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Groups > linux.kernel > #1443747 > unrolled thread

[PATCH 00/11] x86: misc prep patches for virtually mapped stacks

Started byAndy Lutomirski <luto@kernel.org>
First post2016-07-14 22:30 +0200
Last post2016-07-15 14:10 +0200
Articles 7 — 2 participants

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Contents

  [PATCH 00/11] x86: misc prep patches for virtually mapped stacks Andy Lutomirski <luto@kernel.org> - 2016-07-14 22:30 +0200
    [PATCH 09/11] x86: Move addr_limit to thread_struct Andy Lutomirski <luto@kernel.org> - 2016-07-14 22:30 +0200
      [tip:x86/mm] x86/uaccess: Move thread_info::addr_limit to  thread_struct tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-07-15 14:10 +0200
    [PATCH 06/11] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm Andy Lutomirski <luto@kernel.org> - 2016-07-14 22:30 +0200
      [tip:x86/mm] x86/mm/64: In vmalloc_fault(), use CR3 instead of  current->active_mm tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-07-15 14:10 +0200
    [PATCH 11/11] x86/smp: Remove unnecessary initialization of thread_info::cpu Andy Lutomirski <luto@kernel.org> - 2016-07-14 22:30 +0200
      [tip:x86/mm] x86/smp: Remove unnecessary initialization of  thread_info::cpu tip-bot for Andy Lutomirski <tipbot@zytor.com> - 2016-07-15 14:10 +0200

#1443747 — [PATCH 00/11] x86: misc prep patches for virtually mapped stacks

FromAndy Lutomirski <luto@kernel.org>
Date2016-07-14 22:30 +0200
Subject[PATCH 00/11] x86: misc prep patches for virtually mapped stacks
Message-ID<rUVqF-5SB-3@gated-at.bofh.it>
Hi Ingo-

Here are eleven miscellaneous, mostly standalone x86 patches that I pulled
from the virtually mapped stack patch set.  They're based on 4.7-rc6, and
I imagine they apply cleanly on most or all -tip branches.

Once these land, I'll see if the THREAD_INFO_IN_TASK stuff splits out
cleanly as well.  That code certainly needs a couple of these patches,
but I think it might get stuck behind "signal: Consolidate
{TS,TLF}_RESTORE_SIGMASK code", and I asked akpm to queue that one for
-mm.

Andy Lutomirski (10):
  x86/cpa: In populate_pgd, don't set the pgd entry until it's populated
  x86/mm: Remove kernel_unmap_pages_in_pgd() and
    efi_cleanup_page_tables()
  x86/dumpstack: Try harder to get a call trace on stack overflow
  x86/dumpstack/64: Handle faults when printing the "Stack:" part of an
    OOPS
  x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm
  x86/dumpstack: When OOPSing, rewind the stack before do_exit()
  x86: Move uaccess_err and sig_on_uaccess_err to thread_struct
  x86: Move addr_limit to thread_struct
  x86/smp: Remove stack_smp_processor_id()
  x86/smp: Remove unnecessary initialization of thread_info::cpu

Ingo Molnar (1):
  x86/mm/hotplug: Don't remove PGD entries in remove_pagetable()

 arch/x86/entry/entry_32.S             | 11 +++++++++++
 arch/x86/entry/entry_64.S             | 11 +++++++++++
 arch/x86/entry/vsyscall/vsyscall_64.c |  6 +++---
 arch/x86/include/asm/checksum_32.h    |  3 +--
 arch/x86/include/asm/cpu.h            |  1 -
 arch/x86/include/asm/efi.h            |  1 -
 arch/x86/include/asm/pgtable_types.h  |  2 --
 arch/x86/include/asm/processor.h      | 20 ++++++++++++-------
 arch/x86/include/asm/smp.h            |  6 ------
 arch/x86/include/asm/thread_info.h    |  9 ---------
 arch/x86/include/asm/uaccess.h        | 10 +++++-----
 arch/x86/kernel/asm-offsets.c         |  4 +++-
 arch/x86/kernel/cpu/common.c          |  2 +-
 arch/x86/kernel/dumpstack.c           | 20 +++++++++++++++++--
 arch/x86/kernel/dumpstack_64.c        | 12 ++++++++++--
 arch/x86/kernel/smpboot.c             |  1 -
 arch/x86/lib/copy_user_64.S           |  8 ++++----
 arch/x86/lib/csum-wrappers_64.c       |  1 +
 arch/x86/lib/getuser.S                | 20 +++++++++----------
 arch/x86/lib/putuser.S                | 10 +++++-----
 arch/x86/lib/usercopy_64.c            |  2 +-
 arch/x86/mm/extable.c                 |  2 +-
 arch/x86/mm/fault.c                   |  4 ++--
 arch/x86/mm/init_64.c                 | 27 -------------------------
 arch/x86/mm/pageattr.c                | 37 ++++++-----------------------------
 arch/x86/platform/efi/efi.c           |  2 --
 arch/x86/platform/efi/efi_32.c        |  3 ---
 arch/x86/platform/efi/efi_64.c        |  5 -----
 drivers/pnp/isapnp/proc.c             |  2 +-
 lib/bitmap.c                          |  2 +-
 30 files changed, 108 insertions(+), 136 deletions(-)

