Merge branch fixes into next

Merge our fixes branch to bring in commits that are prerequisities for further
development or would cause conflicts.

1 files changed, 36 insertions, 20 deletions

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index a52c786c2aec..fe3f720c9cd6 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1514,23 +1514,11 @@ static void do_program_check(struct pt_regs *regs)
 			return;
 		}
 
-		if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE) && user_mode(regs)) {
-			ppc_inst_t insn;
-
-			if (get_user_instr(insn, (void __user *)regs->nip)) {
-				_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
-				return;
-			}
-
-			if (ppc_inst_primary_opcode(insn) == 31 &&
-			    get_xop(ppc_inst_val(insn)) == OP_31_XOP_HASHCHK) {
-				_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
-				return;
-			}
+		/* User mode considers other cases after enabling IRQs */
+		if (!user_mode(regs)) {
+			_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
+			return;
 		}
-
-		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
-		return;
 	}
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 	if (reason & REASON_TM) {
@@ -1563,16 +1551,44 @@ static void do_program_check(struct pt_regs *regs)
 
 	/*
 	 * If we took the program check in the kernel skip down to sending a
-	 * SIGILL. The subsequent cases all relate to emulating instructions
-	 * which we should only do for userspace. We also do not want to enable
-	 * interrupts for kernel faults because that might lead to further
-	 * faults, and loose the context of the original exception.
+	 * SIGILL. The subsequent cases all relate to user space, such as
+	 * emulating instructions which we should only do for user space. We
+	 * also do not want to enable interrupts for kernel faults because that
+	 * might lead to further faults, and loose the context of the original
+	 * exception.
 	 */
 	if (!user_mode(regs))
 		goto sigill;
 
 	interrupt_cond_local_irq_enable(regs);
 
+	/*
+	 * (reason & REASON_TRAP) is mostly handled before enabling IRQs,
+	 * except get_user_instr() can sleep so we cannot reliably inspect the
+	 * current instruction in that context. Now that we know we are
+	 * handling a user space trap and can sleep, we can check if the trap
+	 * was a hashchk failure.
+	 */
+	if (reason & REASON_TRAP) {
+		if (cpu_has_feature(CPU_FTR_DEXCR_NPHIE)) {
+			ppc_inst_t insn;
+
+			if (get_user_instr(insn, (void __user *)regs->nip)) {
+				_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
+				return;
+			}
+
+			if (ppc_inst_primary_opcode(insn) == 31 &&
+			    get_xop(ppc_inst_val(insn)) == OP_31_XOP_HASHCHK) {
+				_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
+				return;
+			}
+		}
+
+		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
+		return;
+	}
+
 	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
 	 * but there seems to be a hardware bug on the 405GP (RevD)
 	 * that means ESR is sometimes set incorrectly - either to