1 files changed, 279 insertions, 364 deletions

diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 50314850400..337518c5042 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -1,102 +1,114 @@
 /*
- * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include <pty.h>
 #include <stdio.h>
-#include <stddef.h>
-#include <stdarg.h>
 #include <stdlib.h>
-#include <string.h>
+#include <stdarg.h>
 #include <unistd.h>
-#include <signal.h>
-#include <sched.h>
-#include <fcntl.h>
 #include <errno.h>
-#include <setjmp.h>
-#include <sys/time.h>
-#include <sys/wait.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <signal.h>
+#include <string.h>
 #include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
 #include <asm/unistd.h>
-#include <asm/page.h>
-#include <sys/types.h>
-#include "user_util.h"
-#include "kern_util.h"
-#include "user.h"
-#include "signal_kern.h"
-#include "sysdep/ptrace.h"
-#include "sysdep/sigcontext.h"
-#include "irq_user.h"
-#include "ptrace_user.h"
-#include "mem_user.h"
-#include "init.h"
-#include "os.h"
-#include "uml-config.h"
-#include "choose-mode.h"
-#include "mode.h"
-#include "tempfile.h"
-#include "kern_constants.h"
-
-#ifdef UML_CONFIG_MODE_SKAS
-#include "skas.h"
-#include "skas_ptrace.h"
-#include "registers.h"
-#endif
-
-static int ptrace_child(void *arg)
+#include <init.h>
+#include <os.h>
+#include <mem_user.h>
+#include <ptrace_user.h>
+#include <registers.h>
+#include <skas.h>
+#include <skas_ptrace.h>
+
+static void ptrace_child(void)
 {
 	int ret;
+	/* Calling os_getpid because some libcs cached getpid incorrectly */
 	int pid = os_getpid(), ppid = getppid();
 	int sc_result;
 
-	change_sig(SIGWINCH, 0);
-	if(ptrace(PTRACE_TRACEME, 0, 0, 0) < 0){
+	if (change_sig(SIGWINCH, 0) < 0 ||
+	    ptrace(PTRACE_TRACEME, 0, 0, 0) < 0) {
 		perror("ptrace");
-		os_kill_process(pid, 0);
+		kill(pid, SIGKILL);
 	}
-	os_stop_process(pid);
+	kill(pid, SIGSTOP);
 
-	/*This syscall will be intercepted by the parent. Don't call more than
-	 * once, please.*/
+	/*
+	 * This syscall will be intercepted by the parent. Don't call more than
+	 * once, please.
+	 */
 	sc_result = os_getpid();
 
 	if (sc_result == pid)
-		ret = 1; /*Nothing modified by the parent, we are running
-			   normally.*/
+		/* Nothing modified by the parent, we are running normally. */
+		ret = 1;
 	else if (sc_result == ppid)
-		ret = 0; /*Expected in check_ptrace and check_sysemu when they
-			   succeed in modifying the stack frame*/
+		/*
+		 * Expected in check_ptrace and check_sysemu when they succeed
+		 * in modifying the stack frame
+		 */
+		ret = 0;
 	else
-		ret = 2; /*Serious trouble! This could be caused by a bug in
-			   host 2.6 SKAS3/2.6 patch before release -V6, together
-			   with a bug in the UML code itself.*/
-	_exit(ret);
+		/* Serious trouble! This could be caused by a bug in host 2.6
+		 * SKAS3/2.6 patch before release -V6, together with a bug in
+		 * the UML code itself.
+		 */
+		ret = 2;
+
+	exit(ret);
+}
+
+static void fatal_perror(const char *str)
+{
+	perror(str);
+	exit(1);
+}
+
+static void fatal(char *fmt, ...)
+{
+	va_list list;
+
+	va_start(list, fmt);
+	vfprintf(stderr, fmt, list);
+	va_end(list);
+
+	exit(1);
+}
+
+static void non_fatal(char *fmt, ...)
+{
+	va_list list;
+
+	va_start(list, fmt);
+	vfprintf(stderr, fmt, list);
+	va_end(list);
 }
 
