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fgraph: Replace fgraph_ret_regs with ftrace_regs

Browse source 
Use ftrace_regs instead of fgraph_ret_regs for tracing return value
on function_graph tracer because of simplifying the callback interface.

The CONFIG_HAVE_FUNCTION_GRAPH_RETVAL is also replaced by
CONFIG_HAVE_FUNCTION_GRAPH_FREGS.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Florent Revest <revest@chromium.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alan Maguire <alan.maguire@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/173518991508.391279.16635322774382197642.stgit@devnote2
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu (Google) 2024-12-26 14:11:55 +09:00 • committed by Steven Rostedt (Google)
parent 41705c4262
commit a3ed4157b7
24 changed files with 119 additions and 207 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
arch/arm64/Kconfig
View file

@ -219,6 +219,7 @@ config ARM64
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_FREGS
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_RETVAL
select HAVE_GCC_PLUGINS

23
arch/arm64/include/asm/ftrace.h
View file

@ -129,6 +129,12 @@ ftrace_override_function_with_return(struct ftrace_regs *fregs)
arch_ftrace_regs(fregs)->pc = arch_ftrace_regs(fregs)->lr;
}
static __always_inline unsigned long
ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs)
{
return arch_ftrace_regs(fregs)->fp;
}
int ftrace_regs_query_register_offset(const char *name);
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
@ -186,23 +192,6 @@ static inline bool arch_syscall_match_sym_name(const char *sym,
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
/* x0 - x7 */
unsigned long regs[8];
unsigned long fp;
unsigned long __unused;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->regs[0];
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->fp;
}
void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent,
unsigned long frame_pointer);

12
arch/arm64/kernel/asm-offsets.c
View file

@ -179,18 +179,6 @@ int main(void)
DEFINE(FTRACE_OPS_FUNC, offsetof(struct ftrace_ops, func));
#endif
BLANK();
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
DEFINE(FGRET_REGS_X0, offsetof(struct fgraph_ret_regs, regs[0]));
DEFINE(FGRET_REGS_X1, offsetof(struct fgraph_ret_regs, regs[1]));
DEFINE(FGRET_REGS_X2, offsetof(struct fgraph_ret_regs, regs[2]));
DEFINE(FGRET_REGS_X3, offsetof(struct fgraph_ret_regs, regs[3]));
DEFINE(FGRET_REGS_X4, offsetof(struct fgraph_ret_regs, regs[4]));
DEFINE(FGRET_REGS_X5, offsetof(struct fgraph_ret_regs, regs[5]));
DEFINE(FGRET_REGS_X6, offsetof(struct fgraph_ret_regs, regs[6]));
DEFINE(FGRET_REGS_X7, offsetof(struct fgraph_ret_regs, regs[7]));
DEFINE(FGRET_REGS_FP, offsetof(struct fgraph_ret_regs, fp));
DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
#endif
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
DEFINE(FTRACE_OPS_DIRECT_CALL, offsetof(struct ftrace_ops, direct_call));
#endif

32
arch/arm64/kernel/entry-ftrace.S
View file

@ -329,24 +329,28 @@ SYM_FUNC_END(ftrace_stub_graph)
* @fp is checked against the value passed by ftrace_graph_caller().
*/
SYM_CODE_START(return_to_handler)
/* save return value regs */
sub sp, sp, #FGRET_REGS_SIZE
stp x0, x1, [sp, #FGRET_REGS_X0]
stp x2, x3, [sp, #FGRET_REGS_X2]
stp x4, x5, [sp, #FGRET_REGS_X4]
stp x6, x7, [sp, #FGRET_REGS_X6]
str x29, [sp, #FGRET_REGS_FP] // parent's fp
/* Make room for ftrace_regs */
sub sp, sp, #FREGS_SIZE
/* Save return value regs */
stp x0, x1, [sp, #FREGS_X0]
stp x2, x3, [sp, #FREGS_X2]
stp x4, x5, [sp, #FREGS_X4]
stp x6, x7, [sp, #FREGS_X6]
/* Save the callsite's FP */
str x29, [sp, #FREGS_FP]
mov x0, sp
bl ftrace_return_to_handler // addr = ftrace_return_to_hander(regs);
bl ftrace_return_to_handler // addr = ftrace_return_to_hander(fregs);
mov x30, x0 // restore the original return address
/* restore return value regs */
ldp x0, x1, [sp, #FGRET_REGS_X0]
ldp x2, x3, [sp, #FGRET_REGS_X2]
ldp x4, x5, [sp, #FGRET_REGS_X4]
ldp x6, x7, [sp, #FGRET_REGS_X6]
add sp, sp, #FGRET_REGS_SIZE
/* Restore return value regs */
ldp x0, x1, [sp, #FREGS_X0]
ldp x2, x3, [sp, #FREGS_X2]
ldp x4, x5, [sp, #FREGS_X4]
ldp x6, x7, [sp, #FREGS_X6]
add sp, sp, #FREGS_SIZE
ret
SYM_CODE_END(return_to_handler)

