1 files changed, 208 insertions, 127 deletions

diff --git a/arch/sparc/kernel/traps_64.c b/arch/sparc/kernel/traps_64.c
index ad31af1dd726..28cb0d66ab40 100644
--- a/arch/sparc/kernel/traps_64.c
+++ b/arch/sparc/kernel/traps_64.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* arch/sparc64/kernel/traps.c
  *
  * Copyright (C) 1995,1997,2008,2009,2012 David S. Miller (davem@davemloft.net)
@@ -8,6 +9,7 @@
  * I like traps on v9, :))))
  */
 
+#include <linux/cpu.h>
 #include <linux/extable.h>
 #include <linux/sched/mm.h>
 #include <linux/sched/debug.h>
@@ -17,6 +19,7 @@
 #include <linux/smp.h>
 #include <linux/mm.h>
 #include <linux/init.h>
+#include <linux/kallsyms.h>
 #include <linux/kdebug.h>
 #include <linux/ftrace.h>
 #include <linux/reboot.h>
@@ -28,7 +31,6 @@
 #include <asm/ptrace.h>
 #include <asm/oplib.h>
 #include <asm/page.h>
-#include <asm/pgtable.h>
 #include <asm/unistd.h>
 #include <linux/uaccess.h>
 #include <asm/fpumacro.h>
@@ -87,7 +89,6 @@ static void dump_tl1_traplog(struct tl1_traplog *p)
 void bad_trap(struct pt_regs *regs, long lvl)
 {
 	char buffer[36];
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "bad trap", regs,
 		       0, lvl, SIGTRAP) == NOTIFY_STOP)
@@ -107,12 +108,8 @@ void bad_trap(struct pt_regs *regs, long lvl)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGILL;
-	info.si_errno = 0;
-	info.si_code = ILL_ILLTRP;
-	info.si_addr = (void __user *)regs->tpc;
-	info.si_trapno = lvl;
-	force_sig_info(SIGILL, &info, current);
+	force_sig_fault_trapno(SIGILL, ILL_ILLTRP,
+			       (void __user *)regs->tpc, lvl);
 }
 
 void bad_trap_tl1(struct pt_regs *regs, long lvl)
@@ -191,7 +188,6 @@ EXPORT_SYMBOL_GPL(unregister_dimm_printer);
 void spitfire_insn_access_exception(struct pt_regs *regs, unsigned long sfsr, unsigned long sfar)
 {
 	enum ctx_state prev_state = exception_enter();
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "instruction access exception", regs,
 		       0, 0x8, SIGTRAP) == NOTIFY_STOP)
@@ -206,12 +202,7 @@ void spitfire_insn_access_exception(struct pt_regs *regs, unsigned long sfsr, un
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_code = SEGV_MAPERR;
-	info.si_addr = (void __user *)regs->tpc;
-	info.si_trapno = 0;
-	force_sig_info(SIGSEGV, &info, current);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }
@@ -230,7 +221,6 @@ void sun4v_insn_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 {
 	unsigned short type = (type_ctx >> 16);
 	unsigned short ctx  = (type_ctx & 0xffff);
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "instruction access exception", regs,
 		       0, 0x8, SIGTRAP) == NOTIFY_STOP)
@@ -247,12 +237,7 @@ void sun4v_insn_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_code = SEGV_MAPERR;
-	info.si_addr = (void __user *) addr;
-	info.si_trapno = 0;
-	force_sig_info(SIGSEGV, &info, current);
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *) addr);
 }
 
 void sun4v_insn_access_exception_tl1(struct pt_regs *regs, unsigned long addr, unsigned long type_ctx)
@@ -265,10 +250,47 @@ void sun4v_insn_access_exception_tl1(struct pt_regs *regs, unsigned long addr, u
 	sun4v_insn_access_exception(regs, addr, type_ctx);
 }
 