-static int start_ptraced_child(void **stack_out)
+static int start_ptraced_child(void)
 {
-	void *stack;
-	unsigned long sp;
 	int pid, n, status;
 
-	stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
-		     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-	if(stack == MAP_FAILED)
-		panic("check_ptrace : mmap failed, errno = %d", errno);
-	sp = (unsigned long) stack + PAGE_SIZE - sizeof(void *);
-	pid = clone(ptrace_child, (void *) sp, SIGCHLD, NULL);
-	if(pid < 0)
-		panic("start_ptraced_child : clone failed, errno = %d", errno);
+	pid = fork();
+	if (pid == 0)
+		ptrace_child();
+	else if (pid < 0)
+		fatal_perror("start_ptraced_child : fork failed");
+
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-	if(n < 0)
-		panic("check_ptrace : clone failed, errno = %d", errno);
-	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-		panic("check_ptrace : expected SIGSTOP, got status = %d",
+	if (n < 0)
+		fatal_perror("check_ptrace : waitpid failed");
+	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
+		fatal("check_ptrace : expected SIGSTOP, got status = %d",
 		      status);
 
-	*stack_out = stack;
-	return(pid);
+	return pid;
 }
 
 /* When testing for SYSEMU support, if it is one of the broken versions, we
@@ -105,43 +117,53 @@ static int start_ptraced_child(void **stack_out)
  * So only for SYSEMU features we test mustpanic, while normal host features
  * must work anyway!
  */
-static int stop_ptraced_child(int pid, void *stack, int exitcode,
-			      int mustpanic)
+static int stop_ptraced_child(int pid, int exitcode, int mustexit)
 {
 	int status, n, ret = 0;
 
-	if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		panic("check_ptrace : ptrace failed, errno = %d", errno);
+	if (ptrace(PTRACE_CONT, pid, 0, 0) < 0) {
+		perror("stop_ptraced_child : ptrace failed");
+		return -1;
+	}
 	CATCH_EINTR(n = waitpid(pid, &status, 0));
-	if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
+	if (!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
 		int exit_with = WEXITSTATUS(status);
 		if (exit_with == 2)
-			printf("check_ptrace : child exited with status 2. "
-			       "Serious trouble happening! Try updating your "
-			       "host skas patch!\nDisabling SYSEMU support.");
-		printf("check_ptrace : child exited with exitcode %d, while "
-		      "expecting %d; status 0x%x", exit_with,
-		      exitcode, status);
-		if (mustpanic)
-			panic("\n");
-		else
-			printf("\n");
+			non_fatal("check_ptrace : child exited with status 2. "
+				  "\nDisabling SYSEMU support.\n");
+		non_fatal("check_ptrace : child exited with exitcode %d, while "
+			  "expecting %d; status 0x%x\n", exit_with,
+			  exitcode, status);
+		if (mustexit)
+			exit(1);
 		ret = -1;
 	}
 
-	if(munmap(stack, PAGE_SIZE) < 0)
-		panic("check_ptrace : munmap failed, errno = %d", errno);
 	return ret;
 }
 
-int ptrace_faultinfo = 1;
-int ptrace_ldt = 1;
-int proc_mm = 1;
-int skas_needs_stub = 0;
+/* Changed only during early boot */
+int ptrace_faultinfo;
+static int disable_ptrace_faultinfo;
+
+int ptrace_ldt;
+static int disable_ptrace_ldt;
+
+int proc_mm;
+static int disable_proc_mm;
+
+int have_switch_mm;
+static int disable_switch_mm;
+
+int skas_needs_stub;
 
 static int __init skas0_cmd_param(char *str, int* add)
 {
-	ptrace_faultinfo = proc_mm = 0;
+	disable_ptrace_faultinfo = 1;
+	disable_ptrace_ldt = 1;
+	disable_proc_mm = 1;
+	disable_switch_mm = 1;
+
 	return 0;
 }
 
