Merge tag 'x86-urgent-2020-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:

 - more generic entry code ABI fallout

 - debug register handling bugfixes

 - fix vmalloc mappings on 32-bit kernels

 - kprobes instrumentation output fix on 32-bit kernels

 - fix over-eager WARN_ON_ONCE() on !SMAP hardware

 - NUMA debugging fix

 - fix Clang related crash on !RETPOLINE kernels

* tag 'x86-urgent-2020-09-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry: Unbreak 32bit fast syscall
  x86/debug: Allow a single level of #DB recursion
  x86/entry: Fix AC assertion
  tracing/kprobes, x86/ptrace: Fix regs argument order for i386
  x86, fakenuma: Fix invalid starting node ID
  x86/mm/32: Bring back vmalloc faulting on x86_32
  x86/cmdline: Disable jump tables for cmdline.c

1 files changed, 29 insertions, 6 deletions

diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index fcae019158ca..18683598edbc 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -69,22 +69,45 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
 	return ret ? : syscall_get_nr(current, regs);
 }
 
-noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall)
+static __always_inline long
+__syscall_enter_from_user_work(struct pt_regs *regs, long syscall)
 {
 	unsigned long ti_work;
 
-	enter_from_user_mode(regs);
-	instrumentation_begin();
-
-	local_irq_enable();
 	ti_work = READ_ONCE(current_thread_info()->flags);
 	if (ti_work & SYSCALL_ENTER_WORK)
 		syscall = syscall_trace_enter(regs, syscall, ti_work);
-	instrumentation_end();
 
 	return syscall;
 }
 
+long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall)
+{
+	return __syscall_enter_from_user_work(regs, syscall);
+}
+
+noinstr long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall)
+{
+	long ret;
+
+	enter_from_user_mode(regs);
+
+	instrumentation_begin();
+	local_irq_enable();
+	ret = __syscall_enter_from_user_work(regs, syscall);
+	instrumentation_end();
+
+	return ret;
+}
+
+noinstr void syscall_enter_from_user_mode_prepare(struct pt_regs *regs)
+{
+	enter_from_user_mode(regs);
+	instrumentation_begin();
+	local_irq_enable();
+	instrumentation_end();
+}
+
 /**
  * exit_to_user_mode - Fixup state when exiting to user mode
  *