329 lines
8.6 KiB
C
329 lines
8.6 KiB
C
/*
|
|
* Copyright (C) 2013-2014 Altera Corporation
|
|
* Copyright (C) 2011-2012 Tobias Klauser <tklauser@distanz.ch>
|
|
* Copyright (C) 2004 Microtronix Datacom Ltd
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*
|
|
* This file is subject to the terms and conditions of the GNU General Public
|
|
* License. See the file COPYING in the main directory of this archive
|
|
* for more details.
|
|
*/
|
|
|
|
#include <linux/signal.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/resume_user_mode.h>
|
|
|
|
#include <asm/ucontext.h>
|
|
#include <asm/cacheflush.h>
|
|
|
|
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
|
|
|
|
/*
|
|
* Do a signal return; undo the signal stack.
|
|
*
|
|
* Keep the return code on the stack quadword aligned!
|
|
* That makes the cache flush below easier.
|
|
*/
|
|
|
|
struct rt_sigframe {
|
|
struct siginfo info;
|
|
struct ucontext uc;
|
|
};
|
|
|
|
static inline int rt_restore_ucontext(struct pt_regs *regs,
|
|
struct switch_stack *sw,
|
|
struct ucontext __user *uc, int *pr2)
|
|
{
|
|
int temp;
|
|
unsigned long __user *gregs = uc->uc_mcontext.gregs;
|
|
int err;
|
|
|
|
/* Always make any pending restarted system calls return -EINTR */
|
|
current->restart_block.fn = do_no_restart_syscall;
|
|
|
|
err = __get_user(temp, &uc->uc_mcontext.version);
|
|
if (temp != MCONTEXT_VERSION)
|
|
goto badframe;
|
|
/* restore passed registers */
|
|
err |= __get_user(regs->r1, &gregs[0]);
|
|
err |= __get_user(regs->r2, &gregs[1]);
|
|
err |= __get_user(regs->r3, &gregs[2]);
|
|
err |= __get_user(regs->r4, &gregs[3]);
|
|
err |= __get_user(regs->r5, &gregs[4]);
|
|
err |= __get_user(regs->r6, &gregs[5]);
|
|
err |= __get_user(regs->r7, &gregs[6]);
|
|
err |= __get_user(regs->r8, &gregs[7]);
|
|
err |= __get_user(regs->r9, &gregs[8]);
|
|
err |= __get_user(regs->r10, &gregs[9]);
|
|
err |= __get_user(regs->r11, &gregs[10]);
|
|
err |= __get_user(regs->r12, &gregs[11]);
|
|
err |= __get_user(regs->r13, &gregs[12]);
|
|
err |= __get_user(regs->r14, &gregs[13]);
|
|
err |= __get_user(regs->r15, &gregs[14]);
|
|
err |= __get_user(sw->r16, &gregs[15]);
|
|
err |= __get_user(sw->r17, &gregs[16]);
|
|
err |= __get_user(sw->r18, &gregs[17]);
|
|
err |= __get_user(sw->r19, &gregs[18]);
|
|
err |= __get_user(sw->r20, &gregs[19]);
|
|
err |= __get_user(sw->r21, &gregs[20]);
|
|
err |= __get_user(sw->r22, &gregs[21]);
|
|
err |= __get_user(sw->r23, &gregs[22]);
|
|
/* gregs[23] is handled below */
|
|
err |= __get_user(sw->fp, &gregs[24]); /* Verify, should this be
|
|
settable */
|
|
err |= __get_user(sw->gp, &gregs[25]); /* Verify, should this be
|
|
settable */
|
|
|
|
err |= __get_user(temp, &gregs[26]); /* Not really necessary no user
|
|
settable bits */
|
|
err |= __get_user(regs->ea, &gregs[27]);
|
|
|
|
err |= __get_user(regs->ra, &gregs[23]);
|
|
err |= __get_user(regs->sp, &gregs[28]);
|
|
|
|
regs->orig_r2 = -1; /* disable syscall checks */
|
|