-- 
2.7.4

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#1443748 — [PATCH 09/11] x86: Move addr_limit to thread_struct

FromAndy Lutomirski <luto@kernel.org>
Date2016-07-14 22:30 +0200
Subject[PATCH 09/11] x86: Move addr_limit to thread_struct
Message-ID<rUVqG-5SB-39@gated-at.bofh.it>
In reply to#1443747
thread_info is a legacy mess.  To prepare for its partial removal,
move addr_limit out.

As an added benefit, this way is simpler.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/include/asm/checksum_32.h |  3 +--
 arch/x86/include/asm/processor.h   | 17 ++++++++++-------
 arch/x86/include/asm/thread_info.h |  7 -------
 arch/x86/include/asm/uaccess.h     |  6 +++---
 arch/x86/kernel/asm-offsets.c      |  4 +++-
 arch/x86/lib/copy_user_64.S        |  8 ++++----
 arch/x86/lib/csum-wrappers_64.c    |  1 +
 arch/x86/lib/getuser.S             | 20 ++++++++++----------
 arch/x86/lib/putuser.S             | 10 +++++-----
 arch/x86/lib/usercopy_64.c         |  2 +-
 drivers/pnp/isapnp/proc.c          |  2 +-
 lib/bitmap.c                       |  2 +-
 12 files changed, 40 insertions(+), 42 deletions(-)

diff --git a/arch/x86/include/asm/checksum_32.h b/arch/x86/include/asm/checksum_32.h
index 532f85e6651f..7b53743ed267 100644
--- a/arch/x86/include/asm/checksum_32.h
+++ b/arch/x86/include/asm/checksum_32.h
@@ -2,8 +2,7 @@
 #define _ASM_X86_CHECKSUM_32_H
 
 #include <linux/in6.h>
-
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 /*
  * computes the checksum of a memory block at buff, length len,
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index f53ae57bd985..a2e20d6d01fe 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -371,6 +371,10 @@ extern unsigned int xstate_size;
 
 struct perf_event;
 
+typedef struct {
+	unsigned long		seg;
+} mm_segment_t;
+
 struct thread_struct {
 	/* Cached TLS descriptors: */
 	struct desc_struct	tls_array[GDT_ENTRY_TLS_ENTRIES];
@@ -419,6 +423,8 @@ struct thread_struct {
 	/* Max allowed port in the bitmap, in bytes: */
 	unsigned		io_bitmap_max;
 
+	mm_segment_t		addr_limit;
+
 	unsigned int		sig_on_uaccess_error:1;
 	unsigned int		uaccess_err:1;	/* uaccess failed */
 
@@ -493,11 +499,6 @@ static inline void load_sp0(struct tss_struct *tss,
 #define set_iopl_mask native_set_iopl_mask
 #endif /* CONFIG_PARAVIRT */
 
-typedef struct {
-	unsigned long		seg;
-} mm_segment_t;
-
-
 /* Free all resources held by a thread. */
 extern void release_thread(struct task_struct *);
 
@@ -719,6 +720,7 @@ static inline void spin_lock_prefetch(const void *x)
 	.sp0			= TOP_OF_INIT_STACK,			  \
 	.sysenter_cs		= __KERNEL_CS,				  \
 	.io_bitmap_ptr		= NULL,					  \
+	.addr_limit		= KERNEL_DS,				  \
 }
 
 extern unsigned long thread_saved_pc(struct task_struct *tsk);
@@ -768,8 +770,9 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk);
 #define STACK_TOP		TASK_SIZE
 #define STACK_TOP_MAX		TASK_SIZE_MAX
 
