[PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly

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* [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly
@ 2022-11-16  3:13 Song Shuai
  2022-11-16  3:13 ` [PATCH v2 1/3] riscv/ftrace: add ftrace_graph_func Song Shuai
                   ` (3 more replies)
  0 siblings, 4 replies; 9+ messages in thread
From: Song Shuai @ 2022-11-16  3:13 UTC (permalink / raw)
  To: guoren, rostedt, mhiramat, mark.rutland, paul.walmsley, palmer, aou
  Cc: linux-riscv, linux-kernel, Song Shuai

In RISC-V architecture, when we enable the ftrace_graph tracer on some
functions, the function tracings on other functions will suffer extra
graph tracing work. In essence, graph_ops isn't limited by its func_hash
due to the global ftrace_graph_[regs]_call label. That should be corrected.

What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function
graph use ftrace directly") that uses graph_ops::func function to install
return_hooker and makes the function called against its func_hash.

This series of patches makes function graph use ftrace directly for riscv.

If FTRACE_WITH_REGS isn't defined, ftrace_caller keeps ftrace_graph_call
so that it can be replaced with the calling of prepare_ftrace_return by
the enable/disable helper.

As for defining FTRACE_WITH_REGS, ftrace_caller is adjusted to save the
necessary regs against the pt_regs layout, so it can reasonably call the
graph_ops::func function - ftrace_graph_func. And ftrace_graph_[regs]_call
and its enable/disable helper aren't needed.

The tests generated by CONFIG_FTRACE_STARTUP_TEST have passed in the local
qemu-system-riscv64 virt machine. The following is the log during startup.

```
Nov 15 03:07:13 stage4 kernel: Testing tracer function: PASSED
Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace: PASSED
Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #1: 
Nov 15 03:07:13 stage4 kernel: (1 0 1 0 0)  
Nov 15 03:07:13 stage4 kernel: (1 1 2 0 0)  
Nov 15 03:07:13 stage4 kernel: (2 1 3 0 365) 
Nov 15 03:07:13 stage4 kernel: (2 2 4 0 399) 
Nov 15 03:07:13 stage4 kernel: (3 2 4 0 146071) 
Nov 15 03:07:13 stage4 kernel: (3 3 5 0 146105) PASSED
Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #2: 
Nov 15 03:07:13 stage4 kernel: (1 0 1 589 0)  
Nov 15 03:07:13 stage4 kernel: (1 1 2 635 0)  
Nov 15 03:07:13 stage4 kernel: (2 1 3 1 2)  
Nov 15 03:07:13 stage4 kernel: (2 2 4 125 126) 
Nov 15 03:07:13 stage4 kernel: (3 2 4 146001 146078) 
Nov 15 03:07:13 stage4 kernel: (3 3 5 146035 146112) PASSED
Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion: PASSED
Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion safe: PASSED
Nov 15 03:07:13 stage4 kernel: Testing ftrace regs: PASSED
Nov 15 03:07:13 stage4 kernel: Testing tracer nop: PASSED
Nov 15 03:07:13 stage4 kernel: Testing tracer irqsoff: PASSED
Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup:
Nov 15 03:07:13 stage4 kernel: sched: DL replenish lagged too much
Nov 15 03:07:13 stage4 kernel: PASSED
Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_rt: PASSED
Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_dl: PASSED
Nov 15 03:07:13 stage4 kernel: Testing tracer function_graph: PASSED
```

Note that the changes of mcount-dyn.S conflicts with this unmerged
commit (riscv: entry: consolidate general regs saving/restoring).
https://lore.kernel.org/linux-riscv/20221103075047.1634923-15-guoren@kernel.org

Changes since v1
-  fixed the checkpatch warnings in patch 1
Link: https://lore.kernel.org/linux-riscv/20221115061525.112757-1-suagrfillet@gmail.com

Song Shuai (3):
  riscv/ftrace: add ftrace_graph_func
  riscv/ftrace: SAVE_ALL supports lightweight save
  riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller

 arch/riscv/include/asm/ftrace.h |  13 ++-
 arch/riscv/kernel/ftrace.c      |  35 ++++----
 arch/riscv/kernel/mcount-dyn.S  | 145 +++++++++++++++++++++++---------
 3 files changed, 136 insertions(+), 57 deletions(-)

-- 
2.20.1

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v2 1/3] riscv/ftrace: add ftrace_graph_func
  2022-11-16  3:13 [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Song Shuai
@ 2022-11-16  3:13 ` Song Shuai
  2022-11-16  3:13 ` [PATCH v2 2/3] riscv/ftrace: SAVE_ALL supports lightweight save Song Shuai
                   ` (2 subsequent siblings)
  3 siblings, 0 replies; 9+ messages in thread
From: Song Shuai @ 2022-11-16  3:13 UTC (permalink / raw)
  To: guoren, rostedt, mhiramat, mark.rutland, paul.walmsley, palmer, aou
  Cc: linux-riscv, linux-kernel, Song Shuai

Here implements ftrace_graph_func as the function graph tracing function
with FTRACE_WITH_REGS defined.

function_graph_func gets the point of the parent IP and the frame pointer
from fregs and call prepare_ftrace_return for function graph tracing.