2
arch/loongarch/Kconfig
View file

@ -137,7 +137,7 @@ config LOONGARCH
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_ARG_ACCESS_API
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_FREGS
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS

26
arch/loongarch/include/asm/ftrace.h
View file

@ -57,6 +57,10 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs, unsigned long ip)
instruction_pointer_set(&arch_ftrace_regs(fregs)->regs, ip);
}
#undef ftrace_regs_get_frame_pointer
#define ftrace_regs_get_frame_pointer(fregs) \
(arch_ftrace_regs(fregs)->regs.regs[22])
#define ftrace_graph_func ftrace_graph_func
void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
@ -78,26 +82,4 @@ __arch_ftrace_set_direct_caller(struct pt_regs *regs, unsigned long addr)
#endif /* CONFIG_FUNCTION_TRACER */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
/* a0 - a1 */
unsigned long regs[2];
unsigned long fp;
unsigned long __unused;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->regs[0];
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->fp;
}
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* _ASM_LOONGARCH_FTRACE_H */

12
arch/loongarch/kernel/asm-offsets.c
View file

@ -280,18 +280,6 @@ static void __used output_pbe_defines(void)
}
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static void __used output_fgraph_ret_regs_defines(void)
{
COMMENT("LoongArch fgraph_ret_regs offsets.");
OFFSET(FGRET_REGS_A0, fgraph_ret_regs, regs[0]);
OFFSET(FGRET_REGS_A1, fgraph_ret_regs, regs[1]);
OFFSET(FGRET_REGS_FP, fgraph_ret_regs, fp);
DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
BLANK();
}
#endif
static void __used output_kvm_defines(void)
{
COMMENT("KVM/LoongArch Specific offsets.");

17
arch/loongarch/kernel/mcount.S
View file

@ -79,10 +79,11 @@ SYM_FUNC_START(ftrace_graph_caller)
SYM_FUNC_END(ftrace_graph_caller)
SYM_FUNC_START(return_to_handler)
PTR_ADDI sp, sp, -FGRET_REGS_SIZE
PTR_S a0, sp, FGRET_REGS_A0
PTR_S a1, sp, FGRET_REGS_A1
PTR_S zero, sp, FGRET_REGS_FP
/* Save return value regs */
PTR_ADDI sp, sp, -PT_SIZE
PTR_S a0, sp, PT_R4
PTR_S a1, sp, PT_R5
PTR_S zero, sp, PT_R22
move a0, sp
bl ftrace_return_to_handler
@ -90,9 +91,11 @@ SYM_FUNC_START(return_to_handler)
/* Restore the real parent address: a0 -> ra */
move ra, a0
PTR_L a0, sp, FGRET_REGS_A0
PTR_L a1, sp, FGRET_REGS_A1
PTR_ADDI sp, sp, FGRET_REGS_SIZE
/* Restore return value regs */
PTR_L a0, sp, PT_R4
PTR_L a1, sp, PT_R5
PTR_ADDI sp, sp, PT_SIZE
jr ra
SYM_FUNC_END(return_to_handler)
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

14
arch/loongarch/kernel/mcount_dyn.S
View file

@ -140,19 +140,19 @@ SYM_CODE_END(ftrace_graph_caller)
SYM_CODE_START(return_to_handler)
UNWIND_HINT_UNDEFINED
/* Save return value regs */
PTR_ADDI sp, sp, -FGRET_REGS_SIZE
PTR_S a0, sp, FGRET_REGS_A0
PTR_S a1, sp, FGRET_REGS_A1
PTR_S zero, sp, FGRET_REGS_FP
PTR_ADDI sp, sp, -PT_SIZE
PTR_S a0, sp, PT_R4
PTR_S a1, sp, PT_R5
PTR_S zero, sp, PT_R22
move a0, sp
bl ftrace_return_to_handler
move ra, a0
/* Restore return value regs */
PTR_L a0, sp, FGRET_REGS_A0
PTR_L a1, sp, FGRET_REGS_A1
PTR_ADDI sp, sp, FGRET_REGS_SIZE
PTR_L a0, sp, PT_R4
PTR_L a1, sp, PT_R5
PTR_ADDI sp, sp, PT_SIZE
jr ra
SYM_CODE_END(return_to_handler)