-#define INIT_THREAD  { \
-	.sp0 = TOP_OF_INIT_STACK \
+#define INIT_THREAD  {						\
+	.sp0			= TOP_OF_INIT_STACK,		\
+	.addr_limit		= KERNEL_DS,			\
 }
 
 /*
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 7c47bb659ecd..89bff044a6f5 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -57,7 +57,6 @@ struct thread_info {
 	__u32			flags;		/* low level flags */
 	__u32			status;		/* thread synchronous flags */
 	__u32			cpu;		/* current CPU */
-	mm_segment_t		addr_limit;
 };
 
 #define INIT_THREAD_INFO(tsk)			\
@@ -65,7 +64,6 @@ struct thread_info {
 	.task		= &tsk,			\
 	.flags		= 0,			\
 	.cpu		= 0,			\
-	.addr_limit	= KERNEL_DS,		\
 }
 
 #define init_thread_info	(init_thread_union.thread_info)
@@ -184,11 +182,6 @@ static inline unsigned long current_stack_pointer(void)
 # define cpu_current_top_of_stack (cpu_tss + TSS_sp0)
 #endif
 
-/* Load thread_info address into "reg" */
-#define GET_THREAD_INFO(reg) \
-	_ASM_MOV PER_CPU_VAR(cpu_current_top_of_stack),reg ; \
-	_ASM_SUB $(THREAD_SIZE),reg ;
-
 /*
  * ASM operand which evaluates to a 'thread_info' address of
  * the current task, if it is known that "reg" is exactly "off"
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 4d2a726e8e6d..0eb18b4ac492 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -29,12 +29,12 @@
 #define USER_DS 	MAKE_MM_SEG(TASK_SIZE_MAX)
 
 #define get_ds()	(KERNEL_DS)
-#define get_fs()	(current_thread_info()->addr_limit)
-#define set_fs(x)	(current_thread_info()->addr_limit = (x))
+#define get_fs()	(current->thread.addr_limit)
+#define set_fs(x)	(current->thread.addr_limit = (x))
 
 #define segment_eq(a, b)	((a).seg == (b).seg)
 
-#define user_addr_max() (current_thread_info()->addr_limit.seg)
+#define user_addr_max() (current->thread.addr_limit.seg)
 #define __addr_ok(addr) 	\
 	((unsigned long __force)(addr) < user_addr_max())
 
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 674134e9f5e5..2bd5c6ff7ee7 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -31,7 +31,9 @@ void common(void) {
 	BLANK();
 	OFFSET(TI_flags, thread_info, flags);
 	OFFSET(TI_status, thread_info, status);
-	OFFSET(TI_addr_limit, thread_info, addr_limit);
+
+	BLANK();
+	OFFSET(TASK_addr_limit, task_struct, thread.addr_limit);
 
 	BLANK();
 	OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 2b0ef26da0bd..bf603ebbfd8e 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -17,11 +17,11 @@
 
 /* Standard copy_to_user with segment limit checking */
 ENTRY(_copy_to_user)
-	GET_THREAD_INFO(%rax)
+	mov PER_CPU_VAR(current_task), %rax
 	movq %rdi,%rcx
 	addq %rdx,%rcx
 	jc bad_to_user
-	cmpq TI_addr_limit(%rax),%rcx
+	cmpq TASK_addr_limit(%rax),%rcx
 	ja bad_to_user
 	ALTERNATIVE_2 "jmp copy_user_generic_unrolled",		\
 		      "jmp copy_user_generic_string",		\
@@ -32,11 +32,11 @@ ENDPROC(_copy_to_user)
 
 /* Standard copy_from_user with segment limit checking */
 ENTRY(_copy_from_user)
-	GET_THREAD_INFO(%rax)
+	mov PER_CPU_VAR(current_task), %rax
 	movq %rsi,%rcx
 	addq %rdx,%rcx
 	jc bad_from_user
-	cmpq TI_addr_limit(%rax),%rcx
+	cmpq TASK_addr_limit(%rax),%rcx
 	ja bad_from_user
 	ALTERNATIVE_2 "jmp copy_user_generic_unrolled",		\
 		      "jmp copy_user_generic_string",		\
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
index 28a6654f0d08..b6fcb9a9ddbc 100644
--- a/arch/x86/lib/csum-wrappers_64.c
+++ b/arch/x86/lib/csum-wrappers_64.c
@@ -6,6 +6,7 @@
  */
 #include <asm/checksum.h>
 #include <linux/module.h>
+#include <linux/uaccess.h>
 #include <asm/smap.h>
 
