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

Pull x86 fixes from Ingo Molnar:
 "Misc fixes: three build fixes, an unwinder fix and a microcode loader
  fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/AMD: Fix more fallout from CONFIG_RANDOMIZE_MEMORY=y
  x86: Fix export for mcount and __fentry__
  x86/quirks: Hide maybe-uninitialized warning
  x86/build: Fix build with older GCC versions
  x86/unwind: Fix empty stack dereference in guess unwinder

5 files changed, 14 insertions, 7 deletions

diff --git a/arch/x86/entry/Makefile b/arch/x86/entry/Makefile
index 77f28ce9c646..9976fcecd17e 100644
--- a/arch/x86/entry/Makefile
+++ b/arch/x86/entry/Makefile
@@ -5,8 +5,8 @@
 OBJECT_FILES_NON_STANDARD_entry_$(BITS).o   := y
 OBJECT_FILES_NON_STANDARD_entry_64_compat.o := y
 
-CFLAGS_syscall_64.o		+= -Wno-override-init
-CFLAGS_syscall_32.o		+= -Wno-override-init
+CFLAGS_syscall_64.o		+= $(call cc-option,-Wno-override-init,)
+CFLAGS_syscall_32.o		+= $(call cc-option,-Wno-override-init,)
 obj-y				:= entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
 obj-y				+= common.o
 
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 620ab06bcf45..017bda12caae 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -429,7 +429,7 @@ int __init save_microcode_in_initrd_amd(void)
 	 * We need the physical address of the container for both bitness since
 	 * boot_params.hdr.ramdisk_image is a physical address.
 	 */
-	cont    = __pa(container);
+	cont    = __pa_nodebug(container);
 	cont_va = container;
 #endif
 
diff --git a/arch/x86/kernel/mcount_64.S b/arch/x86/kernel/mcount_64.S
index efe73aacf966..7b0d3da52fb4 100644
--- a/arch/x86/kernel/mcount_64.S
+++ b/arch/x86/kernel/mcount_64.S
@@ -18,8 +18,10 @@
 
 #ifdef CC_USING_FENTRY
 # define function_hook	__fentry__
+EXPORT_SYMBOL(__fentry__)
 #else
 # define function_hook	mcount
+EXPORT_SYMBOL(mcount)
 #endif
 
 /* All cases save the original rbp (8 bytes) */
@@ -295,7 +297,6 @@ trace:
 	jmp fgraph_trace
 END(function_hook)
 #endif /* CONFIG_DYNAMIC_FTRACE */
-EXPORT_SYMBOL(function_hook)
 #endif /* CONFIG_FUNCTION_TRACER */
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index 51402a7e4ca6..0bee04d41bed 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -625,8 +625,6 @@ static void amd_disable_seq_and_redirect_scrub(struct pci_dev *dev)
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3,
 			amd_disable_seq_and_redirect_scrub);
 
-#endif
-
 #if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
 #include <linux/jump_label.h>
 #include <asm/string_64.h>
@@ -657,3 +655,4 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
 #endif
+#endif
diff --git a/arch/x86/kernel/unwind_guess.c b/arch/x86/kernel/unwind_guess.c
index 9298993dc8b7..2d721e533cf4 100644
--- a/arch/x86/kernel/unwind_guess.c
+++ b/arch/x86/kernel/unwind_guess.c
@@ -47,7 +47,14 @@ void __unwind_start(struct unwind_state *state, struct task_struct *task,
 	get_stack_info(first_frame, state->task, &state->stack_info,
 		       &state->stack_mask);
 
-	if (!__kernel_text_address(*first_frame))
+	/*
+	 * The caller can provide the address of the first frame directly
+	 * (first_frame) or indirectly (regs->sp) to indicate which stack frame
+	 * to start unwinding at.  Skip ahead until we reach it.
+	 */
+	if (!unwind_done(state) &&
+	    (!on_stack(&state->stack_info, first_frame, sizeof(long)) ||
+	    !__kernel_text_address(*first_frame)))
 		unwind_next_frame(state);
 }
 EXPORT_SYMBOL_GPL(__unwind_start);