9 files changed, 105 insertions, 48 deletions

diff --git a/arch/um/drivers/chan_kern.c b/arch/um/drivers/chan_kern.c
index 14a12d6b3df6..16e7dc89f61d 100644
--- a/arch/um/drivers/chan_kern.c
+++ b/arch/um/drivers/chan_kern.c
@@ -19,18 +19,44 @@
 #include "line.h"
 #include "os.h"
 
-#ifdef CONFIG_NOCONFIG_CHAN
+/* XXX: could well be moved to somewhere else, if needed. */
+static int my_printf(const char * fmt, ...)
+        __attribute__ ((format (printf, 1, 2)));
+
+static int my_printf(const char * fmt, ...)
+{
+        /* Yes, can be called on atomic context.*/
+        char *buf = kmalloc(4096, GFP_ATOMIC);
+        va_list args;
+        int r;
+
+        if (!buf) {
+                /* We print directly fmt.
+                 * Yes, yes, yes, feel free to complain. */
+                r = strlen(fmt);
+        } else {
+                va_start(args, fmt);
+                r = vsprintf(buf, fmt, args);
+                va_end(args);
+                fmt = buf;
+        }
 
-/* The printk's here are wrong because we are complaining that there is no
- * output device, but printk is printing to that output device.  The user will
- * never see the error.  printf would be better, except it can't run on a
- * kernel stack because it will overflow it.
- * Use printk for now since that will avoid crashing.
- */
+        if (r)
+                r = os_write_file(1, fmt, r);
+        return r;
+
+}
+
+#ifdef CONFIG_NOCONFIG_CHAN
+/* Despite its name, there's no added trailing newline. */
+static int my_puts(const char * buf)
+{
+        return os_write_file(1, buf, strlen(buf));
+}
 
 static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(NULL);
 }
@@ -38,27 +64,27 @@ static void *not_configged_init(char *str, int device, struct chan_opts *opts)
 static int not_configged_open(int input, int output, int primary, void *data,
                               char **dev_out)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-ENODEV);
 }
 
 static void not_configged_close(int fd, void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
 }
 
 static int not_configged_read(int fd, char *c_out, void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-EIO);
 }
 
 static int not_configged_write(int fd, const char *buf, int len, void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-EIO);
 }
@@ -66,7 +92,7 @@ static int not_configged_write(int fd, const char *buf, int len, void *data)
 static int not_configged_console_write(int fd, const char *buf, int len,
                                        void *data)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-EIO);
 }
@@ -74,14 +100,14 @@ static int not_configged_console_write(int fd, const char *buf, int len,
 static int not_configged_window_size(int fd, void *data, unsigned short *rows,
                                      unsigned short *cols)
 {
-        printk(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
         return(-ENODEV);
 }
 
 static void not_configged_free(void *data)
 {
-        printf(KERN_ERR "Using a channel type which is configured out of "
+        my_puts("Using a channel type which is configured out of "
                "UML\n");
 }
 
@@ -457,7 +483,7 @@ static struct chan *parse_chan(char *str, int pri, int device,
                 }
         }
         if(ops == NULL){
-                printk(KERN_ERR "parse_chan couldn't parse \"%s\"\n", 
+                my_printf("parse_chan couldn't parse \"%s\"\n",
                        str);
                 return(NULL);
         }
@@ -465,7 +491,7 @@ static struct chan *parse_chan(char *str, int pri, int device,
         data = (*ops->init)(str, device, opts);
         if(data == NULL) return(NULL);
 
-        chan = kmalloc(sizeof(*chan), GFP_KERNEL);
+        chan = kmalloc(sizeof(*chan), GFP_ATOMIC);
         if(chan == NULL) return(NULL);
         *chan = ((struct chan) { .list          = LIST_HEAD_INIT(chan->list),
                                  .primary       = 1,
diff --git a/arch/um/drivers/mconsole_user.c b/arch/um/drivers/mconsole_user.c
index 310c1f823f26..04383f98f4d5 100644
--- a/arch/um/drivers/mconsole_user.c
+++ b/arch/um/drivers/mconsole_user.c
@@ -23,7 +23,7 @@ static struct mconsole_command commands[] = {
         { "reboot", mconsole_reboot, MCONSOLE_PROC },
         { "config", mconsole_config, MCONSOLE_PROC },
         { "remove", mconsole_remove, MCONSOLE_PROC },
-        { "sysrq", mconsole_sysrq, MCONSOLE_INTR },
+        { "sysrq", mconsole_sysrq, MCONSOLE_PROC },
         { "help", mconsole_help, MCONSOLE_INTR },
         { "cad", mconsole_cad, MCONSOLE_INTR },
         { "stop", mconsole_stop, MCONSOLE_PROC },
diff --git a/arch/um/include/user.h b/arch/um/include/user.h
index 57ee9e261228..0f865ef46918 100644
--- a/arch/um/include/user.h
+++ b/arch/um/include/user.h
@@ -14,7 +14,9 @@ extern void *um_kmalloc_atomic(int size);
 extern void kfree(void *ptr);
 extern int in_aton(char *str);
 extern int open_gdb_chan(void);
-extern int strlcpy(char *, const char *, int);
+/* These use size_t, however unsigned long is correct on both i386 and x86_64. */
+extern unsigned long strlcpy(char *, const char *, unsigned long);
+extern unsigned long strlcat(char *, const char *, unsigned long);
 extern void *um_vmalloc(int size);
 extern void vfree(void *ptr);
 
