/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/suspend.h>
#include <linux/ptrace.h>
#include <linux/elf.h>
#include <linux/compat.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <asm/processor.h>
#include <asm/ucontext.h>
#include <asm/sigframe.h>
#include <asm/syscalls.h>
#include <arch/interrupts.h>
struct compat_sigaction {
compat_uptr_t sa_handler;
compat_ulong_t sa_flags;
compat_uptr_t sa_restorer;
sigset_t sa_mask __packed;
};
struct compat_sigaltstack {
compat_uptr_t ss_sp;
int ss_flags;
compat_size_t ss_size;
};
struct compat_ucontext {
compat_ulong_t uc_flags;
compat_uptr_t uc_link;
struct compat_sigaltstack uc_stack;
struct sigcontext uc_mcontext;
sigset_t uc_sigmask; /* mask last for extensibility */
};
#define COMPAT_SI_PAD_SIZE ((SI_MAX_SIZE - 3 * sizeof(int)) / sizeof(int))
struct compat_siginfo {
int si_signo;
int si_errno;
int si_code;
union {
int _pad[COMPAT_SI_PAD_SIZE];
/* kill() */
struct {
unsigned int _pid; /* sender's pid */
unsigned int _uid; /* sender's uid */
} _kill;
/* POSIX.1b timers */
struct {
compat_timer_t _tid; /* timer id */
int _overrun; /* overrun count */
compat_sigval_t _sigval; /* same as below */
int _sys_private; /* not to be passed to user */
int _overrun_incr; /* amount to add to overrun */
} _timer;
/* POSIX.1b signals */
struct {
unsigned int _pid; /* sender's pid */
unsigned int _uid; /* sender's uid */
compat_sigval_t _sigval;
} _rt;
/* SIGCHLD */
struct {
unsigned int _pid; /* which child */
unsigned int _uid; /* sender's uid */
int _status; /* exit code */
compat_clock_t _utime;
compat_clock_t _stime;
} _sigchld;
/* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
struct {
unsigned int _addr; /* faulting insn/memory ref. */
#ifdef __ARCH_SI_TRAPNO
int _trapno; /* TRAP # which caused the signal */
#endif
} _sigfault;
/* SIGPOLL */
struct {
int _band; /* POLL_IN, POLL_OUT, POLL_MSG */
int _fd;
} _sigpoll;
} _sifields;
};
struct compat_rt_sigframe {
unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */
struct compat_siginfo info;
struct compat_ucontext uc;
};
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
long compat_sys_rt_sigaction(int sig, struct compat_sigaction __user *act,
struct compat_sigaction __user *oact,
size_t sigsetsize)
{
struct k_sigaction new_sa, old_sa;
int ret = -EINVAL;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(sigset_t))
goto out;
if (act) {
compat_uptr_t handler, restorer;
if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
__get_user(handler, &act->sa_handler) ||
__get_user(new_sa.sa.sa_flags, &act->sa_flags) ||
__get_user(restorer, &act->sa_restorer) ||
__copy_from_user(&new_sa.sa.sa_mask, &act->sa_mask,
sizeof(sigset_t)))
return -EFAULT;
new_sa.sa.sa_handler = compat_ptr(handler);
new_sa.sa.sa_restorer = compat_ptr(restorer);
}
ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL);
if (!ret && oact) {
if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
__put_user(ptr_to_compat(old_sa.sa.sa_handler),
&oact->sa_handler) ||
__put_user(ptr_to_compat(old_sa.sa.sa_restorer),
&oact->sa_restorer) ||
__put_user(old_sa.sa.sa_flags, &oact->sa_flags) ||
__copy_to_user(&oact->sa_mask, &old_sa.sa.sa_mask,
sizeof(sigset_t)))
return -EFAULT;
}
out:
return ret;
}
long compat_sys_rt_sigqueueinfo(int pid, int sig,
struct compat_siginfo __user *uinfo)
{
siginfo_t info;
int ret;
mm_segment_t old_fs = get_fs();
if (copy_siginfo_from_user32(&info, uinfo))
return -EFAULT;
set_fs(KERNEL_DS);
ret = sys_rt_sigqueueinfo(pid, sig, (siginfo_t __force __user *)&info);
set_fs(old_fs);
return ret;
}
int copy_siginfo_to_user32(struct compat_siginfo __user *to, siginfo_t *from)
{
int err;
if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo)))
return -EFAULT;
/* If you change siginfo_t structure, please make sure that
this code is fixed accordingly.
