diff mbox series

[v9,7/8] LoongArch: ftrace: Enable HAVE_FUNCTION_GRAPH_RETVAL

Message ID df4919a76bbf733330158f6ec43c2d424b02d6e1.1680176068.git.pengdonglin@sangfor.com.cn (mailing list archive)
State Superseded
Headers show
Series function_graph: Support recording and printing the return value of function | expand

Commit Message

pengdonglin March 30, 2023, 11:39 a.m. UTC 
The previous patch ("function_graph: Support recording and printing
the return value of function") has laid the groundwork for the for
the funcgraph-retval, and this modification makes it available on
the LoongArch platform.

We introduce a new structure called fgraph_ret_regs for the LoongArch
platform to hold return registers and the frame pointer. We then fill
its content in the return_to_handler and pass its address to the
function ftrace_return_to_handler to record the return value.

Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn>
---
v9:
 - Fix stack pointer align issues
 - Update the commit message

v8:
 - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
---
 arch/loongarch/Kconfig              |  1 +
 arch/loongarch/include/asm/ftrace.h | 20 ++++++++++++++++++++
 arch/loongarch/kernel/asm-offsets.c | 12 ++++++++++++
 arch/loongarch/kernel/mcount.S      | 14 ++++++++------
 arch/loongarch/kernel/mcount_dyn.S  | 15 ++++++++-------
 5 files changed, 49 insertions(+), 13 deletions(-)

Comments

Huacai Chen March 30, 2023, 12:48 p.m. UTC | #1 
Hi, Donglin,

On Thu, Mar 30, 2023 at 7:39 PM Donglin Peng <pengdonglin@sangfor.com.cn> wrote:
>
> The previous patch ("function_graph: Support recording and printing
> the return value of function") has laid the groundwork for the for
> the funcgraph-retval, and this modification makes it available on
> the LoongArch platform.
>
> We introduce a new structure called fgraph_ret_regs for the LoongArch
> platform to hold return registers and the frame pointer. We then fill
> its content in the return_to_handler and pass its address to the
> function ftrace_return_to_handler to record the return value.
>
> Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn>
> ---
> v9:
>  - Fix stack pointer align issues
>  - Update the commit message
>
> v8:
>  - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
> ---
>  arch/loongarch/Kconfig              |  1 +
>  arch/loongarch/include/asm/ftrace.h | 20 ++++++++++++++++++++
>  arch/loongarch/kernel/asm-offsets.c | 12 ++++++++++++
>  arch/loongarch/kernel/mcount.S      | 14 ++++++++------
>  arch/loongarch/kernel/mcount_dyn.S  | 15 ++++++++-------
>  5 files changed, 49 insertions(+), 13 deletions(-)
>
> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> index 7fd51257e0ed..4bf60132869b 100644
> --- a/arch/loongarch/Kconfig
> +++ b/arch/loongarch/Kconfig
> @@ -99,6 +99,7 @@ config LOONGARCH
>         select HAVE_FAST_GUP
>         select HAVE_FTRACE_MCOUNT_RECORD
>         select HAVE_FUNCTION_ARG_ACCESS_API
> +       select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
>         select HAVE_FUNCTION_GRAPH_TRACER
>         select HAVE_FUNCTION_TRACER
>         select HAVE_GENERIC_VDSO
> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
> index 3418d32d4fc7..01e7f92de03c 100644
> --- a/arch/loongarch/include/asm/ftrace.h
> +++ b/arch/loongarch/include/asm/ftrace.h
> @@ -63,4 +63,24 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
>
>  #endif /* CONFIG_FUNCTION_TRACER */
>
> +#ifndef __ASSEMBLY__
> +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
> +
>  #endif /* _ASM_LOONGARCH_FTRACE_H */
> diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c
> index 4bdb203fc66e..fab5bcddeb23 100644
> --- a/arch/loongarch/kernel/asm-offsets.c
> +++ b/arch/loongarch/kernel/asm-offsets.c
> @@ -12,6 +12,7 @@
>  #include <asm/cpu-info.h>
>  #include <asm/ptrace.h>
>  #include <asm/processor.h>
> +#include <asm/ftrace.h>
>
>  void output_ptreg_defines(void)
>  {
> @@ -60,6 +61,17 @@ void output_ptreg_defines(void)
>         BLANK();
>  }
>
> +
> +void output_fgraph_ret_regs_defines(void)
> +{
> +       COMMENT(" LoongArch fgraph_ret_regs offsets. ");
No space needed at the beginning, and I prefer to move this function
to the end of this file.