 /**
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 46668cda4ffd..0ef5128c2de8 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -35,8 +35,8 @@
 
 	.text
 ENTRY(__get_user_1)
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 1:	movzbl (%_ASM_AX),%edx
@@ -48,8 +48,8 @@ ENDPROC(__get_user_1)
 ENTRY(__get_user_2)
 	add $1,%_ASM_AX
 	jc bad_get_user
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 2:	movzwl -1(%_ASM_AX),%edx
@@ -61,8 +61,8 @@ ENDPROC(__get_user_2)
 ENTRY(__get_user_4)
 	add $3,%_ASM_AX
 	jc bad_get_user
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 3:	movl -3(%_ASM_AX),%edx
@@ -75,8 +75,8 @@ ENTRY(__get_user_8)
 #ifdef CONFIG_X86_64
 	add $7,%_ASM_AX
 	jc bad_get_user
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 4:	movq -7(%_ASM_AX),%rdx
@@ -86,8 +86,8 @@ ENTRY(__get_user_8)
 #else
 	add $7,%_ASM_AX
 	jc bad_get_user_8
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user_8
 	ASM_STAC
 4:	movl -7(%_ASM_AX),%edx
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index e0817a12d323..c891ece81e5b 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -29,14 +29,14 @@
  * as they get called from within inline assembly.
  */
 
-#define ENTER	GET_THREAD_INFO(%_ASM_BX)
+#define ENTER	mov PER_CPU_VAR(current_task), %_ASM_BX
 #define EXIT	ASM_CLAC ;	\
 		ret
 
 .text
 ENTRY(__put_user_1)
 	ENTER
-	cmp TI_addr_limit(%_ASM_BX),%_ASM_CX
+	cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX
 	jae bad_put_user
 	ASM_STAC
 1:	movb %al,(%_ASM_CX)
@@ -46,7 +46,7 @@ ENDPROC(__put_user_1)
 
 ENTRY(__put_user_2)
 	ENTER
-	mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
 	sub $1,%_ASM_BX
 	cmp %_ASM_BX,%_ASM_CX
 	jae bad_put_user
@@ -58,7 +58,7 @@ ENDPROC(__put_user_2)
 
 ENTRY(__put_user_4)
 	ENTER
-	mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
 	sub $3,%_ASM_BX
 	cmp %_ASM_BX,%_ASM_CX
 	jae bad_put_user
@@ -70,7 +70,7 @@ ENDPROC(__put_user_4)
 
 ENTRY(__put_user_8)
 	ENTER
-	mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
 	sub $7,%_ASM_BX
 	cmp %_ASM_BX,%_ASM_CX
 	jae bad_put_user
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 0a42327a59d7..9f760cdcaf40 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -6,7 +6,7 @@
  * Copyright 2002 Andi Kleen <ak@suse.de>
  */
 #include <linux/module.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 /*
  * Zero Userspace
diff --git a/drivers/pnp/isapnp/proc.c b/drivers/pnp/isapnp/proc.c
index 5edee645d890..262285e48a09 100644
--- a/drivers/pnp/isapnp/proc.c
+++ b/drivers/pnp/isapnp/proc.c
@@ -21,7 +21,7 @@
 #include <linux/isapnp.h>
 #include <linux/proc_fs.h>
 #include <linux/init.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 extern struct pnp_protocol isapnp_protocol;
 
diff --git a/lib/bitmap.c b/lib/bitmap.c
index c66da508cbf7..eca88087fa8a 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -14,9 +14,9 @@
 #include <linux/bug.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
+#include <linux/uaccess.h>
 
 #include <asm/page.h>
-#include <asm/uaccess.h>
 
 /*
  * bitmaps provide an array of bits, implemented using an an
-- 
2.7.4

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#1444217 — [tip:x86/mm] x86/uaccess: Move thread_info::addr_limit to thread_struct

Fromtip-bot for Andy Lutomirski <tipbot@zytor.com>
Date2016-07-15 14:10 +0200
Subject[tip:x86/mm] x86/uaccess: Move thread_info::addr_limit to thread_struct
Message-ID<rVa6l-6K7-1@gated-at.bofh.it>
In reply to#1443748
Commit-ID:  13d4ea097d18b419ad2a2b696063d44bf59acec0
Gitweb:     http://git.kernel.org/tip/13d4ea097d18b419ad2a2b696063d44bf59acec0
Author:     Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 14 Jul 2016 13:22:57 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 15 Jul 2016 10:26:30 +0200

x86/uaccess: Move thread_info::addr_limit to thread_struct

struct thread_info is a legacy mess.  To prepare for its partial removal,
move thread_info::addr_limit out.