+static bool is_no_fault_exception(struct pt_regs *regs)
+{
+	unsigned char asi;
+	u32 insn;
+
+	if (get_user(insn, (u32 __user *)regs->tpc) == -EFAULT)
+		return false;
+
+	/*
+	 * Must do a little instruction decoding here in order to
+	 * decide on a course of action. The bits of interest are:
+	 *  insn[31:30] = op, where 3 indicates the load/store group
+	 *  insn[24:19] = op3, which identifies individual opcodes
+	 *  insn[13] indicates an immediate offset
+	 *  op3[4]=1 identifies alternate space instructions
+	 *  op3[5:4]=3 identifies floating point instructions
+	 *  op3[2]=1 identifies stores
+	 * See "Opcode Maps" in the appendix of any Sparc V9
+	 * architecture spec for full details.
+	 */
+	if ((insn & 0xc0800000) == 0xc0800000) {    /* op=3, op3[4]=1   */
+		if (insn & 0x2000)		    /* immediate offset */
+			asi = (regs->tstate >> 24); /* saved %asi       */
+		else
+			asi = (insn >> 5);	    /* immediate asi    */
+		if ((asi & 0xf6) == ASI_PNF) {
+			if (insn & 0x200000)        /* op3[2], stores   */
+				return false;
+			if (insn & 0x1000000)       /* op3[5:4]=3 (fp)  */
+				handle_ldf_stq(insn, regs);
+			else
+				handle_ld_nf(insn, regs);
+			return true;
+		}
+	}
+	return false;
+}
+
 void spitfire_data_access_exception(struct pt_regs *regs, unsigned long sfsr, unsigned long sfar)
 {
 	enum ctx_state prev_state = exception_enter();
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "data access exception", regs,
 		       0, 0x30, SIGTRAP) == NOTIFY_STOP)
@@ -296,12 +318,10 @@ void spitfire_data_access_exception(struct pt_regs *regs, unsigned long sfsr, un
 		die_if_kernel("Dax", regs);
 	}
 
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_code = SEGV_MAPERR;
-	info.si_addr = (void __user *)sfar;
-	info.si_trapno = 0;
-	force_sig_info(SIGSEGV, &info, current);
+	if (is_no_fault_exception(regs))
+		return;
+
+	force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)sfar);
 out:
 	exception_exit(prev_state);
 }
@@ -320,7 +340,6 @@ void sun4v_data_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 {
 	unsigned short type = (type_ctx >> 16);
 	unsigned short ctx  = (type_ctx & 0xffff);
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "data access exception", regs,
 		       0, 0x8, SIGTRAP) == NOTIFY_STOP)
@@ -352,12 +371,29 @@ void sun4v_data_access_exception(struct pt_regs *regs, unsigned long addr, unsig
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_code = SEGV_MAPERR;
-	info.si_addr = (void __user *) addr;
-	info.si_trapno = 0;
-	force_sig_info(SIGSEGV, &info, current);
+	if (is_no_fault_exception(regs))
+		return;
+
+	/* MCD (Memory Corruption Detection) disabled trap (TT=0x19) in HV
+	 * is vectored thorugh data access exception trap with fault type
+	 * set to HV_FAULT_TYPE_MCD_DIS. Check for MCD disabled trap.
+	 * Accessing an address with invalid ASI for the address, for
+	 * example setting an ADI tag on an address with ASI_MCD_PRIMARY
+	 * when TTE.mcd is not set for the VA, is also vectored into
+	 * kerbel by HV as data access exception with fault type set to
+	 * HV_FAULT_TYPE_INV_ASI.
+	 */
+	switch (type) {
+	case HV_FAULT_TYPE_INV_ASI:
+		force_sig_fault(SIGILL, ILL_ILLADR, (void __user *)addr);
+		break;
+	case HV_FAULT_TYPE_MCD_DIS:
+		force_sig_fault(SIGSEGV, SEGV_ACCADI, (void __user *)addr);
+		break;
+	default:
+		force_sig_fault(SIGSEGV, SEGV_MAPERR, (void __user *)addr);
+		break;
+	}
 }
 
 void sun4v_data_access_exception_tl1(struct pt_regs *regs, unsigned long addr, unsigned long type_ctx)
@@ -498,8 +534,6 @@ static void spitfire_cee_log(unsigned long afsr, unsigned long afar, unsigned lo
 
