7 files changed, 145 insertions, 51 deletions

diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index 71bb90a7606d..c6432e729241 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -8,6 +8,7 @@
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/mman.h>
+#include <sys/statfs.h>
 #include "kern_util.h"
 #include "user.h"
 #include "user_util.h"
@@ -19,6 +20,7 @@
 
 #include <sys/param.h>
 
+static char *default_tmpdir = "/tmp";
 static char *tempdir = NULL;
 
 static void __init find_tempdir(void)
@@ -34,7 +36,7 @@ static void __init find_tempdir(void)
                         break;
         }
         if((dir == NULL) || (*dir == '\0'))
-                dir = "/tmp";
+                dir = default_tmpdir;
 
         tempdir = malloc(strlen(dir) + 2);
         if(tempdir == NULL){
@@ -46,6 +48,96 @@ static void __init find_tempdir(void)
         strcat(tempdir, "/");
 }
 
+/* This will return 1, with the first character in buf being the
+ * character following the next instance of c in the file.  This will
+ * read the file as needed.  If there's an error, -errno is returned;
+ * if the end of the file is reached, 0 is returned.
+ */
+static int next(int fd, char *buf, int size, char c)
+{
+        int n;
+        char *ptr;
+
+        while((ptr = strchr(buf, c)) == NULL){
+                n = read(fd, buf, size - 1);
+                if(n == 0)
+                        return 0;
+                else if(n < 0)
+                        return -errno;
+
+                buf[n] = '\0';
+        }
+
+        ptr++;
+        memmove(buf, ptr, strlen(ptr) + 1);
+        return 1;
+}
+
+static int checked_tmpdir = 0;
+
+/* Look for a tmpfs mounted at /dev/shm.  I couldn't find a cleaner
+ * way to do this than to parse /proc/mounts.  statfs will return the
+ * same filesystem magic number and fs id for both /dev and /dev/shm
+ * when they are both tmpfs, so you can't tell if they are different
+ * filesystems.  Also, there seems to be no other way of finding the
+ * mount point of a filesystem from within it.
+ *
+ * If a /dev/shm tmpfs entry is found, then we switch to using it.
+ * Otherwise, we stay with the default /tmp.
+ */
+static void which_tmpdir(void)
+{
+        int fd, found;
+        char buf[128] = { '\0' };
+
+        if(checked_tmpdir)
+                return;
+
+        checked_tmpdir = 1;
+
+        printf("Checking for tmpfs mount on /dev/shm...");
+
+        fd = open("/proc/mounts", O_RDONLY);
+        if(fd < 0){
+                printf("failed to open /proc/mounts, errno = %d\n", errno);
+                return;
+        }
+
+        while(1){
+                found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
+                if(found != 1)
+                        break;
+
+                if(!strncmp(buf, "/dev/shm", strlen("/dev/shm")))
+                        goto found;
+
+                found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), '\n');
+                if(found != 1)
+                        break;
+        }
+
+err:
+        if(found == 0)
+                printf("nothing mounted on /dev/shm\n");
+        else if(found < 0)
+                printf("read returned errno %d\n", -found);
+
+        return;
+
+found:
+        found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
+        if(found != 1)
+                goto err;
+
+        if(strncmp(buf, "tmpfs", strlen("tmpfs"))){
+                printf("not tmpfs\n");
+                return;
+        }
+
+        printf("OK\n");
+        default_tmpdir = "/dev/shm";
+}
+
 /*
  * This proc still used in tt-mode
  * (file: kernel/tt/ptproxy/proxy.c, proc: start_debugger).
@@ -56,6 +148,7 @@ int make_tempfile(const char *template, char **out_tempname, int do_unlink)
         char *tempname;
         int fd;
 
+        which_tmpdir();
         tempname = malloc(MAXPATHLEN);
 
         find_tempdir();
@@ -137,3 +230,26 @@ int create_mem_file(unsigned long long len)
         }
         return(fd);
 }
+
+
+void check_tmpexec(void)
+{
+        void *addr;
+        int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
+
+        addr = mmap(NULL, UM_KERN_PAGE_SIZE,
+                    PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
+        printf("Checking PROT_EXEC mmap in %s...",tempdir);
+        fflush(stdout);
+        if(addr == MAP_FAILED){
+                err = errno;
+                perror("failed");
+                if(err == EPERM)
+                        printf("%s must be not mounted noexec\n",tempdir);
+                exit(1);
+        }
+        printf("OK\n");
+        munmap(addr, UM_KERN_PAGE_SIZE);
+
+        close(fd);
+}
diff --git a/arch/um/os-Linux/process.c b/arch/um/os-Linux/process.c
index 8176b0b52047..3505f44f8a25 100644
--- a/arch/um/os-Linux/process.c
+++ b/arch/um/os-Linux/process.c
@@ -190,7 +190,7 @@ int os_unmap_memory(void *addr, int len)
 }
 
