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authorBodo Stroesser <bstroesser@fujitsu-siemens.com>2005-11-07 00:58:55 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2005-11-07 07:53:31 -0800
commit858259cf7d1c443c836a2022b78cb281f0a9b95e (patch)
tree7d306450dd0dfa907bbee1d95f96191c67f74232 /arch/um/kernel/skas/mmu.c
parente763b793f7e5c09a859fc420eb0de385d80cf636 (diff)
[PATCH] uml: maintain own LDT entries
Patch imlements full LDT handling in SKAS: * UML holds it's own LDT table, used to deliver data on modify_ldt(READ) * UML disables the default_ldt, inherited from the host (SKAS3) or resets LDT entries, set by host's clib and inherited in SKAS0 * A new global variable skas_needs_stub is inserted, that can be used to decide, whether stub-pages must be supported or not. * Uses the syscall-stub to replace missing PTRACE_LDT (therefore, write_ldt_entry needs to be modified) Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/kernel/skas/mmu.c')
-rw-r--r--arch/um/kernel/skas/mmu.c44
1 files changed, 27 insertions, 17 deletions
diff --git a/arch/um/kernel/skas/mmu.c b/arch/um/kernel/skas/mmu.c
index 9e5e39cea82..677871f1b37 100644
--- a/arch/um/kernel/skas/mmu.c
+++ b/arch/um/kernel/skas/mmu.c
@@ -15,6 +15,7 @@
#include "asm/mmu.h"
#include "asm/pgalloc.h"
#include "asm/pgtable.h"
+#include "asm/ldt.h"
#include "os.h"
#include "skas.h"
@@ -74,13 +75,12 @@ static int init_stub_pte(struct mm_struct *mm, unsigned long proc,
int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
{
- struct mm_struct *cur_mm = current->mm;
- struct mm_id *cur_mm_id = &cur_mm->context.skas.id;
- struct mm_id *mm_id = &mm->context.skas.id;
+ struct mmu_context_skas *from_mm = NULL;
+ struct mmu_context_skas *to_mm = &mm->context.skas;
unsigned long stack = 0;
- int from, ret = -ENOMEM;
+ int from_fd, ret = -ENOMEM;
- if(!proc_mm || !ptrace_faultinfo){
+ if(skas_needs_stub){
stack = get_zeroed_page(GFP_KERNEL);
if(stack == 0)
goto out;
@@ -102,33 +102,43 @@ int init_new_context_skas(struct task_struct *task, struct mm_struct *mm)
mm->nr_ptes--;
}
- mm_id->stack = stack;
+
+ to_mm->id.stack = stack;
+ if(current->mm != NULL && current->mm != &init_mm)
+ from_mm = &current->mm->context.skas;
if(proc_mm){
- if((cur_mm != NULL) && (cur_mm != &init_mm))
- from = cur_mm_id->u.mm_fd;
- else from = -1;
+ if(from_mm)
+ from_fd = from_mm->id.u.mm_fd;
+ else from_fd = -1;
- ret = new_mm(from, stack);
+ ret = new_mm(from_fd, stack);
if(ret < 0){
printk("init_new_context_skas - new_mm failed, "
"errno = %d\n", ret);
goto out_free;
}
- mm_id->u.mm_fd = ret;
+ to_mm->id.u.mm_fd = ret;
}
else {
- if((cur_mm != NULL) && (cur_mm != &init_mm))
- mm_id->u.pid = copy_context_skas0(stack,
- cur_mm_id->u.pid);
- else mm_id->u.pid = start_userspace(stack);
+ if(from_mm)
+ to_mm->id.u.pid = copy_context_skas0(stack,
+ from_mm->id.u.pid);
+ else to_mm->id.u.pid = start_userspace(stack);
+ }
+
+ ret = init_new_ldt(to_mm, from_mm);
+ if(ret < 0){
+ printk("init_new_context_skas - init_ldt"
+ " failed, errno = %d\n", ret);
+ goto out_free;
}
return 0;
out_free:
- if(mm_id->stack != 0)
- free_page(mm_id->stack);
+ if(to_mm->id.stack != 0)
+ free_page(to_mm->id.stack);
out:
return ret;
}