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ftrace: store mcount address in rec->ip

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Record the address of the mcount call-site. Currently all archs except sparc64
record the address of the instruction following the mcount call-site. Some
general cleanups are entailed. Storing mcount addresses in rec->ip enables
looking them up in the kprobe hash table later on to check if they're kprobe'd.

Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: davem@davemloft.net
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Abhishek Sagar 2008-06-21 23:47:27 +05:30 committed by Ingo Molnar
parent f34bfb1bee
commit 395a59d0f8
19 changed files with 111 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
arch/arm/kernel/armksyms.c
View File

@ -18,6 +18,7 @@
#include <asm/io.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/ftrace.h>
/*
* libgcc functions - functions that are used internally by the
@ -48,11 +49,6 @@ extern void __aeabi_ulcmp(void);
extern void fpundefinstr(void);
extern void fp_enter(void);
#ifdef CONFIG_FTRACE
extern void mcount(void);
EXPORT_SYMBOL(mcount);
#endif
/*
* This has a special calling convention; it doesn't
* modify any of the usual registers, except for LR.
@ -186,3 +182,7 @@ EXPORT_SYMBOL(_find_next_bit_be);
#endif
EXPORT_SYMBOL(copy_page);
#ifdef CONFIG_FTRACE
EXPORT_SYMBOL(mcount);
#endif

4
arch/arm/kernel/entry-common.S
View File

@ -9,6 +9,7 @@
*/
#include <asm/unistd.h>
#include <asm/ftrace.h>
#include <asm/arch/entry-macro.S>
#include "entry-header.S"
@ -104,6 +105,7 @@ ENTRY(ret_from_fork)
ENTRY(mcount)
stmdb sp!, {r0-r3, lr}
mov r0, lr
sub r0, r0, #MCOUNT_INSN_SIZE
.globl mcount_call
mcount_call:
@ -114,6 +116,7 @@ ENTRY(ftrace_caller)
stmdb sp!, {r0-r3, lr}
ldr r1, [fp, #-4]
mov r0, lr
sub r0, r0, #MCOUNT_INSN_SIZE
.globl ftrace_call
ftrace_call:
@ -134,6 +137,7 @@ ENTRY(mcount)
trace:
ldr r1, [fp, #-4]
mov r0, lr
sub r0, r0, #MCOUNT_INSN_SIZE
mov lr, pc
mov pc, r2
ldmia sp!, {r0-r3, pc}

18
arch/arm/kernel/ftrace.c
View File

@ -12,9 +12,10 @@
*/
#include <linux/ftrace.h>
#include <asm/cacheflush.h>
#define INSN_SIZE 4
#include <asm/cacheflush.h>
#include <asm/ftrace.h>
#define PC_OFFSET 8
#define BL_OPCODE 0xeb000000
#define BL_OFFSET_MASK 0x00ffffff
@ -32,10 +33,10 @@ unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr)
{
long offset;
offset = (long)addr - (long)(pc - INSN_SIZE + PC_OFFSET);
offset = (long)addr - (long)(pc + PC_OFFSET);
if (unlikely(offset < -33554432 || offset > 33554428)) {
/* Can't generate branches that far (from ARM ARM). Ftrace
* doesn't generate branches outside of core kernel text.
* doesn't generate branches outside of kernel text.
*/
WARN_ON_ONCE(1);
return NULL;
@ -52,7 +53,6 @@ int ftrace_modify_code(unsigned long pc, unsigned char *old_code,
old = *(unsigned long *)old_code;
new = *(unsigned long *)new_code;
pc -= INSN_SIZE;
__asm__ __volatile__ (
"1: ldr %1, [%2] \n"
@ -77,7 +77,7 @@ int ftrace_modify_code(unsigned long pc, unsigned char *old_code,
: "memory");
if (!err && (replaced == old))
flush_icache_range(pc, pc + INSN_SIZE);
flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);
return err;
}
@ -89,8 +89,7 @@ int ftrace_update_ftrace_func(ftrace_func_t func)
unsigned char *new;
pc = (unsigned long)&ftrace_call;
pc += INSN_SIZE;
memcpy(&old, &ftrace_call, INSN_SIZE);
memcpy(&old, &ftrace_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(pc, (unsigned long)func);
ret = ftrace_modify_code(pc, (unsigned char *)&old, new);
return ret;
@ -103,8 +102,7 @@ int ftrace_mcount_set(unsigned long *data)
unsigned char *new;
pc = (unsigned long)&mcount_call;
pc += INSN_SIZE;
memcpy(&old, &mcount_call, INSN_SIZE);
memcpy(&old, &mcount_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(pc, *addr);
*addr = ftrace_modify_code(pc, (unsigned char *)&old, new);
return 0;