 #ifndef MADV_REMOVE
-#define MADV_REMOVE     0x5             /* remove these pages & resources */
+#define MADV_REMOVE KERNEL_MADV_REMOVE
 #endif
 
 int os_drop_memory(void *addr, int length)
@@ -216,7 +216,7 @@ int can_drop_memory(void)
         }
 
         addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
-                      MAP_PRIVATE, fd, 0);
+                      MAP_SHARED, fd, 0);
         if(addr == MAP_FAILED){
                 printk("Mapping test memory file failed, err = %d\n", -errno);
                 return 0;
@@ -266,11 +266,11 @@ void init_new_thread_signals(int altstack)
 
 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
 {
-        sigjmp_buf buf;
+        jmp_buf buf;
         int n, enable;
 
         *jmp_ptr = &buf;
-        n = UML_SIGSETJMP(&buf, enable);
+        n = UML_SETJMP(&buf, enable);
         if(n != 0)
                 return(n);
         (*fn)(arg);
diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index 045ae0037456..0776bc18ca85 100644
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -434,7 +434,7 @@ void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
                 void (*handler)(int))
 {
         unsigned long flags;
-        sigjmp_buf switch_buf, fork_buf;
+        jmp_buf switch_buf, fork_buf;
         int enable;
 
         *switch_buf_ptr = &switch_buf;
@@ -450,7 +450,7 @@ void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
          */
         flags = get_signals();
         block_signals();
-        if(UML_SIGSETJMP(&fork_buf, enable) == 0)
+        if(UML_SETJMP(&fork_buf, enable) == 0)
                 new_thread_proc(stack, handler);
 
         remove_sigstack();
@@ -466,35 +466,35 @@ void new_thread(void *stack, void **switch_buf_ptr, void **fork_buf_ptr,
 
 void thread_wait(void *sw, void *fb)
 {
-        sigjmp_buf buf, **switch_buf = sw, *fork_buf;
+        jmp_buf buf, **switch_buf = sw, *fork_buf;
         int enable;
 
         *switch_buf = &buf;
         fork_buf = fb;
-        if(UML_SIGSETJMP(&buf, enable) == 0)
+        if(UML_SETJMP(&buf, enable) == 0)
                 siglongjmp(*fork_buf, INIT_JMP_REMOVE_SIGSTACK);
 }
 
 void switch_threads(void *me, void *next)
 {
-        sigjmp_buf my_buf, **me_ptr = me, *next_buf = next;
+        jmp_buf my_buf, **me_ptr = me, *next_buf = next;
         int enable;
 
         *me_ptr = &my_buf;
-        if(UML_SIGSETJMP(&my_buf, enable) == 0)
-                UML_SIGLONGJMP(next_buf, 1);
+        if(UML_SETJMP(&my_buf, enable) == 0)
+                UML_LONGJMP(next_buf, 1);
 }
 
-static sigjmp_buf initial_jmpbuf;
+static jmp_buf initial_jmpbuf;
 
 /* XXX Make these percpu */
 static void (*cb_proc)(void *arg);
 static void *cb_arg;
-static sigjmp_buf *cb_back;
+static jmp_buf *cb_back;
 
 int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
 {
-        sigjmp_buf **switch_buf = switch_buf_ptr;
+        jmp_buf **switch_buf = switch_buf_ptr;
         int n, enable;
 
         set_handler(SIGWINCH, (__sighandler_t) sig_handler,
@@ -502,7 +502,7 @@ int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
                     SIGVTALRM, -1);
 
         *fork_buf_ptr = &initial_jmpbuf;
-        n = UML_SIGSETJMP(&initial_jmpbuf, enable);
+        n = UML_SETJMP(&initial_jmpbuf, enable);
         switch(n){
         case INIT_JMP_NEW_THREAD:
                 new_thread_proc((void *) stack, new_thread_handler);
@@ -512,7 +512,7 @@ int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
                 break;
         case INIT_JMP_CALLBACK:
                 (*cb_proc)(cb_arg);
-                UML_SIGLONGJMP(cb_back, 1);
+                UML_LONGJMP(cb_back, 1);
                 break;
         case INIT_JMP_HALT:
                 kmalloc_ok = 0;
@@ -523,12 +523,12 @@ int start_idle_thread(void *stack, void *switch_buf_ptr, void **fork_buf_ptr)
         default:
                 panic("Bad sigsetjmp return in start_idle_thread - %d\n", n);
         }
-        UML_SIGLONGJMP(*switch_buf, 1);
+        UML_LONGJMP(*switch_buf, 1);
 }
 
