/*
* set up the kernel stack and exception frames for a new process
*/
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);
struct pt_regs *regs = current_pt_regs();
p->thread.reg0 = (unsigned long) childregs;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
p->thread->reg12 = usp;
p->thread->reg13 = arg;
p->thread.reg3 = (unsigned long) ret_from_kernel_thread;
} else {
*childregs = *current_pt_regs();
childregs->regs[7] = 0; /* Clear error flag */
childregs->regs[4] = 0; /* Child gets zero as return value */
if (usp)
childregs->regs[0] = usp; /* user fork */
p->thread.reg3 = (unsigned long) ret_from_fork;
}
p->thread.cp0_psr = 0;
return 0;
}
asmlinkage int sys_rt_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
unsigned long usp = rdusp();
struct rt_sigframe *frame = (struct rt_sigframe *)(usp);
sigset_t set;
int r0;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (rt_restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0))
goto badframe;
if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->usp) == -EFAULT)
goto badframe;
return r0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
static inline int
restore_sigcontext(struct sigcontext *usc, int *pd0)
{
struct pt_regs *regs = current_pt_regs();
int err = 0;
unsigned int ccr;
unsigned int usp;
unsigned int er0;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
/* restore passed registers */
#define COPY(r) do { err |= get_user(regs->r, &usc->sc_##r); } while (0)
COPY(er1);
COPY(er2);
COPY(er3);
COPY(er5);
COPY(pc);
ccr = regs->ccr & 0x10;
COPY(ccr);
#undef COPY
regs->ccr &= 0xef;
regs->ccr |= ccr;
regs->orig_er0 = -1; /* disable syscall checks */
err |= __get_user(usp, &usc->sc_usp);
wrusp(usp);
err |= __get_user(er0, &usc->sc_er0);
*pd0 = er0;
return err;
}
asmlinkage int sys_rt_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->sp + 4);
sigset_t set;
current_thread_info()->restart_block.fn = do_no_restart_syscall;
if (!access_ok(VERIFY_READ, 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->r1;
badframe:
force_sig(SIGSEGV, current);
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_thread_info()->restart_block.fn = do_no_restart_syscall;
if (!access_ok(VERIFY_READ, 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, current);
return 0;
}
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_thread_info()->restart_block.fn = do_no_restart_syscall;
if (!access_ok(VERIFY_READ, 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, current);
return 0;
}
asmlinkage void
do_rt_sigreturn(struct rt_sigframe __user *frame)
{
struct pt_regs *regs = current_pt_regs();
sigset_t set;
/* Verify that it's a good ucontext_t before using it */
if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc)))
goto give_sigsegv;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto give_sigsegv;
set_current_blocked(&set);
if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
goto give_sigsegv;
/* Send SIGTRAP if we're single-stepping: */
if (ptrace_cancel_bpt (current)) {
siginfo_t info;
info.si_signo = SIGTRAP;
info.si_errno = 0;
info.si_code = TRAP_BRKPT;
info.si_addr = (void __user *) regs->pc;
info.si_trapno = 0;
send_sig_info(SIGTRAP, &info, current);
}
return;
give_sigsegv:
force_sig(SIGSEGV, current);
}
asmlinkage void
do_sigreturn(struct sigcontext __user *sc)
{
struct pt_regs *regs = current_pt_regs();
sigset_t set;
/* Verify that it's a good sigcontext before using it */
if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
goto give_sigsegv;
if (__get_user(set.sig[0], &sc->sc_mask))
goto give_sigsegv;
set_current_blocked(&set);
if (restore_sigcontext(sc, regs))
goto give_sigsegv;
/* Send SIGTRAP if we're single-stepping: */
if (ptrace_cancel_bpt (current)) {
siginfo_t info;
info.si_signo = SIGTRAP;
info.si_errno = 0;
info.si_code = TRAP_BRKPT;
info.si_addr = (void __user *) regs->pc;
info.si_trapno = 0;
send_sig_info(SIGTRAP, &info, current);
}
return;
give_sigsegv:
force_sig(SIGSEGV, current);
}
void force_signal_inject(int signal, int code, unsigned long address)
{
const char *desc;
struct pt_regs *regs = current_pt_regs();
if (WARN_ON(!user_mode(regs)))
return;
switch (signal) {
case SIGILL:
desc = "undefined instruction";
break;
case SIGSEGV:
desc = "illegal memory access";
break;
default:
desc = "unknown or unrecoverable error";
break;
}
/* Force signals we don't understand to SIGKILL */
if (WARN_ON(signal != SIGKILL &&
siginfo_layout(signal, code) != SIL_FAULT)) {
signal = SIGKILL;
}
arm64_notify_die(desc, regs, signal, code, (void __user *)address, 0);
}
asmlinkage int sys_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct sigframe __user *frame = (struct sigframe *)rdusp();
sigset_t set;
/*
* Since we stacked the signal on a dword boundary,
* then frame should be dword aligned here. If it's
* not, then the user is trying to mess with us.
