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nexedi
linux
Commits
4cc9bed0
Commit
4cc9bed0
authored
Jan 05, 2011
by
Martin Schwidefsky
Committed by
Martin Schwidefsky
Jan 05, 2011
Browse files
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Plain Diff
[S390] cleanup ftrace backend functions
Signed-off-by:
Martin Schwidefsky
<
schwidefsky@de.ibm.com
>
parent
5e9a2692
Changes
4
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Showing
4 changed files
with
135 additions
and
171 deletions
+135
-171
arch/s390/include/asm/ftrace.h
arch/s390/include/asm/ftrace.h
+4
-7
arch/s390/kernel/ftrace.c
arch/s390/kernel/ftrace.c
+117
-121
arch/s390/kernel/mcount.S
arch/s390/kernel/mcount.S
+7
-23
arch/s390/kernel/mcount64.S
arch/s390/kernel/mcount64.S
+7
-20
No files found.
arch/s390/include/asm/ftrace.h
View file @
4cc9bed0
...
@@ -4,20 +4,17 @@
...
@@ -4,20 +4,17 @@
#ifndef __ASSEMBLY__
#ifndef __ASSEMBLY__
extern
void
_mcount
(
void
);
extern
void
_mcount
(
void
);
extern
unsigned
long
ftrace_dyn_func
;
struct
dyn_arch_ftrace
{
};
struct
dyn_arch_ftrace
{
};
#define MCOUNT_ADDR ((long)_mcount)
#define MCOUNT_ADDR ((long)_mcount)
#ifdef CONFIG_64BIT
#ifdef CONFIG_64BIT
#define MCOUNT_OFFSET_RET 18
#define MCOUNT_INSN_SIZE 12
#define MCOUNT_INSN_SIZE 24
#define MCOUNT_OFFSET 14
#else
#define MCOUNT_OFFSET_RET 26
#define MCOUNT_INSN_SIZE 30
#define MCOUNT_OFFSET 8
#define MCOUNT_OFFSET 8
#else
#define MCOUNT_INSN_SIZE 20
#define MCOUNT_OFFSET 4
#endif
#endif
static
inline
unsigned
long
ftrace_call_adjust
(
unsigned
long
addr
)
static
inline
unsigned
long
ftrace_call_adjust
(
unsigned
long
addr
)
...
...
arch/s390/kernel/ftrace.c
View file @
4cc9bed0
...
@@ -4,7 +4,7 @@
...
@@ -4,7 +4,7 @@
* Copyright IBM Corp. 2009
* Copyright IBM Corp. 2009
*
*
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
*
*
Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
*/
#include <linux/hardirq.h>
#include <linux/hardirq.h>
...
@@ -12,176 +12,144 @@
...
@@ -12,176 +12,144 @@
#include <linux/ftrace.h>
#include <linux/ftrace.h>
#include <linux/kernel.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/types.h>
#include <linux/kprobes.h>
#include <trace/syscall.h>
#include <trace/syscall.h>
#include <asm/asm-offsets.h>
#include <asm/asm-offsets.h>
#ifdef CONFIG_64BIT
#define MCOUNT_OFFSET_RET 12
#else
#define MCOUNT_OFFSET_RET 22
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
#ifdef CONFIG_DYNAMIC_FTRACE
void
ftrace_disable_code
(
void
);
void
ftrace_disable_code
(
void
);
void
ftrace_disable_return
(
void
);
void
ftrace_enable_insn
(
void
);
void
ftrace_call_code
(
void
);
void
ftrace_nop_code
(
void
);
#define FTRACE_INSN_SIZE 4
#ifdef CONFIG_64BIT
#ifdef CONFIG_64BIT
/*
* The 64-bit mcount code looks like this:
* stg %r14,8(%r15) # offset 0
* > larl %r1,<&counter> # offset 6
* > brasl %r14,_mcount # offset 12
* lg %r14,8(%r15) # offset 18
* Total length is 24 bytes. The middle two instructions of the mcount
* block get overwritten by ftrace_make_nop / ftrace_make_call.
* The 64-bit enabled ftrace code block looks like this:
* stg %r14,8(%r15) # offset 0
* > lg %r1,__LC_FTRACE_FUNC # offset 6
* > lgr %r0,%r0 # offset 12
* > basr %r14,%r1 # offset 16
* lg %r14,8(%15) # offset 18
* The return points of the mcount/ftrace function have the same offset 18.