|
|
err |= restore_altstack(&uc->uc_stack);
|
|
if (err)
|
|
goto badframe;
|
|
|
|
*pr2 = regs->r2;
|
|
return err;
|
|
|
|
badframe:
|
|
return 1;
|
|
}
|
|
|
|
asmlinkage int do_rt_sigreturn(struct switch_stack *sw)
|
|
{
|
|
struct pt_regs *regs = (struct pt_regs *)(sw + 1);
|
|
/* Verify, can we follow the stack back */
|
|
struct rt_sigframe __user *frame;
|
|
sigset_t set;
|
|
int rval;
|
|
|
|
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 (rt_restore_ucontext(regs, sw, &frame->uc, &rval))
|
|
goto badframe;
|
|
|
|
return rval;
|
|
|
|
badframe:
|
|
force_sig(SIGSEGV);
|
|
return 0;
|
|
}
|
|
|
|
static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
|
|
{
|
|
struct switch_stack *sw = (struct switch_stack *)regs - 1;
|
|
unsigned long __user *gregs = uc->uc_mcontext.gregs;
|
|
int err = 0;
|
|
|
|
err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
|
|
err |= __put_user(regs->r1, &gregs[0]);
|
|
err |= __put_user(regs->r2, &gregs[1]);
|
|
err |= __put_user(regs->r3, &gregs[2]);
|
|
err |= __put_user(regs->r4, &gregs[3]);
|
|
err |= __put_user(regs->r5, &gregs[4]);
|
|
err |= __put_user(regs->r6, &gregs[5]);
|
|
err |= __put_user(regs->r7, &gregs[6]);
|
|
err |= __put_user(regs->r8, &gregs[7]);
|
|
err |= __put_user(regs->r9, &gregs[8]);
|
|
err |= __put_user(regs->r10, &gregs[9]);
|
|
err |= __put_user(regs->r11, &gregs[10]);
|
|
err |= __put_user(regs->r12, &gregs[11]);
|
|
err |= __put_user(regs->r13, &gregs[12]);
|
|
err |= __put_user(regs->r14, &gregs[13]);
|
|
err |= __put_user(regs->r15, &gregs[14]);
|
|
err |= __put_user(sw->r16, &gregs[15]);
|
|
err |= __put_user(sw->r17, &gregs[16]);
|
|
err |= __put_user(sw->r18, &gregs[17]);
|
|
err |= __put_user(sw->r19, &gregs[18]);
|
|
err |= __put_user(sw->r20, &gregs[19]);
|
|
err |= __put_user(sw->r21, &gregs[20]);
|
|
err |= __put_user(sw->r22, &gregs[21]);
|
|
err |= __put_user(sw->r23, &gregs[22]);
|
|
err |= __put_user(regs->ra, &gregs[23]);
|
|
err |= __put_user(sw->fp, &gregs[24]);
|
|
err |= __put_user(sw->gp, &gregs[25]);
|
|
err |= __put_user(regs->ea, &gregs[27]);
|
|
err |= __put_user(regs->sp, &gregs[28]);
|
|
return err;
|
|
}
|
|
|
|
static inline void __user *get_sigframe(struct ksignal *ksig,
|
|
struct pt_regs *regs,
|
|
size_t frame_size)
|
|
{
|
|
unsigned long usp;
|
|
|
|
/* Default to using normal stack. */
|
|
usp = regs->sp;
|
|
|
|
/* This is the X/Open sanctioned signal stack switching. */
|
|
usp = sigsp(usp, ksig);
|
|
|
|
/* Verify, is it 32 or 64 bit aligned */
|
|
return (void __user *)((usp - frame_size) & -8UL);
|
|
}
|
|
|
|
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
int err = 0;
|
|
|
|
frame = get_sigframe(ksig, regs, sizeof(*frame));
|
|
|
|
if (ksig->ka.sa.sa_flags & SA_SIGINFO)
|
|
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 |= __save_altstack(&frame->uc.uc_stack, regs->sp);
|
|
err |= rt_setup_ucontext(&frame->uc, regs);
|
|
err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
|
|
|
|