2
arch/riscv/Kconfig
View file

@ -148,7 +148,7 @@ config RISCV
select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_FREGS
select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION
select HAVE_EBPF_JIT if MMU
select HAVE_GUP_FAST if MMU

26
arch/riscv/include/asm/ftrace.h
View file

@ -168,6 +168,11 @@ static __always_inline unsigned long ftrace_regs_get_stack_pointer(const struct
return arch_ftrace_regs(fregs)->sp;
}
static __always_inline unsigned long ftrace_regs_get_frame_pointer(const struct ftrace_regs *fregs)
{
return arch_ftrace_regs(fregs)->s0;
}
static __always_inline unsigned long ftrace_regs_get_argument(struct ftrace_regs *fregs,
unsigned int n)
{
@ -208,25 +213,4 @@ static inline void arch_ftrace_set_direct_caller(struct ftrace_regs *fregs, unsi
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
unsigned long a1;
unsigned long a0;
unsigned long s0;
unsigned long ra;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->a0;
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->s0;
}
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* _ASM_RISCV_FTRACE_H */

24
arch/riscv/kernel/mcount.S
View file

@ -12,6 +12,8 @@
#include <asm/asm-offsets.h>
#include <asm/ftrace.h>
#define ABI_SIZE_ON_STACK 80
.text
.macro SAVE_ABI_STATE
@ -26,12 +28,12 @@
* register if a0 was not saved.
*/
.macro SAVE_RET_ABI_STATE
addi sp, sp, -4*SZREG
REG_S s0, 2*SZREG(sp)
REG_S ra, 3*SZREG(sp)
REG_S a0, 1*SZREG(sp)
REG_S a1, 0*SZREG(sp)
addi s0, sp, 4*SZREG
addi sp, sp, -ABI_SIZE_ON_STACK
REG_S ra, 1*SZREG(sp)
REG_S s0, 8*SZREG(sp)
REG_S a0, 10*SZREG(sp)
REG_S a1, 11*SZREG(sp)
addi s0, sp, ABI_SIZE_ON_STACK
.endm
.macro RESTORE_ABI_STATE
@ -41,11 +43,11 @@
.endm
.macro RESTORE_RET_ABI_STATE
REG_L ra, 3*SZREG(sp)
REG_L s0, 2*SZREG(sp)
REG_L a0, 1*SZREG(sp)
REG_L a1, 0*SZREG(sp)
addi sp, sp, 4*SZREG
REG_L ra, 1*SZREG(sp)
REG_L s0, 8*SZREG(sp)
REG_L a0, 10*SZREG(sp)
REG_L a1, 11*SZREG(sp)
addi sp, sp, ABI_SIZE_ON_STACK
.endm
SYM_TYPED_FUNC_START(ftrace_stub)

2
arch/s390/Kconfig
View file

@ -192,7 +192,7 @@ config S390
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_ARG_ACCESS_API
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_FUNCTION_GRAPH_RETVAL
select HAVE_FUNCTION_GRAPH_FREGS
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS

24
arch/s390/include/asm/ftrace.h
View file

@ -62,23 +62,6 @@ static __always_inline struct pt_regs *arch_ftrace_get_regs(struct ftrace_regs *
return NULL;
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
unsigned long gpr2;
unsigned long fp;
};
static __always_inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->gpr2;
}
static __always_inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->fp;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
static __always_inline void
ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
unsigned long ip)
@ -86,6 +69,13 @@ ftrace_regs_set_instruction_pointer(struct ftrace_regs *fregs,
arch_ftrace_regs(fregs)->regs.psw.addr = ip;
}
#undef ftrace_regs_get_frame_pointer
static __always_inline unsigned long
ftrace_regs_get_frame_pointer(struct ftrace_regs *fregs)
{
return ftrace_regs_get_stack_pointer(fregs);
}
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
/*
* When an ftrace registered caller is tracing a function that is