@@ -151,16 +173,14 @@ static int __init mode_skas0_cmd_param(char *str, int* add)
 	__attribute__((alias("skas0_cmd_param")));
 
 __uml_setup("skas0", skas0_cmd_param,
-		"skas0\n"
-		"    Disables SKAS3 usage, so that SKAS0 is used, unless \n"
-	        "    you specify mode=tt.\n\n");
+"skas0\n"
+"    Disables SKAS3 and SKAS4 usage, so that SKAS0 is used\n\n");
 
 __uml_setup("mode=skas0", mode_skas0_cmd_param,
-		"mode=skas0\n"
-		"    Disables SKAS3 usage, so that SKAS0 is used, unless you \n"
-		"    specify mode=tt. Note that this was recently added - on \n"
-		"    older kernels you must use simply \"skas0\".\n\n");
+"mode=skas0\n"
+"    Disables SKAS3 and SKAS4 usage, so that SKAS0 is used.\n\n");
 
+/* Changed only during early boot */
 static int force_sysemu_disabled = 0;
 
 static int __init nosysemu_cmd_param(char *str, int* add)
@@ -180,137 +200,185 @@ __uml_setup("nosysemu", nosysemu_cmd_param,
 
 static void __init check_sysemu(void)
 {
-	void *stack;
- 	int pid, n, status, count=0;
+	unsigned long regs[MAX_REG_NR];
+	int pid, n, status, count=0;
 
-	printf("Checking syscall emulation patch for ptrace...");
+	non_fatal("Checking syscall emulation patch for ptrace...");
 	sysemu_supported = 0;
-	pid = start_ptraced_child(&stack);
+	pid = start_ptraced_child();
 
-	if(ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
+	if (ptrace(PTRACE_SYSEMU, pid, 0, 0) < 0)
 		goto fail;
 
 	CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 	if (n < 0)
-		panic("check_sysemu : wait failed, errno = %d", errno);
-	if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-		panic("check_sysemu : expected SIGTRAP, "
-		      "got status = %d", status);
-
-	n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
-		   os_getpid());
-	if(n < 0)
-		panic("check_sysemu : failed to modify system "
-		      "call return, errno = %d", errno);
-
-	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
+		fatal_perror("check_sysemu : wait failed");
+	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
+		fatal("check_sysemu : expected SIGTRAP, got status = %d\n",
+		      status);
+
+	if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
+		fatal_perror("check_sysemu : PTRACE_GETREGS failed");
+	if (PT_SYSCALL_NR(regs) != __NR_getpid) {
+		non_fatal("check_sysemu got system call number %d, "
+			  "expected %d...", PT_SYSCALL_NR(regs), __NR_getpid);
+		goto fail;
+	}
+
+	n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET, os_getpid());
+	if (n < 0) {
+		non_fatal("check_sysemu : failed to modify system call "
+			  "return");
+		goto fail;
+	}
+
+	if (stop_ptraced_child(pid, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 1;
-	printf("OK\n");
+	non_fatal("OK\n");
 	set_using_sysemu(!force_sysemu_disabled);
 
-	printf("Checking advanced syscall emulation patch for ptrace...");
-	pid = start_ptraced_child(&stack);
+	non_fatal("Checking advanced syscall emulation patch for ptrace...");
+	pid = start_ptraced_child();
 
-	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
-		  (void *) PTRACE_O_TRACESYSGOOD) < 0)
-		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d",
-		      errno);
+	if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
+		fatal_perror("check_sysemu: PTRACE_OLDSETOPTIONS failed");
 
