Merge branch 'for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:
"Beside of various fixes this also contains patches to enable features
such was Kcov, kmemleak and TRACE_IRQFLAGS_SUPPORT on UML"

* 'for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
hostfs: Freeing an ERR_PTR in hostfs_fill_sb_common()
um: Support kcov
um: Enable TRACE_IRQFLAGS_SUPPORT
um: Use asm-generic/irqflags.h
um: Fix possible deadlock in sig_handler_common()
um: Select HAVE_DEBUG_KMEMLEAK
um: Setup physical memory in setup_arch()
um: Eliminate null test after alloc_bootmem

arch/um/Kconfig.common

···
 config UML
 	bool
 	default y
+	select ARCH_HAS_KCOV
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_SECCOMP_FILTER
 	select HAVE_UID16
 	select HAVE_FUTEX_CMPXCHG if FUTEX
+	select HAVE_DEBUG_KMEMLEAK
 	select GENERIC_IRQ_SHOW
 	select GENERIC_CPU_DEVICES
 	select GENERIC_IO
···
 config PCMCIA
 	bool
 
-# Yet to do!
 config TRACE_IRQFLAGS_SUPPORT
 	bool
-	default n
+	default y
 
 config LOCKDEP_SUPPORT
 	bool

arch/um/include/asm/irqflags.h

···
 extern void block_signals(void);
 extern void unblock_signals(void);
 
+#define arch_local_save_flags arch_local_save_flags
 static inline unsigned long arch_local_save_flags(void)
 {
 	return get_signals();
 }
 
+#define arch_local_irq_restore arch_local_irq_restore
 static inline void arch_local_irq_restore(unsigned long flags)
 {
 	set_signals(flags);
 }
 
+#define arch_local_irq_enable arch_local_irq_enable
 static inline void arch_local_irq_enable(void)
 {
 	unblock_signals();
 }
 
+#define arch_local_irq_disable arch_local_irq_disable
 static inline void arch_local_irq_disable(void)
 {
 	block_signals();
 }
 
-static inline unsigned long arch_local_irq_save(void)
-{
-	unsigned long flags;
-	flags = arch_local_save_flags();
-	arch_local_irq_disable();
-	return flags;
-}
+#define ARCH_IRQ_DISABLED	0
+#define ARCh_IRQ_ENABLED	(SIGIO|SIGVTALRM)
 
-static inline bool arch_irqs_disabled(void)
-{
-	return arch_local_save_flags() == 0;
-}
+#include <asm-generic/irqflags.h>
 
 #endif

arch/um/kernel/Makefile

···
 # Licensed under the GPL
 #
 
+# Don't instrument UML-specific code; without this, we may crash when
+# accessing the instrumentation buffer for the first time from the
+# kernel.
+KCOV_INSTRUMENT                := n
+
 CPPFLAGS_vmlinux.lds := -DSTART=$(LDS_START)		\
                         -DELF_ARCH=$(LDS_ELF_ARCH)	\
                         -DELF_FORMAT=$(LDS_ELF_FORMAT)	\

arch/um/kernel/initrd.c

···
 	}
 
 	area = alloc_bootmem(size);
-	if (area == NULL)
-		return 0;
 
 	if (load_initrd(initrd, area, size) == -1)
 		return 0;

arch/um/kernel/um_arch.c

···
 
 	start_vm = VMALLOC_START;
 
-	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
-	mem_total_pages(physmem_size, iomem_size, highmem);
-
 	virtmem_size = physmem_size;
 	stack = (unsigned long) argv;
 	stack &= ~(1024 * 1024 - 1);
···
 		printf("Kernel virtual memory size shrunk to %lu bytes\n",
 		       virtmem_size);
 
-	stack_protections((unsigned long) &init_thread_info);
 	os_flush_stdout();
 
 	return start_uml();
···
 
 void __init setup_arch(char **cmdline_p)
 {
+	stack_protections((unsigned long) &init_thread_info);
+	setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
+	mem_total_pages(physmem_size, iomem_size, highmem);
+
 	paging_init();
 	strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 	*cmdline_p = command_line;

arch/um/os-Linux/Makefile

···
 # Licensed under the GPL
 #
 
+# Don't instrument UML-specific code
+KCOV_INSTRUMENT                := n
+
 obj-y = aio.o execvp.o file.o helper.o irq.o main.o mem.o process.o \
 	registers.o sigio.o signal.o start_up.o time.o tty.o \
 	umid.o user_syms.o util.o drivers/ skas/

arch/um/os-Linux/signal.c

···
 #include <kern_util.h>
 #include <os.h>
 #include <sysdep/mcontext.h>
+#include <um_malloc.h>
 
 void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
 	[SIGTRAP]	= relay_signal,
···
 	struct uml_pt_regs *r;
 	int save_errno = errno;
 
-	r = malloc(sizeof(struct uml_pt_regs));
+	r = uml_kmalloc(sizeof(struct uml_pt_regs), UM_GFP_ATOMIC);
 	if (!r)
 		panic("out of memory");
 
···
 {
 	struct uml_pt_regs *regs;
 
-	regs = malloc(sizeof(struct uml_pt_regs));
+	regs = uml_kmalloc(sizeof(struct uml_pt_regs), UM_GFP_ATOMIC);
 	if (!regs)
 		panic("out of memory");
 

arch/x86/um/vdso/Makefile

···
 # Building vDSO images for x86.
 #
 
+# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
+KCOV_INSTRUMENT                := n
+
 VDSO64-y		:= y
 
 vdso-install-$(VDSO64-y)	+= vdso.so

fs/hostfs/hostfs_kern.c

···
 
 	if (S_ISLNK(root_inode->i_mode)) {
 		char *name = follow_link(host_root_path);
-		if (IS_ERR(name))
+		if (IS_ERR(name)) {
 			err = PTR_ERR(name);
-		else
-			err = read_name(root_inode, name);
+			goto out_put;
+		}
+		err = read_name(root_inode, name);
 		kfree(name);
 		if (err)
 			goto out_put;