1 files changed, 92 insertions, 62 deletions

diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 735d035a7f33..5178eba9afa5 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -73,6 +73,34 @@ static int ptrace_child(void *arg)
         _exit(ret);
 }
 
+static void fatal_perror(char *str)
+{
+        perror(str);
+        exit(1);
+}
+
+static void fatal(char *fmt, ...)
+{
+        va_list list;
+
+        va_start(list, fmt);
+        vprintf(fmt, list);
+        va_end(list);
+        fflush(stdout);
+
+        exit(1);
+}
+
+static void non_fatal(char *fmt, ...)
+{
+        va_list list;
+
+        va_start(list, fmt);
+        vprintf(fmt, list);
+        va_end(list);
+        fflush(stdout);
+}
+
 static int start_ptraced_child(void **stack_out)
 {
         void *stack;
@@ -82,16 +110,16 @@ static int start_ptraced_child(void **stack_out)
         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);
+                fatal_perror("check_ptrace : mmap failed");
         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);
+                fatal_perror("start_ptraced_child : clone failed");
         CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
         if(n < 0)
-                panic("check_ptrace : clone failed, errno = %d", errno);
+                fatal_perror("check_ptrace : clone failed");
         if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP))
-                panic("check_ptrace : expected SIGSTOP, got status = %d",
+                fatal("check_ptrace : expected SIGSTOP, got status = %d",
                       status);
 
         *stack_out = stack;
@@ -105,31 +133,30 @@ static int start_ptraced_child(void **stack_out)
  * must work anyway!
  */
 static int stop_ptraced_child(int pid, void *stack, int exitcode,
-                              int mustpanic)
+                              int mustexit)
 {
         int status, n, ret = 0;
 
         if(ptrace(PTRACE_CONT, pid, 0, 0) < 0)
-                panic("check_ptrace : ptrace failed, errno = %d", errno);
+                fatal_perror("stop_ptraced_child : ptrace failed");
         CATCH_EINTR(n = waitpid(pid, &status, 0));
         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. "
+                                  "Serious trouble happening! Try updating "
+                                  "your host skas patch!\nDisabling SYSEMU "
+                                  "support.");
+                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);
+                fatal_perror("check_ptrace : munmap failed");
         return ret;
 }
 
@@ -184,7 +211,7 @@ static void __init check_sysemu(void)
         void *stack;
         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);
 
@@ -193,31 +220,30 @@ static void __init check_sysemu(void)
 
         CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
         if (n < 0)
-                panic("check_sysemu : wait failed, errno = %d", errno);
+                fatal_perror("check_sysemu : wait failed");
         if(!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGTRAP))
-                panic("check_sysemu : expected SIGTRAP, "
-                      "got status = %d", status);
+                fatal("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);
+                fatal_perror("check_sysemu : failed to modify system call "
+                             "return");
 
         if (stop_ptraced_child(pid, stack, 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...");
+        non_fatal("Checking advanced syscall emulation patch for ptrace...");
         pid = start_ptraced_child(&stack);
 
-        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){
                 count++;
@@ -225,29 +251,30 @@ static void __init check_sysemu(void)
                         goto fail;
                 CATCH_EINTR(n = waitpid(pid, &status, WUNTRACED));
                 if(n < 0)
-                        panic("check_ptrace : wait failed, errno = %d", errno);
+                        fatal_perror("check_ptrace : wait failed");
+
                 if(WIFSTOPPED(status) && (WSTOPSIG(status) == (SIGTRAP|0x80))){
                         if (!count)
-                                panic("check_ptrace : SYSEMU_SINGLESTEP "
+                                fatal("check_ptrace : SYSEMU_SINGLESTEP "
                                       "doesn't singlestep");
                         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);
+                                fatal_perror("check_sysemu : failed to modify "
+                                             "system call return");
                         break;
                 }
                 else if(WIFSTOPPED(status) && (WSTOPSIG(status) == SIGTRAP))
                         count++;
                 else
-                        panic("check_ptrace : expected SIGTRAP or "
-                              "(SIGTRAP|0x80), got status = %d", status);
+                        fatal("check_ptrace : expected SIGTRAP or "
+                              "(SIGTRAP | 0x80), got status = %d", status);
         }
         if (stop_ptraced_child(pid, stack, 0, 0) < 0)
                 goto fail_stopped;
 
