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authorLinus Torvalds <torvalds@linux-foundation.org>2016-02-20 18:32:40 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2016-02-20 18:32:40 +0100
commit0389075ecfb6231818de9b0225d3a5a21a661171 (patch)
tree991154188efee4117974d9aa5bcd7497257c7656 /arch
parentMerge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/ke... (diff)
parentx86/mm: Fix vmalloc_fault() to handle large pages properly (diff)
downloadlinux-0389075ecfb6231818de9b0225d3a5a21a661171.tar.xz
linux-0389075ecfb6231818de9b0225d3a5a21a661171.zip
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar: "This is unusually large, partly due to the EFI fixes that prevent accidental deletion of EFI variables through efivarfs that may brick machines. These fixes are somewhat involved to maintain compatibility with existing install methods and other usage modes, while trying to turn off the 'rm -rf' bricking vector. Other fixes are for large page ioremap()s and for non-temporal user-memcpy()s" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Fix vmalloc_fault() to handle large pages properly hpet: Drop stale URLs x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache() x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable lib/ucs2_string: Correct ucs2 -> utf8 conversion efi: Add pstore variables to the deletion whitelist efi: Make efivarfs entries immutable by default efi: Make our variable validation list include the guid efi: Do variable name validation tests in utf8 efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version lib/ucs2_string: Add ucs2 -> utf8 helper functions
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/Kconfig4
-rw-r--r--arch/x86/lib/copy_user_64.S142
-rw-r--r--arch/x86/mm/fault.c15
3 files changed, 114 insertions, 47 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ab2ed5328f0a..c46662f64c39 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -778,8 +778,8 @@ config HPET_TIMER
HPET is the next generation timer replacing legacy 8254s.
The HPET provides a stable time base on SMP
systems, unlike the TSC, but it is more expensive to access,
- as it is off-chip. You can find the HPET spec at
- <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
+ as it is off-chip. The interface used is documented
+ in the HPET spec, revision 1.
You can safely choose Y here. However, HPET will only be
activated if the platform and the BIOS support this feature.
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 982ce34f4a9b..27f89c79a44b 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -232,17 +232,31 @@ ENDPROC(copy_user_enhanced_fast_string)
/*
* copy_user_nocache - Uncached memory copy with exception handling
- * This will force destination/source out of cache for more performance.
+ * This will force destination out of cache for more performance.
+ *
+ * Note: Cached memory copy is used when destination or size is not
+ * naturally aligned. That is:
+ * - Require 8-byte alignment when size is 8 bytes or larger.
+ * - Require 4-byte alignment when size is 4 bytes.
*/
ENTRY(__copy_user_nocache)
ASM_STAC
+
+ /* If size is less than 8 bytes, go to 4-byte copy */
cmpl $8,%edx
- jb 20f /* less then 8 bytes, go to byte copy loop */
+ jb .L_4b_nocache_copy_entry
+
+ /* If destination is not 8-byte aligned, "cache" copy to align it */
ALIGN_DESTINATION
+
+ /* Set 4x8-byte copy count and remainder */
movl %edx,%ecx
andl $63,%edx
shrl $6,%ecx
- jz 17f
+ jz .L_8b_nocache_copy_entry /* jump if count is 0 */
+
+ /* Perform 4x8-byte nocache loop-copy */
+.L_4x8b_nocache_copy_loop:
1: movq (%rsi),%r8
2: movq 1*8(%rsi),%r9
3: movq 2*8(%rsi),%r10
@@ -262,60 +276,106 @@ ENTRY(__copy_user_nocache)
leaq 64(%rsi),%rsi
leaq 64(%rdi),%rdi
decl %ecx
- jnz 1b
-17: movl %edx,%ecx
+ jnz .L_4x8b_nocache_copy_loop
+
+ /* Set 8-byte copy count and remainder */
+.L_8b_nocache_copy_entry:
+ movl %edx,%ecx
andl $7,%edx
shrl $3,%ecx
- jz 20f
-18: movq (%rsi),%r8
-19: movnti %r8,(%rdi)
+ jz .L_4b_nocache_copy_entry /* jump if count is 0 */
+
+ /* Perform 8-byte nocache loop-copy */
+.L_8b_nocache_copy_loop:
+20: movq (%rsi),%r8
+21: movnti %r8,(%rdi)
leaq 8(%rsi),%rsi
leaq 8(%rdi),%rdi
decl %ecx
- jnz 18b
-20: andl %edx,%edx
- jz 23f
+ jnz .L_8b_nocache_copy_loop
