linux/arch/um/sys-i386/ldt.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

503 lines
12 KiB
C

/*
* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <asm/unistd.h>
#include "os.h"
#include "proc_mm.h"
#include "skas.h"
#include "skas_ptrace.h"
#include "sysdep/tls.h"
extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
static long write_ldt_entry(struct mm_id *mm_idp, int func,
struct user_desc *desc, void **addr, int done)
{
long res;
if (proc_mm) {
/*
* This is a special handling for the case, that the mm to
* modify isn't current->active_mm.
* If this is called directly by modify_ldt,
* (current->active_mm->context.skas.u == mm_idp)
* will be true. So no call to __switch_mm(mm_idp) is done.
* If this is called in case of init_new_ldt or PTRACE_LDT,
* mm_idp won't belong to current->active_mm, but child->mm.
* So we need to switch child's mm into our userspace, then
* later switch back.
*
* Note: I'm unsure: should interrupts be disabled here?
*/
if (!current->active_mm || current->active_mm == &init_mm ||
mm_idp != &current->active_mm->context.id)
__switch_mm(mm_idp);
}
if (ptrace_ldt) {
struct ptrace_ldt ldt_op = (struct ptrace_ldt) {
.func = func,
.ptr = desc,
.bytecount = sizeof(*desc)};
u32 cpu;
int pid;
if (!proc_mm)
pid = mm_idp->u.pid;
else {
cpu = get_cpu();
pid = userspace_pid[cpu];
}
res = os_ptrace_ldt(pid, 0, (unsigned long) &ldt_op);
if (proc_mm)
put_cpu();
}
else {
void *stub_addr;
res = syscall_stub_data(mm_idp, (unsigned long *)desc,
(sizeof(*desc) + sizeof(long) - 1) &
~(sizeof(long) - 1),
addr, &stub_addr);
if (!res) {
unsigned long args[] = { func,
(unsigned long)stub_addr,
sizeof(*desc),
0, 0, 0 };
res = run_syscall_stub(mm_idp, __NR_modify_ldt, args,
0, addr, done);
}
}
if (proc_mm) {
/*
* This is the second part of special handling, that makes
* PTRACE_LDT possible to implement.
*/
if (current->active_mm && current->active_mm != &init_mm &&
mm_idp != &current->active_mm->context.id)
__switch_mm(&current->active_mm->context.id);
}
return res;
}
static long read_ldt_from_host(void __user * ptr, unsigned long bytecount)
{
int res, n;
struct ptrace_ldt ptrace_ldt = (struct ptrace_ldt) {
.func = 0,
.bytecount = bytecount,
.ptr = kmalloc(bytecount, GFP_KERNEL)};
u32 cpu;
if (ptrace_ldt.ptr == NULL)
return -ENOMEM;
/*
* This is called from sys_modify_ldt only, so userspace_pid gives
* us the right number
*/
cpu = get_cpu();
res = os_ptrace_ldt(userspace_pid[cpu], 0, (unsigned long) &ptrace_ldt);
put_cpu();
if (res < 0)
goto out;
n = copy_to_user(ptr, ptrace_ldt.ptr, res);
if (n != 0)
res = -EFAULT;
out:
kfree(ptrace_ldt.ptr);
return res;
}
/*
* In skas mode, we hold our own ldt data in UML.
* Thus, the code implementing sys_modify_ldt_skas
* is very similar to (and mostly stolen from) sys_modify_ldt
* for arch/i386/kernel/ldt.c
* The routines copied and modified in part are:
* - read_ldt
* - read_default_ldt
* - write_ldt
* - sys_modify_ldt_skas
*/
static int read_ldt(void __user * ptr, unsigned long bytecount)
{
int i, err = 0;
unsigned long size;
uml_ldt_t * ldt = &current->mm->context.ldt;
if (!ldt->entry_count)
goto out;
if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES)
bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES;
err = bytecount;
if (ptrace_ldt)
return read_ldt_from_host(ptr, bytecount);
mutex_lock(&ldt->lock);
if (ldt->entry_count <= LDT_DIRECT_ENTRIES) {
size = LDT_ENTRY_SIZE*LDT_DIRECT_ENTRIES;
if (size > bytecount)
size = bytecount;
if (copy_to_user(ptr, ldt->u.entries, size))
err = -EFAULT;
bytecount -= size;
ptr += size;
}
else {
for (i=0; i<ldt->entry_count/LDT_ENTRIES_PER_PAGE && bytecount;
i++) {
size = PAGE_SIZE;
if (size > bytecount)
size = bytecount;
if (copy_to_user(ptr, ldt->u.pages[i], size)) {
err = -EFAULT;
break;
}
bytecount -= size;
ptr += size;
}
}
mutex_unlock(&ldt->lock);
if (bytecount == 0 || err == -EFAULT)
goto out;
if (clear_user(ptr, bytecount))
err = -EFAULT;
out:
return err;
}
static int read_default_ldt(void __user * ptr, unsigned long bytecount)
{
int err;
if (bytecount > 5*LDT_ENTRY_SIZE)
bytecount = 5*LDT_ENTRY_SIZE;
err = bytecount;
/*
* UML doesn't support lcall7 and lcall27.