*/
if (((long)frame) & 3)
goto badframe;
if (!access_ok(VERIFY_READ, 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))
goto badframe;
/* TODO: SIGTRAP when single-stepping as in arm ? */
return regs->r10;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
long sys_rt_sigreturn(void)
{
/* NOTE - Meta stack goes UPWARDS - so we wind the stack back */
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame;
sigset_t set;
frame = (__force struct rt_sigframe __user *)(regs->REG_SP -
sizeof(*frame));
if (!access_ok(VERIFY_READ, 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->REG_RETVAL;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
/* kernel thread fn */
p->thread.cpu_context.r6 = stack_start;
/* kernel thread argument */
p->thread.cpu_context.r7 = stk_sz;
} else {
*childregs = *current_pt_regs();
if (stack_start)
childregs->sp = stack_start;
/* child get zero as ret. */
childregs->uregs[0] = 0;
childregs->osp = 0;
if (clone_flags & CLONE_SETTLS)
childregs->uregs[25] = childregs->uregs[3];
}
/* cpu context switching */
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
p->thread.cpu_context.sp = (unsigned long)childregs;
#ifdef CONFIG_HWZOL
childregs->lb = 0;
childregs->le = 0;
childregs->lc = 0;
#endif
return 0;
}
int copy_thread(unsigned long clone_flags, unsigned long spu,
unsigned long arg, struct task_struct *tsk)
{
struct pt_regs *childregs = task_pt_regs(tsk);
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
if (unlikely(tsk->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
childregs->psw = M32R_PSW_BIE;
childregs->r1 = spu; /* fn */
childregs->r0 = arg;
tsk->thread.lr = (unsigned long)ret_from_kernel_thread;
} else {
/* Copy registers */
*childregs = *current_pt_regs();
if (spu)
childregs->spu = spu;
childregs->r0 = 0; /* Child gets zero as return value */
tsk->thread.lr = (unsigned long)ret_from_fork;
}
tsk->thread.sp = (unsigned long)childregs;
return 0;
}
asmlinkage long sys32_rt_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe_ia32 __user *frame;
sigset_t set;
frame = (struct rt_sigframe_ia32 __user *)(regs->sp - 4);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
set_current_blocked(&set);
if (ia32_restore_sigcontext(regs, &frame->uc.uc_mcontext))
goto badframe;
if (compat_restore_altstack(&frame->uc.uc_stack))
goto badframe;
return regs->ax;
badframe:
signal_fault(regs, frame, "32bit rt sigreturn");
return 0;
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
/* p->thread holds context to be restored by __switch_to() */
if (unlikely(p->flags & PF_KTHREAD)) {
/* Kernel thread */
const register unsigned long gp __asm__ ("gp");
memset(childregs, 0, sizeof(struct pt_regs));
childregs->gp = gp;
childregs->sstatus = SR_PS | SR_PIE; /* Supervisor, irqs on */
p->thread.ra = (unsigned long)ret_from_kernel_thread;
p->thread.s[0] = usp; /* fn */
p->thread.s[1] = arg;
} else {
*childregs = *(current_pt_regs());
if (usp) /* User fork */
childregs->sp = usp;
if (clone_flags & CLONE_SETTLS)
childregs->tp = childregs->a5;
childregs->a0 = 0; /* Return value of fork() */
p->thread.ra = (unsigned long)ret_from_fork;
}
p->thread.sp = (unsigned long)childregs; /* kernel sp */
return 0;
}
/*
* sys_iopl has to be used when you want to access the IO ports
* beyond the 0x3ff range: to get the full 65536 ports bitmapped
* you'd need 8kB of bitmaps/process, which is a bit excessive.