-	while(1){
+	while (1) {
 		count++;
-		if(ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
+		if (ptrace(PTRACE_SYSEMU_SINGLESTEP, pid, 0, 0) < 0)
 			goto fail;
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-		if(n < 0)
-			panic("check_ptrace : wait failed, errno = %d", errno);
-		if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){
-			if (!count)
-				panic("check_ptrace : SYSEMU_SINGLESTEP "
-				      "doesn't singlestep");
-			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
+		if (n < 0)
+			fatal_perror("check_sysemu: wait failed");
+
+		if (WIFSTOPPED(status) &&
+		    (WSTOPSIG(status) == (SIGTRAP|0x80))) {
+			if (!count) {
+				non_fatal("check_sysemu: SYSEMU_SINGLESTEP "
+					  "doesn't singlestep");
+				goto fail;
+			}
+			n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET,
 				   os_getpid());
-			if(n < 0)
-				panic("check_sysemu : failed to modify system "
-				      "call return, errno = %d", errno);
+			if (n < 0)
+				fatal_perror("check_sysemu : failed to modify "
+					     "system call return");
 			break;
 		}
-		else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
+		else if (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
 			count++;
-		else
-			panic("check_ptrace : expected SIGTRAP or "
-			      "(SIGTRAP|0x80), got status = %d", status);
+		else {
+			non_fatal("check_sysemu: expected SIGTRAP or "
+				  "(SIGTRAP | 0x80), got status = %d\n",
+				  status);
+			goto fail;
+		}
 	}
-	if (stop_ptraced_child(pid, stack, 0, 0) < 0)
+	if (stop_ptraced_child(pid, 0, 0) < 0)
 		goto fail_stopped;
 
 	sysemu_supported = 2;
-	printf("OK\n");
+	non_fatal("OK\n");
 
-	if ( !force_sysemu_disabled )
+	if (!force_sysemu_disabled)
 		set_using_sysemu(sysemu_supported);
 	return;
 
 fail:
-	stop_ptraced_child(pid, stack, 1, 0);
+	stop_ptraced_child(pid, 1, 0);
 fail_stopped:
-	printf("missing\n");
+	non_fatal("missing\n");
 }
 
 static void __init check_ptrace(void)
 {
-	void *stack;
 	int pid, syscall, n, status;
 
-	printf("Checking that ptrace can change system call numbers...");
-	pid = start_ptraced_child(&stack);
+	non_fatal("Checking that ptrace can change system call numbers...");
+	pid = start_ptraced_child();
 
-	if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
-		panic("check_ptrace: PTRACE_OLDSETOPTIONS failed, errno = %d", errno);
+	if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
+		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
+		fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
+
+	while (1) {
+		if (ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
+			fatal_perror("check_ptrace : ptrace failed");
 
-	while(1){
-		if(ptrace(PTRACE_SYSCALL, pid, 0, 0) < 0)
-			panic("check_ptrace : ptrace failed, errno = %d",
-			      errno);
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
-		if(n < 0)
-			panic("check_ptrace : wait failed, errno = %d", errno);
-		if(!WIFSTOPPED(status) || (WSTOPSIG(status) != (SIGTRAP|0x80)))
-			panic("check_ptrace : expected (SIGTRAP|0x80), "
-			      "got status = %d", status);
+		if (n < 0)
+			fatal_perror("check_ptrace : wait failed");
+
+		if (!WIFSTOPPED(status) ||
+		   (WSTOPSIG(status) != (SIGTRAP | 0x80)))
+			fatal("check_ptrace : expected (SIGTRAP|0x80), "
+			       "got status = %d", status);
 
-		syscall = ptrace(PTRACE_PEEKUSR, pid, PT_SYSCALL_NR_OFFSET,
+		syscall = ptrace(PTRACE_PEEKUSER, pid, PT_SYSCALL_NR_OFFSET,
 				 0);
-		if(syscall == __NR_getpid){
-			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
+		if (syscall == __NR_getpid) {
+			n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET,
 				   __NR_getppid);
-			if(n < 0)
-				panic("check_ptrace : failed to modify system "
-				      "call, errno = %d", errno);
+			if (n < 0)
+				fatal_perror("check_ptrace : failed to modify "
+					     "system call");
 			break;
 		}
 	}
-	stop_ptraced_child(pid, stack, 0, 1);
-	printf("OK\n");
+	stop_ptraced_child(pid, 0, 1);
+	non_fatal("OK\n");
 	check_sysemu();
 }
 
 extern void check_tmpexec(void);
 