* The 64-bit disable ftrace code block looks like this:
* stg %r14,8(%r15) # offset 0
* > jg .+18 # offset 6
* > lgr %r0,%r0 # offset 12
* > basr %r14,%r1 # offset 16
* lg %r14,8(%15) # offset 18
* The jg instruction branches to offset 24 to skip as many instructions
* as possible.
*/
asm
(
asm
(
" .align 4
\n
"
" .align 4
\n
"
"ftrace_disable_code:
\n
"
"ftrace_disable_code:
\n
"
" j 0f
\n
"
" jg 0f
\n
"
" .word 0x0024
\n
"
" lg %r1,"
__stringify
(
__LC_FTRACE_FUNC
)
"
\n
"
" basr %r14,%r1
\n
"
"ftrace_disable_return:
\n
"
" lg %r14,8(15)
\n
"
" lgr %r0,%r0
\n
"
" lgr %r0,%r0
\n
"
"0:
\n
"
);
" basr %r14,%r1
\n
"
"0:
\n
"
asm
(
" .align 4
\n
"
" .align 4
\n
"
"ftrace_
nop_code
:
\n
"
"ftrace_
enable_insn
:
\n
"
"
j .+"
__stringify
(
MCOUNT_INSN_SIZE
)
"
\n
"
);
"
lg %r1,"
__stringify
(
__LC_FTRACE_FUNC
)
"
\n
"
);
asm
(
#define FTRACE_INSN_SIZE 6
" .align 4
\n
"
"ftrace_call_code:
\n
"
" stg %r14,8(%r15)
\n
"
);
#else
/* CONFIG_64BIT */
#else
/* CONFIG_64BIT */
/*
* The 31-bit mcount code looks like this:
* st %r14,4(%r15) # offset 0
* > bras %r1,0f # offset 4
* > .long _mcount # offset 8
* > .long <&counter> # offset 12
* > 0: l %r14,0(%r1) # offset 16
* > l %r1,4(%r1) # offset 20
* basr %r14,%r14 # offset 24
* l %r14,4(%r15) # offset 26
* Total length is 30 bytes. The twenty bytes starting from offset 4
* to offset 24 get overwritten by ftrace_make_nop / ftrace_make_call.
* The 31-bit enabled ftrace code block looks like this:
* st %r14,4(%r15) # offset 0
* > l %r14,__LC_FTRACE_FUNC # offset 4
* > j 0f # offset 8
* > .fill 12,1,0x07 # offset 12
* 0: basr %r14,%r14 # offset 24
* l %r14,4(%r14) # offset 26
* The return points of the mcount/ftrace function have the same offset 26.
* The 31-bit disabled ftrace code block looks like this:
* st %r14,4(%r15) # offset 0
* > j .+26 # offset 4
* > j 0f # offset 8
* > .fill 12,1,0x07 # offset 12
* 0: basr %r14,%r14 # offset 24
* l %r14,4(%r14) # offset 26
* The j instruction branches to offset 30 to skip as many instructions
* as possible.
*/
asm
(
asm
(
" .align 4
\n
"
" .align 4
\n
"
"ftrace_disable_code:
\n
"
"ftrace_disable_code:
\n
"
" j 1f
\n
"
" j 0f
\n
"
" j 0f
\n
"
" l %r1,"
__stringify
(
__LC_FTRACE_FUNC
)
"
\n
"
" .fill 12,1,0x07
\n
"
" basr %r14,%r1
\n
"
"0: basr %r14,%r14
\n
"
"ftrace_disable_return:
\n
"
"1:
\n
"
" l %r14,4(%r15)
\n
"
" j 0f
\n
"
" bcr 0,%r7
\n
"
" bcr 0,%r7
\n
"
" bcr 0,%r7
\n
"
" bcr 0,%r7
\n
"
" bcr 0,%r7
\n
"
" bcr 0,%r7
\n
"
"0:
\n
"
);
asm
(
" .align 4
\n
"
" .align 4
\n
"
"ftrace_
nop_code
:
\n
"
"ftrace_
enable_insn
:
\n
"
"
j .+"
__stringify
(
MCOUNT_INSN_SIZE
)
"
\n
"
);
"
l %r14,"
__stringify
(
__LC_FTRACE_FUNC
)
"
\n
"
);
asm
(
#define FTRACE_INSN_SIZE 4
" .align 4
\n
"
"ftrace_call_code:
\n
"
" st %r14,4(%r15)
\n
"
);
#endif
/* CONFIG_64BIT */
#endif
/* CONFIG_64BIT */
static
int
ftrace_modify_code
(
unsigned
long
ip
,
void
*
old_code
,
int
old_size
,
void
*
new_code
,
int
new_size
)
{
unsigned
char
replaced
[
MCOUNT_INSN_SIZE
];
/*
* Note: Due to modules code can disappear and change.