6
arch/s390/kernel/asm-offsets.c
View file

@ -175,12 +175,6 @@ int main(void)
DEFINE(OLDMEM_SIZE, PARMAREA + offsetof(struct parmarea, oldmem_size));
DEFINE(COMMAND_LINE, PARMAREA + offsetof(struct parmarea, command_line));
DEFINE(MAX_COMMAND_LINE_SIZE, PARMAREA + offsetof(struct parmarea, max_command_line_size));
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* function graph return value tracing */
OFFSET(__FGRAPH_RET_GPR2, fgraph_ret_regs, gpr2);
OFFSET(__FGRAPH_RET_FP, fgraph_ret_regs, fp);
DEFINE(__FGRAPH_RET_SIZE, sizeof(struct fgraph_ret_regs));
#endif
OFFSET(__FTRACE_REGS_PT_REGS, __arch_ftrace_regs, regs);
DEFINE(__FTRACE_REGS_SIZE, sizeof(struct __arch_ftrace_regs));

12
arch/s390/kernel/mcount.S
View file

@ -134,14 +134,14 @@ SYM_CODE_END(ftrace_common)
SYM_FUNC_START(return_to_handler)
stmg %r2,%r5,32(%r15)
lgr %r1,%r15
aghi %r15,-(STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE)
# allocate ftrace_regs and stack frame for ftrace_return_to_handler
aghi %r15,-STACK_FRAME_SIZE_FREGS
stg %r1,__SF_BACKCHAIN(%r15)
la %r3,STACK_FRAME_OVERHEAD(%r15)
stg %r1,__FGRAPH_RET_FP(%r3)
stg %r2,__FGRAPH_RET_GPR2(%r3)
lgr %r2,%r3
stg %r2,(STACK_FREGS_PTREGS_GPRS+2*8)(%r15)
stg %r1,(STACK_FREGS_PTREGS_GPRS+15*8)(%r15)
la %r2,STACK_FRAME_OVERHEAD(%r15)
brasl %r14,ftrace_return_to_handler
aghi %r15,STACK_FRAME_OVERHEAD+__FGRAPH_RET_SIZE
aghi %r15,STACK_FRAME_SIZE_FREGS
lgr %r14,%r2
lmg %r2,%r5,32(%r15)
BR_EX %r14

2
arch/x86/Kconfig
View file

@ -235,7 +235,7 @@ config X86
select HAVE_GUP_FAST
select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
select HAVE_FTRACE_MCOUNT_RECORD
select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_FREGS if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE)
select HAVE_FUNCTION_TRACER
select HAVE_GCC_PLUGINS

20
arch/x86/include/asm/ftrace.h
View file

@ -134,24 +134,4 @@ static inline bool arch_trace_is_compat_syscall(struct pt_regs *regs)
#endif /* !COMPILE_OFFSETS */
#endif /* !__ASSEMBLY__ */
#ifndef __ASSEMBLY__
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ret_regs {
unsigned long ax;
unsigned long dx;
unsigned long bp;
};
static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->ax;
}
static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
{
return ret_regs->bp;
}
#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
#endif
#endif /* _ASM_X86_FTRACE_H */

13
arch/x86/kernel/ftrace_32.S
View file

@ -187,14 +187,15 @@ SYM_CODE_END(ftrace_graph_caller)
.globl return_to_handler
return_to_handler:
pushl $0
pushl %edx
pushl %eax
subl $(PTREGS_SIZE), %esp
movl $0, PT_EBP(%esp)
movl %edx, PT_EDX(%esp)
movl %eax, PT_EAX(%esp)
movl %esp, %eax
call ftrace_return_to_handler
movl %eax, %ecx
popl %eax
popl %edx
addl $4, %esp # skip ebp
movl PT_EAX(%esp), %eax
movl PT_EDX(%esp), %edx
addl $(PTREGS_SIZE), %esp
JMP_NOSPEC ecx
#endif

17
arch/x86/kernel/ftrace_64.S
View file

@ -348,21 +348,22 @@ STACK_FRAME_NON_STANDARD_FP(__fentry__)
SYM_CODE_START(return_to_handler)
UNWIND_HINT_UNDEFINED
ANNOTATE_NOENDBR
subq $24, %rsp
/* Save the return values */
movq %rax, (%rsp)
movq %rdx, 8(%rsp)
movq %rbp, 16(%rsp)
/* Save ftrace_regs for function exit context */
subq $(FRAME_SIZE), %rsp
movq %rax, RAX(%rsp)
movq %rdx, RDX(%rsp)
movq %rbp, RBP(%rsp)
movq %rsp, %rdi
call ftrace_return_to_handler
movq %rax, %rdi
movq 8(%rsp), %rdx
movq (%rsp), %rax
movq RDX(%rsp), %rdx
movq RAX(%rsp), %rax
addq $24, %rsp
addq $(FRAME_SIZE), %rsp
/*
* Jump back to the old return address. This cannot be JMP_NOSPEC rdi
* since IBT would demand that contain ENDBR, which simply isn't so for

