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

Pull UML changes from Richard Weinberger:
 "This pile contains a nice defconfig cleanup, a rewritten stack
  unwinder and various cleanups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Remove unused declarations from <as-layout.h>
  um: remove used STDIO_CONSOLE Kconfig param
  um/vdso: add .gitignore for a couple of targets
  arch/um: make it work with defconfig and x86_64
  um: Make kstack_depth_to_print conform to arch/x86
  um: Get rid of thread_struct->saved_task
  um: Make stack trace reliable against kernel mode faults
  um: Rewrite show_stack()

arch/um/Kconfig.char

@@ -6,10 +6,6 @@ config STDERR_CONSOLE
 	help
 	  console driver which dumps all printk messages to stderr.
 
-config STDIO_CONSOLE
-	bool
-	default y
-
 config SSL
 	bool "Virtual serial line"
 	help

arch/um/Kconfig.common

-config DEFCONFIG_LIST
-	string
-	option defconfig_list
-	default "arch/$ARCH/defconfig"
-
 config UML
 	bool
 	default y

arch/um/Makefile

@@ -6,6 +6,17 @@
 # Licensed under the GPL
 #
 
+# select defconfig based on actual architecture
+ifeq ($(SUBARCH),x86)
+  ifeq ($(shell uname -m),x86_64)
+        KBUILD_DEFCONFIG := x86_64_defconfig
+  else
+        KBUILD_DEFCONFIG := i386_defconfig
+  endif
+else
+        KBUILD_DEFCONFIG := $(SUBARCH)_defconfig
+endif
+
 ARCH_DIR := arch/um
 OS := $(shell uname -s)
 # We require bash because the vmlinux link and loader script cpp use bash

arch/um/configs/i386_defconfig

+CONFIG_3_LEVEL_PGTABLES=y
+# CONFIG_COMPACTION is not set
+CONFIG_BINFMT_MISC=m
+CONFIG_HOSTFS=y
+CONFIG_MAGIC_SYSRQ=y
+CONFIG_KERNEL_STACK_ORDER=1
+CONFIG_SYSVIPC=y
+CONFIG_POSIX_MQUEUE=y
+CONFIG_NO_HZ=y
+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_BSD_PROCESS_ACCT=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
+CONFIG_LOG_BUF_SHIFT=14
+CONFIG_CGROUPS=y
+CONFIG_CGROUP_FREEZER=y
+CONFIG_CGROUP_DEVICE=y
+CONFIG_CPUSETS=y
+CONFIG_CGROUP_CPUACCT=y
+CONFIG_RESOURCE_COUNTERS=y
+CONFIG_CGROUP_SCHED=y
+CONFIG_BLK_CGROUP=y
+# CONFIG_PID_NS is not set
+CONFIG_SYSFS_DEPRECATED=y
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+CONFIG_SLAB=y
+CONFIG_MODULES=y
+CONFIG_MODULE_UNLOAD=y
+# CONFIG_BLK_DEV_BSG is not set
+CONFIG_IOSCHED_CFQ=m
+CONFIG_SSL=y
+CONFIG_NULL_CHAN=y
+CONFIG_PORT_CHAN=y
+CONFIG_PTY_CHAN=y
+CONFIG_TTY_CHAN=y
+CONFIG_XTERM_CHAN=y
+CONFIG_CON_CHAN="pts"
+CONFIG_SSL_CHAN="pts"
+CONFIG_UML_SOUND=m
+CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+CONFIG_BLK_DEV_UBD=y
+CONFIG_BLK_DEV_LOOP=m
+CONFIG_BLK_DEV_NBD=m
+CONFIG_DUMMY=m
+CONFIG_TUN=m
+CONFIG_PPP=m
+CONFIG_SLIP=m
+CONFIG_LEGACY_PTY_COUNT=32
+# CONFIG_HW_RANDOM is not set
+CONFIG_UML_RANDOM=y
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+# CONFIG_INET_LRO is not set
+# CONFIG_IPV6 is not set
+CONFIG_UML_NET=y
+CONFIG_UML_NET_ETHERTAP=y
+CONFIG_UML_NET_TUNTAP=y
+CONFIG_UML_NET_SLIP=y
+CONFIG_UML_NET_DAEMON=y
+CONFIG_UML_NET_MCAST=y
+CONFIG_UML_NET_SLIRP=y
+CONFIG_EXT4_FS=y
+CONFIG_REISERFS_FS=y
+CONFIG_QUOTA=y
+CONFIG_AUTOFS4_FS=m
+CONFIG_ISO9660_FS=m
+CONFIG_JOLIET=y
+CONFIG_PROC_KCORE=y
+CONFIG_TMPFS=y
+CONFIG_NLS=y
+CONFIG_DEBUG_INFO=y
+CONFIG_DEBUG_KERNEL=y