*
* Here we just change the flags value on the stack: we allow
* only the super-user to do it. This depends on the stack-layout
* on system-call entry - see also fork() and the signal handling
* code.
*/
SYSCALL_DEFINE1(iopl, unsigned int, level)
{
struct pt_regs *regs = current_pt_regs();
struct thread_struct *t = ¤t->thread;
/*
* Careful: the IOPL bits in regs->flags are undefined under Xen PV
* and changing them has no effect.
*/
unsigned int old = t->iopl >> X86_EFLAGS_IOPL_BIT;
if (level > 3)
return -EINVAL;
/* Trying to gain more privileges? */
if (level > old) {
if (!capable(CAP_SYS_RAWIO) || (get_securelevel() > 0))
return -EPERM;
}
regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) |
(level << X86_EFLAGS_IOPL_BIT);
t->iopl = level << X86_EFLAGS_IOPL_BIT;
set_iopl_mask(t->iopl);
return 0;
}
asmlinkage long sys32_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
sigset_t set;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__get_user(set.sig[0], &frame->sc.oldmask)
|| (_COMPAT_NSIG_WORDS > 1
&& __copy_from_user((((char *) &set.sig) + 4),
frame->extramask,
sizeof(frame->extramask))))
goto badframe;
set_current_blocked(&set);
if (ia32_restore_sigcontext(regs, &frame->sc))
goto badframe;
return regs->ax;
badframe:
signal_fault(regs, frame, "32bit sigreturn");
return 0;
}
/*
* Copy architecture-specific thread state
*/
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct thread_info *ti = task_thread_info(p);
struct hexagon_switch_stack *ss;
struct pt_regs *childregs;
asmlinkage void ret_from_fork(void);
childregs = (struct pt_regs *) (((unsigned long) ti + THREAD_SIZE) -
sizeof(*childregs));
ti->regs = childregs;
/*
* Establish kernel stack pointer and initial PC for new thread
* Note that unlike the usual situation, we do not copy the
* parent's callee-saved here; those are in pt_regs and whatever
* we leave here will be overridden on return to userland.
*/
ss = (struct hexagon_switch_stack *) ((unsigned long) childregs -
sizeof(*ss));
ss->lr = (unsigned long)ret_from_fork;
p->thread.switch_sp = ss;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(childregs, 0, sizeof(struct pt_regs));
/* r24 <- fn, r25 <- arg */
ss->r24 = usp;
ss->r25 = arg;
pt_set_kmode(childregs);
return 0;
}
memcpy(childregs, current_pt_regs(), sizeof(*childregs));
ss->r2524 = 0;
if (usp)
pt_set_rte_sp(childregs, usp);
/* Child sees zero return value */
childregs->r00 = 0;
/*
* The clone syscall has the C signature:
* int [r0] clone(int flags [r0],
* void *child_frame [r1],
* void *parent_tid [r2],
* void *child_tid [r3],
* void *thread_control_block [r4]);
* ugp is used to provide TLS support.
*/
if (clone_flags & CLONE_SETTLS)
childregs->ugp = childregs->r04;
/*
* Parent sees new pid -- not necessary, not even possible at
* this point in the fork process
* Might also want to set things like ti->addr_limit
*/
return 0;
}
/*
* Synthesize the fault a PL0 process would get by doing a word-load of
* an unaligned address or a high kernel address.