 static void spitfire_ue_log(unsigned long afsr, unsigned long afar, unsigned long udbh, unsigned long udbl, unsigned long tt, int tl1, struct pt_regs *regs)
 {
-	siginfo_t info;
-
 	printk(KERN_WARNING "CPU[%d]: Uncorrectable Error AFSR[%lx] "
 	       "AFAR[%lx] UDBL[%lx] UDBH[%ld] TT[%lx] TL>1[%d]\n",
 	       smp_processor_id(), afsr, afar, udbl, udbh, tt, tl1);
@@ -534,12 +568,7 @@ static void spitfire_ue_log(unsigned long afsr, unsigned long afar, unsigned lon
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGBUS;
-	info.si_errno = 0;
-	info.si_code = BUS_OBJERR;
-	info.si_addr = (void *)0;
-	info.si_trapno = 0;
-	force_sig_info(SIGBUS, &info, current);
+	force_sig_fault(SIGBUS, BUS_OBJERR, (void *)0);
 }
 
 void spitfire_access_error(struct pt_regs *regs, unsigned long status_encoded, unsigned long afar)
@@ -869,7 +898,7 @@ void __init cheetah_ecache_flush_init(void)
 
 	/* Now allocate error trap reporting scoreboard. */
 	sz = NR_CPUS * (2 * sizeof(struct cheetah_err_info));
-	for (order = 0; order < MAX_ORDER; order++) {
+	for (order = 0; order < NR_PAGE_ORDERS; order++) {
 		if ((PAGE_SIZE << order) >= sz)
 			break;
 	}
@@ -1802,6 +1831,7 @@ struct sun4v_error_entry {
 #define SUN4V_ERR_ATTRS_ASI		0x00000080
 #define SUN4V_ERR_ATTRS_PRIV_REG	0x00000100
 #define SUN4V_ERR_ATTRS_SPSTATE_MSK	0x00000600
+#define SUN4V_ERR_ATTRS_MCD		0x00000800
 #define SUN4V_ERR_ATTRS_SPSTATE_SHFT	9
 #define SUN4V_ERR_ATTRS_MODE_MSK	0x03000000
 #define SUN4V_ERR_ATTRS_MODE_SHFT	24
@@ -1999,6 +2029,49 @@ static void sun4v_log_error(struct pt_regs *regs, struct sun4v_error_entry *ent,
 	}
 }
 
+/* Handle memory corruption detected error which is vectored in
+ * through resumable error trap.
+ */
+static void do_mcd_err(struct pt_regs *regs, struct sun4v_error_entry ent)
+{
+	if (notify_die(DIE_TRAP, "MCD error", regs, 0, 0x34,
+		       SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	if (regs->tstate & TSTATE_PRIV) {
+		/* MCD exception could happen because the task was
+		 * running a system call with MCD enabled and passed a
+		 * non-versioned pointer or pointer with bad version
+		 * tag to the system call. In such cases, hypervisor
+		 * places the address of offending instruction in the
+		 * resumable error report. This is a deferred error,
+		 * so the read/write that caused the trap was potentially
+		 * retired long time back and we may have no choice
+		 * but to send SIGSEGV to the process.
+		 */
+		const struct exception_table_entry *entry;
+
+		entry = search_exception_tables(regs->tpc);
+		if (entry) {
+			/* Looks like a bad syscall parameter */
+#ifdef DEBUG_EXCEPTIONS
+			pr_emerg("Exception: PC<%016lx> faddr<UNKNOWN>\n",
+				 regs->tpc);
+			pr_emerg("EX_TABLE: insn<%016lx> fixup<%016lx>\n",
+				 ent.err_raddr, entry->fixup);
+#endif
+			regs->tpc = entry->fixup;
+			regs->tnpc = regs->tpc + 4;
+			return;
+		}
+	}
+
+	/* Send SIGSEGV to the userspace process with the right signal
+	 * code
+	 */
+	force_sig_fault(SIGSEGV, SEGV_ADIDERR, (void __user *)ent.err_raddr);
+}
+
 /* We run with %pil set to PIL_NORMAL_MAX and PSTATE_IE enabled in %pstate.
  * Log the event and clear the first word of the entry.
  */
@@ -2036,6 +2109,14 @@ void sun4v_resum_error(struct pt_regs *regs, unsigned long offset)
 		goto out;
 	}
 