* So, we don't really have a default ldt, but emulate
* an empty ldt of common host default ldt size.
*/
if (clear_user(ptr, bytecount))
err = -EFAULT;
return err;
}
static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
{
uml_ldt_t * ldt = &current->mm->context.ldt;
struct mm_id * mm_idp = &current->mm->context.id;
int i, err;
struct user_desc ldt_info;
struct ldt_entry entry0, *ldt_p;
void *addr = NULL;
err = -EINVAL;
if (bytecount != sizeof(ldt_info))
goto out;
err = -EFAULT;
if (copy_from_user(&ldt_info, ptr, sizeof(ldt_info)))
goto out;
err = -EINVAL;
if (ldt_info.entry_number >= LDT_ENTRIES)
goto out;
if (ldt_info.contents == 3) {
if (func == 1)
goto out;
if (ldt_info.seg_not_present == 0)
goto out;
}
if (!ptrace_ldt)
mutex_lock(&ldt->lock);
err = write_ldt_entry(mm_idp, func, &ldt_info, &addr, 1);
if (err)
goto out_unlock;
else if (ptrace_ldt) {
/* With PTRACE_LDT available, this is used as a flag only */
ldt->entry_count = 1;
goto out;
}
if (ldt_info.entry_number >= ldt->entry_count &&
ldt_info.entry_number >= LDT_DIRECT_ENTRIES) {
for (i=ldt->entry_count/LDT_ENTRIES_PER_PAGE;
i*LDT_ENTRIES_PER_PAGE <= ldt_info.entry_number;
i++) {
if (i == 0)
memcpy(&entry0, ldt->u.entries,
sizeof(entry0));
ldt->u.pages[i] = (struct ldt_entry *)
__get_free_page(GFP_KERNEL|__GFP_ZERO);
if (!ldt->u.pages[i]) {
err = -ENOMEM;
/* Undo the change in host */
memset(&ldt_info, 0, sizeof(ldt_info));
write_ldt_entry(mm_idp, 1, &ldt_info, &addr, 1);
goto out_unlock;
}
if (i == 0) {
memcpy(ldt->u.pages[0], &entry0,
sizeof(entry0));
memcpy(ldt->u.pages[0]+1, ldt->u.entries+1,
sizeof(entry0)*(LDT_DIRECT_ENTRIES-1));
}
ldt->entry_count = (i + 1) * LDT_ENTRIES_PER_PAGE;
}
}
if (ldt->entry_count <= ldt_info.entry_number)
ldt->entry_count = ldt_info.entry_number + 1;
if (ldt->entry_count <= LDT_DIRECT_ENTRIES)
ldt_p = ldt->u.entries + ldt_info.entry_number;
else
ldt_p = ldt->u.pages[ldt_info.entry_number/LDT_ENTRIES_PER_PAGE] +
ldt_info.entry_number%LDT_ENTRIES_PER_PAGE;
if (ldt_info.base_addr == 0 && ldt_info.limit == 0 &&
(func == 1 || LDT_empty(&ldt_info))) {
ldt_p->a = 0;
ldt_p->b = 0;
}
else{
if (func == 1)
ldt_info.useable = 0;
ldt_p->a = LDT_entry_a(&ldt_info);
ldt_p->b = LDT_entry_b(&ldt_info);
}
err = 0;
out_unlock:
mutex_unlock(&ldt->lock);
out:
return err;
}
static long do_modify_ldt_skas(int func, void __user *ptr,
unsigned long bytecount)
{
int ret = -ENOSYS;
switch (func) {
case 0:
ret = read_ldt(ptr, bytecount);
break;
case 1:
case 0x11:
ret = write_ldt(ptr, bytecount, func);
break;
case 2:
ret = read_default_ldt(ptr, bytecount);
break;
}
return ret;
}
static DEFINE_SPINLOCK(host_ldt_lock);
static short dummy_list[9] = {0, -1};
static short * host_ldt_entries = NULL;
static void ldt_get_host_info(void)
{
long ret;
struct ldt_entry * ldt;
short *tmp;
int i, size, k, order;
spin_lock(&host_ldt_lock);
if (host_ldt_entries != NULL) {
spin_unlock(&host_ldt_lock);
return;
}
host_ldt_entries = dummy_list+1;
spin_unlock(&host_ldt_lock);
for (i = LDT_PAGES_MAX-1, order=0; i; i>>=1, order++)
;
ldt = (struct ldt_entry *)
__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
if (ldt == NULL) {
