![Ingo Molnar](/assets/img/avatar_default.png)
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/task_stack.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
336 lines
8.5 KiB
C
336 lines
8.5 KiB
C
/*
|
|
* Copyright (C) 1991,1992 Linus Torvalds
|
|
* Copyright (C) 2005-2012 Imagination Technologies Ltd.
|
|
*
|
|
* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
|
|
*
|
|
*/
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/task_stack.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/ptrace.h>
|
|
#include <linux/unistd.h>
|
|
#include <linux/stddef.h>
|
|
#include <linux/personality.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/tracehook.h>
|
|
|
|
#include <asm/ucontext.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/switch.h>
|
|
#include <asm/syscall.h>
|
|
#include <asm/syscalls.h>
|
|
|
|
#define REG_FLAGS ctx.SaveMask
|
|
#define REG_RETVAL ctx.DX[0].U0
|
|
#define REG_SYSCALL ctx.DX[0].U1
|
|
#define REG_SP ctx.AX[0].U0
|
|
#define REG_ARG1 ctx.DX[3].U1
|
|
#define REG_ARG2 ctx.DX[3].U0
|
|
#define REG_ARG3 ctx.DX[2].U1
|
|
#define REG_PC ctx.CurrPC
|
|
#define REG_RTP ctx.DX[4].U1
|
|
|
|
struct rt_sigframe {
|
|
struct siginfo info;
|
|
struct ucontext uc;
|
|
unsigned long retcode[2];
|
|
};
|
|
|
|
static int restore_sigcontext(struct pt_regs *regs,
|
|
struct sigcontext __user *sc)
|
|
{
|
|
int err;
|
|
|
|
/* Always make any pending restarted system calls return -EINTR */
|
|
current->restart_block.fn = do_no_restart_syscall;
|
|
|
|
err = metag_gp_regs_copyin(regs, 0, sizeof(struct user_gp_regs), NULL,
|
|
&sc->regs);
|
|
if (!err)
|
|
err = metag_cb_regs_copyin(regs, 0,
|
|
sizeof(struct user_cb_regs), NULL,
|
|
&sc->cb);
|
|
if (!err)
|
|
err = metag_rp_state_copyin(regs, 0,
|
|
sizeof(struct user_rp_state), NULL,
|
|
&sc->rp);
|
|
|
|
/* This is a user-mode context. */
|
|
regs->REG_FLAGS |= TBICTX_PRIV_BIT;
|
|
|
|
return err;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
|
|
unsigned long mask)
|
|
{
|
|
int err;
|
|
|
|
err = metag_gp_regs_copyout(regs, 0, sizeof(struct user_gp_regs), NULL,
|
|
&sc->regs);
|
|
|
|
if (!err)
|
|
err = metag_cb_regs_copyout(regs, 0,
|
|
sizeof(struct user_cb_regs), NULL,
|
|
&sc->cb);
|
|
if (!err)
|
|
err = metag_rp_state_copyout(regs, 0,
|
|
sizeof(struct user_rp_state), NULL,
|
|
&sc->rp);
|
|
|
|
/* OK, clear that cbuf flag in the old context, or our stored
|
|
* catch buffer will be restored when we go to call the signal
|
|
* handler. Also clear out the CBRP RA/RD pipe bit incase
|
|
* that is pending as well!
|
|
* Note that as we have already stored this context, these
|
|
* flags will get restored on sigreturn to their original
|
|
* state.
|
|
*/
|
|
regs->REG_FLAGS &= ~(TBICTX_XCBF_BIT | TBICTX_CBUF_BIT |
|
|
TBICTX_CBRP_BIT);
|
|
|
|
/* Clear out the LSM_STEP bits in case we are in the middle of
|
|
* and MSET/MGET.
|
|
*/
|
|
regs->ctx.Flags &= ~TXSTATUS_LSM_STEP_BITS;
|
|
|
|
err |= __put_user(mask, &sc->oldmask);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* Determine which stack to use..
|
|
*/
|
|
static void __user *get_sigframe(struct ksignal *ksig, unsigned long sp)
|
|
{
|
|
sp = sigsp(sp, ksig);
|
|
sp = (sp + 7) & ~7; /* 8byte align stack */
|
|
|
|
return (void __user *)sp;
|
|
}
|
|
|
|
static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct rt_sigframe __user *frame;
|
|
int err;
|
|
unsigned long code;
|
|
|
|
frame = get_sigframe(ksig, regs->REG_SP);
|
|
if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
|
|
return -EFAULT;
|
|
|
|
err = copy_siginfo_to_user(&frame->info, &ksig->info);
|
|
|
|
/* Create the ucontext. */
|
|
err |= __put_user(0, &frame->uc.uc_flags);
|
|
err |= __put_user(0, (unsigned long __user *)&frame->uc.uc_link);
|
|
err |= __save_altstack(&frame->uc.uc_stack, regs->REG_SP);
|
|
err |= setup_sigcontext(&frame->uc.uc_mcontext,
|
|
regs, set->sig[0]);
|
|
err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
/* Set up to return from userspace. */
|
|
|
|
/* MOV D1Re0 (D1.0), #__NR_rt_sigreturn */
|
|
code = 0x03000004 | (__NR_rt_sigreturn << 3);
|
|
err |= __put_user(code, (unsigned long __user *)(&frame->retcode[0]));
|
|
|
|
/* SWITCH #__METAG_SW_SYS */
|
|
code = __METAG_SW_ENCODING(SYS);
|
|
err |= __put_user(code, (unsigned long __user *)(&frame->retcode[1]));
|
|
|
|
if (err)
|
|
return -EFAULT;
|
|
|
|
/* Set up registers for signal handler */
|
|
regs->REG_RTP = (unsigned long) frame->retcode;
|
|
regs->REG_SP = (unsigned long) frame + sizeof(*frame);
|
|
regs->REG_ARG1 = ksig->sig;
|
|
regs->REG_ARG2 = (unsigned long) &frame->info;
|
|
regs->REG_ARG3 = (unsigned long) &frame->uc;
|
|
regs->REG_PC = (unsigned long) ksig->ka.sa.sa_handler;
|
|
|
|
pr_debug("SIG deliver (%s:%d): sp=%p pc=%08x pr=%08x\n",
|
|
current->comm, current->pid, frame, regs->REG_PC,
|
|
regs->REG_RTP);
|
|
|
|
/* Now pass size of 'new code' into sigtramp so we can do a more
|
|
* effective cache flush - directed rather than 'full flush'.