4
arch/powerpc/kernel/entry_32.S
View File

@ -30,6 +30,7 @@
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/ftrace.h>
#undef SHOW_SYSCALLS
#undef SHOW_SYSCALLS_TASK
@ -1053,6 +1054,7 @@ _GLOBAL(_mcount)
stw r10,40(r1)
stw r3, 44(r1)
stw r5, 8(r1)
subi r3, r3, MCOUNT_INSN_SIZE
.globl mcount_call
mcount_call:
bl ftrace_stub
@ -1090,6 +1092,7 @@ _GLOBAL(ftrace_caller)
stw r10,40(r1)
stw r3, 44(r1)
stw r5, 8(r1)
subi r3, r3, MCOUNT_INSN_SIZE
.globl ftrace_call
ftrace_call:
bl ftrace_stub
@ -1128,6 +1131,7 @@ _GLOBAL(_mcount)
stw r3, 44(r1)
stw r5, 8(r1)
subi r3, r3, MCOUNT_INSN_SIZE
LOAD_REG_ADDR(r5, ftrace_trace_function)
lwz r5,0(r5)

5
arch/powerpc/kernel/entry_64.S
View File

@ -31,6 +31,7 @@
#include <asm/bug.h>
#include <asm/ptrace.h>
#include <asm/irqflags.h>
#include <asm/ftrace.h>
/*
* System calls.
@ -879,6 +880,7 @@ _GLOBAL(_mcount)
mflr r3
stdu r1, -112(r1)
std r3, 128(r1)
subi r3, r3, MCOUNT_INSN_SIZE
.globl mcount_call
mcount_call:
bl ftrace_stub
@ -895,6 +897,7 @@ _GLOBAL(ftrace_caller)
stdu r1, -112(r1)
std r3, 128(r1)
ld r4, 16(r11)
subi r3, r3, MCOUNT_INSN_SIZE
.globl ftrace_call
ftrace_call:
bl ftrace_stub
@ -916,7 +919,7 @@ _GLOBAL(_mcount)
std r3, 128(r1)
ld r4, 16(r11)
subi r3, r3, MCOUNT_INSN_SIZE
LOAD_REG_ADDR(r5,ftrace_trace_function)
ld r5,0(r5)
ld r5,0(r5)

21
arch/powerpc/kernel/ftrace.c
View File

@ -15,8 +15,8 @@
#include <linux/list.h>
#include <asm/cacheflush.h>
#include <asm/ftrace.h>
#define CALL_BACK 4
static unsigned int ftrace_nop = 0x60000000;
@ -27,9 +27,10 @@ static unsigned int ftrace_nop = 0x60000000;
# define GET_ADDR(addr) *(unsigned long *)addr
#endif
static unsigned int notrace ftrace_calc_offset(long ip, long addr)
{
return (int)((addr + CALL_BACK) - ip);
return (int)(addr - ip);
}
notrace unsigned char *ftrace_nop_replace(void)
@ -76,9 +77,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned new = *(unsigned *)new_code;
int faulted = 0;
/* move the IP back to the start of the call */
ip -= CALL_BACK;
/*
* Note: Due to modules and __init, code can
* disappear and change, we need to protect against faulting
@ -118,12 +116,10 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
notrace int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long ip = (unsigned long)(&ftrace_call);
unsigned char old[4], *new;
unsigned char old[MCOUNT_INSN_SIZE], *new;
int ret;
ip += CALL_BACK;
memcpy(old, &ftrace_call, 4);
memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, (unsigned long)func);
ret = ftrace_modify_code(ip, old, new);
@ -134,16 +130,13 @@ notrace int ftrace_mcount_set(unsigned long *data)
{
unsigned long ip = (long)(&mcount_call);
unsigned long *addr = data;
unsigned char old[4], *new;
/* ip is at the location, but modify code will subtact this */
ip += CALL_BACK;
unsigned char old[MCOUNT_INSN_SIZE], *new;
/*
* Replace the mcount stub with a pointer to the
* ip recorder function.
*/
memcpy(old, &mcount_call, 4);
memcpy(old, &mcount_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, *addr);
*addr = ftrace_modify_code(ip, old, new);

10
arch/sparc64/kernel/ftrace.c
View File

@ -5,6 +5,8 @@
#include <linux/init.h>
#include <linux/list.h>
#include <asm/ftrace.h>
static const u32 ftrace_nop = 0x01000000;
notrace unsigned char *ftrace_nop_replace(void)
@ -60,9 +62,9 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
notrace int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long ip = (unsigned long)(&ftrace_call);
unsigned char old[4], *new;
unsigned char old[MCOUNT_INSN_SIZE], *new;
memcpy(old, &ftrace_call, 4);
memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, (unsigned long)func);
return ftrace_modify_code(ip, old, new);
}
@ -71,13 +73,13 @@ notrace int ftrace_mcount_set(unsigned long *data)
{
unsigned long ip = (long)(&mcount_call);
unsigned long *addr = data;
unsigned char old[4], *new;
unsigned char old[MCOUNT_INSN_SIZE], *new;
/*
* Replace the mcount stub with a pointer to the
* ip recorder function.
*/
memcpy(old, &mcount_call, 4);
memcpy(old, &mcount_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, *addr);
*addr = ftrace_modify_code(ip, old, new);

