Merge master.kernel.org:/pub/scm/linux/kernel/git/sfrench/cifs-2.6

[sfrench/cifs-2.6.git] / arch / um / os-Linux / start_up.c

diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index b99ab414542fcb6700b39285fe28aeb5f881c33b..6c5b17ed59e1170baca1f67854211d2c127e869a 100644 (file)
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -24,13 +24,11 @@
 #include "kern_util.h"
 #include "user.h"
 #include "signal_kern.h"
-#include "signal_user.h"
 #include "sysdep/ptrace.h"
 #include "sysdep/sigcontext.h"
 #include "irq_user.h"
 #include "ptrace_user.h"
 #include "mem_user.h"
-#include "time_user.h"
 #include "init.h"
 #include "os.h"
 #include "uml-config.h"
@@ -116,16 +114,16 @@ static int stop_ptraced_child(int pid, void *stack, int exitcode,
        if(!WIFEXITED(status) || (WEXITSTATUS(status) != exitcode)) {
                int exit_with = WEXITSTATUS(status);
                if (exit_with == 2)
-                       printk("check_ptrace : child exited with status 2. "
+                       printf("check_ptrace : child exited with status 2. "
                               "Serious trouble happening! Try updating your "
                               "host skas patch!\nDisabling SYSEMU support.");
-               printk("check_ptrace : child exited with exitcode %d, while "
+               printf("check_ptrace : child exited with exitcode %d, while "
                      "expecting %d; status 0x%x", exit_with,
                      exitcode, status);
                if (mustpanic)
                        panic("\n");
                else
-                       printk("\n");
+                       printf("\n");
                ret = -1;
        }
 
@@ -135,7 +133,9 @@ static int stop_ptraced_child(int pid, void *stack, int exitcode,
 }
 
 int ptrace_faultinfo = 1;
+int ptrace_ldt = 1;
 int proc_mm = 1;
+int skas_needs_stub = 0;
 
 static int __init skas0_cmd_param(char *str, int* add)
 {
@@ -181,7 +181,7 @@ static void __init check_sysemu(void)
        void *stack;
        int pid, n, status, count=0;
 
-       printk("Checking syscall emulation patch for ptrace...");
+       printf("Checking syscall emulation patch for ptrace...");
        sysemu_supported = 0;
        pid = start_ptraced_child(&stack);
 
@@ -205,10 +205,10 @@ static void __init check_sysemu(void)
                goto fail_stopped;
 
        sysemu_supported = 1;
-       printk("OK\n");
+       printf("OK\n");
        set_using_sysemu(!force_sysemu_disabled);
 
-       printk("Checking advanced syscall emulation patch for ptrace...");
+       printf("Checking advanced syscall emulation patch for ptrace...");
        pid = start_ptraced_child(&stack);
 
        if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0,
@@ -244,7 +244,7 @@ static void __init check_sysemu(void)
                goto fail_stopped;
 
        sysemu_supported = 2;
-       printk("OK\n");
+       printf("OK\n");
 
        if ( !force_sysemu_disabled )
                set_using_sysemu(sysemu_supported);
@@ -253,7 +253,7 @@ static void __init check_sysemu(void)
 fail:
        stop_ptraced_child(pid, stack, 1, 0);
 fail_stopped:
-       printk("missing\n");
+       printf("missing\n");
 }
 
 static void __init check_ptrace(void)
@@ -261,7 +261,7 @@ static void __init check_ptrace(void)
        void *stack;
        int pid, syscall, n, status;
 
-       printk("Checking that ptrace can change system call numbers...");
+       printf("Checking that ptrace can change system call numbers...");
        pid = start_ptraced_child(&stack);
 
        if(ptrace(PTRACE_OLDSETOPTIONS, pid, 0, (void *)PTRACE_O_TRACESYSGOOD) < 0)
@@ -290,11 +290,11 @@ static void __init check_ptrace(void)
                }
        }
        stop_ptraced_child(pid, stack, 0, 1);
-       printk("OK\n");
+       printf("OK\n");
        check_sysemu();
 }
 
-extern int create_tmp_file(unsigned long len);
+extern int create_tmp_file(unsigned long long len);
 
 static void check_tmpexec(void)
 {
@@ -352,14 +352,26 @@ __uml_setup("noptracefaultinfo", noptracefaultinfo_cmd_param,
 "    it. To support PTRACE_FAULTINFO, the host needs to be patched\n"
 "    using the current skas3 patch.\n\n");
 
+static int __init noptraceldt_cmd_param(char *str, int* add)
+{
+       ptrace_ldt = 0;
+       return 0;
+}
+
+__uml_setup("noptraceldt", noptraceldt_cmd_param,
+"noptraceldt\n"
+"    Turns off usage of PTRACE_LDT, even if host supports it.\n"
+"    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_support(void)
+static inline void check_skas3_ptrace_faultinfo(void)
 {
        struct ptrace_faultinfo fi;
        void *stack;
        int pid, n;
 
-       printf("Checking for the skas3 patch in the host...");
+       printf("  - PTRACE_FAULTINFO...");
        pid = start_ptraced_child(&stack);
 
        n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
@@ -381,9 +393,49 @@ static inline void check_skas3_ptrace_support(void)
        stop_ptraced_child(pid, stack, 1, 1);
 }
 
-int can_do_skas(void)
+static inline void check_skas3_ptrace_ldt(void)
 {
-       printf("Checking for /proc/mm...");
+#ifdef PTRACE_LDT
+       void *stack;
+       int pid, n;
+       unsigned char ldtbuf[40];
+       struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
+               .func = 2, /* read default ldt */
+               .ptr = ldtbuf,
+               .bytecount = sizeof(ldtbuf)};
+
+       printf("  - PTRACE_LDT...");
+       pid = start_ptraced_child(&stack);
+
+       n = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
+       if (n < 0) {
+               if(errno == EIO)
+                       printf("not found\n");
+               else {
+                       perror("not found");
+               }
+               ptrace_ldt = 0;
+       }
+       else {
+               if(ptrace_ldt)
+                       printf("found\n");
+               else
+                       printf("found, but use is disabled\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;
+#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");
@@ -394,8 +446,19 @@ int can_do_skas(void)
                else
                        printf("found\n");
        }
+}
+
+int can_do_skas(void)
+{
+       printf("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)
+               skas_needs_stub = 1;
 
-       check_skas3_ptrace_support();
        return 1;
 }
 #else
@@ -407,6 +470,8 @@ int can_do_skas(void)
 
 int have_devanon = 0;
 
+/* Runs on boot kernel stack - already safe to use printk. */
+
 void check_devanon(void)
 {
        int fd;