         sysemu_supported = 2;
-        printf("OK\n");
+        non_fatal("OK\n");
 
         if ( !force_sysemu_disabled )
                 set_using_sysemu(sysemu_supported);
@@ -256,7 +283,7 @@ static void __init check_sysemu(void)
 fail:
         stop_ptraced_child(pid, stack, 1, 0);
 fail_stopped:
-        printf("missing\n");
+        non_fatal("missing\n");
 }
 
 static void __init check_ptrace(void)
@@ -264,22 +291,25 @@ static void __init check_ptrace(void)
         void *stack;
         int pid, syscall, n, status;
 
-        printf("Checking that ptrace can change system call numbers...");
+        non_fatal("Checking that ptrace can change system call numbers...");
         pid = start_ptraced_child(&stack);
 
-        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)
-                        panic("check_ptrace : ptrace failed, errno = %d",
-                              errno);
+                        fatal_perror("check_ptrace : ptrace failed");
+
                 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);
+                        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,
                                  0);
@@ -287,13 +317,13 @@ static void __init check_ptrace(void)
                         n = ptrace(PTRACE_POKEUSR, pid, PT_SYSCALL_NR_OFFSET,
                                    __NR_getppid);
                         if(n < 0)
-                                panic("check_ptrace : failed to modify system "
-                                      "call, errno = %d", errno);
+                                fatal_perror("check_ptrace : failed to modify "
+                                             "system call");
                         break;
                 }
         }
         stop_ptraced_child(pid, stack, 0, 1);
-        printf("OK\n");
+        non_fatal("OK\n");
         check_sysemu();
 }
 
@@ -352,22 +382,22 @@ static inline void check_skas3_ptrace_faultinfo(void)
         void *stack;
         int pid, n;
 
-        printf("  - PTRACE_FAULTINFO...");
+        non_fatal("  - PTRACE_FAULTINFO...");
         pid = start_ptraced_child(&stack);
 
         n = ptrace(PTRACE_FAULTINFO, pid, 0, &fi);
         if (n < 0) {
                 ptrace_faultinfo = 0;
                 if(errno == EIO)
-                        printf("not found\n");
+                        non_fatal("not found\n");
                 else
                         perror("not found");
         }
         else {
                 if (!ptrace_faultinfo)
-                        printf("found but disabled on command line\n");
+                        non_fatal("found but disabled on command line\n");
                 else
-                        printf("found\n");
+                        non_fatal("found\n");
         }
 
         init_registers(pid);
@@ -385,13 +415,13 @@ static inline void check_skas3_ptrace_ldt(void)
                 .ptr = ldtbuf,
                 .bytecount = sizeof(ldtbuf)};
 
-        printf("  - PTRACE_LDT...");
+        non_fatal("  - 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");
+                        non_fatal("not found\n");
                 else {
                         perror("not found");
                 }
@@ -399,9 +429,9 @@ static inline void check_skas3_ptrace_ldt(void)
         }
         else {
                 if(ptrace_ldt)
-                        printf("found\n");
+                        non_fatal("found\n");
                 else
-                        printf("found, but use is disabled\n");
+                        non_fatal("found, but use is disabled\n");
         }
 
         stop_ptraced_child(pid, stack, 1, 1);
@@ -416,22 +446,22 @@ static inline void check_skas3_ptrace_ldt(void)
 
 static inline void check_skas3_proc_mm(void)
 {
-        printf("  - /proc/mm...");
+        non_fatal("  - /proc/mm...");
         if (access("/proc/mm", W_OK) < 0) {
                 proc_mm = 0;
-                printf("not found\n");
+                perror("not found");
         }
         else {
                 if (!proc_mm)
-                        printf("found but disabled on command line\n");
+                        non_fatal("found but disabled on command line\n");
                 else
-                        printf("found\n");
+                        non_fatal("found\n");
         }
 }
 
 int 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();