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Message-Id: <1354132230-21854-7-git-send-email-hpa@linux.intel.com>
Date: Wed, 28 Nov 2012 11:50:28 -0800
From: "H. Peter Anvin" <hpa@...ux.intel.com>
To: "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>,
Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Mario Gzuk <mariogzuk@...hnikz.de>,
"H. Peter Anvin" <hpa@...ux.intel.com>
Subject: [PATCH 6/8] x86, 386 removal: Remove CONFIG_X86_WP_WORKS_OK
From: "H. Peter Anvin" <hpa@...ux.intel.com>
All 486+ CPUs support WP in supervisor mode, so remove the fallback
386 support code.
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
---
arch/x86/Kconfig.cpu | 3 ---
arch/x86/include/asm/uaccess.h | 42 -------------------------------
arch/x86/lib/usercopy_32.c | 57 ------------------------------------------
arch/x86/mm/init_32.c | 5 +---
4 files changed, 1 insertion(+), 106 deletions(-)
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index d3bdc18..159ee9c 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -325,9 +325,6 @@ config X86_INVD_BUG
def_bool y
depends on M486
-config X86_WP_WORKS_OK
- def_bool y
-
config X86_POPAD_OK
def_bool y
depends on X86_32
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 7ccf8d1..1709801 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -237,8 +237,6 @@ extern void __put_user_2(void);
extern void __put_user_4(void);
extern void __put_user_8(void);
-#ifdef CONFIG_X86_WP_WORKS_OK
-
/**
* put_user: - Write a simple value into user space.
* @x: Value to copy to user space.
@@ -326,29 +324,6 @@ do { \
} \
} while (0)
-#else
-
-#define __put_user_size(x, ptr, size, retval, errret) \
-do { \
- __typeof__(*(ptr))__pus_tmp = x; \
- retval = 0; \
- \
- if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp, size) != 0)) \
- retval = errret; \
-} while (0)
-
-#define put_user(x, ptr) \
-({ \
- int __ret_pu; \
- __typeof__(*(ptr))__pus_tmp = x; \
- __ret_pu = 0; \
- if (unlikely(__copy_to_user_ll(ptr, &__pus_tmp, \
- sizeof(*(ptr))) != 0)) \
- __ret_pu = -EFAULT; \
- __ret_pu; \
-})
-#endif
-
#ifdef CONFIG_X86_32
#define __get_user_asm_u64(x, ptr, retval, errret) (x) = __get_user_bad()
#define __get_user_asm_ex_u64(x, ptr) (x) = __get_user_bad()
@@ -543,29 +518,12 @@ struct __large_struct { unsigned long buf[100]; };
(x) = (__force __typeof__(*(ptr)))__gue_val; \
} while (0)
-#ifdef CONFIG_X86_WP_WORKS_OK
-
#define put_user_try uaccess_try
#define put_user_catch(err) uaccess_catch(err)
#define put_user_ex(x, ptr) \
__put_user_size_ex((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
-#else /* !CONFIG_X86_WP_WORKS_OK */
-
-#define put_user_try do { \
- int __uaccess_err = 0;
-
-#define put_user_catch(err) \
- (err) |= __uaccess_err; \
-} while (0)
-
-#define put_user_ex(x, ptr) do { \
- __uaccess_err |= __put_user(x, ptr); \
-} while (0)
-
-#endif /* CONFIG_X86_WP_WORKS_OK */
-
extern unsigned long
copy_from_user_nmi(void *to, const void __user *from, unsigned long n);
extern __must_check long
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 98f6d6b6..f0312d7 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -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@...orfullife.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(¤t->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(¤t->mm->mmap_sem);
- congestion_wait(BLK_RW_ASYNC, HZ/50);
- goto survive;
- }
-
- if (retval != 1) {
- up_read(¤t->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(¤t->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);
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 11a5800..745d66b 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -715,10 +715,7 @@ static void __init test_wp_bit(void)
if (!boot_cpu_data.wp_works_ok) {
printk(KERN_CONT "No.\n");
-#ifdef CONFIG_X86_WP_WORKS_OK
- panic(
- "This kernel doesn't support CPU's with broken WP. Recompile it for a 386!");
-#endif
+ panic("Linux doesn't support CPUs with broken WP.");
} else {
printk(KERN_CONT "Ok.\n");
}
--
1.7.11.7
--
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