1 files changed, 89 insertions, 78 deletions

diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 7b81f6c08a5..337518c5042 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -13,27 +13,28 @@
 #include <signal.h>
 #include <string.h>
 #include <sys/mman.h>
-#include <sys/ptrace.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <sys/time.h>
+#include <sys/resource.h>
 #include <asm/unistd.h>
-#include "init.h"
-#include "kern_constants.h"
-#include "os.h"
-#include "mem_user.h"
-#include "ptrace_user.h"
-#include "registers.h"
-#include "skas_ptrace.h"
-
-static int ptrace_child(void)
+#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");
 		kill(pid, SIGKILL);
 	}
@@ -60,10 +61,11 @@ static int ptrace_child(void)
 		 * the UML code itself.
 		 */
 		ret = 2;
-	_exit(ret);
+
+	exit(ret);
 }
 
-static void fatal_perror(char *str)
+static void fatal_perror(const char *str)
 {
 	perror(str);
 	exit(1);
@@ -74,9 +76,8 @@ static void fatal(char *fmt, ...)
 	va_list list;
 
 	va_start(list, fmt);
-	vprintf(fmt, list);
+	vfprintf(stderr, fmt, list);
 	va_end(list);
-	fflush(stdout);
 
 	exit(1);
 }
@@ -86,9 +87,8 @@ static void non_fatal(char *fmt, ...)
 	va_list list;
 
 	va_start(list, fmt);
-	vprintf(fmt, list);
+	vfprintf(stderr, fmt, list);
 	va_end(list);
-	fflush(stdout);
 }
 
 static int start_ptraced_child(void)
@@ -121,8 +121,10 @@ static int stop_ptraced_child(int pid, int exitcode, int mustexit)
 {
 	int status, n, ret = 0;
 
-	if (ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-		fatal_perror("stop_ptraced_child : ptrace failed");
+	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)) {
 		int exit_with = WEXITSTATUS(status);
@@ -141,14 +143,27 @@ static int stop_ptraced_child(int pid, int exitcode, int mustexit)
 }
 
 /* Changed only during early boot */
-int ptrace_faultinfo = 1;
-int ptrace_ldt = 1;
-int proc_mm = 1;
-int skas_needs_stub = 0;
+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;
 }
 
@@ -158,15 +173,12 @@ 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;
@@ -202,7 +214,7 @@ static void __init check_sysemu(void)
 	if (n < 0)
 		fatal_perror("check_sysemu : wait failed");
 	if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-		fatal("check_sysemu : expected SIGTRAP, got status = %d",
+		fatal("check_sysemu : expected SIGTRAP, got status = %d\n",
 		      status);
 
 	if (ptrace(PTRACE_GETREGS, pid, 0, regs) < 0)
@@ -213,7 +225,7 @@ static void __init check_sysemu(void)
 		goto fail;
 	}
 
-	n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET, os_getpid());
+	n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_RET_OFFSET, os_getpid());
 	if (n < 0) {
 		non_fatal("check_sysemu : failed to modify system call "
 			  "return");
@@ -232,7 +244,7 @@ static void __init check_sysemu(void)
 
 	if ((ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
 		   (void *) PTRACE_O_TRACESYSGOOD) < 0))
-		fatal_perror("check_ptrace: PTRACE_OLDSETOPTIONS failed");
+		fatal_perror("check_sysemu: PTRACE_OLDSETOPTIONS failed");
 
 	while (1) {
 		count++;
@@ -240,14 +252,16 @@ static void __init check_sysemu(void)
 			goto fail;
 		CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
 		if (n < 0)
-			fatal_perror("check_ptrace : wait failed");
+			fatal_perror("check_sysemu: wait failed");
 
 		if (WIFSTOPPED(status) &&
 		    (WSTOPSIG(status) == (SIGTRAP|0x80))) {
-			if (!count)
-				fatal("check_ptrace : SYSEMU_SINGLESTEP "
-				      "doesn't singlestep");
-			n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_RET_OFFSET,
+			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)
 				fatal_perror("check_sysemu : failed to modify "
@@ -256,9 +270,12 @@ static void __init check_sysemu(void)
 		}
 		else if (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
 			count++;
-		else
-			fatal("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, 0, 0) < 0)
 		goto fail_stopped;
@@ -300,10 +317,10 @@ static void __init check_ptrace(void)
 			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,
+			n = ptrace(PTRACE_POKEUSER, pid, PT_SYSCALL_NR_OFFSET,
 				   __NR_getppid);
 			if (n < 0)
 				fatal_perror("check_ptrace : failed to modify "
@@ -341,6 +358,8 @@ static void __init check_coredump_limit(void)
 
 void __init os_early_checks(void)
 {
+	int pid;
+
 	/* Print out the core dump limits early */
 	check_coredump_limit();
 
@@ -350,11 +369,16 @@ void __init os_early_checks(void)
 	 * 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;
 }
 
@@ -366,7 +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;
 }
 
@@ -378,7 +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;
 }
 
@@ -398,20 +422,17 @@ static inline void check_skas3_ptrace_faultinfo(void)
 
 	n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
 	if (n < 0) {
-		ptrace_faultinfo = 0;
 		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)
-			non_fatal("found but disabled on command line\n");
-		else
-			non_fatal("found\n");
+		ptrace_faultinfo = 1;
+		non_fatal("found\n");
 	}
 
-	init_registers(pid);
 	stop_ptraced_child(pid, 1, 1);
 }
 
@@ -432,41 +453,33 @@ static inline void check_skas3_ptrace_ldt(void)
 	if (n < 0) {
 		if (errno == EIO)
 			non_fatal("not found\n");
-		else {
+		else
 			perror("not found");
-		}
-		ptrace_ldt = 0;
-	}
+	} else if (disable_ptrace_ldt)
+		non_fatal("found, but use is disabled\n");
 	else {
-		if (ptrace_ldt)
-			non_fatal("found\n");
-		else
-			non_fatal("found, but use is disabled\n");
+		ptrace_ldt = 1;
+		non_fatal("found\n");
 	}
 
 	stop_ptraced_child(pid, 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;
 #endif
 }
 
 static inline void check_skas3_proc_mm(void)
 {
 	non_fatal("  - /proc/mm...");
-	if (access("/proc/mm", W_OK) < 0) {
-		proc_mm = 0;
+	if (access("/proc/mm", W_OK) < 0)
 		perror("not found");
-	}
-	else if (!proc_mm)
+	else if (disable_proc_mm)
 		non_fatal("found but disabled on command line\n");
-	else non_fatal("found\n");
+	else {
+		proc_mm = 1;
+		non_fatal("found\n");
+	}
 }
 
-int can_do_skas(void)
+void can_do_skas(void)
 {
 	non_fatal("Checking for the skas3 patch in the host:\n");
 
@@ -476,8 +489,6 @@ int can_do_skas(void)
 
 	if (!proc_mm || !ptrace_faultinfo || !ptrace_ldt)
 		skas_needs_stub = 1;
-
-	return 1;
 }
 
 int __init parse_iomem(char *str, int *add)
@@ -490,7 +501,7 @@ int __init parse_iomem(char *str, int *add)
 	driver = str;
 	file = strchr(str,',');
 	if (file == NULL) {
-		printf("parse_iomem : failed to parse iomem\n");
+		fprintf(stderr, "parse_iomem : failed to parse iomem\n");
 		goto out;
 	}
 	*file = '\0';