12
include/linux/ftrace.h
View file

@ -43,9 +43,8 @@ struct dyn_ftrace;
char *arch_ftrace_match_adjust(char *str, const char *search);
#ifdef CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
struct fgraph_ret_regs;
unsigned long ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs);
#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FREGS
unsigned long ftrace_return_to_handler(struct ftrace_regs *fregs);
#else
unsigned long ftrace_return_to_handler(unsigned long frame_pointer);
#endif
@ -134,6 +133,13 @@ extern int ftrace_enabled;
* Also, architecture dependent fields can be used for internal process.
* (e.g. orig_ax on x86_64)
*
* Basically, ftrace_regs stores the registers related to the context.
* On function entry, registers for function parameters and hooking the
* function call are stored, and on function exit, registers for function
* return value and frame pointers are stored.
*
* And also, it dpends on the context that which registers are restored
* from the ftrace_regs.
* On the function entry, those registers will be restored except for
* the stack pointer, so that user can change the function parameters
* and instruction pointer (e.g. live patching.)

2
include/linux/ftrace_regs.h
View file

@ -30,6 +30,8 @@ struct ftrace_regs;
override_function_with_return(&arch_ftrace_regs(fregs)->regs)
#define ftrace_regs_query_register_offset(name) \
regs_query_register_offset(name)
#define ftrace_regs_get_frame_pointer(fregs) \
frame_pointer(&arch_ftrace_regs(fregs)->regs)
#endif /* HAVE_ARCH_FTRACE_REGS */

4
kernel/trace/Kconfig
View file

@ -31,7 +31,7 @@ config HAVE_FUNCTION_GRAPH_TRACER
help
See Documentation/trace/ftrace-design.rst
config HAVE_FUNCTION_GRAPH_RETVAL
config HAVE_FUNCTION_GRAPH_FREGS
bool
config HAVE_DYNAMIC_FTRACE
@ -232,7 +232,7 @@ config FUNCTION_GRAPH_TRACER
config FUNCTION_GRAPH_RETVAL
bool "Kernel Function Graph Return Value"
depends on HAVE_FUNCTION_GRAPH_RETVAL
depends on HAVE_FUNCTION_GRAPH_FREGS
depends on FUNCTION_GRAPH_TRACER
default n
help

21
kernel/trace/fgraph.c
View file

@ -801,15 +801,12 @@ static struct notifier_block ftrace_suspend_notifier = {
.notifier_call = ftrace_suspend_notifier_call,
};
/* fgraph_ret_regs is not defined without CONFIG_FUNCTION_GRAPH_RETVAL */
struct fgraph_ret_regs;
/*
* Send the trace to the ring-buffer.
* @return the original return address.
*/
static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs,
unsigned long frame_pointer)
static inline unsigned long
__ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointer)
{
struct ftrace_ret_stack *ret_stack;
struct ftrace_graph_ret trace;
@ -829,7 +826,7 @@ static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs
trace.rettime = trace_clock_local();
#ifdef CONFIG_FUNCTION_GRAPH_RETVAL
trace.retval = fgraph_ret_regs_return_value(ret_regs);
trace.retval = ftrace_regs_get_return_value(fregs);
#endif
bitmap = get_bitmap_bits(current, offset);
@ -864,14 +861,14 @@ static unsigned long __ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs
}
/*
* After all architecures have selected HAVE_FUNCTION_GRAPH_RETVAL, we can
* leave only ftrace_return_to_handler(ret_regs).
* After all architecures have selected HAVE_FUNCTION_GRAPH_FREGS, we can
* leave only ftrace_return_to_handler(fregs).
*/
#ifdef CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
unsigned long ftrace_return_to_handler(struct fgraph_ret_regs *ret_regs)
#ifdef CONFIG_HAVE_FUNCTION_GRAPH_FREGS
unsigned long ftrace_return_to_handler(struct ftrace_regs *fregs)
{
return __ftrace_return_to_handler(ret_regs,
fgraph_ret_regs_frame_pointer(ret_regs));
return __ftrace_return_to_handler(fregs,
ftrace_regs_get_frame_pointer(fregs));
}
#else
unsigned long ftrace_return_to_handler(unsigned long frame_pointer)