It should never copy any pad contained in the structure
to avoid security leaks, but must copy the generic
3 ints plus the relevant union member. */
err = __put_user(from->si_signo, &to->si_signo);
err |= __put_user(from->si_errno, &to->si_errno);
err |= __put_user((short)from->si_code, &to->si_code);
if (from->si_code < 0) {
err |= __put_user(from->si_pid, &to->si_pid);
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(ptr_to_compat(from->si_ptr), &to->si_ptr);
} else {
/*
* First 32bits of unions are always present:
* si_pid === si_band === si_tid === si_addr(LS half)
*/
err |= __put_user(from->_sifields._pad[0],
&to->_sifields._pad[0]);
switch (from->si_code >> 16) {
case __SI_FAULT >> 16:
break;
case __SI_CHLD >> 16:
err |= __put_user(from->si_utime, &to->si_utime);
err |= __put_user(from->si_stime, &to->si_stime);
err |= __put_user(from->si_status, &to->si_status);
/* FALL THROUGH */
default:
case __SI_KILL >> 16:
err |= __put_user(from->si_uid, &to->si_uid);
break;
case __SI_POLL >> 16:
err |= __put_user(from->si_fd, &to->si_fd);
break;
case __SI_TIMER >> 16:
err |= __put_user(from->si_overrun, &to->si_overrun);
err |= __put_user(ptr_to_compat(from->si_ptr),
&to->si_ptr);
break;
/* This is not generated by the kernel as of now. */
case __SI_RT >> 16:
case __SI_MESGQ >> 16:
err |= __put_user(from->si_uid, &to->si_uid);
err |= __put_user(from->si_int, &to->si_int);
break;
}
}
return err;
}
int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
{
int err;
u32 ptr32;
if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo)))
return -EFAULT;
err = __get_user(to->si_signo, &from->si_signo);
err |= __get_user(to->si_errno, &from->si_errno);
err |= __get_user(to->si_code, &from->si_code);
err |= __get_user(to->si_pid, &from->si_pid);
err |= __get_user(to->si_uid, &from->si_uid);
err |= __get_user(ptr32, &from->si_ptr);
to->si_ptr = compat_ptr(ptr32);
return err;
}
long compat_sys_sigaltstack(const struct compat_sigaltstack __user *uss_ptr,
struct compat_sigaltstack __user *uoss_ptr,
struct pt_regs *regs)
{
stack_t uss, uoss;
int ret;
mm_segment_t seg;
if (uss_ptr) {
u32 ptr;
memset(&uss, 0, sizeof(stack_t));
if (!access_ok(VERIFY_READ, uss_ptr, sizeof(*uss_ptr)) ||
__get_user(ptr, &uss_ptr->ss_sp) ||
__get_user(uss.ss_flags, &uss_ptr->ss_flags) ||
__get_user(uss.ss_size, &uss_ptr->ss_size))
return -EFAULT;
uss.ss_sp = compat_ptr(ptr);
}
seg = get_fs();
set_fs(KERNEL_DS);
ret = do_sigaltstack(uss_ptr ? (stack_t __user __force *)&uss : NULL,
(stack_t __user __force *)&uoss,
(unsigned long)compat_ptr(regs->sp));
set_fs(seg);
if (ret >= 0 && uoss_ptr) {
if (!access_ok(VERIFY_WRITE, uoss_ptr, sizeof(*uoss_ptr)) ||
__put_user(ptr_to_compat(uoss.ss_sp), &uoss_ptr->ss_sp) ||
__put_user(uoss.ss_flags, &uoss_ptr->ss_flags) ||
__put_user(uoss.ss_size, &uoss_ptr->ss_size))
ret = -EFAULT;
}
return ret;
}
/* The assembly shim for this function arranges to ignore the return value. */
long compat_sys_rt_sigreturn(struct pt_regs *regs)
{
struct compat_rt_sigframe __user *frame =
(struct compat_rt_sigframe __user *) compat_ptr(regs->sp);
sigset_t set;
if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
goto badframe;
if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
goto badframe;
sigdelsetmask(&set, ~_BLOCKABLE);
spin_lock_irq(¤t->sighand->siglock);
current->blocked = set;
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
goto badframe;
if (compat_sys_sigaltstack(&frame->uc.uc_stack, NULL, regs) != 0)
goto badframe;
return 0;
badframe:
force_sig(SIGSEGV, current);
return 0;
}
/*
* Determine which stack to use..
