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

Pull core fixes from Thomas Gleixner:
 "A small set of core updates:

   - Make the watchdog respect the selected CPU mask again. That was
     broken by the rework of the watchdog thread management and caused
     inconsistent state and NMI watchdog being unstoppable.

   - Ensure that the objtool build can find the libelf location.

   - Remove dead kcore stub code"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  watchdog: Respect watchdog cpumask on CPU hotplug
  objtool: Query pkg-config for libelf location
  proc/kcore: Remove unused kclist_add_remap()

Author: torvalds

Makefile

@@ -953,9 +953,11 @@ mod_sign_cmd = true
 endif
 export mod_sign_cmd
 
+HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
+
 ifdef CONFIG_STACK_VALIDATION
   has_libelf := $(call try-run,\
-		echo "int main() {}" | $(HOSTCC) -xc -o /dev/null -lelf -,1,0)
+		echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
   ifeq ($(has_libelf),1)
     objtool_target := tools/objtool FORCE
   else

include/linux/kcore.h

@@ -38,24 +38,13 @@ struct vmcoredd_node {
 
 #ifdef CONFIG_PROC_KCORE
 void __init kclist_add(struct kcore_list *, void *, size_t, int type);
-static inline
-void kclist_add_remap(struct kcore_list *m, void *addr, void *vaddr, size_t sz)
-{
-	m->vaddr = (unsigned long)vaddr;
-	kclist_add(m, addr, sz, KCORE_REMAP);
-}
 
 extern int __init register_mem_pfn_is_ram(int (*fn)(unsigned long pfn));
 #else
 static inline
 void kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
 {
 }
-
-static inline
-void kclist_add_remap(struct kcore_list *m, void *addr, void *vaddr, size_t sz)
-{
-}
 #endif
 
 #endif /* _LINUX_KCORE_H */

kernel/watchdog.c

@@ -554,13 +554,15 @@ static void softlockup_start_all(void)
 
 int lockup_detector_online_cpu(unsigned int cpu)
 {
-	watchdog_enable(cpu);
+	if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
+		watchdog_enable(cpu);
 	return 0;
 }
 
 int lockup_detector_offline_cpu(unsigned int cpu)
 {
-	watchdog_disable(cpu);
+	if (cpumask_test_cpu(cpu, &watchdog_allowed_mask))
+		watchdog_disable(cpu);
 	return 0;
 }
 

tools/objtool/Makefile

@@ -25,14 +25,17 @@ LIBSUBCMD		= $(LIBSUBCMD_OUTPUT)libsubcmd.a
 OBJTOOL    := $(OUTPUT)objtool
 OBJTOOL_IN := $(OBJTOOL)-in.o
 
+LIBELF_FLAGS := $(shell pkg-config libelf --cflags 2>/dev/null)
+LIBELF_LIBS  := $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
+
 all: $(OBJTOOL)
 
 INCLUDES := -I$(srctree)/tools/include \
 	    -I$(srctree)/tools/arch/$(HOSTARCH)/include/uapi \
 	    -I$(srctree)/tools/objtool/arch/$(ARCH)/include
 WARNINGS := $(EXTRA_WARNINGS) -Wno-switch-default -Wno-switch-enum -Wno-packed
-CFLAGS   += -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES)
-LDFLAGS  += -lelf $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
+CFLAGS   += -Werror $(WARNINGS) $(KBUILD_HOSTCFLAGS) -g $(INCLUDES) $(LIBELF_FLAGS)
+LDFLAGS  += $(LIBELF_LIBS) $(LIBSUBCMD) $(KBUILD_HOSTLDFLAGS)
 
 # Allow old libelf to be used:
 elfshdr := $(shell echo '$(pound)include <libelf.h>' | $(CC) $(CFLAGS) -x c -E - | grep elf_getshdr)