-void os_early_checks(void)
+static void __init check_coredump_limit(void)
+{
+	struct rlimit lim;
+	int err = getrlimit(RLIMIT_CORE, &lim);
+
+	if (err) {
+		perror("Getting core dump limit");
+		return;
+	}
+
+	printf("Core dump limits :\n\tsoft - ");
+	if (lim.rlim_cur == RLIM_INFINITY)
+		printf("NONE\n");
+	else printf("%lu\n", lim.rlim_cur);
+
+	printf("\thard - ");
+	if (lim.rlim_max == RLIM_INFINITY)
+		printf("NONE\n");
+	else printf("%lu\n", lim.rlim_max);
+}
+
+void __init os_early_checks(void)
 {
+	int pid;
+
+	/* Print out the core dump limits early */
+	check_coredump_limit();
+
 	check_ptrace();
 
 	/* Need to check this early because mmapping happens before the
 	 * kernel is running.
 	 */
 	check_tmpexec();
+
+	pid = start_ptraced_child();
+	if (init_registers(pid))
+		fatal("Failed to initialize default registers");
+	stop_ptraced_child(pid, 1, 1);
 }
 
 static int __init noprocmm_cmd_param(char *str, int* add)
 {
-	proc_mm = 0;
+	disable_proc_mm = 1;
 	return 0;
 }
 
@@ -322,7 +390,7 @@ __uml_setup("noprocmm", noprocmm_cmd_param,
 
 static int __init noptracefaultinfo_cmd_param(char *str, int* add)
 {
-	ptrace_faultinfo = 0;
+	disable_ptrace_faultinfo = 1;
 	return 0;
 }
 
@@ -334,7 +402,7 @@ __uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
 
 static int __init noptraceldt_cmd_param(char *str, int* add)
 {
-	ptrace_ldt = 0;
+	disable_ptrace_ldt = 1;
 	return 0;
 }
 
@@ -344,39 +412,33 @@ __uml_setup("noptraceldt", noptraceldt_cmd_param,
 "    To support PTRACE_LDT, the host needs to be patched using\n"
 "    the current skas3 patch.\n\n");
 
-#ifdef UML_CONFIG_MODE_SKAS
 static inline void check_skas3_ptrace_faultinfo(void)
 {
 	struct ptrace_faultinfo fi;
-	void *stack;
 	int pid, n;
 
-	printf("  - PTRACE_FAULTINFO...");
-	pid = start_ptraced_child(&stack);
+	non_fatal("  - PTRACE_FAULTINFO...");
+	pid = start_ptraced_child();
 
 	n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
 	if (n < 0) {
-		ptrace_faultinfo = 0;
-		if(errno == EIO)
-			printf("not found\n");
+		if (errno == EIO)
+			non_fatal("not found\n");
 		else
 			perror("not found");
-	}
+	} else if (disable_ptrace_faultinfo)
+		non_fatal("found but disabled on command line\n");
 	else {
-		if (!ptrace_faultinfo)
-			printf("found but disabled on command line\n");
-		else
-			printf("found\n");
+		ptrace_faultinfo = 1;
+		non_fatal("found\n");
 	}
 
-	init_registers(pid);
-	stop_ptraced_child(pid, stack, 1, 1);
+	stop_ptraced_child(pid, 1, 1);
 }
 
 static inline void check_skas3_ptrace_ldt(void)
 {
 #ifdef PTRACE_LDT
-	void *stack;
 	int pid, n;
 	unsigned char ldtbuf[40];
 	struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
@@ -384,104 +446,84 @@ static inline void check_skas3_ptrace_ldt(void)
 		.ptr = ldtbuf,
 		.bytecount = sizeof(ldtbuf)};
 