2
arch/sparc64/kernel/sparc64_ksyms.c
View File

@ -53,6 +53,7 @@
#include <asm/ns87303.h>
#include <asm/timer.h>
#include <asm/cpudata.h>
#include <asm/ftrace.h>
struct poll {
int fd;
@ -112,7 +113,6 @@ EXPORT_SYMBOL(smp_call_function);
#endif /* CONFIG_SMP */
#if defined(CONFIG_MCOUNT)
extern void _mcount(void);
EXPORT_SYMBOL(_mcount);
#endif

4
arch/x86/kernel/entry_32.S
View File

@ -51,6 +51,7 @@
#include <asm/percpu.h>
#include <asm/dwarf2.h>
#include <asm/processor-flags.h>
#include <asm/ftrace.h>
#include "irq_vectors.h"
/*
@ -1118,6 +1119,7 @@ ENTRY(mcount)
pushl %ecx
pushl %edx
movl 0xc(%esp), %eax
subl $MCOUNT_INSN_SIZE, %eax
.globl mcount_call
mcount_call:
@ -1136,6 +1138,7 @@ ENTRY(ftrace_caller)
pushl %edx
movl 0xc(%esp), %eax
movl 0x4(%ebp), %edx
subl $MCOUNT_INSN_SIZE, %eax
.globl ftrace_call
ftrace_call:
@ -1166,6 +1169,7 @@ trace:
pushl %edx
movl 0xc(%esp), %eax
movl 0x4(%ebp), %edx
subl $MCOUNT_INSN_SIZE, %eax
call *ftrace_trace_function

4
arch/x86/kernel/entry_64.S
View File

@ -51,6 +51,7 @@
#include <asm/page.h>
#include <asm/irqflags.h>
#include <asm/paravirt.h>
#include <asm/ftrace.h>
.code64
@ -68,6 +69,7 @@ ENTRY(mcount)
movq %r9, 48(%rsp)
movq 0x38(%rsp), %rdi
subq $MCOUNT_INSN_SIZE, %rdi
.globl mcount_call
mcount_call:
@ -99,6 +101,7 @@ ENTRY(ftrace_caller)
movq 0x38(%rsp), %rdi
movq 8(%rbp), %rsi
subq $MCOUNT_INSN_SIZE, %rdi
.globl ftrace_call
ftrace_call:
@ -139,6 +142,7 @@ trace:
movq 0x38(%rsp), %rdi
movq 8(%rbp), %rsi
subq $MCOUNT_INSN_SIZE, %rdi
call *ftrace_trace_function

26
arch/x86/kernel/ftrace.c
View File

@ -17,20 +17,21 @@
#include <linux/list.h>
#include <asm/alternative.h>
#include <asm/ftrace.h>
#define CALL_BACK 5
/* Long is fine, even if it is only 4 bytes ;-) */
static long *ftrace_nop;
union ftrace_code_union {
char code[5];
char code[MCOUNT_INSN_SIZE];
struct {
char e8;
int offset;
} __attribute__((packed));
};
static int notrace ftrace_calc_offset(long ip, long addr)
{
return (int)(addr - ip);
@ -46,7 +47,7 @@ notrace unsigned char *ftrace_call_replace(unsigned long ip, unsigned long addr)
static union ftrace_code_union calc;
calc.e8 = 0xe8;
calc.offset = ftrace_calc_offset(ip, addr);
calc.offset = ftrace_calc_offset(ip + MCOUNT_INSN_SIZE, addr);
/*
* No locking needed, this must be called via kstop_machine
@ -65,9 +66,6 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
unsigned char newch = new_code[4];
int faulted = 0;
/* move the IP back to the start of the call */
ip -= CALL_BACK;
/*
* Note: Due to modules and __init, code can
* disappear and change, we need to protect against faulting
@ -102,12 +100,10 @@ ftrace_modify_code(unsigned long ip, unsigned char *old_code,
notrace int ftrace_update_ftrace_func(ftrace_func_t func)
{
unsigned long ip = (unsigned long)(&ftrace_call);
unsigned char old[5], *new;
unsigned char old[MCOUNT_INSN_SIZE], *new;
int ret;
ip += CALL_BACK;
memcpy(old, &ftrace_call, 5);
memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, (unsigned long)func);
ret = ftrace_modify_code(ip, old, new);
@ -118,16 +114,13 @@ notrace int ftrace_mcount_set(unsigned long *data)
{
unsigned long ip = (long)(&mcount_call);
unsigned long *addr = data;
unsigned char old[5], *new;
/* ip is at the location, but modify code will subtact this */
ip += CALL_BACK;
unsigned char old[MCOUNT_INSN_SIZE], *new;
/*
* Replace the mcount stub with a pointer to the
* ip recorder function.
*/
memcpy(old, &mcount_call, 5);
memcpy(old, &mcount_call, MCOUNT_INSN_SIZE);
new = ftrace_call_replace(ip, *addr);
*addr = ftrace_modify_code(ip, old, new);
@ -142,8 +135,7 @@ int __init ftrace_dyn_arch_init(void *data)
ftrace_mcount_set(data);
ftrace_nop = (unsigned long *)noptable[CALL_BACK];
ftrace_nop = (unsigned long *)noptable[MCOUNT_INSN_SIZE];
return 0;
}