* We need to protect against faulting as well as code
* changing. We do this by using the probe_kernel_*
* functions.
* This however is just a simple sanity check.
*/
if
(
probe_kernel_read
(
replaced
,
(
void
*
)
ip
,
old_size
))
return
-
EFAULT
;
if
(
memcmp
(
replaced
,
old_code
,
old_size
)
!=
0
)
return
-
EINVAL
;
if
(
probe_kernel_write
((
void
*
)
ip
,
new_code
,
new_size
))
return
-
EPERM
;
return
0
;
}
static
int
ftrace_make_initial_nop
(
struct
module
*
mod
,
struct
dyn_ftrace
*
rec
,
unsigned
long
addr
)
{
return
ftrace_modify_code
(
rec
->
ip
,
ftrace_call_code
,
FTRACE_INSN_SIZE
,
ftrace_disable_code
,
MCOUNT_INSN_SIZE
);
}
int
ftrace_make_nop
(
struct
module
*
mod
,
struct
dyn_ftrace
*
rec
,
int
ftrace_make_nop
(
struct
module
*
mod
,
struct
dyn_ftrace
*
rec
,
unsigned
long
addr
)
unsigned
long
addr
)
{
{
if
(
addr
==
MCOUNT_ADDR
)
if
(
probe_kernel_write
((
void
*
)
rec
->
ip
,
ftrace_disable_code
,
return
ftrace_make_initial_nop
(
mod
,
rec
,
addr
);
MCOUNT_INSN_SIZE
))
return
ftrace_modify_code
(
rec
->
ip
,
return
-
EPERM
;
ftrace_call_code
,
FTRACE_INSN_SIZE
,
return
0
;
ftrace_nop_code
,
FTRACE_INSN_SIZE
);
}
}
int
ftrace_make_call
(
struct
dyn_ftrace
*
rec
,
unsigned
long
addr
)
int
ftrace_make_call
(
struct
dyn_ftrace
*
rec
,
unsigned
long
addr
)
{
{
return
ftrace_modify_code
(
rec
->
ip
,
if
(
probe_kernel_write
((
void
*
)
rec
->
ip
,
ftrace_enable_insn
,
ftrace_nop_code
,
FTRACE_INSN_SIZE
,
FTRACE_INSN_SIZE
))
ftrace_call_code
,
FTRACE_INSN_SIZE
);
return
-
EPERM
;
return
0
;
}
}
int
ftrace_update_ftrace_func
(
ftrace_func_t
func
)
int
ftrace_update_ftrace_func
(
ftrace_func_t
func
)
{
{
ftrace_dyn_func
=
(
unsigned
long
)
func
;
return
0
;
return
0
;
}
}
int
__init
ftrace_dyn_arch_init
(
void
*
data
)
int
__init
ftrace_dyn_arch_init
(
void
*
data
)
{
{
*
(
unsigned
long
*
)
data
=
0
;
*
(
unsigned
long
*
)
data
=
0
;
return
0
;
return
0
;
}
}
#endif
/* CONFIG_DYNAMIC_FTRACE */
#endif
/* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
/*
* Patch the kernel code at ftrace_graph_caller location:
* The instruction there is branch relative on condition. The condition mask
* is either all ones (always branch aka disable ftrace_graph_caller) or all
* zeroes (nop aka enable ftrace_graph_caller).
* Instruction format for brc is a7m4xxxx where m is the condition mask.
*/
int
ftrace_enable_ftrace_graph_caller
(
void
)
{
unsigned
short
opcode
=
0xa704
;
return
probe_kernel_write
(
ftrace_graph_caller
,
&
opcode
,
sizeof
(
opcode
));
}
int
ftrace_disable_ftrace_graph_caller
(
void
)
{
unsigned
short
opcode
=
0xa7f4
;
return
probe_kernel_write
(
ftrace_graph_caller
,
&
opcode
,
sizeof
(
opcode
));
}
static
inline
unsigned
long
ftrace_mcount_call_adjust
(
unsigned
long
addr
)
{
return
addr
-
(
ftrace_disable_return
-
ftrace_disable_code
);
}
#else
/* CONFIG_DYNAMIC_FTRACE */
static
inline
unsigned
long
ftrace_mcount_call_adjust
(
unsigned
long
addr
)
{
return
addr
-
MCOUNT_OFFSET_RET
;
}
#endif
/* CONFIG_DYNAMIC_FTRACE */
/*
/*
* Hook the return address and push it in the stack of return addresses
* Hook the return address and push it in the stack of return addresses
* in current thread info.