Huacai
> +       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();
> +}
> +
>  void output_task_defines(void)
>  {
>         COMMENT("LoongArch task_struct offsets.");
> diff --git a/arch/loongarch/kernel/mcount.S b/arch/loongarch/kernel/mcount.S
> index 8cdc1563cd33..cb8e5803de4b 100644
> --- a/arch/loongarch/kernel/mcount.S
> +++ b/arch/loongarch/kernel/mcount.S
> @@ -79,18 +79,20 @@ SYM_FUNC_START(ftrace_graph_caller)
>  SYM_FUNC_END(ftrace_graph_caller)
>
>  SYM_FUNC_START(return_to_handler)
> -       PTR_ADDI        sp, sp, -2 * SZREG
> -       PTR_S           a0, sp, 0
> -       PTR_S           a1, sp, SZREG
> +       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
>
> +       move            a0, sp
>         bl              ftrace_return_to_handler
>
>         /* Restore the real parent address: a0 -> ra */
>         move            ra, a0
>
> -       PTR_L           a0, sp, 0
> -       PTR_L           a1, sp, SZREG
> -       PTR_ADDI        sp, sp, 2 * SZREG
> +       PTR_L           a0, sp, FGRET_REGS_A0
> +       PTR_L           a1, sp, FGRET_REGS_A1
> +       PTR_ADDI        sp, sp, FGRET_REGS_SIZE
>         jr              ra
>  SYM_FUNC_END(return_to_handler)
>  #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
> diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S
> index bbabf06244c2..ec24ae1de741 100644
> --- a/arch/loongarch/kernel/mcount_dyn.S
> +++ b/arch/loongarch/kernel/mcount_dyn.S
> @@ -131,18 +131,19 @@ SYM_CODE_END(ftrace_graph_caller)
>
>  SYM_CODE_START(return_to_handler)
>         /* Save return value regs */
> -       PTR_ADDI        sp, sp, -2 * SZREG
> -       PTR_S           a0, sp, 0
> -       PTR_S           a1, sp, SZREG
> +       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
>
> -       move            a0, zero
> +       move            a0, sp
>         bl              ftrace_return_to_handler
>         move            ra, a0
>
>         /* Restore return value regs */
> -       PTR_L           a0, sp, 0
> -       PTR_L           a1, sp, SZREG
> -       PTR_ADDI        sp, sp, 2 * SZREG
> +       PTR_L           a0, sp, FGRET_REGS_A0
> +       PTR_L           a1, sp, FGRET_REGS_A1
> +       PTR_ADDI        sp, sp, FGRET_REGS_SIZE
>
>         jr              ra
>  SYM_CODE_END(return_to_handler)
> --
> 2.25.1
>
pengdonglin March 30, 2023, 1:07 p.m. UTC | #2 
On 2023/3/30 20:48, Huacai Chen wrote:
> Hi, Donglin,
> 
> On Thu, Mar 30, 2023 at 7:39 PM Donglin Peng <pengdonglin@sangfor.com.cn> wrote:
>>
>> The previous patch ("function_graph: Support recording and printing
>> the return value of function") has laid the groundwork for the for
>> the funcgraph-retval, and this modification makes it available on
>> the LoongArch platform.
>>
>> We introduce a new structure called fgraph_ret_regs for the LoongArch
>> platform to hold return registers and the frame pointer. We then fill
>> its content in the return_to_handler and pass its address to the
>> function ftrace_return_to_handler to record the return value.
>>
>> Signed-off-by: Donglin Peng <pengdonglin@sangfor.com.cn>
>> ---
>> v9:
>>   - Fix stack pointer align issues
>>   - Update the commit message
>>
>> v8:
>>   - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
>> ---
>>   arch/loongarch/Kconfig              |  1 +
>>   arch/loongarch/include/asm/ftrace.h | 20 ++++++++++++++++++++
>>   arch/loongarch/kernel/asm-offsets.c | 12 ++++++++++++
>>   arch/loongarch/kernel/mcount.S      | 14 ++++++++------
>>   arch/loongarch/kernel/mcount_dyn.S  | 15 ++++++++-------
>>   5 files changed, 49 insertions(+), 13 deletions(-)
>>
>> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
>> index 7fd51257e0ed..4bf60132869b 100644
>> --- a/arch/loongarch/Kconfig
>> +++ b/arch/loongarch/Kconfig
>> @@ -99,6 +99,7 @@ config LOONGARCH
>>          select HAVE_FAST_GUP
>>          select HAVE_FTRACE_MCOUNT_RECORD
>>          select HAVE_FUNCTION_ARG_ACCESS_API
>> +       select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
>>          select HAVE_FUNCTION_GRAPH_TRACER
>>          select HAVE_FUNCTION_TRACER
>>          select HAVE_GENERIC_VDSO
>> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
>> index 3418d32d4fc7..01e7f92de03c 100644
>> --- a/arch/loongarch/include/asm/ftrace.h
>> +++ b/arch/loongarch/include/asm/ftrace.h
>> @@ -63,4 +63,24 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
>>
>>   #endif /* CONFIG_FUNCTION_TRACER */
>>
>> +#ifndef __ASSEMBLY__
>> +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
>> +
>>   #endif /* _ASM_LOONGARCH_FTRACE_H */
>> diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c
>> index 4bdb203fc66e..fab5bcddeb23 100644
>> --- a/arch/loongarch/kernel/asm-offsets.c
>> +++ b/arch/loongarch/kernel/asm-offsets.c
>> @@ -12,6 +12,7 @@
>>   #include <asm/cpu-info.h>
>>   #include <asm/ptrace.h>
>>   #include <asm/processor.h>
>> +#include <asm/ftrace.h>
>>
>>   void output_ptreg_defines(void)
>>   {
>> @@ -60,6 +61,17 @@ void output_ptreg_defines(void)
>>          BLANK();
>>   }
>>
>> +
>> +void output_fgraph_ret_regs_defines(void)
>> +{
>> +       COMMENT(" LoongArch fgraph_ret_regs offsets. ");
> No space needed at the beginning, and I prefer to move this function
> to the end of this file.
> 

