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x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK

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All 486+ CPUs support WP in supervisor mode, so remove the fallback
386 support code.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1354132230-21854-7-git-send-email-hpa@linux.intel.com
This commit is contained in:
H. Peter Anvin
2012-11-28 11:50:28 -08:00
parent 094ab1db7c
commit a5c2a893db
4 changed files with 1 additions and 106 deletions
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57
arch/x86/lib/usercopy_32.c
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@@ -570,63 +570,6 @@ do { \
unsigned long __copy_to_user_ll(void __user *to, const void *from,
unsigned long n)
{
#ifndef CONFIG_X86_WP_WORKS_OK
if (unlikely(boot_cpu_data.wp_works_ok == 0) &&
((unsigned long)to) < TASK_SIZE) {
/*
* When we are in an atomic section (see
* mm/filemap.c:file_read_actor), return the full
* length to take the slow path.
*/
if (in_atomic())
return n;
/*
* CPU does not honor the WP bit when writing
* from supervisory mode, and due to preemption or SMP,
* the page tables can change at any time.
* Do it manually. Manfred <manfred@colorfullife.com>
*/
while (n) {
unsigned long offset = ((unsigned long)to)%PAGE_SIZE;
unsigned long len = PAGE_SIZE - offset;
int retval;
struct page *pg;
void *maddr;
if (len > n)
len = n;
survive:
down_read(&current->mm->mmap_sem);
retval = get_user_pages(current, current->mm,
(unsigned long)to, 1, 1, 0, &pg, NULL);
if (retval == -ENOMEM && is_global_init(current)) {
up_read(&current->mm->mmap_sem);
congestion_wait(BLK_RW_ASYNC, HZ/50);
goto survive;
}
if (retval != 1) {
up_read(&current->mm->mmap_sem);
break;
}
maddr = kmap_atomic(pg);
memcpy(maddr + offset, from, len);
kunmap_atomic(maddr);
set_page_dirty_lock(pg);
put_page(pg);
up_read(&current->mm->mmap_sem);
from += len;
to += len;
n -= len;
}
return n;
}
#endif
stac();
if (movsl_is_ok(to, from, n))
__copy_user(to, from, n);