*/
SYSCALL_DEFINE1(cmpxchg_badaddr, unsigned long, address)
{
struct pt_regs *regs = current_pt_regs();
if (address >= PAGE_OFFSET)
force_sig_info_fault("atomic segfault", SIGSEGV, SEGV_MAPERR,
address, INT_DTLB_MISS, current, regs);
else
force_sig_info_fault("atomic alignment fault", SIGBUS,
BUS_ADRALN, address,
INT_UNALIGN_DATA, current, regs);
/*
* Adjust pc to point at the actual instruction, which is unusual
* for syscalls normally, but is appropriate when we are claiming
* that a syscall swint1 caused a page fault or bus error.
*/
regs->pc -= 8;
/*
* Mark this as a caller-save interrupt, like a normal page fault,
* so that when we go through the signal handler path we will
* properly restore r0, r1, and r2 for the signal handler arguments.
*/
regs->flags |= PT_FLAGS_CALLER_SAVES;
return 0;
}
asmlinkage int sys_rt_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame = (struct rt_sigframe *)rdusp();
sigset_t set;
/*
* Since we stacked the signal on a dword boundary,
* then frame should be dword aligned here. If it's
* not, then the user is trying to mess with us.
*/
if (((long)frame) & 3)
goto badframe;
if (!access_ok(VERIFY_READ, 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->r10;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
int copy_thread(unsigned long clone_flags, unsigned long usp_thread_fn,
unsigned long thread_fn_arg,
struct task_struct *p, struct pt_regs *unused)
{
struct pt_regs *childregs = task_pt_regs(p);
#if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_IO_PORTS)
struct thread_info *ti;
#endif
/* Create a call4 dummy-frame: a0 = 0, a1 = childregs. */
*((int*)childregs - 3) = (unsigned long)childregs;
*((int*)childregs - 4) = 0;
p->thread.sp = (unsigned long)childregs;
if (!(p->flags & PF_KTHREAD)) {
struct pt_regs *regs = current_pt_regs();
unsigned long usp = usp_thread_fn ?
usp_thread_fn : regs->areg[1];
p->thread.ra = MAKE_RA_FOR_CALL(
(unsigned long)ret_from_fork, 0x1);
/* This does not copy all the regs.
* In a bout of brilliance or madness,
* ARs beyond a0-a15 exist past the end of the struct.
*/
*childregs = *regs;
childregs->areg[1] = usp;
childregs->areg[2] = 0;
/* When sharing memory with the parent thread, the child
usually starts on a pristine stack, so we have to reset
windowbase, windowstart and wmask.
(Note that such a new thread is required to always create
an initial call4 frame)
The exception is vfork, where the new thread continues to
run on the parent's stack until it calls execve. This could
be a call8 or call12, which requires a legal stack frame
of the previous caller for the overflow handlers to work.
(Note that it's always legal to overflow live registers).
In this case, ensure to spill at least the stack pointer
of that frame. */
if (clone_flags & CLONE_VM) {
/* check that caller window is live and same stack */
int len = childregs->wmask & ~0xf;
if (regs->areg[1] == usp && len != 0) {
int callinc = (regs->areg[0] >> 30) & 3;
int caller_ars = XCHAL_NUM_AREGS - callinc * 4;
put_user(regs->areg[caller_ars+1],
(unsigned __user*)(usp - 12));
}
childregs->wmask = 1;
childregs->windowstart = 1;
childregs->windowbase = 0;
} else {
void flush_thread(void)
{
void *data = NULL;
int ret;
arch_flush_thread(¤t->thread.arch);
ret = unmap(¤t->mm->context.id, 0, STUB_START, 0, &data);
ret = ret || unmap(¤t->mm->context.id, STUB_END,
host_task_size - STUB_END, 1, &data);
if (ret) {
printk(KERN_ERR "flush_thread - clearing address space failed, "
"err = %d\n", ret);
force_sig(SIGKILL, current);
}
get_safe_registers(current_pt_regs()->regs.gp,
current_pt_regs()->regs.fp);
__switch_mm(¤t->mm->context.id);
}
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
struct switch_stack *swstack = ((struct switch_stack *) childregs) - 1;
/*
* Put the pt_regs structure at the end of the new kernel stack page and
* fix it up. Note: the task_struct doubles as the kernel stack for the
* task.