Yes, I will fix it. I copy it from output_pbe_defines, and it has a
space at the beginning, so I will fix it too.

> Huacai
>> +       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();
>> +}
>> +
>>   void output_task_defines(void)
>>   {
>>          COMMENT("LoongArch task_struct offsets.");
>> diff --git a/arch/loongarch/kernel/mcount.S b/arch/loongarch/kernel/mcount.S
>> index 8cdc1563cd33..cb8e5803de4b 100644
>> --- a/arch/loongarch/kernel/mcount.S
>> +++ b/arch/loongarch/kernel/mcount.S
>> @@ -79,18 +79,20 @@ SYM_FUNC_START(ftrace_graph_caller)
>>   SYM_FUNC_END(ftrace_graph_caller)
>>
>>   SYM_FUNC_START(return_to_handler)
>> -       PTR_ADDI        sp, sp, -2 * SZREG
>> -       PTR_S           a0, sp, 0
>> -       PTR_S           a1, sp, SZREG
>> +       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
>>
>> +       move            a0, sp
>>          bl              ftrace_return_to_handler
>>
>>          /* Restore the real parent address: a0 -> ra */
>>          move            ra, a0
>>
>> -       PTR_L           a0, sp, 0
>> -       PTR_L           a1, sp, SZREG
>> -       PTR_ADDI        sp, sp, 2 * SZREG
>> +       PTR_L           a0, sp, FGRET_REGS_A0
>> +       PTR_L           a1, sp, FGRET_REGS_A1
>> +       PTR_ADDI        sp, sp, FGRET_REGS_SIZE
>>          jr              ra
>>   SYM_FUNC_END(return_to_handler)
>>   #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
>> diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S
>> index bbabf06244c2..ec24ae1de741 100644
>> --- a/arch/loongarch/kernel/mcount_dyn.S
>> +++ b/arch/loongarch/kernel/mcount_dyn.S
>> @@ -131,18 +131,19 @@ SYM_CODE_END(ftrace_graph_caller)
>>
>>   SYM_CODE_START(return_to_handler)
>>          /* Save return value regs */
>> -       PTR_ADDI        sp, sp, -2 * SZREG
>> -       PTR_S           a0, sp, 0
>> -       PTR_S           a1, sp, SZREG
>> +       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
>>
>> -       move            a0, zero
>> +       move            a0, sp
>>          bl              ftrace_return_to_handler
>>          move            ra, a0
>>
>>          /* Restore return value regs */
>> -       PTR_L           a0, sp, 0
>> -       PTR_L           a1, sp, SZREG
>> -       PTR_ADDI        sp, sp, 2 * SZREG
>> +       PTR_L           a0, sp, FGRET_REGS_A0
>> +       PTR_L           a1, sp, FGRET_REGS_A1
>> +       PTR_ADDI        sp, sp, FGRET_REGS_SIZE
>>
>>          jr              ra
>>   SYM_CODE_END(return_to_handler)
>> --
>> 2.25.1
>>
diff mbox series