arch/um/configs/x86_64_defconfig

+# CONFIG_COMPACTION is not set
+CONFIG_BINFMT_MISC=m
+CONFIG_HOSTFS=y
+CONFIG_MAGIC_SYSRQ=y
+CONFIG_SYSVIPC=y
+CONFIG_POSIX_MQUEUE=y
+CONFIG_NO_HZ=y
+CONFIG_HIGH_RES_TIMERS=y
+CONFIG_BSD_PROCESS_ACCT=y
+CONFIG_IKCONFIG=y
+CONFIG_IKCONFIG_PROC=y
+CONFIG_LOG_BUF_SHIFT=14
+CONFIG_CGROUPS=y
+CONFIG_CGROUP_FREEZER=y
+CONFIG_CGROUP_DEVICE=y
+CONFIG_CPUSETS=y
+CONFIG_CGROUP_CPUACCT=y
+CONFIG_RESOURCE_COUNTERS=y
+CONFIG_CGROUP_SCHED=y
+CONFIG_BLK_CGROUP=y
+# CONFIG_PID_NS is not set
+CONFIG_SYSFS_DEPRECATED=y
+CONFIG_CC_OPTIMIZE_FOR_SIZE=y
+CONFIG_SLAB=y
+CONFIG_MODULES=y
+CONFIG_MODULE_UNLOAD=y
+# CONFIG_BLK_DEV_BSG is not set
+CONFIG_IOSCHED_CFQ=m
+CONFIG_SSL=y
+CONFIG_NULL_CHAN=y
+CONFIG_PORT_CHAN=y
+CONFIG_PTY_CHAN=y
+CONFIG_TTY_CHAN=y
+CONFIG_XTERM_CHAN=y
+CONFIG_CON_CHAN="pts"
+CONFIG_SSL_CHAN="pts"
+CONFIG_UML_SOUND=m
+CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
+CONFIG_DEVTMPFS=y
+CONFIG_DEVTMPFS_MOUNT=y
+CONFIG_BLK_DEV_UBD=y
+CONFIG_BLK_DEV_LOOP=m
+CONFIG_BLK_DEV_NBD=m
+CONFIG_DUMMY=m
+CONFIG_TUN=m
+CONFIG_PPP=m
+CONFIG_SLIP=m
+CONFIG_LEGACY_PTY_COUNT=32
+# CONFIG_HW_RANDOM is not set
+CONFIG_UML_RANDOM=y
+CONFIG_NET=y
+CONFIG_PACKET=y
+CONFIG_UNIX=y
+CONFIG_INET=y
+# CONFIG_INET_LRO is not set
+# CONFIG_IPV6 is not set
+CONFIG_UML_NET=y
+CONFIG_UML_NET_ETHERTAP=y
+CONFIG_UML_NET_TUNTAP=y
+CONFIG_UML_NET_SLIP=y
+CONFIG_UML_NET_DAEMON=y
+CONFIG_UML_NET_MCAST=y
+CONFIG_UML_NET_SLIRP=y
+CONFIG_EXT4_FS=y
+CONFIG_REISERFS_FS=y
+CONFIG_QUOTA=y
+CONFIG_AUTOFS4_FS=m
+CONFIG_ISO9660_FS=m
+CONFIG_JOLIET=y
+CONFIG_PROC_KCORE=y
+CONFIG_TMPFS=y
+CONFIG_NLS=y
+CONFIG_DEBUG_INFO=y
+CONFIG_FRAME_WARN=1024
+CONFIG_DEBUG_KERNEL=y

arch/um/drivers/mconsole_kern.c

@@ -645,11 +645,9 @@ void mconsole_sysrq(struct mc_request *req)
 
 static void stack_proc(void *arg)
 {
-	struct task_struct *from = current, *to = arg;
+	struct task_struct *task = arg;
 
-	to->thread.saved_task = from;
-	rcu_user_hooks_switch(from, to);
-	switch_to(from, to, from);
+	show_stack(task, NULL);
 }
 
 /*

arch/um/include/asm/processor-generic.h

@@ -19,8 +19,8 @@ struct task_struct;
 struct mm_struct;
 
 struct thread_struct {
-	struct task_struct *saved_task;
 	struct pt_regs regs;
+	struct pt_regs *segv_regs;
 	int singlestep_syscall;
 	void *fault_addr;
 	jmp_buf *fault_catcher;

arch/um/include/shared/as-layout.h

@@ -44,7 +44,6 @@ struct cpu_task {
 
 extern struct cpu_task cpu_tasks[];
 