+	/* If this is a memory corruption detected error vectored in
+	 * by HV through resumable error trap, call the handler
+	 */
+	if (local_copy.err_attrs & SUN4V_ERR_ATTRS_MCD) {
+		do_mcd_err(regs, local_copy);
+		return;
+	}
+
 	sun4v_log_error(regs, &local_copy, cpu,
 			KERN_ERR "RESUMABLE ERROR",
 			&sun4v_resum_oflow_cnt);
@@ -2069,14 +2150,13 @@ static unsigned long sun4v_get_vaddr(struct pt_regs *regs)
 /* Attempt to handle non-resumable errors generated from userspace.
  * Returns true if the signal was handled, false otherwise.
  */
-bool sun4v_nonresum_error_user_handled(struct pt_regs *regs,
-				  struct sun4v_error_entry *ent) {
-
+static bool sun4v_nonresum_error_user_handled(struct pt_regs *regs,
+					      struct sun4v_error_entry *ent)
+{
 	unsigned int attrs = ent->err_attrs;
 
 	if (attrs & SUN4V_ERR_ATTRS_MEMORY) {
 		unsigned long addr = ent->err_raddr;
-		siginfo_t info;
 
 		if (addr == ~(u64)0) {
 			/* This seems highly unlikely to ever occur */
@@ -2097,21 +2177,13 @@ bool sun4v_nonresum_error_user_handled(struct pt_regs *regs,
 				addr += PAGE_SIZE;
 			}
 		}
-		info.si_signo = SIGKILL;
-		info.si_errno = 0;
-		info.si_trapno = 0;
-		force_sig_info(info.si_signo, &info, current);
+		force_sig(SIGKILL);
 
 		return true;
 	}
 	if (attrs & SUN4V_ERR_ATTRS_PIO) {
-		siginfo_t info;
-
-		info.si_signo = SIGBUS;
-		info.si_code = BUS_ADRERR;
-		info.si_addr = (void __user *)sun4v_get_vaddr(regs);
-		force_sig_info(info.si_signo, &info, current);
-
+		force_sig_fault(SIGBUS, BUS_ADRERR,
+				(void __user *)sun4v_get_vaddr(regs));
 		return true;
 	}
 
@@ -2248,30 +2320,26 @@ static void do_fpe_common(struct pt_regs *regs)
 		regs->tnpc += 4;
 	} else {
 		unsigned long fsr = current_thread_info()->xfsr[0];
-		siginfo_t info;
+		int code;
 
 		if (test_thread_flag(TIF_32BIT)) {
 			regs->tpc &= 0xffffffff;
 			regs->tnpc &= 0xffffffff;
 		}
-		info.si_signo = SIGFPE;
-		info.si_errno = 0;
-		info.si_addr = (void __user *)regs->tpc;
-		info.si_trapno = 0;
-		info.si_code = __SI_FAULT;
+		code = FPE_FLTUNK;
 		if ((fsr & 0x1c000) == (1 << 14)) {
 			if (fsr & 0x10)
-				info.si_code = FPE_FLTINV;
+				code = FPE_FLTINV;
 			else if (fsr & 0x08)
-				info.si_code = FPE_FLTOVF;
+				code = FPE_FLTOVF;
 			else if (fsr & 0x04)
-				info.si_code = FPE_FLTUND;
+				code = FPE_FLTUND;
 			else if (fsr & 0x02)
-				info.si_code = FPE_FLTDIV;
+				code = FPE_FLTDIV;
 			else if (fsr & 0x01)
-				info.si_code = FPE_FLTRES;
+				code = FPE_FLTRES;
 		}
-		force_sig_info(SIGFPE, &info, current);
+		force_sig_fault(SIGFPE, code, (void __user *)regs->tpc);
 	}
 }
 
@@ -2314,7 +2382,6 @@ out:
 void do_tof(struct pt_regs *regs)
 {
 	enum ctx_state prev_state = exception_enter();
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "tagged arithmetic overflow", regs,
 		       0, 0x26, SIGEMT) == NOTIFY_STOP)
@@ -2326,12 +2393,7 @@ void do_tof(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGEMT;
-	info.si_errno = 0;
-	info.si_code = EMT_TAGOVF;
-	info.si_addr = (void __user *)regs->tpc;
-	info.si_trapno = 0;
-	force_sig_info(SIGEMT, &info, current);
+	force_sig_fault(SIGEMT, EMT_TAGOVF, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }
@@ -2339,7 +2401,6 @@ out:
 void do_div0(struct pt_regs *regs)
 {
 	enum ctx_state prev_state = exception_enter();
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "integer division by zero", regs,
 		       0, 0x28, SIGFPE) == NOTIFY_STOP)
@@ -2351,12 +2412,7 @@ void do_div0(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGFPE;
-	info.si_errno = 0;
-	info.si_code = FPE_INTDIV;
-	info.si_addr = (void __user *)regs->tpc;
-	info.si_trapno = 0;
-	force_sig_info(SIGFPE, &info, current);
+	force_sig_fault(SIGFPE, FPE_INTDIV, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }
@@ -2391,7 +2447,7 @@ static void user_instruction_dump(unsigned int __user *pc)
 	printk("\n");
 }
 