-	printf("  - PTRACE_LDT...");
-	pid = start_ptraced_child(&stack);
+	non_fatal("  - PTRACE_LDT...");
+	pid = start_ptraced_child();
 
 	n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
 	if (n < 0) {
-		if(errno == EIO)
-			printf("not found\n");
-		else {
+		if (errno == EIO)
+			non_fatal("not found\n");
+		else
 			perror("not found");
-		}
-		ptrace_ldt = 0;
-	}
+	} else if (disable_ptrace_ldt)
+		non_fatal("found, but use is disabled\n");
 	else {
-		if(ptrace_ldt)
-			printf("found\n");
-		else
-			printf("found, but use is disabled\n");
+		ptrace_ldt = 1;
+		non_fatal("found\n");
 	}
 
-	stop_ptraced_child(pid, stack, 1, 1);
-#else
-	/* PTRACE_LDT might be disabled via cmdline option.
-	 * We want to override this, else we might use the stub
-	 * without real need
-	 */
-	ptrace_ldt = 1;
+	stop_ptraced_child(pid, 1, 1);
 #endif
 }
 
 static inline void check_skas3_proc_mm(void)
 {
-	printf("  - /proc/mm...");
-	if (os_access("/proc/mm", OS_ACC_W_OK) < 0) {
- 		proc_mm = 0;
-		printf("not found\n");
-	}
+	non_fatal("  - /proc/mm...");
+	if (access("/proc/mm", W_OK) < 0)
+		perror("not found");
+	else if (disable_proc_mm)
+		non_fatal("found but disabled on command line\n");
 	else {
-		if (!proc_mm)
-			printf("found but disabled on command line\n");
-		else
-			printf("found\n");
+		proc_mm = 1;
+		non_fatal("found\n");
 	}
 }
 
-int can_do_skas(void)
+void can_do_skas(void)
 {
-	printf("Checking for the skas3 patch in the host:\n");
+	non_fatal("Checking for the skas3 patch in the host:\n");
 
 	check_skas3_proc_mm();
 	check_skas3_ptrace_faultinfo();
 	check_skas3_ptrace_ldt();
 
-	if(!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
+	if (!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
 		skas_needs_stub = 1;
-
-	return 1;
-}
-#else
-int can_do_skas(void)
-{
-	return(0);
 }
-#endif
 
 int __init parse_iomem(char *str, int *add)
 {
 	struct iomem_region *new;
-	struct uml_stat buf;
+	struct stat64 buf;
 	char *file, *driver;
-	int fd, err, size;
+	int fd, size;
 
 	driver = str;
 	file = strchr(str,',');
-	if(file == NULL){
-		printf("parse_iomem : failed to parse iomem\n");
+	if (file == NULL) {
+		fprintf(stderr, "parse_iomem : failed to parse iomem\n");
 		goto out;
 	}
 	*file = '\0';
 	file++;
-	fd = os_open_file(file, of_rdwr(OPENFLAGS()), 0);
-	if(fd < 0){
-		os_print_error(fd, "parse_iomem - Couldn't open io file");
+	fd = open(file, O_RDWR, 0);
+	if (fd < 0) {
+		perror("parse_iomem - Couldn't open io file");
 		goto out;
 	}
 
-	err = os_stat_fd(fd, &buf);
-	if(err < 0){
-		os_print_error(err, "parse_iomem - cannot stat_fd file");
+	if (fstat64(fd, &buf) < 0) {
+		perror("parse_iomem - cannot stat_fd file");
 		goto out_close;
 	}
 
 	new = malloc(sizeof(*new));
-	if(new == NULL){
+	if (new == NULL) {
 		perror("Couldn't allocate iomem_region struct");
 		goto out_close;
 	}
 
-	size = (buf.ust_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
+	size = (buf.st_size + UM_KERN_PAGE_SIZE) & ~(UM_KERN_PAGE_SIZE - 1);
 
 	*new = ((struct iomem_region) { .next		= iomem_regions,
 					.driver		= driver,
@@ -492,136 +534,9 @@ int __init parse_iomem(char *str, int *add)
 	iomem_regions = new;
 	iomem_size += new->size + UM_KERN_PAGE_SIZE;
 
