |
|
if (thread_info_flags & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) |
|
do_signal(regs); |
|
|
|
if (thread_info_flags & _TIF_NOTIFY_RESUME) |
|
tracehook_notify_resume(regs); |
|
}
|
|
|