-void show_stack(struct task_struct *tsk, unsigned long *_ksp)
+void show_stack(struct task_struct *tsk, unsigned long *_ksp, const char *loglvl)
 {
 	unsigned long fp, ksp;
 	struct thread_info *tp;
@@ -2415,7 +2471,7 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)
 
 	fp = ksp + STACK_BIAS;
 
-	printk("Call Trace:\n");
+	printk("%sCall Trace:\n", loglvl);
 	do {
 		struct sparc_stackf *sf;
 		struct pt_regs *regs;
@@ -2436,13 +2492,14 @@ void show_stack(struct task_struct *tsk, unsigned long *_ksp)
 			fp = (unsigned long)sf->fp + STACK_BIAS;
 		}
 
-		printk(" [%016lx] %pS\n", pc, (void *) pc);
+		print_ip_sym(loglvl, pc);
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 		if ((pc + 8UL) == (unsigned long) &return_to_handler) {
-			int index = tsk->curr_ret_stack;
-			if (tsk->ret_stack && index >= graph) {
-				pc = tsk->ret_stack[index - graph].ret;
-				printk(" [%016lx] %pS\n", pc, (void *) pc);
+			struct ftrace_ret_stack *ret_stack;
+			ret_stack = ftrace_graph_get_ret_stack(tsk, graph);
+			if (ret_stack) {
+				pc = ret_stack->ret;
+				print_ip_sym(loglvl, pc);
 				graph++;
 			}
 		}
@@ -2503,9 +2560,7 @@ void __noreturn die_if_kernel(char *str, struct pt_regs *regs)
 	}
 	if (panic_on_oops)
 		panic("Fatal exception");
-	if (regs->tstate & TSTATE_PRIV)
-		do_exit(SIGKILL);
-	do_exit(SIGSEGV);
+	make_task_dead((regs->tstate & TSTATE_PRIV)? SIGKILL : SIGSEGV);
 }
 EXPORT_SYMBOL(die_if_kernel);
 
@@ -2518,7 +2573,6 @@ void do_illegal_instruction(struct pt_regs *regs)
 	unsigned long pc = regs->tpc;
 	unsigned long tstate = regs->tstate;
 	u32 insn;
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "illegal instruction", regs,
 		       0, 0x10, SIGILL) == NOTIFY_STOP)
@@ -2552,12 +2606,7 @@ void do_illegal_instruction(struct pt_regs *regs)
 			}
 		}
 	}
-	info.si_signo = SIGILL;
-	info.si_errno = 0;
-	info.si_code = ILL_ILLOPC;
-	info.si_addr = (void __user *)pc;
-	info.si_trapno = 0;
-	force_sig_info(SIGILL, &info, current);
+	force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)pc);
 out:
 	exception_exit(prev_state);
 }
@@ -2565,7 +2614,6 @@ out:
 void mem_address_unaligned(struct pt_regs *regs, unsigned long sfar, unsigned long sfsr)
 {
 	enum ctx_state prev_state = exception_enter();
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "memory address unaligned", regs,
 		       0, 0x34, SIGSEGV) == NOTIFY_STOP)
@@ -2575,20 +2623,16 @@ void mem_address_unaligned(struct pt_regs *regs, unsigned long sfar, unsigned lo
 		kernel_unaligned_trap(regs, *((unsigned int *)regs->tpc));
 		goto out;
 	}
-	info.si_signo = SIGBUS;
-	info.si_errno = 0;
-	info.si_code = BUS_ADRALN;
-	info.si_addr = (void __user *)sfar;
-	info.si_trapno = 0;
-	force_sig_info(SIGBUS, &info, current);
+	if (is_no_fault_exception(regs))
+		return;
+
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)sfar);
 out:
 	exception_exit(prev_state);
 }
 