-	return(0);
+	return 0;
  out_close:
-	os_close_file(fd);
+	close(fd);
  out:
-	return(1);
-}
-
-
-/* Changed during early boot */
-int pty_output_sigio = 0;
-int pty_close_sigio = 0;
-
-/* Used as a flag during SIGIO testing early in boot */
-static volatile int got_sigio = 0;
-
-static void __init handler(int sig)
-{
-	got_sigio = 1;
-}
-
-struct openpty_arg {
-	int master;
-	int slave;
-	int err;
-};
-
-static void openpty_cb(void *arg)
-{
-	struct openpty_arg *info = arg;
-
-	info->err = 0;
-	if(openpty(&info->master, &info->slave, NULL, NULL, NULL))
-		info->err = -errno;
-}
-
-static void __init check_one_sigio(void (*proc)(int, int))
-{
-	struct sigaction old, new;
-	struct openpty_arg pty = { .master = -1, .slave = -1 };
-	int master, slave, err;
-
-	initial_thread_cb(openpty_cb, &pty);
-	if(pty.err){
-		printk("openpty failed, errno = %d\n", -pty.err);
-		return;
-	}
-
-	master = pty.master;
-	slave = pty.slave;
-
-	if((master == -1) || (slave == -1)){
-		printk("openpty failed to allocate a pty\n");
-		return;
-	}
-
-	/* Not now, but complain so we now where we failed. */
-	err = raw(master);
-	if (err < 0)
-		panic("check_sigio : __raw failed, errno = %d\n", -err);
-
-	err = os_sigio_async(master, slave);
-	if(err < 0)
-		panic("tty_fds : sigio_async failed, err = %d\n", -err);
-
-	if(sigaction(SIGIO, NULL, &old) < 0)
-		panic("check_sigio : sigaction 1 failed, errno = %d\n", errno);
-	new = old;
-	new.sa_handler = handler;
-	if(sigaction(SIGIO, &new, NULL) < 0)
-		panic("check_sigio : sigaction 2 failed, errno = %d\n", errno);
-
-	got_sigio = 0;
-	(*proc)(master, slave);
-
-	close(master);
-	close(slave);
-
-	if(sigaction(SIGIO, &old, NULL) < 0)
-		panic("check_sigio : sigaction 3 failed, errno = %d\n", errno);
-}
-
-static void tty_output(int master, int slave)
-{
-	int n;
-	char buf[512];
-
-	printk("Checking that host ptys support output SIGIO...");
-
-	memset(buf, 0, sizeof(buf));
-
-	while(os_write_file(master, buf, sizeof(buf)) > 0) ;
-	if(errno != EAGAIN)
-		panic("check_sigio : write failed, errno = %d\n", errno);
-	while(((n = os_read_file(slave, buf, sizeof(buf))) > 0) && !got_sigio) ;
-
-	if(got_sigio){
-		printk("Yes\n");
-		pty_output_sigio = 1;
-	}
-	else if(n == -EAGAIN) printk("No, enabling workaround\n");
-	else panic("check_sigio : read failed, err = %d\n", n);
-}
-
-static void tty_close(int master, int slave)
-{
-	printk("Checking that host ptys support SIGIO on close...");
-
-	close(slave);
-	if(got_sigio){
-		printk("Yes\n");
-		pty_close_sigio = 1;
-	}
-	else printk("No, enabling workaround\n");
-}
-
-void __init check_sigio(void)
-{
-	if((os_access("/dev/ptmx", OS_ACC_R_OK) < 0) &&
-	   (os_access("/dev/ptyp0", OS_ACC_R_OK) < 0)){
-		printk("No pseudo-terminals available - skipping pty SIGIO "
-		       "check\n");
-		return;
-	}
-	check_one_sigio(tty_output);
-	check_one_sigio(tty_close);
-}
-
-void os_check_bugs(void)
-{
-	check_ptrace();
-	check_sigio();
+	return 1;
 }
-