arch/c6x/kernel/signal.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  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>
  */

 #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(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);
 	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(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);
 	}
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* 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>
	*/

	#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(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);
	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(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);
	}
	}