-extern unsigned long low_physmem;
 extern unsigned long high_physmem;
 extern unsigned long uml_physmem;
 extern unsigned long uml_reserved;
@@ -52,8 +51,6 @@ extern unsigned long end_vm;
 extern unsigned long start_vm;
 extern unsigned long long highmem;
 
-extern unsigned long _stext, _etext, _sdata, _edata, __bss_start, _end;
-extern unsigned long _unprotected_end;
 extern unsigned long brk_start;
 
 extern unsigned long host_task_size;

arch/um/include/shared/os.h

@@ -227,6 +227,7 @@ extern void block_signals(void);
 extern void unblock_signals(void);
 extern int get_signals(void);
 extern int set_signals(int enable);
+extern int os_is_signal_stack(void);
 
 /* util.c */
 extern void stack_protections(unsigned long address);

arch/um/kernel/process.c

@@ -82,20 +82,9 @@ void *__switch_to(struct task_struct *from, struct task_struct *to)
 	to->thread.prev_sched = from;
 	set_current(to);
 
-	do {
-		current->thread.saved_task = NULL;
-
-		switch_threads(&from->thread.switch_buf,
-			       &to->thread.switch_buf);
-
+	switch_threads(&from->thread.switch_buf, &to->thread.switch_buf);
 	arch_switch_to(current);
 
-		if (current->thread.saved_task)
-			show_regs(&(current->thread.regs));
-		to = current->thread.saved_task;
-		from = current;
-	} while (current->thread.saved_task);
-
 	return current->thread.prev_sched;
 }
 

arch/um/kernel/sysrq.c

 /*
  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
- * Licensed under the GPL
+ * Copyright (C) 2013 Richard Weinberger <richrd@nod.at>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
  */
 
 #include <linux/kallsyms.h>
@@ -8,59 +12,87 @@
 #include <linux/module.h>
 #include <linux/sched.h>
 #include <asm/sysrq.h>
+#include <os.h>
 
-/* Catch non-i386 SUBARCH's. */
-#if !defined(CONFIG_UML_X86) || defined(CONFIG_64BIT)
-void show_trace(struct task_struct *task, unsigned long * stack)
+struct stack_frame {
+	struct stack_frame *next_frame;
+	unsigned long return_address;
+};
+
+static void print_stack_trace(unsigned long *sp, unsigned long bp)
 {
+	int reliable;
 	unsigned long addr;
+	struct stack_frame *frame = (struct stack_frame *)bp;
 
-	if (!stack) {
-		stack = (unsigned long*) &stack;
-		WARN_ON(1);
+	printk(KERN_INFO "Call Trace:\n");
+	while (((long) sp & (THREAD_SIZE-1)) != 0) {
+		addr = *sp;
+		if (__kernel_text_address(addr)) {
+			reliable = 0;
+			if ((unsigned long) sp == bp + sizeof(long)) {
+				frame = frame ? frame->next_frame : NULL;
+				bp = (unsigned long)frame;
+				reliable = 1;
 			}
 
-	printk(KERN_INFO "Call Trace: \n");
-	while (((long) stack & (THREAD_SIZE-1)) != 0) {
-		addr = *stack;
-		if (__kernel_text_address(addr)) {
-			printk(KERN_INFO "%08lx:  [<%08lx>]",
-			       (unsigned long) stack, addr);
-			print_symbol(KERN_CONT " %s", addr);
+			printk(KERN_INFO " [<%08lx>]", addr);
+			printk(KERN_CONT " %s", reliable ? "" : "? ");
+			print_symbol(KERN_CONT "%s", addr);
 			printk(KERN_CONT "\n");
 		}
-		stack++;
+		sp++;
 	}
 	printk(KERN_INFO "\n");
 }
-#endif
 
-/*Stolen from arch/i386/kernel/traps.c */
-static const int kstack_depth_to_print = 24;
+static unsigned long get_frame_pointer(struct task_struct *task,
+				       struct pt_regs *segv_regs)
+{
+	if (!task || task == current)
+		return segv_regs ? PT_REGS_BP(segv_regs) : current_bp();
+	else
+		return KSTK_EBP(task);
+}
 
-/* This recently started being used in arch-independent code too, as in
- * kernel/sched/core.c.*/
-void show_stack(struct task_struct *task, unsigned long *esp)
+static unsigned long *get_stack_pointer(struct task_struct *task,
+					struct pt_regs *segv_regs)
 {
-	unsigned long *stack;
+	if (!task || task == current)
+		return segv_regs ? (unsigned long *)PT_REGS_SP(segv_regs) : current_sp();
+	else
+		return (unsigned long *)KSTK_ESP(task);
+}
+
+void show_stack(struct task_struct *task, unsigned long *stack)
+{
+	unsigned long *sp = stack, bp = 0;
+	struct pt_regs *segv_regs = current->thread.segv_regs;
 	int i;
 
