[PARISC] factor syscall_restart code out of do_signal (2b163b71) · Commits · e / devices / android_kernel_teracube_2e

arch/parisc/kernel/signal.c

+98 −79

Original line number	Diff line number	Diff line
		@@ -471,6 +471,97 @@ handle_signal(unsigned long sig, siginfo_t info, struct k_sigaction ka,
		return 1;
		}

		static inline void
		syscall_restart(struct pt_regs regs, struct k_sigaction ka)
		{
		/* Check the return code */
		switch (regs->gr[28]) {
		case -ERESTART_RESTARTBLOCK:
		current_thread_info()->restart_block.fn =
		do_no_restart_syscall;
		case -ERESTARTNOHAND:
		DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
		regs->gr[28] = -EINTR;
		break;

		case -ERESTARTSYS:
		if (!(ka->sa.sa_flags & SA_RESTART)) {
		DBG(1,"ERESTARTSYS: putting -EINTR\n");
		regs->gr[28] = -EINTR;
		break;
		}
		/* fallthrough */
		case -ERESTARTNOINTR:
		/* A syscall is just a branch, so all
		* we have to do is fiddle the return pointer.
		*/
		regs->gr[31] -= 8; /* delayed branching */
		/* Preserve original r28. */
		regs->gr[28] = regs->orig_r28;
		break;
		}
		}

		static inline void
		insert_restart_trampoline(struct pt_regs *regs)
		{
		switch(regs->gr[28]) {
		case -ERESTART_RESTARTBLOCK: {
		/* Restart the system call - no handlers present */
		unsigned int usp = (unsigned int )regs->gr[30];

		/* Setup a trampoline to restart the syscall
		* with __NR_restart_syscall
		*
		* 0: <return address (orig r31)>
		* 4: <2nd half for 64-bit>
		* 8: ldw 0(%sp), %r31
		* 12: be 0x100(%sr2, %r0)
		* 16: ldi __NR_restart_syscall, %r20
		*/
		#ifdef CONFIG_64BIT
		put_user(regs->gr[31] >> 32, &usp[0]);
		put_user(regs->gr[31] & 0xffffffff, &usp[1]);
		put_user(0x0fc010df, &usp[2]);
		#else
		put_user(regs->gr[31], &usp[0]);
		put_user(0x0fc0109f, &usp[2]);
		#endif
		put_user(0xe0008200, &usp[3]);
		put_user(0x34140000, &usp[4]);

		/* Stack is 64-byte aligned, and we only need
		* to flush 1 cache line.
		* Flushing one cacheline is cheap.
		* "sync" on bigger (> 4 way) boxes is not.
		*/
		flush_icache_range(regs->gr[30], regs->gr[30] + 4);

		regs->gr[31] = regs->gr[30] + 8;
		/* Preserve original r28. */
		regs->gr[28] = regs->orig_r28;

		return;
		}
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR: {
		/* Hooray for delayed branching. We don't
		* have to restore %r20 (the system call
		* number) because it gets loaded in the delay
		* slot of the branch external instruction.
		*/
		regs->gr[31] -= 8;
		/* Preserve original r28. */
		regs->gr[28] = regs->orig_r28;

		return;
		}
		default:
		break;
		}
		}

		/*
		* Note that 'init' is a special process: it doesn't get signals it doesn't
		* want to handle. Thus you cannot kill init even with a SIGKILL even by
		@@ -482,7 +573,6 @@ handle_signal(unsigned long sig, siginfo_t info, struct k_sigaction ka,
		* registers). As noted below, the syscall number gets restored for
		* us due to the magic of delayed branching.
		*/

		asmlinkage void
		do_signal(struct pt_regs *regs, long in_syscall)
		{
		@@ -518,36 +608,14 @@ do_signal(struct pt_regs *regs, long in_syscall)
		break;

