326 lines
8.1 KiB
C
326 lines
8.1 KiB
C
/*
|
|
* Port on Texas Instruments TMS320C6x architecture
|
|
*
|
|
* Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
|
|
* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
|
|
*
|
|
* Updated for 2.6.34: Mark Salter <msalter@redhat.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/tracehook.h>
|
|
|
|
#include <asm/ucontext.h>
|
|
#include <asm/cacheflush.h>
|
|
|
|
|
|
/*
|
|
* Do a signal return, undo the signal stack.
|
|
*/
|
|
|
|
#define RETCODE_SIZE (9 << 2) /* 9 instructions = 36 bytes */
|
|
|
|
struct rt_sigframe {
|
|
struct siginfo __user *pinfo;
|
|
void __user *puc;
|
|
struct siginfo info;
|
|
struct ucontext uc;
|
|
unsigned long retcode[RETCODE_SIZE >> 2];
|
|
};
|
|
|
|
static int restore_sigcontext(struct pt_regs *regs,
|
|
struct sigcontext __user *sc)
|
|
{
|
|
int err = 0;
|
|
|
|
/* The access_ok check was done by caller, so use __get_user here */
|
|
#define COPY(x) (err |= __get_user(regs->x, &sc->sc_##x))
|
|
|
|
COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
|
|
COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
|
|
COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
|
|
|
|
COPY(a16); COPY(a17); COPY(a18); COPY(a19);
|
|
COPY(a20); COPY(a21); COPY(a22); COPY(a23);
|
|
COPY(a24); COPY(a25); COPY(a26); COPY(a27);
|
|
COPY(a28); COPY(a29); COPY(a30); COPY(a31);
|
|
COPY(b16); COPY(b17); COPY(b18); COPY(b19);
|
|
COPY(b20); COPY(b21); COPY(b22); COPY(b23);
|
|
COPY(b24); COPY(b25); COPY(b26); COPY(b27);
|
|
COPY(b28); COPY(b29); COPY(b30); COPY(b31);
|
|
|
|
COPY(csr); COPY(pc);
|
|
|
|
#undef COPY
|
|
|
|
return err;
|
|
}
|
|
|
|
asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
sigset_t set;
|
|
|
|
/* Always make any pending restarted system calls return -EINTR */
|
|
current->restart_block.fn = do_no_restart_syscall;
|
|
|
|
/*
|
|
* Since we stacked the signal on a dword boundary,
|
|
* 'sp' should be dword aligned here. If it's
|
|
* not, then the user is trying to mess with us.
|
|
*/
|
|
if (regs->sp & 7)
|
|
goto badframe;
|
|
|
|
frame = (struct rt_sigframe __user *) ((unsigned long) regs->sp + 8);
|
|
|
|
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;
|
|
|
|
return regs->a4;
|
|
|
|
badframe:
|
|
force_sig(SIGSEGV, current);
|
|
return 0;
|
|
}
|
|
|
|
static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
|
|
unsigned long mask)
|
|
{
|
|
int err = 0;
|
|
|
|
err |= __put_user(mask, &sc->sc_mask);
|
|
|
|
/* The access_ok check was done by caller, so use __put_user here */
|
|
#define COPY(x) (err |= __put_user(regs->x, &sc->sc_##x))
|
|
|
|
COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
|
|
COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
|
|
COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
|
|
|
|
COPY(a16); COPY(a17); COPY(a18); COPY(a19);
|
|
COPY(a20); COPY(a21); COPY(a22); COPY(a23);
|
|
COPY(a24); COPY(a25); COPY(a26); COPY(a27);
|
|
COPY(a28); COPY(a29); COPY(a30); COPY(a31);
|
|
COPY(b16); COPY(b17); COPY(b18); COPY(b19);
|
|
COPY(b20); COPY(b21); COPY(b22); COPY(b23);
|
|
COPY(b24); COPY(b25); COPY(b26); COPY(b27);
|
|
COPY(b28); COPY(b29); COPY(b30); COPY(b31);
|
|
|
|
COPY(csr); COPY(pc);
|
|
|
|
#undef COPY
|
|
|
|
return err;
|
|
}
|
|
|
|
static inline void __user *get_sigframe(struct ksignal *ksig,
|
|
struct pt_regs *regs,
|
|
unsigned long framesize)
|
|
{
|
|
unsigned long sp = sigsp(regs->sp, ksig);
|
|
|
|
/*
|
|
* No matter what happens, 'sp' must be dword
|
|
* aligned. Otherwise, nasty things will happen
|
|
*/
|
|
return (void __user *)((sp - framesize) & ~7);
|
|
}
|
|
|
|
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
unsigned long __user *retcode;
|
|
int err = 0;
|
|
|
|
frame = get_sigframe(ksig, regs, sizeof(*frame));
|
|
|
|
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
|
|
return -EFAULT;
|
|
|
|
err |= __put_user(&frame->info, &frame->pinfo);
|
|
err |= __put_user(&frame->uc, &frame->puc);
|
|
err |= copy_siginfo_to_user(&frame->info, &ksig->info);
|
|
|
|
/* Clear all the bits of the ucontext we don't use. */
|
|
err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