As an added benefit, this way is simpler.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/15bee834d09402b47ac86f2feccdf6529f9bc5b0.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/asm/checksum_32.h |  3 +--
 arch/x86/include/asm/processor.h   | 17 ++++++++++-------
 arch/x86/include/asm/thread_info.h |  7 -------
 arch/x86/include/asm/uaccess.h     |  6 +++---
 arch/x86/kernel/asm-offsets.c      |  4 +++-
 arch/x86/lib/copy_user_64.S        |  8 ++++----
 arch/x86/lib/csum-wrappers_64.c    |  1 +
 arch/x86/lib/getuser.S             | 20 ++++++++++----------
 arch/x86/lib/putuser.S             | 10 +++++-----
 arch/x86/lib/usercopy_64.c         |  2 +-
 drivers/pnp/isapnp/proc.c          |  2 +-
 lib/bitmap.c                       |  2 +-
 12 files changed, 40 insertions(+), 42 deletions(-)

diff --git a/arch/x86/include/asm/checksum_32.h b/arch/x86/include/asm/checksum_32.h
index 532f85e..7b53743 100644
--- a/arch/x86/include/asm/checksum_32.h
+++ b/arch/x86/include/asm/checksum_32.h
@@ -2,8 +2,7 @@
 #define _ASM_X86_CHECKSUM_32_H
 
 #include <linux/in6.h>
-
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 /*
  * computes the checksum of a memory block at buff, length len,
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index cbdfe5f..89314ed 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -371,6 +371,10 @@ extern unsigned int xstate_size;
 
 struct perf_event;
 
+typedef struct {
+	unsigned long		seg;
+} mm_segment_t;
+
 struct thread_struct {
 	/* Cached TLS descriptors: */
 	struct desc_struct	tls_array[GDT_ENTRY_TLS_ENTRIES];
@@ -419,6 +423,8 @@ struct thread_struct {
 	/* Max allowed port in the bitmap, in bytes: */
 	unsigned		io_bitmap_max;
 
+	mm_segment_t		addr_limit;
+
 	unsigned int		sig_on_uaccess_err:1;
 	unsigned int		uaccess_err:1;	/* uaccess failed */
 
@@ -493,11 +499,6 @@ static inline void load_sp0(struct tss_struct *tss,
 #define set_iopl_mask native_set_iopl_mask
 #endif /* CONFIG_PARAVIRT */
 
-typedef struct {
-	unsigned long		seg;
-} mm_segment_t;
-
-
 /* Free all resources held by a thread. */
 extern void release_thread(struct task_struct *);
 
@@ -719,6 +720,7 @@ static inline void spin_lock_prefetch(const void *x)
 	.sp0			= TOP_OF_INIT_STACK,			  \
 	.sysenter_cs		= __KERNEL_CS,				  \
 	.io_bitmap_ptr		= NULL,					  \
+	.addr_limit		= KERNEL_DS,				  \
 }
 
 extern unsigned long thread_saved_pc(struct task_struct *tsk);
@@ -768,8 +770,9 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk);
 #define STACK_TOP		TASK_SIZE
 #define STACK_TOP_MAX		TASK_SIZE_MAX
 
-#define INIT_THREAD  { \
-	.sp0 = TOP_OF_INIT_STACK \
+#define INIT_THREAD  {						\
+	.sp0			= TOP_OF_INIT_STACK,		\
+	.addr_limit		= KERNEL_DS,			\
 }
 
 /*
diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index 7c47bb6..89bff04 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -57,7 +57,6 @@ struct thread_info {
 	__u32			flags;		/* low level flags */
 	__u32			status;		/* thread synchronous flags */
 	__u32			cpu;		/* current CPU */
-	mm_segment_t		addr_limit;
 };
 