If FTRACE_WITH_REGS isn't defined, the enable/disable helpers of
ftrace_graph_[regs]_call remain for serving the !FTRACE_WITH_REGS
version ftrace_caller.

Signed-off-by: Song Shuai <suagrfillet@gmail.com>
---
 arch/riscv/include/asm/ftrace.h | 13 +++++++++++--
 arch/riscv/kernel/ftrace.c      | 16 ++++++++++++++++
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/include/asm/ftrace.h b/arch/riscv/include/asm/ftrace.h
index 04dad3380041..61a8f4be67eb 100644
--- a/arch/riscv/include/asm/ftrace.h
+++ b/arch/riscv/include/asm/ftrace.h
@@ -81,8 +81,17 @@ do {									\
 struct dyn_ftrace;
 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
 #define ftrace_init_nop ftrace_init_nop
-#endif
 
-#endif
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+struct ftrace_ops;
+struct ftrace_regs;
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+		       struct ftrace_ops *op, struct ftrace_regs *fregs);
+#define ftrace_graph_func ftrace_graph_func
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* CONFIG_DYNAMIC_FTRACE */
 
 #endif /* _ASM_RISCV_FTRACE_H */
diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 2086f6585773..148a5480076b 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -196,6 +196,20 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
 }
 
 #ifdef CONFIG_DYNAMIC_FTRACE
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+		       struct ftrace_ops *op, struct ftrace_regs *fregs)
+{
+	struct pt_regs *regs = arch_ftrace_get_regs(fregs);
+	unsigned long *parent = (unsigned long *)&regs->ra;
+
+	prepare_ftrace_return(parent, ip, frame_pointer(regs));
+}
+
+#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
 extern void ftrace_graph_call(void);
 extern void ftrace_graph_regs_call(void);
 int ftrace_enable_ftrace_graph_caller(void)
@@ -223,5 +237,7 @@ int ftrace_disable_ftrace_graph_caller(void)
 	return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
 				    (unsigned long)&prepare_ftrace_return, false);
 }
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
 #endif /* CONFIG_DYNAMIC_FTRACE */
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
-- 
2.20.1


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v2 2/3] riscv/ftrace: SAVE_ALL supports lightweight save
  2022-11-16  3:13 [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Song Shuai
  2022-11-16  3:13 ` [PATCH v2 1/3] riscv/ftrace: add ftrace_graph_func Song Shuai
@ 2022-11-16  3:13 ` Song Shuai
  2022-11-16  8:45   ` Andrew Jones
  2022-11-16  3:13 ` [PATCH v2 3/3] riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller Song Shuai
  2022-11-17  1:45 ` [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Guo Ren
  3 siblings, 1 reply; 9+ messages in thread
From: Song Shuai @ 2022-11-16  3:13 UTC (permalink / raw)
  To: guoren, rostedt, mhiramat, mark.rutland, paul.walmsley, palmer, aou
  Cc: linux-riscv, linux-kernel, Song Shuai

In order to make the function graph use ftrace directly, ftrace_caller
should be adjusted to save the necessary regs against the pt_regs layout
so it can call ftrace_graph_func reasonably.

SAVE_ALL now saves all the regs according to the pt_regs struct. Here
introduces a lightweight option for SAVE_ALL to save only the necessary
regs for ftrace_caller.

For convenience, the original argument setup for the tracing function in
ftrace_[regs]_caller is killed and appended to the tail of SAVE_ALL.

Signed-off-by: Song Shuai <suagrfillet@gmail.com>
---
 arch/riscv/kernel/mcount-dyn.S | 110 +++++++++++++++++++++++++++------
 1 file changed, 92 insertions(+), 18 deletions(-)

diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index d171eca623b6..2f0a280bd7a0 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -56,7 +56,51 @@
 	.endm
 