2
arch/x86/kernel/i386_ksyms_32.c
View File

@ -1,9 +1,9 @@
#include <linux/ftrace.h>
#include <linux/module.h>
#include <asm/checksum.h>
#include <asm/pgtable.h>
#include <asm/desc.h>
#include <asm/ftrace.h>
#ifdef CONFIG_FTRACE
/* mcount is defined in assembly */

2
arch/x86/kernel/x8664_ksyms_64.c
View File

@ -1,7 +1,6 @@
/* Exports for assembly files.
All C exports should go in the respective C files. */
#include <linux/ftrace.h>
#include <linux/module.h>
#include <linux/smp.h>
@ -11,6 +10,7 @@
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/desc.h>
#include <asm/ftrace.h>
#ifdef CONFIG_FTRACE
/* mcount is defined in assembly */

14
include/asm-arm/ftrace.h Normal file
View File

@ -0,0 +1,14 @@
#ifndef _ASM_ARM_FTRACE
#define _ASM_ARM_FTRACE
#ifdef CONFIG_FTRACE
#define MCOUNT_ADDR ((long)(mcount))
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
#ifndef __ASSEMBLY__
extern void mcount(void);
#endif
#endif
#endif /* _ASM_ARM_FTRACE */

8
include/asm-powerpc/ftrace.h
View File

@ -1,6 +1,14 @@
#ifndef _ASM_POWERPC_FTRACE
#define _ASM_POWERPC_FTRACE
#ifdef CONFIG_FTRACE
#define MCOUNT_ADDR ((long)(_mcount))
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
#ifndef __ASSEMBLY__
extern void _mcount(void);
#endif
#endif
#endif /* _ASM_POWERPC_FTRACE */

14
include/asm-sparc64/ftrace.h Normal file
View File

@ -0,0 +1,14 @@
#ifndef _ASM_SPARC64_FTRACE
#define _ASM_SPARC64_FTRACE
#ifdef CONFIG_FTRACE
#define MCOUNT_ADDR ((long)(_mcount))
#define MCOUNT_INSN_SIZE 4 /* sizeof mcount call */
#ifndef __ASSEMBLY__
extern void _mcount(void);
#endif
#endif
#endif /* _ASM_SPARC64_FTRACE */

14
include/asm-x86/ftrace.h Normal file
View File

@ -0,0 +1,14 @@
#ifndef _ASM_X86_FTRACE
#define _ASM_SPARC64_FTRACE
#ifdef CONFIG_FTRACE
#define MCOUNT_ADDR ((long)(mcount))
#define MCOUNT_INSN_SIZE 5 /* sizeof mcount call */
#ifndef __ASSEMBLY__
extern void mcount(void);
#endif
#endif /* CONFIG_FTRACE */
#endif /* _ASM_X86_FTRACE */

3
include/linux/ftrace.h
View File

@ -31,7 +31,6 @@ int unregister_ftrace_function(struct ftrace_ops *ops);
void clear_ftrace_function(void);
extern void ftrace_stub(unsigned long a0, unsigned long a1);
extern void mcount(void);
#else /* !CONFIG_FTRACE */
# define register_ftrace_function(ops) do { } while (0)
@ -54,7 +53,7 @@ enum {
struct dyn_ftrace {
struct hlist_node node;
unsigned long ip;
unsigned long ip; /* address of mcount call-site */
unsigned long flags;
};

3
kernel/trace/ftrace.c
View File

@ -27,6 +27,8 @@
#include <linux/hash.h>
#include <linux/list.h>
#include <asm/ftrace.h>
#include "trace.h"
/* ftrace_enabled is a method to turn ftrace on or off */
@ -329,7 +331,6 @@ ftrace_record_ip(unsigned long ip)
}
#define FTRACE_ADDR ((long)(ftrace_caller))
#define MCOUNT_ADDR ((long)(mcount))
static int
__ftrace_replace_code(struct dyn_ftrace *rec,