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

Pull arm64 fixes from Catalin Marinas:

 - support for nr_cpus= command line argument (maxcpus was previously
   changed to allow secondary CPUs to be hot-plugged)

 - ARM PMU interrupt handling fix

 - fix potential TLB conflict in the hibernate code

 - improved handling of EL1 instruction aborts (better error reporting)

 - removal of useless jprobes code for stack saving/restoring

 - defconfig updates

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: defconfig: enable CONFIG_LOCALVERSION_AUTO
  arm64: defconfig: add options for virtualization and containers
  arm64: hibernate: handle allocation failures
  arm64: hibernate: avoid potential TLB conflict
  arm64: Handle el1 synchronous instruction aborts cleanly
  arm64: Remove stack duplicating code from jprobes
  drivers/perf: arm-pmu: Fix handling of SPI lacking "interrupt-affinity" property
  drivers/perf: arm-pmu: convert arm_pmu_mutex to spinlock
  arm64: Support hard limit of cpu count by nr_cpus

1 files changed, 12 insertions, 2 deletions

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index c8beaa0da7df..05d2bd776c69 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -153,6 +153,11 @@ int ptep_set_access_flags(struct vm_area_struct *vma,
 }
 #endif
 
+static bool is_el1_instruction_abort(unsigned int esr)
+{
+	return ESR_ELx_EC(esr) == ESR_ELx_EC_IABT_CUR;
+}
+
 /*
  * The kernel tried to access some page that wasn't present.
  */
@@ -161,8 +166,9 @@ static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
 {
 	/*
 	 * Are we prepared to handle this kernel fault?
+	 * We are almost certainly not prepared to handle instruction faults.
 	 */
-	if (fixup_exception(regs))
+	if (!is_el1_instruction_abort(esr) && fixup_exception(regs))
 		return;
 
 	/*
@@ -267,7 +273,8 @@ static inline bool is_permission_fault(unsigned int esr)
 	unsigned int ec       = ESR_ELx_EC(esr);
 	unsigned int fsc_type = esr & ESR_ELx_FSC_TYPE;
 
-	return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM);
+	return (ec == ESR_ELx_EC_DABT_CUR && fsc_type == ESR_ELx_FSC_PERM) ||
+	       (ec == ESR_ELx_EC_IABT_CUR && fsc_type == ESR_ELx_FSC_PERM);
 }
 
 static bool is_el0_instruction_abort(unsigned int esr)
@@ -312,6 +319,9 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
 		if (regs->orig_addr_limit == KERNEL_DS)
 			die("Accessing user space memory with fs=KERNEL_DS", regs, esr);
 
+		if (is_el1_instruction_abort(esr))
+			die("Attempting to execute userspace memory", regs, esr);
+
 		if (!search_exception_tables(regs->pc))
 			die("Accessing user space memory outside uaccess.h routines", regs, esr);
 	}