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 pile of x86 updates:

   - Prevent exceeding he valid physical address space in the /dev/mem
     limit checks.

   - Move all header content inside the header guard to prevent compile
     failures.

   - Fix the bogus __percpu annotation in this_cpu_has() which makes
     sparse very noisy.

   - Disable switch jump tables completely when retpolines are enabled.

   - Prevent leaking the trampoline address"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/realmode: Make set_real_mode_mem() static inline
  x86/cpufeature: Fix __percpu annotation in this_cpu_has()
  x86/mm: Don't exceed the valid physical address space
  x86/retpolines: Disable switch jump tables when retpolines are enabled
  x86/realmode: Don't leak the trampoline kernel address
  x86/boot: Fix incorrect ifdeffery scope
  x86/resctrl: Remove unused variable

arch/x86/Makefile

@@ -219,8 +219,12 @@ ifdef CONFIG_RETPOLINE
   # Additionally, avoid generating expensive indirect jumps which
   # are subject to retpolines for small number of switch cases.
   # clang turns off jump table generation by default when under
-  # retpoline builds, however, gcc does not for x86.
-  KBUILD_CFLAGS += $(call cc-option,--param=case-values-threshold=20)
+  # retpoline builds, however, gcc does not for x86. This has
+  # only been fixed starting from gcc stable version 8.4.0 and
+  # onwards, but not for older ones. See gcc bug #86952.
+  ifndef CONFIG_CC_IS_CLANG
+    KBUILD_CFLAGS += $(call cc-option,-fno-jump-tables)
+  endif
 endif
 
 archscripts: scripts_basic

arch/x86/boot/compressed/misc.h

@@ -120,8 +120,6 @@ static inline void console_init(void)
 
 void set_sev_encryption_mask(void);
 
-#endif
-
 /* acpi.c */
 #ifdef CONFIG_ACPI
 acpi_physical_address get_rsdp_addr(void);
@@ -135,3 +133,5 @@ int count_immovable_mem_regions(void);
 #else
 static inline int count_immovable_mem_regions(void) { return 0; }
 #endif
+
+#endif /* BOOT_COMPRESSED_MISC_H */

arch/x86/include/asm/cpufeature.h

@@ -113,7 +113,8 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 
 #define this_cpu_has(bit)						\
 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
-	 x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability))
+	 x86_this_cpu_test_bit(bit,					\
+		(unsigned long __percpu *)&cpu_info.x86_capability))
 
 /*
  * This macro is for detection of features which need kernel

arch/x86/include/asm/realmode.h

@@ -77,7 +77,11 @@ static inline size_t real_mode_size_needed(void)
 	return ALIGN(real_mode_blob_end - real_mode_blob, PAGE_SIZE);
 }
 
-void set_real_mode_mem(phys_addr_t mem, size_t size);
+static inline void set_real_mode_mem(phys_addr_t mem)
+{
+	real_mode_header = (struct real_mode_header *) __va(mem);
+}
+
 void reserve_real_mode(void);
 
 #endif /* __ASSEMBLY__ */

arch/x86/kernel/cpu/resctrl/monitor.c

@@ -501,11 +501,8 @@ out_unlock:
 void cqm_setup_limbo_handler(struct rdt_domain *dom, unsigned long delay_ms)
 {
 	unsigned long delay = msecs_to_jiffies(delay_ms);
-	struct rdt_resource *r;
 	int cpu;
 
-	r = &rdt_resources_all[RDT_RESOURCE_L3];
-
 	cpu = cpumask_any(&dom->cpu_mask);
 	dom->cqm_work_cpu = cpu;
 

arch/x86/mm/mmap.c

@@ -230,7 +230,7 @@ bool mmap_address_hint_valid(unsigned long addr, unsigned long len)
 /* Can we access it for direct reading/writing? Must be RAM: */
 int valid_phys_addr_range(phys_addr_t addr, size_t count)
 {
-	return addr + count <= __pa(high_memory);
+	return addr + count - 1 <= __pa(high_memory - 1);
 }
 
 /* Can we access it through mmap? Must be a valid physical address: */

arch/x86/platform/efi/quirks.c

@@ -449,7 +449,7 @@ void __init efi_free_boot_services(void)
 		 */
 		rm_size = real_mode_size_needed();
 		if (rm_size && (start + rm_size) < (1<<20) && size >= rm_size) {
-			set_real_mode_mem(start, rm_size);
+			set_real_mode_mem(start);
 			start += rm_size;
 			size -= rm_size;
 		}

arch/x86/realmode/init.c

@@ -15,15 +15,6 @@ u32 *trampoline_cr4_features;
 /* Hold the pgd entry used on booting additional CPUs */
 pgd_t trampoline_pgd_entry;
 
-void __init set_real_mode_mem(phys_addr_t mem, size_t size)
-{
-	void *base = __va(mem);
-
-	real_mode_header = (struct real_mode_header *) base;
-	printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
-	       base, (unsigned long long)mem, size);
-}
-
 void __init reserve_real_mode(void)
 {
 	phys_addr_t mem;
@@ -42,7 +33,7 @@ void __init reserve_real_mode(void)
 	}
 
 	memblock_reserve(mem, size);
-	set_real_mode_mem(mem, size);
+	set_real_mode_mem(mem);
 }
 
 static void __init setup_real_mode(void)