10 files changed, 78 insertions, 39 deletions

diff --git a/arch/um/drivers/cow.h b/arch/um/drivers/cow.h
index dc36b222100b..04e3958266e0 100644
--- a/arch/um/drivers/cow.h
+++ b/arch/um/drivers/cow.h
@@ -46,7 +46,7 @@ extern int file_reader(__u64 offset, char *buf, int len, void *arg);
 extern int read_cow_header(int (*reader)(__u64, char *, int, void *),
                            void *arg, __u32 *version_out,
                            char **backing_file_out, time_t *mtime_out,
-                           unsigned long long *size_out, int *sectorsize_out,
+                           __u64 *size_out, int *sectorsize_out,
                            __u32 *align_out, int *bitmap_offset_out);
 
 extern int write_cow_header(char *cow_file, int fd, char *backing_file,
diff --git a/arch/um/drivers/cow_sys.h b/arch/um/drivers/cow_sys.h
index c83fc5d68936..94de4ead4f7a 100644
--- a/arch/um/drivers/cow_sys.h
+++ b/arch/um/drivers/cow_sys.h
@@ -23,17 +23,17 @@ static inline char *cow_strdup(char *str)
         return(uml_strdup(str));
 }
 
-static inline int cow_seek_file(int fd, unsigned long long offset)
+static inline int cow_seek_file(int fd, __u64 offset)
 {
         return(os_seek_file(fd, offset));
 }
 
-static inline int cow_file_size(char *file, unsigned long long *size_out)
+static inline int cow_file_size(char *file, __u64 *size_out)
 {
         return(os_file_size(file, size_out));
 }
 
-static inline int cow_write_file(int fd, char *buf, int size)
+static inline int cow_write_file(int fd, void *buf, int size)
 {
         return(os_write_file(fd, buf, size));
 }
diff --git a/arch/um/drivers/cow_user.c b/arch/um/drivers/cow_user.c
index fbe2217db5dd..61951b721268 100644
--- a/arch/um/drivers/cow_user.c
+++ b/arch/um/drivers/cow_user.c
@@ -176,7 +176,7 @@ int write_cow_header(char *cow_file, int fd, char *backing_file,
         err = -ENOMEM;
         header = cow_malloc(sizeof(*header));
         if(header == NULL){
-                cow_printf("Failed to allocate COW V3 header\n");
+                cow_printf("write_cow_header - failed to allocate COW V3 header\n");
                 goto out;
         }
         header->magic = htonl(COW_MAGIC);
@@ -196,15 +196,17 @@ int write_cow_header(char *cow_file, int fd, char *backing_file,
 
         err = os_file_modtime(header->backing_file, &modtime);
         if(err < 0){
-                cow_printf("Backing file '%s' mtime request failed, "
-                           "err = %d\n", header->backing_file, -err);
+                cow_printf("write_cow_header - backing file '%s' mtime "
+                           "request failed, err = %d\n", header->backing_file,
+                           -err);
                 goto out_free;
         }
 
         err = cow_file_size(header->backing_file, size);
         if(err < 0){
-                cow_printf("Couldn't get size of backing file '%s', "
-                           "err = %d\n", header->backing_file, -err);
+                cow_printf("write_cow_header - couldn't get size of "
+                           "backing file '%s', err = %d\n",
+                           header->backing_file, -err);
                 goto out_free;
         }
 
@@ -214,10 +216,11 @@ int write_cow_header(char *cow_file, int fd, char *backing_file,
         header->alignment = htonl(alignment);
         header->cow_format = COW_BITMAP;
 
-        err = os_write_file(fd, header, sizeof(*header));
+        err = cow_write_file(fd, header, sizeof(*header));
         if(err != sizeof(*header)){
-                cow_printf("Write of header to new COW file '%s' failed, "
-                           "err = %d\n", cow_file, -err);
+                cow_printf("write_cow_header - write of header to "
+                           "new COW file '%s' failed, err = %d\n", cow_file,
+                           -err);
                 goto out_free;
         }
         err = 0;
@@ -299,7 +302,7 @@ int read_cow_header(int (*reader)(__u64, char *, int, void *), void *arg,
         }
         else if(version == 3){
                 if(n < sizeof(header->v3)){
-                        cow_printf("read_cow_header - failed to read V2 "
+                        cow_printf("read_cow_header - failed to read V3 "
                                    "header\n");
                         goto out;
                 }
@@ -359,7 +362,8 @@ int init_cow_file(int fd, char *cow_file, char *backing_file, int sectorsize,
         if(err != sizeof(zero)){
                 cow_printf("Write of bitmap to new COW file '%s' failed, "
                            "err = %d\n", cow_file, -err);
-                err = -EINVAL;
+                if (err >= 0)
+                        err = -EINVAL;
                 goto out;
         }
 
diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c
index 098fa65981ab..0e2f06187ea7 100644
--- a/arch/um/drivers/net_user.c
+++ b/arch/um/drivers/net_user.c
@@ -47,10 +47,12 @@ void tap_check_ips(char *gate_addr, unsigned char *eth_addr)
         }
 }
 
+/* Do reliable error handling as this fails frequently enough. */
 void read_output(int fd, char *output, int len)
 {
-        int remain, n, actual;
+        int remain, ret, expected;
         char c;
+        char *str;
 
         if(output == NULL){
                 output = &c;
@@ -58,23 +60,31 @@ void read_output(int fd, char *output, int len)
         }
                 