diff --git a/arch/um/kernel/process_kern.c b/arch/um/kernel/process_kern.c
index 39cf568ccfaf..ea65db679e9c 100644
--- a/arch/um/kernel/process_kern.c
+++ b/arch/um/kernel/process_kern.c
@@ -82,7 +82,8 @@ unsigned long alloc_stack(int order, int atomic)
         unsigned long page;
         int flags = GFP_KERNEL;
 
-        if(atomic) flags |= GFP_ATOMIC;
+        if (atomic)
+                flags = GFP_ATOMIC;
         page = __get_free_pages(flags, order);
         if(page == 0)
                 return(0);
diff --git a/arch/um/kernel/sigio_user.c b/arch/um/kernel/sigio_user.c
index e89218958f38..a52751108aa1 100644
--- a/arch/um/kernel/sigio_user.c
+++ b/arch/um/kernel/sigio_user.c
@@ -340,7 +340,7 @@ static int setup_initial_poll(int fd)
 {
         struct pollfd *p;
 
-        p = um_kmalloc(sizeof(struct pollfd));
+        p = um_kmalloc_atomic(sizeof(struct pollfd));
         if(p == NULL){
                 printk("setup_initial_poll : failed to allocate poll\n");
                 return(-1);
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 0a562c3c0fd8..f5b0636f9ad7 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -193,12 +193,12 @@ void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
                 r = pte_read(*npte);
                 w = pte_write(*npte);
                 x = pte_exec(*npte);
-                if(!pte_dirty(*npte))
-                        w = 0;
-                if(!pte_young(*npte)){
-                        r = 0;
-                        w = 0;
-                }
+                if (!pte_young(*npte)) {
+                        r = 0;
+                        w = 0;
+                } else if (!pte_dirty(*npte)) {
+                        w = 0;
+                }
                 if(force || pte_newpage(*npte)){
                         if(pte_present(*npte))
                           ret = add_mmap(addr,
diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c
index 87cc6fd76ced..d297429ac360 100644
--- a/arch/um/kernel/trap_kern.c
+++ b/arch/um/kernel/trap_kern.c
@@ -18,6 +18,7 @@
 #include "asm/a.out.h"
 #include "asm/current.h"
 #include "asm/irq.h"
+#include "sysdep/sigcontext.h"
 #include "user_util.h"
 #include "kern_util.h"
 #include "kern.h"
@@ -39,6 +40,12 @@ int handle_page_fault(unsigned long address, unsigned long ip,
         int err = -EFAULT;
 
         *code_out = SEGV_MAPERR;
+
+        /* If the fault was during atomic operation, don't take the fault, just
+         * fail. */
+        if (in_atomic())
+                goto out_nosemaphore;
+
         down_read(&mm->mmap_sem);
         vma = find_vma(mm, address);
         if(!vma) 
@@ -89,6 +96,7 @@ survive:
         flush_tlb_page(vma, address);
 out:
         up_read(&mm->mmap_sem);
+out_nosemaphore:
         return(err);
 
 /*
@@ -125,7 +133,15 @@ unsigned long segv(struct faultinfo fi, unsigned long ip, int is_user, void *sc)
         }
         else if(current->mm == NULL)
                 panic("Segfault with no mm");
-        err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
+
+        if (SEGV_IS_FIXABLE(&fi))
+                err = handle_page_fault(address, ip, is_write, is_user, &si.si_code);
+        else {
+                err = -EFAULT;
+                /* A thread accessed NULL, we get a fault, but CR2 is invalid.
+                 * This code is used in __do_copy_from_user() of TT mode. */
+                address = 0;
+        }
 
         catcher = current->thread.fault_catcher;
         if(!err)
diff --git a/arch/um/kernel/tt/uaccess_user.c b/arch/um/kernel/tt/uaccess_user.c
index f01475512ecb..8c220f054b61 100644
--- a/arch/um/kernel/tt/uaccess_user.c
+++ b/arch/um/kernel/tt/uaccess_user.c
@@ -22,8 +22,15 @@ int __do_copy_from_user(void *to, const void *from, int n,
                                __do_copy, &faulted);
         TASK_REGS(get_current())->tt = save;
 