|
|
*/
|
|
flush_cache_sigtramp(regs->REG_RTP, sizeof(frame->retcode));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
|
|
{
|
|
sigset_t *oldset = sigmask_to_save();
|
|
int ret;
|
|
|
|
/* Set up the stack frame */
|
|
ret = setup_rt_frame(ksig, oldset, regs);
|
|
|
|
signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
|
|
}
|
|
|
|
/*
|
|
* Notes for Meta.
|
|
* We have moved from the old 2.4.9 SH way of using syscall_nr (in the stored
|
|
* context) to passing in the syscall flag on the stack.
|
|
* This is because having syscall_nr in our context does not fit with TBX, and
|
|
* corrupted the stack.
|
|
*/
|
|
static int do_signal(struct pt_regs *regs, int syscall)
|
|
{
|
|
unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
|
|
int restart = 0;
|
|
struct ksignal ksig;
|
|
|
|
/*
|
|
* By the end of rt_sigreturn the context describes the point that the
|
|
* signal was taken (which may happen to be just before a syscall if
|
|
* it's already been restarted). This should *never* be mistaken for a
|
|
* system call in need of restarting.
|
|
*/
|
|
if (syscall == __NR_rt_sigreturn)
|
|
syscall = -1;
|
|
|
|
/* Did we come from a system call? */
|
|
if (syscall >= 0) {
|
|
continue_addr = regs->REG_PC;
|
|
restart_addr = continue_addr - 4;
|
|
retval = regs->REG_RETVAL;
|
|
|
|
/*
|
|
* 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;
|
|
case -ERESTARTNOHAND:
|
|
case -ERESTARTSYS:
|
|
case -ERESTARTNOINTR:
|
|
++restart;
|
|
regs->REG_PC = restart_addr;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get the signal to deliver. When running under ptrace, at this point
|
|
* the debugger may change all our registers ...
|
|
*/
|
|
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->REG_PC != restart_addr)
|
|
restart = 0;
|
|
if (ksig.sig > 0) {
|
|
if (unlikely(restart)) {
|
|
if (retval == -ERESTARTNOHAND
|
|
|| retval == -ERESTART_RESTARTBLOCK
|
|
|| (retval == -ERESTARTSYS
|
|
&& !(ksig.ka.sa.sa_flags & SA_RESTART))) {
|
|
regs->REG_RETVAL = -EINTR;
|
|
regs->REG_PC = continue_addr;
|
|
}
|
|
}
|
|
|
|
/* Whee! Actually deliver the signal. */
|
|
handle_signal(&ksig, regs);
|
|
return 0;
|
|
}
|
|
|
|
/* Handlerless -ERESTART_RESTARTBLOCK re-enters via restart_syscall */
|
|
if (unlikely(restart < 0))
|
|
regs->REG_SYSCALL = __NR_restart_syscall;
|
|
|
|
/*
|
|
* If there's no signal to deliver, we just put the saved sigmask back.
|
|
*/
|
|
restore_saved_sigmask();
|
|
|
|
return restart;
|
|
}
|
|
|
|
int do_work_pending(struct pt_regs *regs, unsigned int thread_flags,
|
|
int syscall)
|
|
{
|
|
do {
|
|
if (likely(thread_flags & _TIF_NEED_RESCHED)) {
|
|
schedule();
|
|
} else {
|
|
if (unlikely(!user_mode(regs)))
|
|
return 0;
|
|
local_irq_enable();
|
|
if (thread_flags & _TIF_SIGPENDING) {
|
|
int restart = do_signal(regs, syscall);
|
|
if (unlikely(restart)) {
|
|
/*
|
|
* Restart without handlers.
|
|
* Deal with it without leaving
|
|
* the kernel space.
|
|
*/
|
|
return restart;
|
|
}
|
|
syscall = -1;
|
|
} else {
|
|
clear_thread_flag(TIF_NOTIFY_RESUME);
|
|
tracehook_notify_resume(regs);
|
|
}
|
|
}
|
|
local_irq_disable();
|
|
thread_flags = current_thread_info()->flags;
|
|
} while (thread_flags & _TIF_WORK_MASK);
|
|
return 0;
|
|
}
|