4 files changed, 59 insertions, 4 deletions
diff --git a/arch/um/kernel/Makefile b/arch/um/kernel/Makefile
index 1119233597a..c4491c15afb 100644
--- a/arch/um/kernel/Makefile
+++ b/arch/um/kernel/Makefile
@@ -17,6 +17,7 @@ obj-y = config.o exec.o exitcode.o init_task.o irq.o ksyms.o mem.o \
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
 obj-$(CONFIG_GPROF)	+= gprof_syms.o
 obj-$(CONFIG_GCOV)	+= gmon_syms.o
+obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
 
 USER_OBJS := config.o
 
diff --git a/arch/um/kernel/early_printk.c b/arch/um/kernel/early_printk.c
new file mode 100644
index 00000000000..ec649bf72f6
--- /dev/null
+++ b/arch/um/kernel/early_printk.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2011 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/kernel.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include "os.h"
+
+static void early_console_write(struct console *con, const char *s, unsigned int n)
+{
+	um_early_printk(s, n);
+}
+
+static struct console early_console = {
+	.name = "earlycon",
+	.write = early_console_write,
+	.flags = CON_BOOT,
+	.index = -1,
+};
+
+static int __init setup_early_printk(char *buf)
+{
+	register_console(&early_console);
+
+	return 0;
+}
+
+early_param("earlyprintk", setup_early_printk);
diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
index 106bf27e2a9..155206a6690 100644
--- a/arch/um/kernel/smp.c
+++ b/arch/um/kernel/smp.c
@@ -7,9 +7,6 @@
 #include "asm/pgalloc.h"
 #include "asm/tlb.h"
 
-/* For some reason, mmu_gathers are referenced when CONFIG_SMP is off. */
-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
-
 #ifdef CONFIG_SMP
 
 #include "linux/sched.h"
@@ -173,7 +170,7 @@ void IPI_handler(int cpu)
 			break;
 
 		case 'R':
-			set_tsk_need_resched(current);
+			scheduler_ipi();
 			break;
 
 		case 'S':
diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index 637c6505dc0..8c7b8823d1f 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -113,6 +113,27 @@ out_of_memory:
 	return 0;
 }
 
+static void show_segv_info(struct uml_pt_regs *regs)
+{
+	struct task_struct *tsk = current;
+	struct faultinfo *fi = UPT_FAULTINFO(regs);
+
+	if (!unhandled_signal(tsk, SIGSEGV))
+		return;
+
+	if (!printk_ratelimit())
+		return;
+
+	printk("%s%s[%d]: segfault at %lx ip %p sp %p error %x",
+		task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG,
+		tsk->comm, task_pid_nr(tsk), FAULT_ADDRESS(*fi),
+		(void *)UPT_IP(regs), (void *)UPT_SP(regs),
+		fi->error_code);
+
+	print_vma_addr(KERN_CONT " in ", UPT_IP(regs));
+	printk(KERN_CONT "\n");
+}
+
 static void bad_segv(struct faultinfo fi, unsigned long ip)
 {
 	struct siginfo si;
@@ -141,6 +162,7 @@ void segv_handler(int sig, struct uml_pt_regs *regs)
 	struct faultinfo * fi = UPT_FAULTINFO(regs);
 
 	if (UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)) {
+		show_segv_info(regs);
 		bad_segv(*fi, UPT_IP(regs));
 		return;
 	}
@@ -202,6 +224,8 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user,
 		      address, ip);
 	}
 
+	show_segv_info(regs);
+
 	if (err == -EACCES) {
 		si.si_signo = SIGBUS;
 		si.si_errno = 0;