if (err)
|
|
goto give_sigsegv;
|
|
|
|
/* Set up to return from userspace; jump to fixed address sigreturn
|
|
trampoline on kuser page. */
|
|
regs->ra = (unsigned long) (0x1044);
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->sp = (unsigned long) frame;
|
|
regs->r4 = (unsigned long) ksig->sig;
|
|
regs->r5 = (unsigned long) &frame->info;
|
|
regs->r6 = (unsigned long) &frame->uc;
|
|
regs->ea = (unsigned long) ksig->ka.sa.sa_handler;
|
|
return 0;
|
|
|
|
give_sigsegv:
|
|
force_sigsegv(ksig->sig);
|
|
return -EFAULT;
|
|
}
|
|
|
|
/*
|
|
* OK, we're invoking a handler
|
|
*/
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
|
|
{
|
|
int ret;
|
|
sigset_t *oldset = sigmask_to_save();
|
|
|
|
/* set up the stack frame */
|
|
ret = setup_rt_frame(ksig, oldset, regs);
|
|
|
|
signal_setup_done(ret, ksig, 0);
|
|
}
|
|
|
|
static int do_signal(struct pt_regs *regs)
|
|
{
|
|
unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
|
|
int restart = 0;
|
|
struct ksignal ksig;
|
|
|
|
current->thread.kregs = regs;
|
|
|
|
/*
|
|
* If we were from a system call, check for system call restarting...
|
|
*/
|
|
if (regs->orig_r2 >= 0 && regs->r1) {
|
|
continue_addr = regs->ea;
|
|
restart_addr = continue_addr - 4;
|
|
retval = regs->r2;
|
|
|
|
/*
|
|
* Prepare for system call restart. We do this here so that a
|
|
* debugger will see the already changed PC.
|
|
*/
|
|
switch (retval) {
|
|
case ERESTART_RESTARTBLOCK:
|
|
restart = -2;
|
|
fallthrough;
|
|
case ERESTARTNOHAND:
|
|
case ERESTARTSYS:
|
|
case ERESTARTNOINTR:
|
|
restart++;
|
|
regs->r2 = regs->orig_r2;
|
|
regs->r7 = regs->orig_r7;
|
|
regs->ea = restart_addr;
|
|
break;
|
|
}
|
|
regs->orig_r2 = -1;
|
|
}
|
|
|
|
if (get_signal(&ksig)) {
|
|
/* handler */
|
|
if (unlikely(restart && regs->ea == restart_addr)) {
|
|
if (retval == ERESTARTNOHAND ||
|
|
retval == ERESTART_RESTARTBLOCK ||
|
|
(retval == ERESTARTSYS
|
|
&& !(ksig.ka.sa.sa_flags & SA_RESTART))) {
|
|
regs->r2 = EINTR;
|
|
regs->r7 = 1;
|
|
regs->ea = continue_addr;
|
|
}
|
|
}
|
|
handle_signal(&ksig, regs);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* No handler present
|
|
*/
|
|
if (unlikely(restart) && regs->ea == restart_addr) {
|
|
regs->ea = continue_addr;
|
|
regs->r2 = __NR_restart_syscall;
|
|
}
|
|
|
|
/*
|
|
* If there's no signal to deliver, we just put the saved sigmask back.
|
|
*/
|
|
restore_saved_sigmask();
|
|
|
|
return restart;
|
|
}
|
|
|
|
asmlinkage int do_notify_resume(struct pt_regs *regs)
|
|
{
|
|
/*
|
|
* 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 0;
|
|
|
|
if (test_thread_flag(TIF_SIGPENDING) ||
|
|
test_thread_flag(TIF_NOTIFY_SIGNAL)) {
|
|
int restart = do_signal(regs);
|
|
|
|
if (unlikely(restart)) {
|
|
/*
|
|
* Restart without handlers.
|
|
* Deal with it without leaving
|
|
* the kernel space.
|
|
*/
|
|
return restart;
|
|
}
|
|
} else if (test_thread_flag(TIF_NOTIFY_RESUME))
|
|
resume_user_mode_work(regs);
|
|
|
|
return 0;
|
|
}
|