Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Will Deacon:
 "Most of these are CC'd for stable, but there are a few fixing issues
  introduced during the recent merge window too.

  There's also a fix for the xgene PMU driver, but it seemed daft to
  send as a separate pull request, so I've included it here with the
  rest of the fixes.

   - Fix ACPI boot due to recent broken NUMA changes
   - Fix remote enabling of CPU features requiring PSTATE bit manipulation
   - Add address range check when emulating user cache maintenance
   - Fix LL/SC loops that allow compiler to introduce memory accesses
   - Fix recently added write_sysreg_s macro
   - Ensure MDCR_EL2 is initialised on qemu targets without a PMU
   - Avoid kaslr breakage due to MODVERSIONs and DYNAMIC_FTRACE
   - Correctly drive recent ld when building relocatable Image
   - Remove junk IS_ERR check from xgene PMU driver added during merge window
   - pr_cont fixes after core changes in the merge window"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: remove pr_cont abuse from mem_init
  arm64: fix show_regs fallout from KERN_CONT changes
  arm64: kernel: force ET_DYN ELF type for CONFIG_RELOCATABLE=y
  arm64: suspend: Reconfigure PSTATE after resume from idle
  arm64: mm: Set PSTATE.PAN from the cpu_enable_pan() call
  arm64: cpufeature: Schedule enable() calls instead of calling them via IPI
  arm64: Cortex-A53 errata workaround: check for kernel addresses
  arm64: percpu: rewrite ll/sc loops in assembly
  arm64: swp emulation: bound LL/SC retries before rescheduling
  arm64: sysreg: Fix use of XZR in write_sysreg_s
  arm64: kaslr: keep modules close to the kernel when DYNAMIC_FTRACE=y
  arm64: kernel: Init MDCR_EL2 even in the absence of a PMU
  perf: xgene: Remove bogus IS_ERR() check
  arm64: kernel: numa: fix ACPI boot cpu numa node mapping
  arm64: kaslr: fix breakage with CONFIG_MODVERSIONS=y

1 files changed, 13 insertions, 2 deletions

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 53d9159662fe..0f8788374815 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -29,7 +29,9 @@
 #include <linux/sched.h>
 #include <linux/highmem.h>
 #include <linux/perf_event.h>
+#include <linux/preempt.h>
 
+#include <asm/bug.h>
 #include <asm/cpufeature.h>
 #include <asm/exception.h>
 #include <asm/debug-monitors.h>
@@ -670,9 +672,17 @@ asmlinkage int __exception do_debug_exception(unsigned long addr,
 NOKPROBE_SYMBOL(do_debug_exception);
 
 #ifdef CONFIG_ARM64_PAN
-void cpu_enable_pan(void *__unused)
+int cpu_enable_pan(void *__unused)
 {
+	/*
+	 * We modify PSTATE. This won't work from irq context as the PSTATE
+	 * is discarded once we return from the exception.
+	 */
+	WARN_ON_ONCE(in_interrupt());
+
 	config_sctlr_el1(SCTLR_EL1_SPAN, 0);
+	asm(SET_PSTATE_PAN(1));
+	return 0;
 }
 #endif /* CONFIG_ARM64_PAN */
 
@@ -683,8 +693,9 @@ void cpu_enable_pan(void *__unused)
  * We need to enable the feature at runtime (instead of adding it to
  * PSR_MODE_EL1h) as the feature may not be implemented by the cpu.
  */
-void cpu_enable_uao(void *__unused)
+int cpu_enable_uao(void *__unused)
 {
 	asm(SET_PSTATE_UAO(1));
+	return 0;
 }
 #endif /* CONFIG_ARM64_UAO */