Patch

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 7fd51257e0ed..4bf60132869b 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -99,6 +99,7 @@  config LOONGARCH
 	select HAVE_FAST_GUP
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_ARG_ACCESS_API
+	select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
 	select HAVE_GENERIC_VDSO
diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
index 3418d32d4fc7..01e7f92de03c 100644
--- a/arch/loongarch/include/asm/ftrace.h
+++ b/arch/loongarch/include/asm/ftrace.h
@@ -63,4 +63,24 @@  void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
 
 #endif /* CONFIG_FUNCTION_TRACER */
 
+#ifndef __ASSEMBLY__
+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
+
 #endif /* _ASM_LOONGARCH_FTRACE_H */
diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c
index 4bdb203fc66e..fab5bcddeb23 100644
--- a/arch/loongarch/kernel/asm-offsets.c
+++ b/arch/loongarch/kernel/asm-offsets.c
@@ -12,6 +12,7 @@ 
 #include <asm/cpu-info.h>
 #include <asm/ptrace.h>
 #include <asm/processor.h>
+#include <asm/ftrace.h>
 
 void output_ptreg_defines(void)
 {
@@ -60,6 +61,17 @@  void output_ptreg_defines(void)
 	BLANK();
 }
 
+
+void 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();
+}
+
 void output_task_defines(void)
 {
 	COMMENT("LoongArch task_struct offsets.");
diff --git a/arch/loongarch/kernel/mcount.S b/arch/loongarch/kernel/mcount.S
index 8cdc1563cd33..cb8e5803de4b 100644
--- a/arch/loongarch/kernel/mcount.S
+++ b/arch/loongarch/kernel/mcount.S
@@ -79,18 +79,20 @@  SYM_FUNC_START(ftrace_graph_caller)
 SYM_FUNC_END(ftrace_graph_caller)
 
 SYM_FUNC_START(return_to_handler)
-	PTR_ADDI	sp, sp, -2 * SZREG
-	PTR_S		a0, sp, 0
-	PTR_S		a1, sp, SZREG
+	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
 
+	move		a0, sp
 	bl		ftrace_return_to_handler
 
 	/* Restore the real parent address: a0 -> ra */
 	move		ra, a0
 
-	PTR_L		a0, sp, 0
-	PTR_L		a1, sp, SZREG
-	PTR_ADDI	sp, sp, 2 * SZREG
+	PTR_L		a0, sp, FGRET_REGS_A0
+	PTR_L		a1, sp, FGRET_REGS_A1
+	PTR_ADDI	sp, sp, FGRET_REGS_SIZE
 	jr		ra
 SYM_FUNC_END(return_to_handler)
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S
index bbabf06244c2..ec24ae1de741 100644
--- a/arch/loongarch/kernel/mcount_dyn.S
+++ b/arch/loongarch/kernel/mcount_dyn.S
@@ -131,18 +131,19 @@  SYM_CODE_END(ftrace_graph_caller)
 
 SYM_CODE_START(return_to_handler)
 	/* Save return value regs */
-	PTR_ADDI 	sp, sp, -2 * SZREG
-	PTR_S		a0, sp, 0
-	PTR_S		a1, sp, SZREG
+	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
 
-	move		a0, zero
+	move		a0, sp
 	bl		ftrace_return_to_handler
 	move		ra, a0
 
 	/* Restore return value regs */
-	PTR_L		a0, sp, 0
-	PTR_L		a1, sp, SZREG
-	PTR_ADDI 	sp, sp, 2 * SZREG
+	PTR_L		a0, sp, FGRET_REGS_A0
+	PTR_L		a1, sp, FGRET_REGS_A1
+	PTR_ADDI	sp, sp, FGRET_REGS_SIZE
 
 	jr		ra
 SYM_CODE_END(return_to_handler)