powerpc fixes for 5.6 #4

One fix for a recent regression to our breakpoint/watchpoint code.
 
 Another fix for our KUAP support, this time a missing annotation in a rarely
 used path in signal handling.
 
 A fix for our handling of a CPU feature that effects the PMU, when booting
 guests in some configurations.
 
 A minor fix to our linker script to explicitly include the .BTF section.
 
 Thanks to:
   Christophe Leroy, Desnes A. Nunes do Rosario, Leonardo Bras, Naveen N. Rao,
   Ravi Bangoria, Stefan Berger.
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Merge tag 'powerpc-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
 "Some more powerpc fixes for 5.6:

   - One fix for a recent regression to our breakpoint/watchpoint code.

   - Another fix for our KUAP support, this time a missing annotation in
     a rarely used path in signal handling.

   - A fix for our handling of a CPU feature that effects the PMU, when
     booting guests in some configurations.

   - A minor fix to our linker script to explicitly include the .BTF
     section.

  Thanks to: Christophe Leroy, Desnes A. Nunes do Rosario, Leonardo
  Bras, Naveen N. Rao, Ravi Bangoria, Stefan Berger"

* tag 'powerpc-5.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/mm: Fix missing KUAP disable in flush_coherent_icache()
  powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systems
  powerpc: Include .BTF section
  powerpc/watchpoint: Don't call dar_within_range() for Book3S

arch/powerpc/kernel/cputable.c

@@ -2193,11 +2193,13 @@ static struct cpu_spec * __init setup_cpu_spec(unsigned long offset,
 		 * oprofile_cpu_type already has a value, then we are
 		 * possibly overriding a real PVR with a logical one,
 		 * and, in that case, keep the current value for
-		 * oprofile_cpu_type.
+		 * oprofile_cpu_type. Futhermore, let's ensure that the
+		 * fix for the PMAO bug is enabled on compatibility mode.
 		 */
 		if (old.oprofile_cpu_type != NULL) {
 			t->oprofile_cpu_type = old.oprofile_cpu_type;
 			t->oprofile_type = old.oprofile_type;
+			t->cpu_features |= old.cpu_features & CPU_FTR_PMAO_BUG;
 		}
 	}
 

arch/powerpc/kernel/hw_breakpoint.c

@@ -331,11 +331,13 @@ int hw_breakpoint_handler(struct die_args *args)
 	}
 
 	info->type &= ~HW_BRK_TYPE_EXTRANEOUS_IRQ;
-	if (!dar_within_range(regs->dar, info))
-		info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
-
-	if (!IS_ENABLED(CONFIG_PPC_8xx) && !stepping_handler(regs, bp, info))
-		goto out;
+	if (IS_ENABLED(CONFIG_PPC_8xx)) {
+		if (!dar_within_range(regs->dar, info))
+			info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
+	} else {
+		if (!stepping_handler(regs, bp, info))
+			goto out;
+	}
 
 	/*
 	 * As a policy, the callback is invoked in a 'trigger-after-execute'

arch/powerpc/kernel/vmlinux.lds.S

@@ -303,6 +303,12 @@ SECTIONS
 		*(.branch_lt)
 	}
 
+#ifdef CONFIG_DEBUG_INFO_BTF
+	.BTF : AT(ADDR(.BTF) - LOAD_OFFSET) {
+		*(.BTF)
+	}
+#endif
+
 	.opd : AT(ADDR(.opd) - LOAD_OFFSET) {
 		__start_opd = .;
 		KEEP(*(.opd))

arch/powerpc/mm/mem.c

@@ -373,7 +373,9 @@ static inline bool flush_coherent_icache(unsigned long addr)
 	 */
 	if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
 		mb(); /* sync */
+		allow_read_from_user((const void __user *)addr, L1_CACHE_BYTES);
 		icbi((void *)addr);
+		prevent_read_from_user((const void __user *)addr, L1_CACHE_BYTES);
 		mb(); /* sync */
 		isync();
 		return true;