 void initial_thread_cb_skas(void (*proc)(void *), void *arg)
 {
-        sigjmp_buf here;
+        jmp_buf here;
         int enable;
 
         cb_proc = proc;
@@ -536,8 +536,8 @@ void initial_thread_cb_skas(void (*proc)(void *), void *arg)
         cb_back = &here;
 
         block_signals();
-        if(UML_SIGSETJMP(&here, enable) == 0)
-                UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
+        if(UML_SETJMP(&here, enable) == 0)
+                UML_LONGJMP(&initial_jmpbuf, INIT_JMP_CALLBACK);
         unblock_signals();
 
         cb_proc = NULL;
@@ -548,13 +548,13 @@ void initial_thread_cb_skas(void (*proc)(void *), void *arg)
 void halt_skas(void)
 {
         block_signals();
-        UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
+        UML_LONGJMP(&initial_jmpbuf, INIT_JMP_HALT);
 }
 
 void reboot_skas(void)
 {
         block_signals();
-        UML_SIGLONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
+        UML_LONGJMP(&initial_jmpbuf, INIT_JMP_REBOOT);
 }
 
 void switch_mm_skas(struct mm_id *mm_idp)
diff --git a/arch/um/os-Linux/start_up.c b/arch/um/os-Linux/start_up.c
index 387e26af301a..503148504009 100644
--- a/arch/um/os-Linux/start_up.c
+++ b/arch/um/os-Linux/start_up.c
@@ -296,29 +296,7 @@ static void __init check_ptrace(void)
         check_sysemu();
 }
 
-extern int create_tmp_file(unsigned long long len);
-
-static void check_tmpexec(void)
-{
-        void *addr;
-        int err, fd = create_tmp_file(UM_KERN_PAGE_SIZE);
-
-        addr = mmap(NULL, UM_KERN_PAGE_SIZE,
-                    PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, fd, 0);
-        printf("Checking PROT_EXEC mmap in /tmp...");
-        fflush(stdout);
-        if(addr == MAP_FAILED){
-                err = errno;
-                perror("failed");
-                if(err == EPERM)
-                        printf("/tmp must be not mounted noexec\n");
-                exit(1);
-        }
-        printf("OK\n");
-        munmap(addr, UM_KERN_PAGE_SIZE);
-
-        close(fd);
-}
+extern void check_tmpexec(void);
 
 void os_early_checks(void)
 {
diff --git a/arch/um/os-Linux/trap.c b/arch/um/os-Linux/trap.c
index a9f6b26f9828..90b29ae9af46 100644
--- a/arch/um/os-Linux/trap.c
+++ b/arch/um/os-Linux/trap.c
@@ -35,7 +35,7 @@ void os_fill_handlinfo(struct kern_handlers h)
 
 void do_longjmp(void *b, int val)
 {
-        sigjmp_buf *buf = b;
+        jmp_buf *buf = b;
 
-        UML_SIGLONGJMP(buf, val);
+        UML_LONGJMP(buf, val);
 }
diff --git a/arch/um/os-Linux/uaccess.c b/arch/um/os-Linux/uaccess.c
index 166fb66995df..e523719330b2 100644
--- a/arch/um/os-Linux/uaccess.c
+++ b/arch/um/os-Linux/uaccess.c
@@ -16,9 +16,9 @@ unsigned long __do_user_copy(void *to, const void *from, int n,
         unsigned long *faddrp = (unsigned long *) fault_addr, ret;
         int enable;
 
-        sigjmp_buf jbuf;
+        jmp_buf jbuf;
         *fault_catcher = &jbuf;
-        if(UML_SIGSETJMP(&jbuf, enable) == 0){
+        if(UML_SETJMP(&jbuf, enable) == 0){
                 (*op)(to, from, n);
                 ret = 0;
                 *faulted_out = 0;
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index e32065e2fdc8..c47a2a7ce70e 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -104,7 +104,7 @@ void setup_hostinfo(void)
 int setjmp_wrapper(void (*proc)(void *, void *), ...)
 {
         va_list args;
-        sigjmp_buf buf;
+        jmp_buf buf;
         int n;
 
         n = sigsetjmp(buf, 1);