*/
static inline void __user *compat_get_sigframe(struct k_sigaction *ka,
struct pt_regs *regs,
size_t frame_size)
{
unsigned long sp;
/* Default to using normal stack */
sp = (unsigned long)compat_ptr(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 - frame_size)))
return (void __user __force *)-1UL;
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa.sa_flags & SA_ONSTACK) {
if (sas_ss_flags(sp) == 0)
sp = current->sas_ss_sp + current->sas_ss_size;
}
sp -= frame_size;
/*
* Align the stack pointer according to the TILE ABI,
* i.e. so that on function entry (sp & 15) == 0.
*/
sp &= -16UL;
return (void __user *) sp;
}
int compat_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
sigset_t *set, struct pt_regs *regs)
{
unsigned long restorer;
struct compat_rt_sigframe __user *frame;
int err = 0;
int usig;
frame = compat_get_sigframe(ka, regs, sizeof(*frame));
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
goto give_sigsegv;
usig = current_thread_info()->exec_domain
&& current_thread_info()->exec_domain->signal_invmap
&& sig < 32
? current_thread_info()->exec_domain->signal_invmap[sig]
: sig;
/* Always write at least the signal number for the stack backtracer. */
if (ka->sa.sa_flags & SA_SIGINFO) {
/* At sigreturn time, restore the callee-save registers too. */
err |= copy_siginfo_to_user32(&frame->info, info);
regs->flags |= PT_FLAGS_RESTORE_REGS;
} else {
err |= __put_user(info->si_signo, &frame->info.si_signo);
}
/* Create the ucontext. */
err |= __clear_user(&frame->save_area, sizeof(frame->save_area));
err |= __put_user(0, &frame->uc.uc_flags);
err |= __put_user(0, &frame->uc.uc_link);
err |= __put_user(ptr_to_compat((void *)(current->sas_ss_sp)),
&frame->uc.uc_stack.ss_sp);
err |= __put_user(sas_ss_flags(regs->sp),
&frame->uc.uc_stack.ss_flags);
err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs);
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
if (err)
goto give_sigsegv;
restorer = VDSO_BASE;
if (ka->sa.sa_flags & SA_RESTORER)
restorer = ptr_to_compat_reg(ka->sa.sa_restorer);
/*
* 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.
*/
regs->pc = ptr_to_compat_reg(ka->sa.sa_handler);
regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
regs->sp = ptr_to_compat_reg(frame);
regs->lr = restorer;
regs->regs[0] = (unsigned long) usig;
if (ka->sa.sa_flags & SA_SIGINFO) {
/* Need extra arguments, so mark to restore caller-saves. */
regs->regs[1] = ptr_to_compat_reg(&frame->info);
regs->regs[2] = ptr_to_compat_reg(&frame->uc);
regs->flags |= PT_FLAGS_CALLER_SAVES;
}
/*
* Notify any tracer that was single-stepping it.
* The tracer may want to single-step inside the
* handler too.
*/
if (test_thread_flag(TIF_SINGLESTEP))
ptrace_notify(SIGTRAP);
return 0;
give_sigsegv:
force_sigsegv(sig, current);
return -EFAULT;
}