printk(KERN_ERR "ldt_get_host_info: couldn't allocate buffer "
"for host ldt\n");
return;
}
ret = modify_ldt(0, ldt, (1<<order)*PAGE_SIZE);
if (ret < 0) {
printk(KERN_ERR "ldt_get_host_info: couldn't read host ldt\n");
goto out_free;
}
if (ret == 0) {
/* default_ldt is active, simply write an empty entry 0 */
host_ldt_entries = dummy_list;
goto out_free;
}
for (i=0, size=0; i<ret/LDT_ENTRY_SIZE; i++) {
if (ldt[i].a != 0 || ldt[i].b != 0)
size++;
}
if (size < ARRAY_SIZE(dummy_list))
host_ldt_entries = dummy_list;
else {
size = (size + 1) * sizeof(dummy_list[0]);
tmp = kmalloc(size, GFP_KERNEL);
if (tmp == NULL) {
printk(KERN_ERR "ldt_get_host_info: couldn't allocate "
"host ldt list\n");
goto out_free;
}
host_ldt_entries = tmp;
}
for (i=0, k=0; i<ret/LDT_ENTRY_SIZE; i++) {
if (ldt[i].a != 0 || ldt[i].b != 0)
host_ldt_entries[k++] = i;
}
host_ldt_entries[k] = -1;
out_free:
free_pages((unsigned long)ldt, order);
}
long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
{
struct user_desc desc;
short * num_p;
int i;
long page, err=0;
void *addr = NULL;
struct proc_mm_op copy;
if (!ptrace_ldt)
mutex_init(&new_mm->ldt.lock);
if (!from_mm) {
memset(&desc, 0, sizeof(desc));
/*
* We have to initialize a clean ldt.
*/
if (proc_mm) {
/*
* If the new mm was created using proc_mm, host's
* default-ldt currently is assigned, which normally
* contains the call-gates for lcall7 and lcall27.
* To remove these gates, we simply write an empty
* entry as number 0 to the host.
*/
err = write_ldt_entry(&new_mm->id, 1, &desc, &addr, 1);
}
else{
/*
* Now we try to retrieve info about the ldt, we
* inherited from the host. All ldt-entries found
* will be reset in the following loop
*/
ldt_get_host_info();
for (num_p=host_ldt_entries; *num_p != -1; num_p++) {
desc.entry_number = *num_p;
err = write_ldt_entry(&new_mm->id, 1, &desc,
&addr, *(num_p + 1) == -1);
if (err)
break;
}
}
new_mm->ldt.entry_count = 0;
goto out;
}
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, &copy, sizeof(copy));
if (i != sizeof(copy))
printk(KERN_ERR "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
* can't handle the big read buffer of up to 64kB.
*/
mutex_lock(&from_mm->ldt.lock);
if (from_mm->ldt.entry_count <= LDT_DIRECT_ENTRIES)
memcpy(new_mm->ldt.u.entries, from_mm->ldt.u.entries,
sizeof(new_mm->ldt.u.entries));
else {
i = from_mm->ldt.entry_count / LDT_ENTRIES_PER_PAGE;
while (i-->0) {
page = __get_free_page(GFP_KERNEL|__GFP_ZERO);
if (!page) {
err = -ENOMEM;
break;
}
new_mm->ldt.u.pages[i] =
(struct ldt_entry *) page;
memcpy(new_mm->ldt.u.pages[i],
from_mm->ldt.u.pages[i], PAGE_SIZE);
}
}
new_mm->ldt.entry_count = from_mm->ldt.entry_count;
mutex_unlock(&from_mm->ldt.lock);
}
out:
return err;
}
void free_ldt(struct mm_context *mm)
{
int i;
if (!ptrace_ldt && mm->ldt.entry_count > LDT_DIRECT_ENTRIES) {
i = mm->ldt.entry_count / LDT_ENTRIES_PER_PAGE;
while (i-- > 0)
free_page((long) mm->ldt.u.pages[i]);
}
mm->ldt.entry_count = 0;
}
int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
{
return do_modify_ldt_skas(func, ptr, bytecount);
}