-	if (esp == NULL) {
-		if (task != current && task != NULL) {
-			esp = (unsigned long *) KSTK_ESP(task);
-		} else {
-			esp = (unsigned long *) &esp;
-		}
+	if (!segv_regs && os_is_signal_stack()) {
+		printk(KERN_ERR "Received SIGSEGV in SIGSEGV handler,"
+				" aborting stack trace!\n");
+		return;
 	}
 
-	stack = esp;
-	for (i = 0; i < kstack_depth_to_print; i++) {
+#ifdef CONFIG_FRAME_POINTER
+	bp = get_frame_pointer(task, segv_regs);
+#endif
+
+	if (!stack)
+		sp = get_stack_pointer(task, segv_regs);
+
+	printk(KERN_INFO "Stack:\n");
+	stack = sp;
+	for (i = 0; i < 3 * STACKSLOTS_PER_LINE; i++) {
 		if (kstack_end(stack))
 			break;
-		if (i && ((i % 8) == 0))
-			printk(KERN_INFO "       ");
-		printk(KERN_CONT "%08lx ", *stack++);
+		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
+			printk(KERN_CONT "\n");
+		printk(KERN_CONT " %08lx", *stack++);
 	}
+	printk(KERN_CONT "\n");
 
-	show_trace(task, esp);
+	print_stack_trace(sp, bp);
 }

arch/um/kernel/trap.c

@@ -206,9 +206,12 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 	int is_write = FAULT_WRITE(fi);
 	unsigned long address = FAULT_ADDRESS(fi);
 
+	if (regs)
+		current->thread.segv_regs = container_of(regs, struct pt_regs, regs);
+
 	if (!is_user && (address >= start_vm) && (address < end_vm)) {
 		flush_tlb_kernel_vm();
-		return 0;
+		goto out;
 	}
 	else if (current->mm == NULL) {
 		show_regs(container_of(regs, struct pt_regs, regs));
@@ -230,7 +233,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 
 	catcher = current->thread.fault_catcher;
 	if (!err)
-		return 0;
+		goto out;
 	else if (catcher != NULL) {
 		current->thread.fault_addr = (void *) address;
 		UML_LONGJMP(catcher, 1);
@@ -238,7 +241,7 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 	else if (current->thread.fault_addr != NULL)
 		panic("fault_addr set but no fault catcher");
 	else if (!is_user && arch_fixup(ip, regs))
-		return 0;
+		goto out;
 
 	if (!is_user) {
 		show_regs(container_of(regs, struct pt_regs, regs));
@@ -262,6 +265,11 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 		current->thread.arch.faultinfo = fi;
 		force_sig_info(SIGSEGV, &si, current);
 	}
+
+out:
+	if (regs)
+		current->thread.segv_regs = NULL;
+
 	return 0;
 }
 

arch/um/kernel/um_arch.c

@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <asm/pgtable.h>
 #include <asm/processor.h>
+#include <asm/sections.h>
 #include <asm/setup.h>
 #include <as-layout.h>
 #include <arch.h>
@@ -234,7 +235,6 @@ static int panic_exit(struct notifier_block *self, unsigned long unused1,
 		      void *unused2)
 {
 	bust_spinlocks(1);
-	show_regs(&(current->thread.regs));
 	bust_spinlocks(0);
 	uml_exitcode = 1;
 	os_dump_core();

arch/um/os-Linux/signal.c

@@ -304,3 +304,11 @@ int set_signals(int enable)
 
 	return ret;
 }
+
+int os_is_signal_stack(void)
+{
+	stack_t ss;
+	sigaltstack(NULL, &ss);
+
+	return ss.ss_flags & SS_ONSTACK;
+}

arch/x86/um/Kconfig

@@ -31,6 +31,11 @@ config X86_64
 	def_bool 64BIT
 	select MODULES_USE_ELF_RELA
 
+config ARCH_DEFCONFIG
+	string
+	default "arch/um/configs/i386_defconfig" if X86_32
+	default "arch/um/configs/x86_64_defconfig" if X86_64
+
 config RWSEM_XCHGADD_ALGORITHM
 	def_bool 64BIT
 

arch/x86/um/asm/processor_32.h

@@ -33,6 +33,8 @@ struct arch_thread {
 	.faultinfo		= { 0, 0, 0 } \
 }
 
+#define STACKSLOTS_PER_LINE 8
+
 static inline void arch_flush_thread(struct arch_thread *thread)
 {
 	/* Clear any TLS still hanging */
@@ -53,4 +55,7 @@ static inline void arch_copy_thread(struct arch_thread *from,
 #define current_text_addr() \
 	({ void *pc; __asm__("movl $1f,%0\n1:":"=g" (pc)); pc; })
 