 #define INIT_THREAD_INFO(tsk)			\
@@ -65,7 +64,6 @@ struct thread_info {
 	.task		= &tsk,			\
 	.flags		= 0,			\
 	.cpu		= 0,			\
-	.addr_limit	= KERNEL_DS,		\
 }
 
 #define init_thread_info	(init_thread_union.thread_info)
@@ -184,11 +182,6 @@ static inline unsigned long current_stack_pointer(void)
 # define cpu_current_top_of_stack (cpu_tss + TSS_sp0)
 #endif
 
-/* Load thread_info address into "reg" */
-#define GET_THREAD_INFO(reg) \
-	_ASM_MOV PER_CPU_VAR(cpu_current_top_of_stack),reg ; \
-	_ASM_SUB $(THREAD_SIZE),reg ;
-
 /*
  * ASM operand which evaluates to a 'thread_info' address of
  * the current task, if it is known that "reg" is exactly "off"
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index 8f66e56..c03bfb6 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -29,12 +29,12 @@
 #define USER_DS 	MAKE_MM_SEG(TASK_SIZE_MAX)
 
 #define get_ds()	(KERNEL_DS)
-#define get_fs()	(current_thread_info()->addr_limit)
-#define set_fs(x)	(current_thread_info()->addr_limit = (x))
+#define get_fs()	(current->thread.addr_limit)
+#define set_fs(x)	(current->thread.addr_limit = (x))
 
 #define segment_eq(a, b)	((a).seg == (b).seg)
 
-#define user_addr_max() (current_thread_info()->addr_limit.seg)
+#define user_addr_max() (current->thread.addr_limit.seg)
 #define __addr_ok(addr) 	\
 	((unsigned long __force)(addr) < user_addr_max())
 
diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c
index 674134e..2bd5c6f 100644
--- a/arch/x86/kernel/asm-offsets.c
+++ b/arch/x86/kernel/asm-offsets.c
@@ -31,7 +31,9 @@ void common(void) {
 	BLANK();
 	OFFSET(TI_flags, thread_info, flags);
 	OFFSET(TI_status, thread_info, status);
-	OFFSET(TI_addr_limit, thread_info, addr_limit);
+
+	BLANK();
+	OFFSET(TASK_addr_limit, task_struct, thread.addr_limit);
 
 	BLANK();
 	OFFSET(crypto_tfm_ctx_offset, crypto_tfm, __crt_ctx);
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 2b0ef26..bf603eb 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -17,11 +17,11 @@
 
 /* Standard copy_to_user with segment limit checking */
 ENTRY(_copy_to_user)
-	GET_THREAD_INFO(%rax)
+	mov PER_CPU_VAR(current_task), %rax
 	movq %rdi,%rcx
 	addq %rdx,%rcx
 	jc bad_to_user
-	cmpq TI_addr_limit(%rax),%rcx
+	cmpq TASK_addr_limit(%rax),%rcx
 	ja bad_to_user
 	ALTERNATIVE_2 "jmp copy_user_generic_unrolled",		\
 		      "jmp copy_user_generic_string",		\
@@ -32,11 +32,11 @@ ENDPROC(_copy_to_user)
 
 /* Standard copy_from_user with segment limit checking */
 ENTRY(_copy_from_user)
-	GET_THREAD_INFO(%rax)
+	mov PER_CPU_VAR(current_task), %rax
 	movq %rsi,%rcx
 	addq %rdx,%rcx
 	jc bad_from_user
-	cmpq TI_addr_limit(%rax),%rcx
+	cmpq TASK_addr_limit(%rax),%rcx
 	ja bad_from_user
 	ALTERNATIVE_2 "jmp copy_user_generic_unrolled",		\
 		      "jmp copy_user_generic_string",		\
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
index 28a6654..b6fcb9a 100644
--- a/arch/x86/lib/csum-wrappers_64.c
+++ b/arch/x86/lib/csum-wrappers_64.c
@@ -6,6 +6,7 @@
  */
 #include <asm/checksum.h>
 #include <linux/module.h>
+#include <linux/uaccess.h>
 #include <asm/smap.h>
 
 /**
diff --git a/arch/x86/lib/getuser.S b/arch/x86/lib/getuser.S
index 46668cd..0ef5128 100644
--- a/arch/x86/lib/getuser.S
+++ b/arch/x86/lib/getuser.S
@@ -35,8 +35,8 @@
 