*/
if (unlikely(p->flags & PF_KTHREAD)) {
memset(swstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
swstack->r1 = usp;
swstack->r2 = arg;
childregs->ccs = 1 << (I_CCS_BITNR + CCS_SHIFT);
swstack->return_ip = (unsigned long) ret_from_kernel_thread;
p->thread.ksp = (unsigned long) swstack;
p->thread.usp = 0;
return 0;
}
*childregs = *current_pt_regs(); /* Struct copy of pt_regs. */
childregs->r10 = 0; /* Child returns 0 after a fork/clone. */
/* Set a new TLS ?
* The TLS is in $mof because it is the 5th argument to sys_clone.
*/
if (p->mm && (clone_flags & CLONE_SETTLS)) {
task_thread_info(p)->tls = childregs->mof;
}
/* Put the switch stack right below the pt_regs. */
/* Parameter to ret_from_sys_call. 0 is don't restart the syscall. */
swstack->r9 = 0;
/*
* We want to return into ret_from_sys_call after the _resume.
* ret_from_fork will call ret_from_sys_call.
*/
swstack->return_ip = (unsigned long) ret_from_fork;
/* Fix the user-mode and kernel-mode stackpointer. */
p->thread.usp = usp ?: rdusp();
p->thread.ksp = (unsigned long) swstack;
return 0;
}
void arm64_notify_die(const char *str, struct pt_regs *regs,
int signo, int sicode, void __user *addr,
int err)
{
if (user_mode(regs)) {
WARN_ON(regs != current_pt_regs());
current->thread.fault_address = 0;
current->thread.fault_code = err;
arm64_force_sig_fault(signo, sicode, addr, str);
} else {
die(str, regs, err);
}
}
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg, struct task_struct *p)
{
struct pt_regs *userregs;
struct pt_regs *kregs;
unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
unsigned long top_of_kernel_stack;
top_of_kernel_stack = sp;
p->set_child_tid = p->clear_child_tid = NULL;
/* Locate userspace context on stack... */
sp -= STACK_FRAME_OVERHEAD; /* redzone */
sp -= sizeof(struct pt_regs);
userregs = (struct pt_regs *) sp;
/* ...and kernel context */
sp -= STACK_FRAME_OVERHEAD; /* redzone */
sp -= sizeof(struct pt_regs);
kregs = (struct pt_regs *)sp;
if (unlikely(p->flags & PF_KTHREAD)) {
memset(kregs, 0, sizeof(struct pt_regs));
kregs->gpr[20] = usp; /* fn, kernel thread */
kregs->gpr[22] = arg;
} else {
*userregs = *current_pt_regs();
if (usp)
userregs->sp = usp;
userregs->gpr[11] = 0; /* Result from fork() */
kregs->gpr[20] = 0; /* Userspace thread */
}
/*
* _switch wants the kernel stack page in pt_regs->sp so that it
* can restore it to thread_info->ksp... see _switch for details.
*/
kregs->sp = top_of_kernel_stack;
kregs->gpr[9] = (unsigned long)ret_from_fork;
task_thread_info(p)->ksp = (unsigned long)kregs;
return 0;
}
static void vdso_fix_landing(const struct vdso_image *image,
struct vm_area_struct *new_vma)
{
#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
if (in_ia32_syscall() && image == &vdso_image_32) {
struct pt_regs *regs = current_pt_regs();
unsigned long vdso_land = image->sym_int80_landing_pad;
unsigned long old_land_addr = vdso_land +
(unsigned long)current->mm->context.vdso;
/* Fixing userspace landing - look at do_fast_syscall_32 */
if (regs->ip == old_land_addr)
regs->ip = new_vma->vm_start + vdso_land;
}
#endif
}
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg,
struct task_struct *p)
{
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
struct thread_info *childti = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);
struct pt_regs *regs = current_pt_regs();
struct switch_stack *childstack, *stack;
childstack = ((struct switch_stack *) childregs) - 1;
childti->pcb.ksp = (unsigned long) childstack;
childti->pcb.flags = 1; /* set FEN, clear everything else */
if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
memset(childstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
childstack->r26 = (unsigned long) ret_from_kernel_thread;
childstack->r9 = usp; /* function */
childstack->r10 = arg;
childregs->hae = alpha_mv.hae_cache,
childti->pcb.usp = 0;
return 0;
}
/* Note: if CLONE_SETTLS is not set, then we must inherit the
value from the parent, which will have been set by the block
copy in dup_task_struct. This is non-intuitive, but is
required for proper operation in the case of a threaded
application calling fork. */
if (clone_flags & CLONE_SETTLS)
childti->pcb.unique = regs->r20;
childti->pcb.usp = usp ?: rdusp();
*childregs = *regs;
childregs->r0 = 0;
childregs->r19 = 0;
childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */
regs->r20 = 0;
stack = ((struct switch_stack *) regs) - 1;
*childstack = *stack;
childstack->r26 = (unsigned long) ret_from_fork;
return 0;
}
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
unsigned long stk_sz, struct task_struct *p)
{
struct pt_regs *childregs = task_pt_regs(p);
memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));
if (likely(!(p->flags & PF_KTHREAD))) {
*childregs = *current_pt_regs();
childregs->regs[0] = 0;
/*
* Read the current TLS pointer from tpidr_el0 as it may be
* out-of-sync with the saved value.
