[PATCH v4 18/29] x86: Move addr_limit to thread_struct

From: Andy Lutomirski
Date: Sun Jun 26 2016 - 18:02:11 EST


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@xxxxxxxxxx>
---
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@xxxxxxx>
*/
#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