+#define current_sp() ({ void *sp; __asm__("movl %%esp, %0" : "=r" (sp) : ); sp; })
+#define current_bp() ({ unsigned long bp; __asm__("movl %%ebp, %0" : "=r" (bp) : ); bp; })
+
 #endif

arch/x86/um/asm/processor_64.h

@@ -19,6 +19,8 @@ struct arch_thread {
 			   .fs			= 0, \
 			   .faultinfo		= { 0, 0, 0 } }
 
+#define STACKSLOTS_PER_LINE 4
+
 static inline void arch_flush_thread(struct arch_thread *thread)
 {
 }
@@ -32,4 +34,7 @@ static inline void arch_copy_thread(struct arch_thread *from,
 #define current_text_addr() \
 	({ void *pc; __asm__("movq $1f,%0\n1:":"=g" (pc)); pc; })
 
+#define current_sp() ({ void *sp; __asm__("movq %%rsp, %0" : "=r" (sp) : ); sp; })
+#define current_bp() ({ unsigned long bp; __asm__("movq %%rbp, %0" : "=r" (bp) : ); bp; })
+
 #endif

arch/x86/um/sysrq_32.c

@@ -30,70 +30,4 @@ void show_regs(struct pt_regs *regs)
         printk(" DS: %04lx ES: %04lx\n",
 	       0xffff & PT_REGS_DS(regs), 
 	       0xffff & PT_REGS_ES(regs));
-
-        show_trace(NULL, (unsigned long *) &regs);
-}
-
-/* Copied from i386. */
-static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
-{
-	return	p > (void *)tinfo &&
-		p < (void *)tinfo + THREAD_SIZE - 3;
-}
-
-/* Adapted from i386 (we also print the address we read from). */
-static inline unsigned long print_context_stack(struct thread_info *tinfo,
-				unsigned long *stack, unsigned long ebp)
-{
-	unsigned long addr;
-
-#ifdef CONFIG_FRAME_POINTER
-	while (valid_stack_ptr(tinfo, (void *)ebp)) {
-		addr = *(unsigned long *)(ebp + 4);
-		printk("%08lx:  [<%08lx>]", ebp + 4, addr);
-		print_symbol(" %s", addr);
-		printk("\n");
-		ebp = *(unsigned long *)ebp;
-	}
-#else
-	while (valid_stack_ptr(tinfo, stack)) {
-		addr = *stack;
-		if (__kernel_text_address(addr)) {
-			printk("%08lx:  [<%08lx>]", (unsigned long) stack, addr);
-			print_symbol(" %s", addr);
-			printk("\n");
-		}
-		stack++;
-	}
-#endif
-	return ebp;
 }
-
-void show_trace(struct task_struct* task, unsigned long * stack)
-{
-	unsigned long ebp;
-	struct thread_info *context;
-
-	/* Turn this into BUG_ON if possible. */
-	if (!stack) {
-		stack = (unsigned long*) &stack;
-		printk("show_trace: got NULL stack, implicit assumption task == current");
-		WARN_ON(1);
-	}
-
-	if (!task)
-		task = current;
-
-	if (task != current) {
-		ebp = (unsigned long) KSTK_EBP(task);
-	} else {
-		asm ("movl %%ebp, %0" : "=r" (ebp) : );
-	}
-
-	context = (struct thread_info *)
-		((unsigned long)stack & (~(THREAD_SIZE - 1)));
-	print_context_stack(context, stack, ebp);
-
-	printk("\n");
-}
-

arch/x86/um/sysrq_64.c

@@ -12,7 +12,7 @@
 #include <asm/ptrace.h>
 #include <asm/sysrq.h>
 
-void __show_regs(struct pt_regs *regs)
+void show_regs(struct pt_regs *regs)
 {
 	printk("\n");
 	print_modules();
@@ -33,9 +33,3 @@ void __show_regs(struct pt_regs *regs)
 	printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
 	       PT_REGS_R13(regs), PT_REGS_R14(regs), PT_REGS_R15(regs));
 }
-
-void show_regs(struct pt_regs *regs)
-{
-	__show_regs(regs);
-	show_trace(current, (unsigned long *) &regs);
-}

arch/x86/um/vdso/.gitignore

+vdso-syms.lds
+vdso.lds