         *output = '\0';
-        n = os_read_file(fd, &remain, sizeof(remain));
-        if(n != sizeof(remain)){
-                printk("read_output - read of length failed, err = %d\n", -n);
-                return;
+        ret = os_read_file(fd, &remain, sizeof(remain));
+
+        if (ret != sizeof(remain)) {
+                expected = sizeof(remain);
+                str = "length";
+                goto err;
         }
 
         while(remain != 0){
-                n = (remain < len) ? remain : len;
-                actual = os_read_file(fd, output, n);
-                if(actual != n){
-                        printk("read_output - read of data failed, "
-                               "err = %d\n", -actual);
-                        return;
+                expected = (remain < len) ? remain : len;
+                ret = os_read_file(fd, output, expected);
+                if (ret != expected) {
+                        str = "data";
+                        goto err;
                 }
-                remain -= actual;
+                remain -= ret;
         }
+
         return;
+
+err:
+        if (ret < 0)
+                printk("read_output - read of %s failed, errno = %d\n", str, -ret);
+        else
+                printk("read_output - read of %s failed, read only %d of %d bytes\n", str, ret, expected);
 }
 
 int net_read(int fd, void *buf, int len)
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 101efd26d467..fa617e0719ab 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -1135,7 +1135,7 @@ static int path_requires_switch(char *from_cmdline, char *from_cow, char *cow)
 static int backing_file_mismatch(char *file, __u64 size, time_t mtime)
 {
         unsigned long modtime;
-        long long actual;
+        unsigned long long actual;
         int err;
 
         err = os_file_modtime(file, &modtime);
diff --git a/arch/um/include/init.h b/arch/um/include/init.h
index cbd79a8d213d..d4de7c0120ce 100644
--- a/arch/um/include/init.h
+++ b/arch/um/include/init.h
@@ -122,7 +122,7 @@ extern struct uml_param __uml_setup_start, __uml_setup_end;
 
 #define __exitcall(fn) static exitcall_t __exitcall_##fn __exit_call = fn
 
-#define __init_call __attribute__ ((unused,__section__ (".initcall.init")))
+#define __init_call     __attribute_used__ __attribute__ ((__section__ (".initcall.init")))
 
 #endif
 
diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index eb1710b81255..2a1c64d8d0bf 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -179,8 +179,11 @@ extern void os_stop_process(int pid);
 extern void os_kill_process(int pid, int reap_child);
 extern void os_kill_ptraced_process(int pid, int reap_child);
 extern void os_usr1_process(int pid);
+extern long os_ptrace_ldt(long pid, long addr, long data);
+
 extern int os_getpid(void);
 extern int os_getpgrp(void);
+
 extern void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int));
 extern void init_new_thread_signals(int altstack);
 extern int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr);
diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c
index f55773c819e6..3bd10deea280 100644
--- a/arch/um/os-Linux/file.c
+++ b/arch/um/os-Linux/file.c
@@ -272,14 +272,23 @@ int os_connect_socket(char *name)
         snprintf(sock.sun_path, sizeof(sock.sun_path), "%s", name);
 
         fd = socket(AF_UNIX, SOCK_STREAM, 0);
-        if(fd < 0)
-                return(fd);
+        if(fd < 0) {
+                err = -errno;
+                goto out;
+        }
 
         err = connect(fd, (struct sockaddr *) &sock, sizeof(sock));
-        if(err)
-                return(-errno);
+        if(err) {
+                err = -errno;
+                goto out_close;
+        }
 
-        return(fd);
+        return fd;
+
+out_close:
+        close(fd);
+out:
+        return err;
 }
 
 void os_close_file(int fd)
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 7f5e2dac2a35..d261888f39c4 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -19,6 +19,7 @@
 #include "irq_user.h"
 #include "kern_util.h"
 #include "longjmp.h"
+#include "skas_ptrace.h"
 
 #define ARBITRARY_ADDR -1
 #define FAILURE_PID    -1
@@ -100,6 +101,21 @@ void os_kill_process(int pid, int reap_child)
                 
 }
 
+/* This is here uniquely to have access to the userspace errno, i.e. the one
+ * used by ptrace in case of error.
+ */
+
+long os_ptrace_ldt(long pid, long addr, long data)
+{
+        int ret;
+
+        ret = ptrace(PTRACE_LDT, pid, addr, data);
+
+        if (ret < 0)
+                return -errno;
+        return ret;
+}
+
 /* Kill off a ptraced child by all means available.  kill it normally first,
  * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
  * which it can't exit directly.
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index 1fa09a79a10b..fe0877b3509c 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -107,7 +107,7 @@ long write_ldt_entry(struct mm_id * mm_idp, int func, struct user_desc * desc,
                  * So we need to switch child's mm into our userspace, then
                  * later switch back.
                  *
-                 * Note: I'm unshure: should interrupts be disabled here?
+                 * Note: I'm unsure: should interrupts be disabled here?
                  */
                 if(!current->active_mm || current->active_mm == &init_mm ||
                    mm_idp != &current->active_mm->context.skas.id)
@@ -129,9 +129,7 @@ long write_ldt_entry(struct mm_id * mm_idp, int func, struct user_desc * desc,
                         pid = userspace_pid[cpu];
                 }
 
-                res = ptrace(PTRACE_LDT, pid, 0, (unsigned long) &ldt_op);
-                if(res)
-                        res = errno;
+                res = os_ptrace_ldt(pid, 0, (unsigned long) &ldt_op);
 
                 if(proc_mm)
                         put_cpu();
@@ -181,8 +179,7 @@ static long read_ldt_from_host(void __user * ptr, unsigned long bytecount)
          */
 
         cpu = get_cpu();
-        res = ptrace(PTRACE_LDT, userspace_pid[cpu], 0,
-                     (unsigned long) &ptrace_ldt);
+        res = os_ptrace_ldt(userspace_pid[cpu], 0, (unsigned long) &ptrace_ldt);
         put_cpu();
         if(res < 0)
                 goto out;