		/* Restart a system call if necessary. */
		if (in_syscall) {
		/* Check the return code */
		switch (regs->gr[28]) {
		case -ERESTART_RESTARTBLOCK:
		current_thread_info()->restart_block.fn = do_no_restart_syscall;
		case -ERESTARTNOHAND:
		DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
		regs->gr[28] = -EINTR;
		break;
		if (in_syscall)
		syscall_restart(regs, &ka);

		case -ERESTARTSYS:
		if (!(ka.sa.sa_flags & SA_RESTART)) {
		DBG(1,"ERESTARTSYS: putting -EINTR\n");
		regs->gr[28] = -EINTR;
		break;
		}
		/* fallthrough */
		case -ERESTARTNOINTR:
		/* A syscall is just a branch, so all
		we have to do is fiddle the return pointer. */
		regs->gr[31] -= 8; /* delayed branching */
		/* Preserve original r28. */
		regs->gr[28] = regs->orig_r28;
		break;
		}
		}
		/* Whee! Actually deliver the signal. If the
		delivery failed, we need to continue to iterate in
		this loop so we can deliver the SIGSEGV... */
		if (handle_signal(signr, &info, &ka, oldset, regs, in_syscall)) {
		if (handle_signal(signr, &info, &ka, oldset,
		regs, in_syscall)) {
		DBG(1,KERN_DEBUG "do_signal: Exit (success), regs->gr[28] = %ld\n",
		regs->gr[28]);
		if (test_thread_flag(TIF_RESTORE_SIGMASK))
		@@ -558,57 +626,8 @@ do_signal(struct pt_regs *regs, long in_syscall)
		/* end of while(1) looping forever if we can't force a signal */

		/* Did we come from a system call? */
		if (in_syscall) {
		/* Restart the system call - no handlers present */
		if (regs->gr[28] == -ERESTART_RESTARTBLOCK) {
		unsigned int usp = (unsigned int )regs->gr[30];

		/* Setup a trampoline to restart the syscall
		* with __NR_restart_syscall
		*
		* 0: <return address (orig r31)>
		* 4: <2nd half for 64-bit>
		* 8: ldw 0(%sp), %r31
		* 12: be 0x100(%sr2, %r0)
		* 16: ldi __NR_restart_syscall, %r20
		*/
		#ifndef __LP64__
		put_user(regs->gr[31], &usp[0]);
		put_user(0x0fc0109f, &usp[2]);
		#else
		put_user(regs->gr[31] >> 32, &usp[0]);
		put_user(regs->gr[31] & 0xffffffff, &usp[1]);
		put_user(0x0fc010df, &usp[2]);
		#endif
		put_user(0xe0008200, &usp[3]);
		put_user(0x34140000, &usp[4]);

		/* Stack is 64-byte aligned, and we only need
		* to flush 1 cache line.
		* Flushing one cacheline is cheap.
		* "sync" on bigger (> 4 way) boxes is not.
		*/
		asm("fdc %%r0(%%sr3, %0)\n"
		"sync\n"
		"fic %%r0(%%sr3, %0)\n"
		"sync\n"
		: : "r"(regs->gr[30]));

		regs->gr[31] = regs->gr[30] + 8;
		/* Preserve original r28. */
		regs->gr[28] = regs->orig_r28;
		} else if (regs->gr[28] == -ERESTARTNOHAND \|\|
		regs->gr[28] == -ERESTARTSYS \|\|
		regs->gr[28] == -ERESTARTNOINTR) {
		/* Hooray for delayed branching. We don't
		have to restore %r20 (the system call
		number) because it gets loaded in the delay
		slot of the branch external instruction. */
		regs->gr[31] -= 8;
		/* Preserve original r28. */
		regs->gr[28] = regs->orig_r28;
		}
		}
		if (in_syscall)
		insert_restart_trampoline(regs);

		DBG(1,"do_signal: Exit (not delivered), regs->gr[28] = %ld\n",
		regs->gr[28]);