* in current thread info.
*/
*/
unsigned
long
prepare_ftrace_return
(
unsigned
long
ip
,
unsigned
long
parent
)
unsigned
long
__kprobes
prepare_ftrace_return
(
unsigned
long
parent
,
unsigned
long
ip
)
{
{
struct
ftrace_graph_ent
trace
;
struct
ftrace_graph_ent
trace
;
...
@@ -189,14 +157,42 @@ unsigned long prepare_ftrace_return(unsigned long ip, unsigned long parent)
...
@@ -189,14 +157,42 @@ unsigned long prepare_ftrace_return(unsigned long ip, unsigned long parent)
goto
out
;
goto
out
;
if
(
ftrace_push_return_trace
(
parent
,
ip
,
&
trace
.
depth
,
0
)
==
-
EBUSY
)
if
(
ftrace_push_return_trace
(
parent
,
ip
,
&
trace
.
depth
,
0
)
==
-
EBUSY
)
goto
out
;
goto
out
;
trace
.
func
=
ftrace_mcount_call_adjust
(
ip
)
&
PSW_ADDR_INSN
;
trace
.
func
=
(
ip
&
PSW_ADDR_INSN
)
-
MCOUNT_OFFSET_RET
;
/* Only trace if the calling function expects to. */
/* Only trace if the calling function expects to. */
if
(
!
ftrace_graph_entry
(
&
trace
))
{
if
(
!
ftrace_graph_entry
(
&
trace
))
{
current
->
curr_ret_stack
--
;
current
->
curr_ret_stack
--
;
goto
out
;
goto
out
;
}
}
parent
=
(
unsigned
long
)
return_to_handler
;
parent
=
(
unsigned
long
)
return_to_handler
;
out:
out:
return
parent
;
return
parent
;
}
}
#ifdef CONFIG_DYNAMIC_FTRACE
/*
* Patch the kernel code at ftrace_graph_caller location. The instruction
* there is branch relative and save to prepare_ftrace_return. To disable
* the call to prepare_ftrace_return we patch the bras offset to point
* directly after the instructions. To enable the call we calculate
* the original offset to prepare_ftrace_return and put it back.
*/
int
ftrace_enable_ftrace_graph_caller
(
void
)
{
unsigned
short
offset
;
offset
=
((
void
*
)
prepare_ftrace_return
-
(
void
*
)
ftrace_graph_caller
)
/
2
;
return
probe_kernel_write
(
ftrace_graph_caller
+
2
,
&
offset
,
sizeof
(
offset
));
}
int
ftrace_disable_ftrace_graph_caller
(
void
)
{
static
unsigned
short
offset
=
0x0002
;
return
probe_kernel_write
(
ftrace_graph_caller
+
2
,
&
offset
,
sizeof
(
offset
));
}
#endif
/* CONFIG_DYNAMIC_FTRACE */
#endif
/* CONFIG_FUNCTION_GRAPH_TRACER */
#endif
/* CONFIG_FUNCTION_GRAPH_TRACER */
arch/s390/kernel/mcount.S
View file @
4cc9bed0
...
@@ -18,22 +18,12 @@ _mcount:
...
@@ -18,22 +18,12 @@ _mcount:
#ifdef CONFIG_DYNAMIC_FTRACE
#ifdef CONFIG_DYNAMIC_FTRACE
br
%
r14
br
%
r14
.
data
.
globl
ftrace_dyn_func
ftrace_dyn_func
:
.
long
ftrace_stub
.
previous
.
globl
ftrace_caller
.
globl
ftrace_caller
ftrace_caller
:
ftrace_caller
:
#endif
#endif
stm
%
r2
,%
r5
,
16
(%
r15
)
stm
%
r2
,%
r5
,
16
(%
r15
)
bras
%
r1
,
2
f
bras
%
r1
,
2
f
#ifdef CONFIG_DYNAMIC_FTRACE
0
:
.
long
ftrace_dyn_func
#else
0
:
.
long
ftrace_trace_function
0
:
.
long
ftrace_trace_function
#endif
1
:
.
long
function_trace_stop
1
:
.
long
function_trace_stop
2
:
l
%
r2
,
1
b
-
0
b
(%
r1
)
2
:
l
%
r2
,
1
b
-
0
b
(%
r1
)
icm
%
r2
,
0xf
,
0
(%
r2
)
icm
%
r2
,
0xf
,
0
(%
r2
)
...