-        if(!faulted) return(0);
-        else return(n - (fault - (unsigned long) from));
+        if(!faulted)
+                return 0;
+        else if (fault)
+                return n - (fault - (unsigned long) from);
+        else
+                /* In case of a general protection fault, we don't have the
+                 * fault address, so NULL is used instead. Pretend we didn't
+                 * copy anything. */
+                return n;
 }
 
 static void __do_strncpy(void *dst, const void *src, int count)
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
index 186c28885016..0b21d59ba0cd 100644
--- a/arch/um/kernel/umid.c
+++ b/arch/um/kernel/umid.c
@@ -31,6 +31,8 @@ static char *uml_dir = UML_DIR;
 /* Changed by set_umid */
 static int umid_is_random = 1;
 static int umid_inited = 0;
+/* Have we created the files? Should we remove them? */
+static int umid_owned = 0;
 
 static int make_umid(int (*printer)(const char *fmt, ...));
 
@@ -82,20 +84,21 @@ int __init umid_file_name(char *name, char *buf, int len)
 
 extern int tracing_pid;
 
-static int __init create_pid_file(void)
+static void __init create_pid_file(void)
 {
         char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
         char pid[sizeof("nnnnn\0")];
         int fd, n;
 
-        if(umid_file_name("pid", file, sizeof(file))) return 0;
+        if(umid_file_name("pid", file, sizeof(file)))
+                return;
 
         fd = os_open_file(file, of_create(of_excl(of_rdwr(OPENFLAGS()))), 
                           0644);
         if(fd < 0){
                 printf("Open of machine pid file \"%s\" failed: %s\n",
                        file, strerror(-fd));
-                return 0;
+                return;
         }
 
         sprintf(pid, "%d\n", os_getpid());
@@ -103,7 +106,6 @@ static int __init create_pid_file(void)
         if(n != strlen(pid))
                 printf("Write of pid file failed - err = %d\n", -n);
         os_close_file(fd);
-        return 0;
 }
 
 static int actually_do_remove(char *dir)
@@ -147,7 +149,8 @@ static int actually_do_remove(char *dir)
 void remove_umid_dir(void)
 {
         char dir[strlen(uml_dir) + UMID_LEN + 1];
-        if(!umid_inited) return;
+        if (!umid_owned)
+                return;
 
         sprintf(dir, "%s%s", uml_dir, umid);
         actually_do_remove(dir);
@@ -155,11 +158,12 @@ void remove_umid_dir(void)
 
 char *get_umid(int only_if_set)
 {
-        if(only_if_set && umid_is_random) return(NULL);
-        return(umid);
+        if(only_if_set && umid_is_random)
+                return NULL;
+        return umid;
 }
 
-int not_dead_yet(char *dir)
+static int not_dead_yet(char *dir)
 {
         char file[strlen(uml_dir) + UMID_LEN + sizeof("/pid\0")];
         char pid[sizeof("nnnnn\0")], *end;
@@ -193,7 +197,8 @@ int not_dead_yet(char *dir)
                    (p == CHOOSE_MODE(tracing_pid, os_getpid())))
                         dead = 1;
         }
-        if(!dead) return(1);
+        if(!dead)
+                return(1);
         return(actually_do_remove(dir));
 }
 
@@ -232,16 +237,13 @@ static int __init make_uml_dir(void)
                 strlcpy(dir, home, sizeof(dir));
                 uml_dir++;
         }
+        strlcat(dir, uml_dir, sizeof(dir));
         len = strlen(dir);
-        strncat(dir, uml_dir, sizeof(dir) - len);
-        len = strlen(dir);
-        if((len > 0) && (len < sizeof(dir) - 1) && (dir[len - 1] != '/')){
-                dir[len] = '/';
-                dir[len + 1] = '\0';
-        }
+        if (len > 0 && dir[len - 1] != '/')
+                strlcat(dir, "/", sizeof(dir));
 
         uml_dir = malloc(strlen(dir) + 1);
-        if(uml_dir == NULL){
+        if (uml_dir == NULL) {
                 printf("make_uml_dir : malloc failed, errno = %d\n", errno);
                 exit(1);
         }
@@ -286,6 +288,7 @@ static int __init make_umid(int (*printer)(const char *fmt, ...))
                 if(errno == EEXIST){
                         if(not_dead_yet(tmp)){
                                 (*printer)("umid '%s' is in use\n", umid);
+                                umid_owned = 0;
                                 return(-1);
                         }
                         err = mkdir(tmp, 0777);
@@ -296,7 +299,8 @@ static int __init make_umid(int (*printer)(const char *fmt, ...))
                 return(-1);
         }
 
-        return(0);
+        umid_owned = 1;
+        return 0;
 }
 
 __uml_setup("uml_dir=", set_uml_dir,
@@ -309,7 +313,8 @@ static int __init make_umid_setup(void)
         /* one function with the ordering we need ... */
         make_uml_dir();
         make_umid(printf);
-        return create_pid_file();
+        create_pid_file();
+        return 0;
 }
 __uml_postsetup(make_umid_setup);