linux_dsm_epyc7002/arch/csky/kernel/signal.c
Linus Torvalds 9ee3b3f4a5 arch/csky patches for 4.21-rc1
Here is the arch/csky patch set for the 4.21-rc1 merge window.
 Contianed in here is three features (cpu_hotplug, basic ftrace,
 basic perf) and some bugfixes.
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Merge tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux

Pull arch/csky updates from Guo Ren:
 "Here are three main features (cpu_hotplug, basic ftrace, basic perf)
  and some bugfixes:

  Features:
   - Add CPU-hotplug support for SMP
   - Add ftrace with function trace and function graph trace
   - Add Perf support
   - Add EM_CSKY_OLD 39
   - optimize kernel panic print.
   - remove syscall_exit_work

  Bugfixes:
   - fix abiv2 mmap(... O_SYNC) failure
   - fix gdb coredump error
   - remove vdsp implement for kernel
   - fix qemu failure to bootup sometimes
   - fix ftrace call-graph panic
   - fix device tree node reference leak
   - remove meaningless header-y
   - fix save hi,lo,dspcr regs in switch_stack
   - remove unused members in processor.h"

* tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux:
  csky: Add perf support for C-SKY
  csky: Add EM_CSKY_OLD 39
  clocksource/drivers/c-sky: fixup ftrace call-graph panic
  csky: ftrace call graph supported.
  csky: basic ftrace supported
  csky: remove unused members in processor.h
  csky: optimize kernel panic print.
  csky: stacktrace supported.
  csky: CPU-hotplug supported for SMP
  clocksource/drivers/c-sky: fixup qemu fail to bootup sometimes.
  csky: fixup save hi,lo,dspcr regs in switch_stack.
  csky: remove syscall_exit_work
  csky: fixup remove vdsp implement for kernel.
  csky: bugfix gdb coredump error.
  csky: fixup abiv2 mmap(... O_SYNC) failed.
  csky: define syscall_get_arch()
  elf-em.h: add EM_CSKY
  csky: remove meaningless header-y
  csky: Don't leak device tree node reference
2019-01-05 09:50:07 -08:00

346 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 (!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(&current->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(&current->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(&current->sighand->siglock);
sigorsets(&current->blocked, &current->blocked, &ksig->ka.sa.sa_mask);
if (!(ksig->ka.sa.sa_flags & SA_NODEFER))
sigaddset(&current->blocked, ksig->sig);
recalc_sigpending();
spin_unlock_irq(&current->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;
/*
* 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, &current->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);
}
}