*/
*task_user_tls(p) = read_sysreg(tpidr_el0);
if (stack_start) {
if (is_compat_thread(task_thread_info(p)))
childregs->compat_sp = stack_start;
else
childregs->sp = stack_start;
}
/*
* If a TLS pointer was passed to clone (4th argument), use it
* for the new thread.
*/
if (clone_flags & CLONE_SETTLS)
p->thread.tp_value = childregs->regs[3];
} else {
memset(childregs, 0, sizeof(struct pt_regs));
childregs->pstate = PSR_MODE_EL1h;
if (IS_ENABLED(CONFIG_ARM64_UAO) &&
cpus_have_const_cap(ARM64_HAS_UAO))
childregs->pstate |= PSR_UAO_BIT;
p->thread.cpu_context.x19 = stack_start;
p->thread.cpu_context.x20 = stk_sz;
}
p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
p->thread.cpu_context.sp = (unsigned long)childregs;
ptrace_hw_copy_thread(p);
return 0;
}
/*
* sys_iopl has to be used when you want to access the IO ports
* beyond the 0x3ff range: to get the full 65536 ports bitmapped
* you'd need 8kB of bitmaps/process, which is a bit excessive.
*
* Here we just change the flags value on the stack: we allow
* only the super-user to do it. This depends on the stack-layout
* on system-call entry - see also fork() and the signal handling
* code.
*/
SYSCALL_DEFINE1(iopl, unsigned int, level)
{
struct pt_regs *regs = current_pt_regs();
unsigned int old = (regs->flags >> 12) & 3;
struct thread_struct *t = ¤t->thread;
if (level > 3)
return -EINVAL;
/* Trying to gain more privileges? */
if (level > old) {
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
}
regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
t->iopl = level << 12;
set_iopl_mask(t->iopl);
return 0;
}
asmlinkage int sys_rt_sigreturn(void)
{
struct pt_regs *regs = current_pt_regs();
struct rt_sigframe __user *frame;
sigset_t blocked;
/* Always make any pending restarted system calls return -EINTR */
current_thread_info()->restart_block.fn = do_no_restart_syscall;
frame = (struct rt_sigframe __user *)pt_psp(regs);
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&blocked, &frame->uc.uc_sigmask, sizeof(blocked)))
goto badframe;
set_current_blocked(&blocked);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
goto badframe;
/* Restore the user's stack as well */
pt_psp(regs) = regs->r29;
/*
* Leave a trace in the stack frame that this was a sigreturn.
* If the system call is to replay, we've already restored the
* number in the GPR slot and it will be regenerated on the
* new system call trap entry. Note that if restore_sigcontext()
* did something other than a bulk copy of the pt_regs struct,
* we could avoid this assignment by simply not overwriting
* regs->syscall_nr.
*/
regs->syscall_nr = __NR_rt_sigreturn;
if (restore_altstack(&frame->uc.uc_stack))
goto badframe;
return 0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
