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

Pull arm64 updates from Catalin Marinas:

 - arm64 support for syscall emulation via PTRACE_SYSEMU{,_SINGLESTEP}

 - Wire up VM_FLUSH_RESET_PERMS for arm64, allowing the core code to
   manage the permissions of executable vmalloc regions more strictly

 - Slight performance improvement by keeping softirqs enabled while
   touching the FPSIMD/SVE state (kernel_neon_begin/end)

 - Expose a couple of ARMv8.5 features to user (HWCAP): CondM (new
   XAFLAG and AXFLAG instructions for floating point comparison flags
   manipulation) and FRINT (rounding floating point numbers to integers)

 - Re-instate ARM64_PSEUDO_NMI support which was previously marked as
   BROKEN due to some bugs (now fixed)

 - Improve parking of stopped CPUs and implement an arm64-specific
   panic_smp_self_stop() to avoid warning on not being able to stop
   secondary CPUs during panic

 - perf: enable the ARM Statistical Profiling Extensions (SPE) on ACPI
   platforms

 - perf: DDR performance monitor support for iMX8QXP

 - cache_line_size() can now be set from DT or ACPI/PPTT if provided to
   cope with a system cache info not exposed via the CPUID registers

 - Avoid warning on hardware cache line size greater than
   ARCH_DMA_MINALIGN if the system is fully coherent

 - arm64 do_page_fault() and hugetlb cleanups

 - Refactor set_pte_at() to avoid redundant READ_ONCE(*ptep)

 - Ignore ACPI 5.1 FADTs reported as 5.0 (infer from the
   'arm_boot_flags' introduced in 5.1)

 - CONFIG_RANDOMIZE_BASE now enabled in defconfig

 - Allow the selection of ARM64_MODULE_PLTS, currently only done via
   RANDOMIZE_BASE (and an erratum workaround), allowing modules to spill
   over into the vmalloc area

 - Make ZONE_DMA32 configurable

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (54 commits)
  perf: arm_spe: Enable ACPI/Platform automatic module loading
  arm_pmu: acpi: spe: Add initial MADT/SPE probing
  ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens
  ACPI/PPTT: Modify node flag detection to find last IDENTICAL
  x86/entry: Simplify _TIF_SYSCALL_EMU handling
  arm64: rename dump_instr as dump_kernel_instr
  arm64/mm: Drop [PTE|PMD]_TYPE_FAULT
  arm64: Implement panic_smp_self_stop()
  arm64: Improve parking of stopped CPUs
  arm64: Expose FRINT capabilities to userspace
  arm64: Expose ARMv8.5 CondM capability to userspace
  arm64: defconfig: enable CONFIG_RANDOMIZE_BASE
  arm64: ARM64_MODULES_PLTS must depend on MODULES
  arm64: bpf: do not allocate executable memory
  arm64/kprobes: set VM_FLUSH_RESET_PERMS on kprobe instruction pages
  arm64/mm: wire up CONFIG_ARCH_HAS_SET_DIRECT_MAP
  arm64: module: create module allocations without exec permissions
  arm64: Allow user selection of ARM64_MODULE_PLTS
  acpi/arm64: ignore 5.1 FADTs that are reported as 5.0
  arm64: Allow selecting Pseudo-NMI again
  ...

2 files changed, 9 insertions, 2 deletions

diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c
index c52b737ab8e3..a92b33593b8d 100644
--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -680,6 +680,8 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq,
  * @hwirq:	The HW irq number to convert to a logical one
  * @regs:	Register file coming from the low-level handling code
  *
+ *		This function must be called from an NMI context.
+ *
  * Returns:	0 on success, or -EINVAL if conversion has failed
  */
 int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
@@ -689,7 +691,10 @@ int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
 	unsigned int irq;
 	int ret = 0;
 
-	nmi_enter();
+	/*
+	 * NMI context needs to be setup earlier in order to deal with tracing.
+	 */
+	WARN_ON(!in_nmi());
 
 	irq = irq_find_mapping(domain, hwirq);
 
@@ -702,7 +707,6 @@ int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq,
 	else
 		ret = -EINVAL;
 
-	nmi_exit();
 	set_irq_regs(old_regs);
 	return ret;
 }
diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 705887f63288..83a531cea2f3 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -116,6 +116,9 @@ void __ptrace_unlink(struct task_struct *child)
 	BUG_ON(!child->ptrace);
 
 	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
+#ifdef TIF_SYSCALL_EMU
+	clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
+#endif
 
 	child->parent = child->real_parent;
 	list_del_init(&child->ptrace_entry);