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		4445229445
		
	
	
	
	
		
			
			Pass signr, sicode, and address into unhandled_exception as explicit parameters instead of members of struct siginfo. Then in unhandled exception generate and send the siginfo using force_sig_fault. This keeps the code simpler and less error prone. Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
		
			
				
	
	
		
			168 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			168 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Traps/Non-MMU Exception handling for ARC
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|  *
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|  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  *
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|  * vineetg: May 2011
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|  *  -user-space unaligned access emulation
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|  *
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|  * Rahul Trivedi: Codito Technologies 2004
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|  */
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| 
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| #include <linux/sched/signal.h>
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| #include <linux/kdebug.h>
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| #include <linux/uaccess.h>
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| #include <linux/ptrace.h>
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| #include <linux/kprobes.h>
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| #include <linux/kgdb.h>
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| #include <asm/setup.h>
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| #include <asm/unaligned.h>
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| #include <asm/kprobes.h>
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| 
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| void __init trap_init(void)
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| {
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| 	return;
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| }
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| 
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| void die(const char *str, struct pt_regs *regs, unsigned long address)
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| {
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| 	show_kernel_fault_diag(str, regs, address);
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| 
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| 	/* DEAD END */
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| 	__asm__("flag 1");
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| }
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| 
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| /*
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|  * Helper called for bulk of exceptions NOT needing specific handling
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|  *  -for user faults enqueues requested signal
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|  *  -for kernel, chk if due to copy_(to|from)_user, otherwise die()
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|  */
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| static noinline int
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| unhandled_exception(const char *str, struct pt_regs *regs,
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| 		    int signo, int si_code, void __user *addr)
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| {
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| 	if (user_mode(regs)) {
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| 		struct task_struct *tsk = current;
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| 
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| 		tsk->thread.fault_address = (__force unsigned int)addr;
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| 
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| 		force_sig_fault(signo, si_code, addr, tsk);
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| 
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| 	} else {
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| 		/* If not due to copy_(to|from)_user, we are doomed */
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| 		if (fixup_exception(regs))
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| 			return 0;
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| 
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| 		die(str, regs, (unsigned long)addr);
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| 	}
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| 
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| 	return 1;
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| }
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| 
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| #define DO_ERROR_INFO(signr, str, name, sicode) \
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| int name(unsigned long address, struct pt_regs *regs) \
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| {								\
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| 	return unhandled_exception(str, regs, signr, sicode,	\
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| 				   (void __user *)address);	\
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| }
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| 
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| /*
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|  * Entry points for exceptions NOT needing specific handling
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|  */
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| DO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC)
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| DO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC)
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| DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC)
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| DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", __weak do_memory_error, BUS_ADRERR)
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| DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT)
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| DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN)
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| DO_ERROR_INFO(SIGSEGV, "gcc generated __builtin_trap", do_trap5_error, 0)
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| 
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| /*
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|  * Entry Point for Misaligned Data access Exception, for emulating in software
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|  */
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| int do_misaligned_access(unsigned long address, struct pt_regs *regs,
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| 			 struct callee_regs *cregs)
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| {
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| 	/* If emulation not enabled, or failed, kill the task */
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| 	if (misaligned_fixup(address, regs, cregs) != 0)
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| 		return do_misaligned_error(address, regs);
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| 
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| 	return 0;
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| }
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| 
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| /*
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|  * Entry point for miscll errors such as Nested Exceptions
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|  *  -Duplicate TLB entry is handled seperately though
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|  */
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| void do_machine_check_fault(unsigned long address, struct pt_regs *regs)
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| {
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| 	die("Unhandled Machine Check Exception", regs, address);
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| }
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| 
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| 
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| /*
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|  * Entry point for traps induced by ARCompact TRAP_S <n> insn
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|  * This is same family as TRAP0/SWI insn (use the same vector).
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|  * The only difference being SWI insn take no operand, while TRAP_S does
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|  * which reflects in ECR Reg as 8 bit param.
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|  * Thus TRAP_S <n> can be used for specific purpose
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|  *  -1 used for software breakpointing (gdb)
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|  *  -2 used by kprobes
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|  *  -5 __builtin_trap() generated by gcc (2018.03 onwards) for toggle such as
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|  *     -fno-isolate-erroneous-paths-dereference
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|  */
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| void do_non_swi_trap(unsigned long address, struct pt_regs *regs)
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| {
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| 	unsigned int param = regs->ecr_param;
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| 
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| 	switch (param) {
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| 	case 1:
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| 		trap_is_brkpt(address, regs);
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| 		break;
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| 
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| 	case 2:
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| 		trap_is_kprobe(address, regs);
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| 		break;
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| 
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| 	case 3:
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| 	case 4:
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| 		kgdb_trap(regs);
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| 		break;
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| 
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| 	case 5:
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| 		do_trap5_error(address, regs);
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| 		break;
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| 	default:
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| 		break;
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| 	}
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| }
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| 
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| /*
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|  * Entry point for Instruction Error Exception
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|  *  -For a corner case, ARC kprobes implementation resorts to using
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|  *   this exception, hence the check
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|  */
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| void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs)
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| {
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| 	int rc;
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| 
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| 	/* Check if this exception is caused by kprobes */
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| 	rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL);
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| 	if (rc == NOTIFY_STOP)
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| 		return;
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| 
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| 	insterror_is_error(address, regs);
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| }
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| 
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| /*
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|  * abort() call generated by older gcc for __builtin_trap()
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|  */
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| void abort(void)
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| {
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| 	__asm__ __volatile__("trap_s  5\n");
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| }
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