@@ -49,21 +39,15 @@ ftrace_caller:
...
@@ -49,21 +39,15 @@ ftrace_caller:
l
%
r14
,
0
(%
r14
)
l
%
r14
,
0
(%
r14
)
basr
%
r14
,%
r14
basr
%
r14
,%
r14
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
l
%
r2
,
100
(%
r15
)
l
%
r3
,
152
(%
r15
)
.
globl
ftrace_graph_caller
.
globl
ftrace_graph_caller
ftrace_graph_caller
:
ftrace_graph_caller
:
#
This
unconditional
branch
gets
runtime
patched
.
Change
only
if
#
The
bras
instruction
gets
runtime
patched
to
call
prepare_ftrace_return
.
#
you
know
what
you
are
doing
.
See
ftrace_enable_graph_caller
()
.
#
See
ftrace_enable_ftrace_graph_caller
.
The
patched
instruction
is
:
j
1
f
#
bras
%
r14
,
prepare_ftrace_return
#endif
bras
%
r14
,
0
f
bras
%
r1
,
0
f
0
:
st
%
r2
,
100
(%
r15
)
.
long
prepare_ftrace_return
0
:
l
%
r2
,
152
(%
r15
)
l
%
r4
,
0
(%
r1
)
l
%
r3
,
100
(%
r15
)
basr
%
r14
,%
r4
st
%
r2
,
100
(%
r15
)
1
:
#endif
#endif
ahi
%
r15
,
96
ahi
%
r15
,
96
l
%
r14
,
56
(%
r15
)
l
%
r14
,
56
(%
r15
)
...
...
arch/s390/kernel/mcount64.S
View file @
4cc9bed0
...
@@ -18,12 +18,6 @@ _mcount:
...
@@ -18,12 +18,6 @@ _mcount:
#ifdef CONFIG_DYNAMIC_FTRACE
#ifdef CONFIG_DYNAMIC_FTRACE
br
%
r14
br
%
r14
.
data
.
globl
ftrace_dyn_func
ftrace_dyn_func
:
.
quad
ftrace_stub
.
previous
.
globl
ftrace_caller
.
globl
ftrace_caller
ftrace_caller
:
ftrace_caller
:
#endif
#endif
...
@@ -37,26 +31,19 @@ ftrace_caller:
...
@@ -37,26 +31,19 @@ ftrace_caller:
stg
%
r1
,
__SF_BACKCHAIN
(%
r15
)
stg
%
r1
,
__SF_BACKCHAIN
(%
r15
)
lgr
%
r2
,%
r14
lgr
%
r2
,%
r14
lg
%
r3
,
168
(%
r15
)
lg
%
r3
,
168
(%
r15
)
#ifdef CONFIG_DYNAMIC_FTRACE
larl
%
r14
,
ftrace_dyn_func
#else
larl
%
r14
,
ftrace_trace_function
larl
%
r14
,
ftrace_trace_function
#endif
lg
%
r14
,
0
(%
r14
)
lg
%
r14
,
0
(%
r14
)
basr
%
r14
,%
r14
basr
%
r14
,%
r14
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifdef CONFIG_DYNAMIC_FTRACE
lg
%
r2
,
168
(%
r15
)
lg
%
r3
,
272
(%
r15
)
.
globl
ftrace_graph_caller
.
globl
ftrace_graph_caller
ftrace_graph_caller
:
ftrace_graph_caller
:
#
This
unconditional
branch
gets
runtime
patched
.
Change
only
if
#
The
bras
instruction
gets
runtime
patched
to
call
prepare_ftrace_return
.
#
you
know
what
you
are
doing
.
See
ftrace_enable_graph_caller
()
.
#
See
ftrace_enable_ftrace_graph_caller
.
The
patched
instruction
is
:
j
0
f
#
bras
%
r14
,
prepare_ftrace_return
#endif
bras
%
r14
,
0
f
lg
%
r2
,
272
(%
r15
)
0
:
stg
%
r2
,
168
(%
r15
)
lg
%
r3
,
168
(%
r15
)
brasl
%
r14
,
prepare_ftrace_return
stg
%
r2
,
168
(%
r15
)
0
:
#endif
#endif
aghi
%
r15
,
160
aghi
%
r15
,
160
lmg
%
r2
,%
r5
,
32
(%
r15
)
lmg
%
r2
,%
r5
,
32
(%
r15
)
...
...
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