Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "A set of x86 specific fixes and updates:

   - The CR2 corruption fixes which store CR2 early in the entry code
     and hand the stored address to the fault handlers.

   - Revert a forgotten leftover of the dropped FSGSBASE series.

   - Plug a memory leak in the boot code.

   - Make the Hyper-V assist functionality robust by zeroing the shadow
     page.

   - Remove a useless check for dead processes with LDT

   - Update paravirt and VMware maintainers entries.

   - A few cleanup patches addressing various compiler warnings"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/entry/64: Prevent clobbering of saved CR2 value
  x86/hyper-v: Zero out the VP ASSIST PAGE on allocation
  x86, boot: Remove multiple copy of static function sanitize_boot_params()
  x86/boot/compressed/64: Remove unused variable
  x86/boot/efi: Remove unused variables
  x86/mm, tracing: Fix CR2 corruption
  x86/entry/64: Update comments and sanity tests for create_gap
  x86/entry/64: Simplify idtentry a little
  x86/entry/32: Simplify common_exception
  x86/paravirt: Make read_cr2() CALLEE_SAVE
  MAINTAINERS: Update PARAVIRT_OPS_INTERFACE and VMWARE_HYPERVISOR_INTERFACE
  x86/process: Delete useless check for dead process with LDT
  x86: math-emu: Hide clang warnings for 16-bit overflow
  x86/e820: Use proper booleans instead of 0/1
  x86/apic: Silence -Wtype-limits compiler warnings
  x86/mm: Free sme_early_buffer after init
  x86/boot: Fix memory leak in default_get_smp_config()
  Revert "x86/ptrace: Prevent ptrace from clearing the FS/GS selector" and fix the test

1 files changed, 11 insertions, 19 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index d1634c59ed56..6c46095cd0d9 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -1490,9 +1490,8 @@ good_area:
 NOKPROBE_SYMBOL(do_user_addr_fault);
 
 /*
- * This routine handles page faults.  It determines the address,
- * and the problem, and then passes it off to one of the appropriate
- * routines.
+ * Explicitly marked noinline such that the function tracer sees this as the
+ * page_fault entry point.
  */
 static noinline void
 __do_page_fault(struct pt_regs *regs, unsigned long hw_error_code,
@@ -1511,33 +1510,26 @@ __do_page_fault(struct pt_regs *regs, unsigned long hw_error_code,
 }
 NOKPROBE_SYMBOL(__do_page_fault);
 
-static nokprobe_inline void
-trace_page_fault_entries(unsigned long address, struct pt_regs *regs,
-			 unsigned long error_code)
+static __always_inline void
+trace_page_fault_entries(struct pt_regs *regs, unsigned long error_code,
+			 unsigned long address)
 {
+	if (!trace_pagefault_enabled())
+		return;
+
 	if (user_mode(regs))
 		trace_page_fault_user(address, regs, error_code);
 	else
 		trace_page_fault_kernel(address, regs, error_code);
 }
 
-/*
- * We must have this function blacklisted from kprobes, tagged with notrace
- * and call read_cr2() before calling anything else. To avoid calling any
- * kind of tracing machinery before we've observed the CR2 value.
- *
- * exception_{enter,exit}() contains all sorts of tracepoints.
- */
-dotraplinkage void notrace
-do_page_fault(struct pt_regs *regs, unsigned long error_code)
+dotraplinkage void
+do_page_fault(struct pt_regs *regs, unsigned long error_code, unsigned long address)
 {
-	unsigned long address = read_cr2(); /* Get the faulting address */
 	enum ctx_state prev_state;
 
 	prev_state = exception_enter();
-	if (trace_pagefault_enabled())
-		trace_page_fault_entries(address, regs, error_code);
-
+	trace_page_fault_entries(regs, error_code, address);
 	__do_page_fault(regs, error_code, address);
 	exception_exit(prev_state);
 }