[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>
diff --git a/arch/um/sys-x86_64/Makefile b/arch/um/sys-x86_64/Makefile
index 06c3633..ea977df 100644
--- a/arch/um/sys-x86_64/Makefile
+++ b/arch/um/sys-x86_64/Makefile
@@ -5,7 +5,7 @@
#
#XXX: why into lib-y?
-lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o mem.o memcpy.o \
+lib-y = bitops.o bugs.o csum-partial.o delay.o fault.o ldt.o mem.o memcpy.o \
ptrace.o ptrace_user.o sigcontext.o signal.o stub.o \
stub_segv.o syscalls.o syscall_table.o sysrq.o thunk.o
@@ -14,7 +14,7 @@
USER_OBJS := ptrace_user.o sigcontext.o
-SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c memcpy.S \
+SYMLINKS = bitops.c csum-copy.S csum-partial.c csum-wrappers.c ldt.c memcpy.S \
thunk.S module.c
include arch/um/scripts/Makefile.rules
@@ -23,6 +23,7 @@
csum-copy.S-dir = lib
csum-partial.c-dir = lib
csum-wrappers.c-dir = lib
+ldt.c-dir = /arch/um/sys-i386
memcpy.S-dir = lib
thunk.S-dir = lib
module.c-dir = kernel
diff --git a/arch/um/sys-x86_64/syscalls.c b/arch/um/sys-x86_64/syscalls.c
index 3259a4d..6acee5c 100644
--- a/arch/um/sys-x86_64/syscalls.c
+++ b/arch/um/sys-x86_64/syscalls.c
@@ -29,81 +29,6 @@
}
#ifdef CONFIG_MODE_TT
-extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
-
-long sys_modify_ldt_tt(int func, void *ptr, unsigned long bytecount)
-{
- /* XXX This should check VERIFY_WRITE depending on func, check this
- * in i386 as well.
- */
- if (!access_ok(VERIFY_READ, ptr, bytecount))
- return -EFAULT;
- return(modify_ldt(func, ptr, bytecount));
-}
-#endif
-
-#ifdef CONFIG_MODE_SKAS
-extern int userspace_pid[];
-
-#include "skas_ptrace.h"
-
-long sys_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
-{
- struct ptrace_ldt ldt;
- void *buf;
- int res, n;
-
- buf = kmalloc(bytecount, GFP_KERNEL);
- if(buf == NULL)
- return(-ENOMEM);
-
- res = 0;
-
- switch(func){
- case 1:
- case 0x11:
- res = copy_from_user(buf, ptr, bytecount);
- break;
- }
-
- if(res != 0){
- res = -EFAULT;
- goto out;
- }
-
- ldt = ((struct ptrace_ldt) { .func = func,
- .ptr = buf,
- .bytecount = bytecount });
-#warning Need to look up userspace_pid by cpu
- res = ptrace(PTRACE_LDT, userspace_pid[0], 0, (unsigned long) &ldt);
- if(res < 0)
- goto out;
-
- switch(func){
- case 0:
- case 2:
- n = res;
- res = copy_to_user(ptr, buf, n);
- if(res != 0)
- res = -EFAULT;
- else
- res = n;
- break;
- }
-
- out:
- kfree(buf);
- return(res);
-}
-#endif
-
-long sys_modify_ldt(int func, void *ptr, unsigned long bytecount)
-{
- return(CHOOSE_MODE_PROC(sys_modify_ldt_tt, sys_modify_ldt_skas, func,
- ptr, bytecount));
-}
-
-#ifdef CONFIG_MODE_TT
extern long arch_prctl(int code, unsigned long addr);
static long arch_prctl_tt(int code, unsigned long addr)