mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-15 08:56:48 +07:00
e9564df753
This patch adds files related to task_switch, sigcontext, signal, fpu context switch. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Eric W. Biederman <ebiederm@xmission.com>
348 lines
8.3 KiB
C
348 lines
8.3 KiB
C
// 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/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>
|
|
|
|
#include <abi/regdef.h>
|
|
|
|
#ifdef CONFIG_CPU_HAS_FPU
|
|
#include <abi/fpu.h>
|
|
|
|
static int restore_fpu_state(struct sigcontext *sc)
|
|
{
|
|
int err = 0;
|
|
struct user_fp 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)
|
|
{
|
|
struct user_fp user_fp;
|
|
|
|
save_to_user_fp(&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; }
|
|
#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)
|
|
{
|
|
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));
|
|
|
|
err |= restore_fpu_state(sc);
|
|
|
|
*pr2 = regs->a0;
|
|
return err;
|
|
}
|
|
|
|
asmlinkage int
|
|
do_rt_sigreturn(void)
|
|
{
|
|
sigset_t set;
|
|
int a0;
|
|
struct pt_regs *regs = current_pt_regs();
|
|
struct rt_sigframe *frame = (struct rt_sigframe *)(regs->usp);
|
|
|
|
if (verify_area(VERIFY_READ, 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);
|
|
|
|
if (restore_sigframe(regs, &frame->uc.uc_mcontext, &a0))
|
|
goto badframe;
|
|
|
|
return a0;
|
|
|
|
badframe:
|
|
force_sig(SIGSEGV, current);
|
|
return 0;
|
|
}
|
|
|
|
static int setup_sigframe(struct sigcontext *sc, struct pt_regs *regs)
|
|
{
|
|
int err = 0;
|
|
|
|
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)
|
|
{
|
|
unsigned long usp;
|
|
|
|
/* Default to using normal stack. */
|
|
usp = regs->usp;
|
|
|
|
/* 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);
|
|
}
|
|
|
|
static int
|
|
setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
|
|
{
|
|
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;
|
|
|
|
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. */
|
|
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));
|
|
|
|
if (err)
|
|
goto give_sigsegv;
|
|
|
|
/* 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;
|
|
|
|
adjust_stack:
|
|
regs->a0 = ksig->sig; /* first arg is signo */
|
|
regs->a1 = (unsigned long)(&(frame->info));
|
|
regs->a2 = (unsigned long)(&(frame->uc));
|
|
return err;
|
|
|
|
give_sigsegv:
|
|
if (ksig->sig == SIGSEGV)
|
|
ksig->ka.sa.sa_handler = SIG_DFL;
|
|
force_sig(SIGSEGV, current);
|
|
goto adjust_stack;
|
|
}
|
|
|
|
/*
|
|
* OK, we're invoking a handler
|
|
*/
|
|
static int
|
|
handle_signal(struct ksignal *ksig, struct pt_regs *regs)
|
|
{
|
|
int ret;
|
|
sigset_t *oldset = sigmask_to_save();
|
|
|
|
/*
|
|
* set up the stack frame, regardless of SA_SIGINFO,
|
|
* and pass info anyway.
|
|
*/
|
|
ret = setup_rt_frame(ksig, oldset, regs);
|
|
|
|
if (ret != 0) {
|
|
force_sigsegv(ksig->sig, current);
|
|
return ret;
|
|
}
|
|
|
|
/* 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);
|
|
|
|
return 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, int syscall)
|
|
{
|
|
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))
|
|
return;
|
|
|
|
current->thread.esp0 = (unsigned long)regs;
|
|
|
|
/*
|
|
* If we were from a system call, check for system call restarting...
|
|
*/
|
|
if (syscall) {
|
|
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) {
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
regs->a0 = regs->orig_a0;
|
|
regs->pc = restart_addr;
|
|
break;
|
|
case -ERESTART_RESTARTBLOCK:
|
|
regs->a0 = -EINTR;
|
|
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 (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 (syscall) {
|
|
/*
|
|
* 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);
|
|
}
|
|
}
|
|
}
|
|
|
|
asmlinkage void
|
|
do_notify_resume(unsigned int thread_flags, struct pt_regs *regs, int syscall)
|
|
{
|
|
if (thread_flags & _TIF_SIGPENDING)
|
|
do_signal(regs, syscall);
|
|
|
|
if (thread_flags & _TIF_NOTIFY_RESUME) {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
}
|
|
}
|