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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
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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,