[PATCH] uml: eliminate some globals

Stop using global variables to hold the file descriptor and offset used to map
the skas0 stubs.  Instead, calculate them using the page physical addresses.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/um/os-Linux/skas/process.c b/arch/um/os-Linux/skas/process.c
index f787854322c4ee365ddeb8334869075f13c5bbc2..b959b2618b7f8e18b086f1370105815208a5066c 100644 (file)
--- a/arch/um/os-Linux/skas/process.c
+++ b/arch/um/os-Linux/skas/process.c
@@ -151,8 +151,6 @@ static void handle_trap(int pid, union uml_pt_regs *regs, int local_using_sysemu
 }
 
 extern int __syscall_stub_start;
-int stub_code_fd = -1;
-__u64 stub_code_offset;
 
 static int userspace_tramp(void *stack)
 {
@@ -167,30 +165,30 @@ static int userspace_tramp(void *stack)
                /* This has a pte, but it can't be mapped in with the usual
                 * tlb_flush mechanism because this is part of that mechanism
                 */
+               int fd;
+               __u64 offset;
+               fd = phys_mapping(to_phys(&__syscall_stub_start), &offset);
                addr = mmap64((void *) UML_CONFIG_STUB_CODE, page_size(),
-                             PROT_EXEC, MAP_FIXED | MAP_PRIVATE,
-                             stub_code_fd, stub_code_offset);
+                             PROT_EXEC, MAP_FIXED | MAP_PRIVATE, fd, offset);
                if(addr == MAP_FAILED){
-                       printk("mapping stub code failed, errno = %d\n",
+                       printk("mapping mmap stub failed, errno = %d\n",
                               errno);
                        exit(1);
                }
 
                if(stack != NULL){
-                       int fd;
-                       __u64 offset;
                        fd = phys_mapping(to_phys(stack), &offset);
                        addr = mmap((void *) UML_CONFIG_STUB_DATA, page_size(),
                                    PROT_READ | PROT_WRITE,
                                    MAP_FIXED | MAP_SHARED, fd, offset);
                        if(addr == MAP_FAILED){
-                               printk("mapping stub stack failed, "
+                               printk("mapping segfault stack failed, "
                                       "errno = %d\n", errno);
                                exit(1);
                        }
                }
        }
-       if(!ptrace_faultinfo){
+       if(!ptrace_faultinfo && (stack != NULL)){
                unsigned long v = UML_CONFIG_STUB_CODE +
                                  (unsigned long) stub_segv_handler -
                                  (unsigned long) &__syscall_stub_start;
@@ -216,10 +214,6 @@ int start_userspace(unsigned long stub_stack)
        unsigned long sp;
        int pid, status, n, flags;
 
-       if ( stub_code_fd == -1 )
-               stub_code_fd = phys_mapping(to_phys(&__syscall_stub_start),
-                                           &stub_code_offset);
-
        stack = mmap(NULL, PAGE_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC,
                     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
        if(stack == MAP_FAILED)
@@ -306,7 +300,6 @@ void userspace(union uml_pt_regs *regs)
                                printk("userspace - child stopped with signal "
                                       "%d\n", WSTOPSIG(status));
                        }
-                   again:
                        pid = userspace_pid[0];
                        interrupt_end();
 
@@ -395,6 +388,9 @@ void map_stub_pages(int fd, unsigned long code,
 {
        struct proc_mm_op mmop;
        int n;
+       __u64 code_offset;
+       int code_fd = phys_mapping(to_phys((void *) &__syscall_stub_start),
+                                  &code_offset);
 
        mmop = ((struct proc_mm_op) { .op        = MM_MMAP,
                                      .u         =
@@ -403,8 +399,8 @@ void map_stub_pages(int fd, unsigned long code,
                                          .len     = PAGE_SIZE,
                                          .prot    = PROT_EXEC,
                                          .flags   = MAP_FIXED | MAP_PRIVATE,
-                                         .fd      = stub_code_fd,
-                                         .offset  = stub_code_offset
+                                         .fd      = code_fd,
+                                         .offset  = code_offset
        } } });
        n = os_write_file(fd, &mmop, sizeof(mmop));
        if(n != sizeof(mmop))