From: Bodo Stroesser <[email protected]>
s390 doesn't have a LDT. So MM_COPY_SEGMENTS will not be
supported on s390.
The only user of MM_COPY_SEGMENTS is new_mm(), but that's
no longer useful, as arch/sys-i386/ldt.c defines init_new_ldt(),
which is called immediately after new_mm().
So we should copy host's LDT in init_new_ldt(), if /proc/mm is
available, to have this subarch specific call in subarch code.
Signed-off-by: Bodo Stroesser <[email protected]>
Signed-off-by: Jeff Dike <[email protected]>
Index: linux-2.6.15/arch/um/kernel/skas/include/skas.h
===================================================================
--- linux-2.6.15.orig/arch/um/kernel/skas/include/skas.h 2006-01-05 16:19:59.000000000 -0500
+++ linux-2.6.15/arch/um/kernel/skas/include/skas.h 2006-01-05 21:26:43.000000000 -0500
@@ -33,7 +33,7 @@ extern int protect(struct mm_id * mm_idp
unsigned long len, int r, int w, int x, int done,
void **data);
extern void user_signal(int sig, union uml_pt_regs *regs, int pid);
-extern int new_mm(int from, unsigned long stack);
+extern int new_mm(unsigned long stack);
extern int start_userspace(unsigned long stub_stack);
extern int copy_context_skas0(unsigned long stack, int pid);
extern void get_skas_faultinfo(int pid, struct faultinfo * fi);
Index: linux-2.6.15/arch/um/kernel/skas/mmu.c
===================================================================
--- linux-2.6.15.orig/arch/um/kernel/skas/mmu.c 2006-01-03 17:39:46.000000000 -0500
+++ linux-2.6.15/arch/um/kernel/skas/mmu.c 2006-01-05 21:26:43.000000000 -0500
@@ -78,7 +78,7 @@ int init_new_context_skas(struct task_st
struct mmu_context_skas *from_mm = NULL;
struct mmu_context_skas *to_mm = &mm->context.skas;
unsigned long stack = 0;
- int from_fd, ret = -ENOMEM;
+ int ret = -ENOMEM;
if(skas_needs_stub){
stack = get_zeroed_page(GFP_KERNEL);
@@ -108,11 +108,7 @@ int init_new_context_skas(struct task_st
from_mm = ¤t->mm->context.skas;
if(proc_mm){
- if(from_mm)
- from_fd = from_mm->id.u.mm_fd;
- else from_fd = -1;
-
- ret = new_mm(from_fd, stack);
+ ret = new_mm(stack);
if(ret < 0){
printk("init_new_context_skas - new_mm failed, "
"errno = %d\n", ret);
Index: linux-2.6.15/arch/um/kernel/skas/process_kern.c
===================================================================
--- linux-2.6.15.orig/arch/um/kernel/skas/process_kern.c 2006-01-05 16:19:59.000000000 -0500
+++ linux-2.6.15/arch/um/kernel/skas/process_kern.c 2006-01-05 21:26:43.000000000 -0500
@@ -20,7 +20,6 @@
#include "tlb.h"
#include "kern.h"
#include "mode.h"
-#include "proc_mm.h"
#include "registers.h"
void switch_to_skas(void *prev, void *next)
@@ -125,25 +124,14 @@ int copy_thread_skas(int nr, unsigned lo
extern void map_stub_pages(int fd, unsigned long code,
unsigned long data, unsigned long stack);
-int new_mm(int from, unsigned long stack)
+int new_mm(unsigned long stack)
{
- struct proc_mm_op copy;
- int n, fd;
+ int fd;
fd = os_open_file("/proc/mm", of_cloexec(of_write(OPENFLAGS())), 0);
if(fd < 0)
return(fd);
- if(from != -1){
- copy = ((struct proc_mm_op) { .op = MM_COPY_SEGMENTS,
- .u =
- { .copy_segments = from } } );
- n = os_write_file(fd, ©, sizeof(copy));
- if(n != sizeof(copy))
- printk("new_mm : /proc/mm copy_segments failed, "
- "err = %d\n", -n);
- }
-
if(skas_needs_stub)
map_stub_pages(fd, CONFIG_STUB_CODE, CONFIG_STUB_DATA, stack);
Index: linux-2.6.15/arch/um/sys-i386/ldt.c
===================================================================
--- linux-2.6.15.orig/arch/um/sys-i386/ldt.c 2006-01-03 17:39:46.000000000 -0500
+++ linux-2.6.15/arch/um/sys-i386/ldt.c 2006-01-05 21:26:43.000000000 -0500
@@ -16,6 +16,8 @@
#include "choose-mode.h"
#include "kern.h"
#include "mode_kern.h"
+#include "proc_mm.h"
+#include "os.h"
extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
@@ -456,13 +458,14 @@ long init_new_ldt(struct mmu_context_ska
int i;
long page, err=0;
void *addr = NULL;
+ struct proc_mm_op copy;
- memset(&desc, 0, sizeof(desc));
if(!ptrace_ldt)
init_MUTEX(&new_mm->ldt.semaphore);
if(!from_mm){
+ memset(&desc, 0, sizeof(desc));
/*
* We have to initialize a clean ldt.
*/
@@ -494,8 +497,26 @@ long init_new_ldt(struct mmu_context_ska
}
}
new_mm->ldt.entry_count = 0;
+
+ goto out;
}
- else if (!ptrace_ldt) {
+
+ if(proc_mm){
+ /* We have a valid from_mm, so we now have to copy the LDT of
+ * from_mm to new_mm, because using proc_mm an new mm with
+ * an empty/default LDT was created in new_mm()
+ */
+ copy = ((struct proc_mm_op) { .op = MM_COPY_SEGMENTS,
+ .u =
+ { .copy_segments =
+ from_mm->id.u.mm_fd } } );
+ i = os_write_file(new_mm->id.u.mm_fd, ©, sizeof(copy));
+ if(i != sizeof(copy))
+ printk("new_mm : /proc/mm copy_segments failed, "
+ "err = %d\n", -i);
+ }
+
+ if(!ptrace_ldt) {
/* Our local LDT is used to supply the data for
* modify_ldt(READLDT), if PTRACE_LDT isn't available,
* i.e., we have to use the stub for modify_ldt, which
@@ -524,6 +545,7 @@ long init_new_ldt(struct mmu_context_ska
up(&from_mm->ldt.semaphore);
}
+ out:
return err;
}