|
|
|
|
err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
|
|
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
|
|
|
|
/* Set up to return from userspace */
|
|
retcode = (unsigned long __user *) &frame->retcode;
|
|
|
|
/* The access_ok check was done above, so use __put_user here */
|
|
#define COPY(x) (err |= __put_user(x, retcode++))
|
|
|
|
COPY(0x0000002AUL | (__NR_rt_sigreturn << 7));
|
|
/* MVK __NR_rt_sigreturn,B0 */
|
|
COPY(0x10000000UL); /* SWE */
|
|
COPY(0x00006000UL); /* NOP 4 */
|
|
COPY(0x00006000UL); /* NOP 4 */
|
|
COPY(0x00006000UL); /* NOP 4 */
|
|
COPY(0x00006000UL); /* NOP 4 */
|
|
COPY(0x00006000UL); /* NOP 4 */
|
|
COPY(0x00006000UL); /* NOP 4 */
|
|
COPY(0x00006000UL); /* NOP 4 */
|
|
|
|
#undef COPY
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
flush_icache_range((unsigned long) &frame->retcode,
|
|
(unsigned long) &frame->retcode + RETCODE_SIZE);
|
|
|
|
retcode = (unsigned long __user *) &frame->retcode;
|
|
|
|
/* Change user context to branch to signal handler */
|
|
regs->sp = (unsigned long) frame - 8;
|
|
regs->b3 = (unsigned long) retcode;
|
|
regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
/* Give the signal number to the handler */
|
|
regs->a4 = ksig->sig;
|
|
|
|
/*
|
|
* For realtime signals we must also set the second and third
|
|
* arguments for the signal handler.
|
|
* -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
|
|
*/
|
|
regs->b4 = (unsigned long)&frame->info;
|
|
regs->a6 = (unsigned long)&frame->uc;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline void
|
|
handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
|
|
{
|
|
switch (regs->a4) {
|
|
case -ERESTARTNOHAND:
|
|
if (!has_handler)
|
|
goto do_restart;
|
|
regs->a4 = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
|
|
regs->a4 = -EINTR;
|
|
break;
|
|
}
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
do_restart:
|
|
regs->a4 = regs->orig_a4;
|
|
regs->pc -= 4;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* handle the actual delivery of a signal to userspace
|
|
*/
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs,
|
|
int syscall)
|
|
{
|
|
int ret;
|
|
|
|
/* Are we from a system call? */
|
|
if (syscall) {
|
|
/* If so, check system call restarting.. */
|
|
switch (regs->a4) {
|
|
case -ERESTART_RESTARTBLOCK:
|
|
case -ERESTARTNOHAND:
|
|
regs->a4 = -EINTR;
|
|
break;
|
|
|
|
case -ERESTARTSYS:
|
|
if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
|
|
regs->a4 = -EINTR;
|
|
break;
|
|
}
|
|
|
|
/* fallthrough */
|
|
case -ERESTARTNOINTR:
|
|
regs->a4 = regs->orig_a4;
|
|
regs->pc -= 4;
|
|
}
|
|
}
|
|
|
|
/* Set up the stack frame */
|
|
ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
|
|
signal_setup_done(ret, ksig, 0);
|
|
}
|
|
|
|
/*
|
|
* handle a potential signal
|
|
*/
|
|
static void do_signal(struct pt_regs *regs, int syscall)
|
|
{
|
|
struct ksignal ksig;
|
|
|
|
/* we want the common case to go fast, which is why we may in certain
|
|
* cases get here from kernel mode */
|
|
if (!user_mode(regs))
|
|
return;
|
|
|
|
if (get_signal(&ksig)) {
|
|
handle_signal(&ksig, regs, syscall);
|
|
return;
|
|
}
|
|
|
|
/* did we come from a system call? */
|
|
if (syscall) {
|
|
/* restart the system call - no handlers present */
|
|
switch (regs->a4) {
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
regs->a4 = regs->orig_a4;
|
|
regs->pc -= 4;
|
|
break;
|
|
|
|
case -ERESTART_RESTARTBLOCK:
|
|
regs->a4 = regs->orig_a4;
|
|
regs->b0 = __NR_restart_syscall;
|
|
regs->pc -= 4;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* if there's no signal to deliver, we just put the saved sigmask
|
|
* back */
|
|
restore_saved_sigmask();
|
|
}
|
|
|
|
/*
|
|
* notification of userspace execution resumption
|
|
* - triggered by current->work.notify_resume
|
|
*/
|
|
asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags,
|
|
int syscall)
|
|
{
|
|
/* deal with pending signal delivery */
|
|
if (thread_info_flags & (1 << TIF_SIGPENDING))
|
|
do_signal(regs, syscall);
|
|
|
|
if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
}
|
|
}
|