 void sun4v_do_mna(struct pt_regs *regs, unsigned long addr, unsigned long type_ctx)
 {
-	siginfo_t info;
-
 	if (notify_die(DIE_TRAP, "memory address unaligned", regs,
 		       0, 0x34, SIGSEGV) == NOTIFY_STOP)
 		return;
@@ -2597,18 +2641,62 @@ void sun4v_do_mna(struct pt_regs *regs, unsigned long addr, unsigned long type_c
 		kernel_unaligned_trap(regs, *((unsigned int *)regs->tpc));
 		return;
 	}
-	info.si_signo = SIGBUS;
-	info.si_errno = 0;
-	info.si_code = BUS_ADRALN;
-	info.si_addr = (void __user *) addr;
-	info.si_trapno = 0;
-	force_sig_info(SIGBUS, &info, current);
+	if (is_no_fault_exception(regs))
+		return;
+
+	force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *) addr);
+}
+
+/* sun4v_mem_corrupt_detect_precise() - Handle precise exception on an ADI
+ * tag mismatch.
+ *
+ * ADI version tag mismatch on a load from memory always results in a
+ * precise exception. Tag mismatch on a store to memory will result in
+ * precise exception if MCDPER or PMCDPER is set to 1.
+ */
+void sun4v_mem_corrupt_detect_precise(struct pt_regs *regs, unsigned long addr,
+				      unsigned long context)
+{
+	if (notify_die(DIE_TRAP, "memory corruption precise exception", regs,
+		       0, 0x8, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	if (regs->tstate & TSTATE_PRIV) {
+		/* MCD exception could happen because the task was running
+		 * a system call with MCD enabled and passed a non-versioned
+		 * pointer or pointer with bad version tag to  the system
+		 * call.
+		 */
+		const struct exception_table_entry *entry;
+
+		entry = search_exception_tables(regs->tpc);
+		if (entry) {
+			/* Looks like a bad syscall parameter */
+#ifdef DEBUG_EXCEPTIONS
+			pr_emerg("Exception: PC<%016lx> faddr<UNKNOWN>\n",
+				 regs->tpc);
+			pr_emerg("EX_TABLE: insn<%016lx> fixup<%016lx>\n",
+				 regs->tpc, entry->fixup);
+#endif
+			regs->tpc = entry->fixup;
+			regs->tnpc = regs->tpc + 4;
+			return;
+		}
+		pr_emerg("%s: ADDR[%016lx] CTX[%lx], going.\n",
+			 __func__, addr, context);
+		die_if_kernel("MCD precise", regs);
+	}
+
+	if (test_thread_flag(TIF_32BIT)) {
+		regs->tpc &= 0xffffffff;
+		regs->tnpc &= 0xffffffff;
+	}
+	force_sig_fault(SIGSEGV, SEGV_ADIPERR, (void __user *)addr);
 }
 
 void do_privop(struct pt_regs *regs)
 {
 	enum ctx_state prev_state = exception_enter();
-	siginfo_t info;
 
 	if (notify_die(DIE_TRAP, "privileged operation", regs,
 		       0, 0x11, SIGILL) == NOTIFY_STOP)
@@ -2618,12 +2706,7 @@ void do_privop(struct pt_regs *regs)
 		regs->tpc &= 0xffffffff;
 		regs->tnpc &= 0xffffffff;
 	}
-	info.si_signo = SIGILL;
-	info.si_errno = 0;
-	info.si_code = ILL_PRVOPC;
-	info.si_addr = (void __user *)regs->tpc;
-	info.si_trapno = 0;
-	force_sig_info(SIGILL, &info, current);
+	force_sig_fault(SIGILL, ILL_PRVOPC, (void __user *)regs->tpc);
 out:
 	exception_exit(prev_state);
 }
@@ -2775,8 +2858,6 @@ void __init trap_init(void)
 		     TI_PRE_COUNT != offsetof(struct thread_info,
 					      preempt_count) ||
 		     TI_NEW_CHILD != offsetof(struct thread_info, new_child) ||
-		     TI_CURRENT_DS != offsetof(struct thread_info,
-						current_ds) ||
 		     TI_KUNA_REGS != offsetof(struct thread_info,
 					      kern_una_regs) ||
 		     TI_KUNA_INSN != offsetof(struct thread_info,