 	.text
 ENTRY(__get_user_1)
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 1:	movzbl (%_ASM_AX),%edx
@@ -48,8 +48,8 @@ ENDPROC(__get_user_1)
 ENTRY(__get_user_2)
 	add $1,%_ASM_AX
 	jc bad_get_user
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 2:	movzwl -1(%_ASM_AX),%edx
@@ -61,8 +61,8 @@ ENDPROC(__get_user_2)
 ENTRY(__get_user_4)
 	add $3,%_ASM_AX
 	jc bad_get_user
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 3:	movl -3(%_ASM_AX),%edx
@@ -75,8 +75,8 @@ ENTRY(__get_user_8)
 #ifdef CONFIG_X86_64
 	add $7,%_ASM_AX
 	jc bad_get_user
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user
 	ASM_STAC
 4:	movq -7(%_ASM_AX),%rdx
@@ -86,8 +86,8 @@ ENTRY(__get_user_8)
 #else
 	add $7,%_ASM_AX
 	jc bad_get_user_8
-	GET_THREAD_INFO(%_ASM_DX)
-	cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
+	mov PER_CPU_VAR(current_task), %_ASM_DX
+	cmp TASK_addr_limit(%_ASM_DX),%_ASM_AX
 	jae bad_get_user_8
 	ASM_STAC
 4:	movl -7(%_ASM_AX),%edx
diff --git a/arch/x86/lib/putuser.S b/arch/x86/lib/putuser.S
index e0817a1..c891ece 100644
--- a/arch/x86/lib/putuser.S
+++ b/arch/x86/lib/putuser.S
@@ -29,14 +29,14 @@
  * as they get called from within inline assembly.
  */
 
-#define ENTER	GET_THREAD_INFO(%_ASM_BX)
+#define ENTER	mov PER_CPU_VAR(current_task), %_ASM_BX
 #define EXIT	ASM_CLAC ;	\
 		ret
 
 .text
 ENTRY(__put_user_1)
 	ENTER
-	cmp TI_addr_limit(%_ASM_BX),%_ASM_CX
+	cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX
 	jae bad_put_user
 	ASM_STAC
 1:	movb %al,(%_ASM_CX)
@@ -46,7 +46,7 @@ ENDPROC(__put_user_1)
 
 ENTRY(__put_user_2)
 	ENTER
-	mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
 	sub $1,%_ASM_BX
 	cmp %_ASM_BX,%_ASM_CX
 	jae bad_put_user
@@ -58,7 +58,7 @@ ENDPROC(__put_user_2)
 
 ENTRY(__put_user_4)
 	ENTER
-	mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
 	sub $3,%_ASM_BX
 	cmp %_ASM_BX,%_ASM_CX
 	jae bad_put_user
@@ -70,7 +70,7 @@ ENDPROC(__put_user_4)
 
 ENTRY(__put_user_8)
 	ENTER
-	mov TI_addr_limit(%_ASM_BX),%_ASM_BX
+	mov TASK_addr_limit(%_ASM_BX),%_ASM_BX
 	sub $7,%_ASM_BX
 	cmp %_ASM_BX,%_ASM_CX
 	jae bad_put_user
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 0a42327..9f760cd 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -6,7 +6,7 @@
  * Copyright 2002 Andi Kleen <ak@suse.de>
  */
 #include <linux/module.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 /*
  * Zero Userspace
diff --git a/drivers/pnp/isapnp/proc.c b/drivers/pnp/isapnp/proc.c
index 5edee64..262285e 100644
--- a/drivers/pnp/isapnp/proc.c
+++ b/drivers/pnp/isapnp/proc.c
@@ -21,7 +21,7 @@
 #include <linux/isapnp.h>
 #include <linux/proc_fs.h>
 #include <linux/init.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 
 extern struct pnp_protocol isapnp_protocol;
 
diff --git a/lib/bitmap.c b/lib/bitmap.c
index c66da50..eca8808 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -14,9 +14,9 @@
 #include <linux/bug.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
+#include <linux/uaccess.h>
 
 #include <asm/page.h>
-#include <asm/uaccess.h>
 
 /*
  * bitmaps provide an array of bits, implemented using an an

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#1443750 — [PATCH 06/11] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm

FromAndy Lutomirski <luto@kernel.org>
Date2016-07-14 22:30 +0200
Subject[PATCH 06/11] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm
Message-ID<rUVqG-5SB-43@gated-at.bofh.it>
In reply to#1443747
If we get a vmalloc fault while current->active_mm->pgd doesn't
match CR3, we'll crash without this change.  I've seen this failure
mode on heavily instrumented kernels with virtually mapped stacks.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/mm/fault.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 7d1fa7cd2374..ca44e2e7fd00 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -439,7 +439,7 @@ static noinline int vmalloc_fault(unsigned long address)
 	 * happen within a race in page table update. In the later
 	 * case just flush:
 	 */
-	pgd = pgd_offset(current->active_mm, address);
+	pgd = (pgd_t *)__va(read_cr3()) + pgd_index(address);
 	pgd_ref = pgd_offset_k(address);
 	if (pgd_none(*pgd_ref))
 		return -1;
-- 
2.7.4

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#1444219 — [tip:x86/mm] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm

Fromtip-bot for Andy Lutomirski <tipbot@zytor.com>
Date2016-07-15 14:10 +0200
Subject[tip:x86/mm] x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm
Message-ID<rVa6l-6K7-5@gated-at.bofh.it>
In reply to#1443750
Commit-ID:  46aea3873401836abb7f01200e7946e7d518b359
Gitweb:     http://git.kernel.org/tip/46aea3873401836abb7f01200e7946e7d518b359
Author:     Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 14 Jul 2016 13:22:54 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 15 Jul 2016 10:26:27 +0200

x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm

If we get a vmalloc fault while current->active_mm->pgd doesn't
match CR3, we'll crash without this change.  I've seen this failure
mode on heavily instrumented kernels with virtually mapped stacks.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4650d7674185f165ed8fdf9ac4c5c35c5c179ba8.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/mm/fault.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 7d1fa7c..ca44e2e 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -439,7 +439,7 @@ static noinline int vmalloc_fault(unsigned long address)
 	 * happen within a race in page table update. In the later
 	 * case just flush:
 	 */
-	pgd = pgd_offset(current->active_mm, address);
+	pgd = (pgd_t *)__va(read_cr3()) + pgd_index(address);
 	pgd_ref = pgd_offset_k(address);
 	if (pgd_none(*pgd_ref))
 		return -1;

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#1443752 — [PATCH 11/11] x86/smp: Remove unnecessary initialization of thread_info::cpu

FromAndy Lutomirski <luto@kernel.org>
Date2016-07-14 22:30 +0200
Subject[PATCH 11/11] x86/smp: Remove unnecessary initialization of thread_info::cpu
Message-ID<rUVqH-5SB-49@gated-at.bofh.it>
In reply to#1443747
It's statically initialized to zero -- no need to dynamically
initialize it to zero as well.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/kernel/smpboot.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index fafe8b923cac..0e91dbeca2fd 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1285,7 +1285,6 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 	cpumask_copy(cpu_callin_mask, cpumask_of(0));
 	mb();
 
-	current_thread_info()->cpu = 0;  /* needed? */
 	for_each_possible_cpu(i) {
 		zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
 		zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);
-- 
2.7.4

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#1444230 — [tip:x86/mm] x86/smp: Remove unnecessary initialization of thread_info::cpu

Fromtip-bot for Andy Lutomirski <tipbot@zytor.com>
Date2016-07-15 14:10 +0200
Subject[tip:x86/mm] x86/smp: Remove unnecessary initialization of thread_info::cpu
Message-ID<rVa6m-6K7-31@gated-at.bofh.it>
In reply to#1443752
Commit-ID:  eb43e8f85fffc1ba535e0362a872101dfe48abe3
Gitweb:     http://git.kernel.org/tip/eb43e8f85fffc1ba535e0362a872101dfe48abe3
Author:     Andy Lutomirski <luto@kernel.org>
AuthorDate: Thu, 14 Jul 2016 13:22:59 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 15 Jul 2016 10:26:31 +0200

x86/smp: Remove unnecessary initialization of thread_info::cpu

It's statically initialized to zero -- no need to dynamically
initialize it to zero as well.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/6cf6314dce3051371a913ee19d1b88e29c68c560.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/kernel/smpboot.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index fafe8b9..0e91dbe 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1285,7 +1285,6 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
 	cpumask_copy(cpu_callin_mask, cpumask_of(0));
 	mb();
 
-	current_thread_info()->cpu = 0;  /* needed? */
 	for_each_possible_cpu(i) {
 		zalloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL);
 		zalloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL);

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