+
+ /* If no byte left, we're done */
+.L_4b_nocache_copy_entry:
+ andl %edx,%edx
+ jz .L_finish_copy
+
+ /* If destination is not 4-byte aligned, go to byte copy: */
+ movl %edi,%ecx
+ andl $3,%ecx
+ jnz .L_1b_cache_copy_entry
+
+ /* Set 4-byte copy count (1 or 0) and remainder */
movl %edx,%ecx
-21: movb (%rsi),%al
-22: movb %al,(%rdi)
+ andl $3,%edx
+ shrl $2,%ecx
+ jz .L_1b_cache_copy_entry /* jump if count is 0 */
+
+ /* Perform 4-byte nocache copy: */
+30: movl (%rsi),%r8d
+31: movnti %r8d,(%rdi)
+ leaq 4(%rsi),%rsi
+ leaq 4(%rdi),%rdi
+
+ /* If no bytes left, we're done: */
+ andl %edx,%edx
+ jz .L_finish_copy
+
+ /* Perform byte "cache" loop-copy for the remainder */
+.L_1b_cache_copy_entry:
+ movl %edx,%ecx
+.L_1b_cache_copy_loop:
+40: movb (%rsi),%al
+41: movb %al,(%rdi)
incq %rsi
incq %rdi
decl %ecx
- jnz 21b
-23: xorl %eax,%eax
+ jnz .L_1b_cache_copy_loop
+
+ /* Finished copying; fence the prior stores */
+.L_finish_copy:
+ xorl %eax,%eax
ASM_CLAC
sfence
ret
.section .fixup,"ax"
-30: shll $6,%ecx
+.L_fixup_4x8b_copy:
+ shll $6,%ecx
addl %ecx,%edx
- jmp 60f
-40: lea (%rdx,%rcx,8),%rdx
- jmp 60f
-50: movl %ecx,%edx
-60: sfence
+ jmp .L_fixup_handle_tail
+.L_fixup_8b_copy:
+ lea (%rdx,%rcx,8),%rdx
+ jmp .L_fixup_handle_tail
+.L_fixup_4b_copy:
+ lea (%rdx,%rcx,4),%rdx
+ jmp .L_fixup_handle_tail
+.L_fixup_1b_copy:
+ movl %ecx,%edx
+.L_fixup_handle_tail:
+ sfence
jmp copy_user_handle_tail
.previous
- _ASM_EXTABLE(1b,30b)
- _ASM_EXTABLE(2b,30b)
- _ASM_EXTABLE(3b,30b)
- _ASM_EXTABLE(4b,30b)
- _ASM_EXTABLE(5b,30b)
- _ASM_EXTABLE(6b,30b)
- _ASM_EXTABLE(7b,30b)
- _ASM_EXTABLE(8b,30b)
- _ASM_EXTABLE(9b,30b)
- _ASM_EXTABLE(10b,30b)
- _ASM_EXTABLE(11b,30b)
- _ASM_EXTABLE(12b,30b)
- _ASM_EXTABLE(13b,30b)
- _ASM_EXTABLE(14b,30b)
- _ASM_EXTABLE(15b,30b)
- _ASM_EXTABLE(16b,30b)
- _ASM_EXTABLE(18b,40b)
- _ASM_EXTABLE(19b,40b)
- _ASM_EXTABLE(21b,50b)
- _ASM_EXTABLE(22b,50b)
+ _ASM_EXTABLE(1b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(2b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(3b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(4b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(5b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(6b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(7b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(8b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(9b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(10b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(11b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(12b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(13b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(14b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(15b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(16b,.L_fixup_4x8b_copy)
+ _ASM_EXTABLE(20b,.L_fixup_8b_copy)
+ _ASM_EXTABLE(21b,.L_fixup_8b_copy)
+ _ASM_EXTABLE(30b,.L_fixup_4b_copy)
+ _ASM_EXTABLE(31b,.L_fixup_4b_copy)
+ _ASM_EXTABLE(40b,.L_fixup_1b_copy)
+ _ASM_EXTABLE(41b,.L_fixup_1b_copy)
ENDPROC(__copy_user_nocache)
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index eef44d9a3f77..e830c71a1323 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -287,6 +287,9 @@ static noinline int vmalloc_fault(unsigned long address)
if (!pmd_k)
return -1;
+ if (pmd_huge(*pmd_k))
+ return 0;
+
pte_k = pte_offset_kernel(pmd_k, address);
if (!pte_present(*pte_k))
return -1;
@@ -360,8 +363,6 @@ void vmalloc_sync_all(void)
* 64-bit:
*
* Handle a fault on the vmalloc area
- *
- * This assumes no large pages in there.
*/
static noinline int vmalloc_fault(unsigned long address)
{
@@ -403,17 +404,23 @@ static noinline int vmalloc_fault(unsigned long address)
if (pud_none(*pud_ref))
return -1;
- if (pud_none(*pud) || pud_page_vaddr(*pud) != pud_page_vaddr(*pud_ref))
+ if (pud_none(*pud) || pud_pfn(*pud) != pud_pfn(*pud_ref))
BUG();
+ if (pud_huge(*pud))
+ return 0;
+
pmd = pmd_offset(pud, address);
pmd_ref = pmd_offset(pud_ref, address);
if (pmd_none(*pmd_ref))
return -1;
- if (pmd_none(*pmd) || pmd_page(*pmd) != pmd_page(*pmd_ref))
+ if (pmd_none(*pmd) || pmd_pfn(*pmd) != pmd_pfn(*pmd_ref))
BUG();
+ if (pmd_huge(*pmd))
+ return 0;
+
pte_ref = pte_offset_kernel(pmd_ref, address);
if (!pte_present(*pte_ref))
return -1;