 #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
-	.macro SAVE_ALL
+
+/**
+* SAVE_ALL - save regs against the pt_regs struct
+*
+* @all: tell if saving all the regs
+*
+* If all is set, all the regs will be saved, otherwise only ABI
+* related regs (a0-a7,epc,ra and optional s0) will be saved.
+*
+* For convenience the argument setup for tracing function is appended here.
+* Especially $sp is passed as the 4th argument of the tracing function.
+*
+* After the stack is established,
+*
+* 0(sp) stores the PC of the traced function which can be accessed
+* by &(fregs)->regs->epc in tracing function. Note that the real
+* function entry address should be computed with -FENTRY_RA_OFFSET.
+*
+* 8(sp) stores the function return address (i.e. parent IP) that
+* can be accessed by &(fregs)->regs->ra in tracing function.
+*
+* The other regs are saved at the respective localtion and accessed
+* by the respective pt_regs member.
+*
+* Here is the layout of stack for your reference.
+*
+*
+*			=========
+*			|  pip  |
+* PT_SIZE_ON_STACK  ->  =========
+*			+ ..... +
+*			+ t3-t6 +
+*			+ s2-s11+
+*			+ a0-a7 + --++++-> ftrace_caller saved
+*			+ s1    +   +
+*			+ s0    + --+
+*			+ t0-t2 +   +
+*			+ tp    +   +
+*			+ gp    +   +
+*			+ sp    +   +
+*			+ ra    + --+ // parent IP
+*		sp  ->  + epc   + --+ // PC of the traced function
+*			+++++++++
+**/
+	.macro SAVE_ALL, all=0
 	addi	sp, sp, -SZREG
 	addi	sp, sp, -PT_SIZE_ON_STACK
 
@@ -67,14 +111,8 @@
 	REG_S x1,  PT_RA(sp)
 	REG_L x1,  PT_EPC(sp)
 
-	REG_S x2,  PT_SP(sp)
-	REG_S x3,  PT_GP(sp)
-	REG_S x4,  PT_TP(sp)
-	REG_S x5,  PT_T0(sp)
-	REG_S x6,  PT_T1(sp)
-	REG_S x7,  PT_T2(sp)
-	REG_S x8,  PT_S0(sp)
-	REG_S x9,  PT_S1(sp)
+	/* always save the ABI regs */
+
 	REG_S x10, PT_A0(sp)
 	REG_S x11, PT_A1(sp)
 	REG_S x12, PT_A2(sp)
@@ -83,6 +121,18 @@
 	REG_S x15, PT_A5(sp)
 	REG_S x16, PT_A6(sp)
 	REG_S x17, PT_A7(sp)
+
+	/* save leftover regs for ftrace_regs_caller*/
+
+	.if \all == 1
+	REG_S x2,  PT_SP(sp)
+	REG_S x3,  PT_GP(sp)
+	REG_S x4,  PT_TP(sp)
+	REG_S x5,  PT_T0(sp)
+	REG_S x6,  PT_T1(sp)
+	REG_S x7,  PT_T2(sp)
+	REG_S x8,  PT_S0(sp)
+	REG_S x9,  PT_S1(sp)
 	REG_S x18, PT_S2(sp)
 	REG_S x19, PT_S3(sp)
 	REG_S x20, PT_S4(sp)
@@ -97,22 +147,31 @@
 	REG_S x29, PT_T4(sp)
 	REG_S x30, PT_T5(sp)
 	REG_S x31, PT_T6(sp)
+	.else
+
+	/* save s0 for ftrace_caller if FP_TEST defined */
+
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+	REG_S x8,  PT_S0(sp)
+#endif
+	.endif
+
+	/* setup 4 args for tracing functions  */
+
+	addi	a0, ra, -FENTRY_RA_OFFSET // ip
+	la	a1, function_trace_op
+	REG_L	a2, 0(a1)		// op
+	REG_L	a1, PT_SIZE_ON_STACK(sp) // parent_ip
+	mv	a3, sp			// fregs
 	.endm
 
-	.macro RESTORE_ALL
+	.macro RESTORE_ALL, all=0
 	REG_L x1,  PT_RA(sp)
 	addi	sp, sp, PT_SIZE_ON_STACK
 	REG_S x1,  (sp)
 	addi	sp, sp, -PT_SIZE_ON_STACK
 	REG_L x1,  PT_EPC(sp)
-	REG_L x2,  PT_SP(sp)
-	REG_L x3,  PT_GP(sp)
-	REG_L x4,  PT_TP(sp)
-	REG_L x5,  PT_T0(sp)
-	REG_L x6,  PT_T1(sp)
-	REG_L x7,  PT_T2(sp)
-	REG_L x8,  PT_S0(sp)
-	REG_L x9,  PT_S1(sp)
+
 	REG_L x10, PT_A0(sp)
 	REG_L x11, PT_A1(sp)
 	REG_L x12, PT_A2(sp)
@@ -121,6 +180,16 @@
 	REG_L x15, PT_A5(sp)
 	REG_L x16, PT_A6(sp)
 	REG_L x17, PT_A7(sp)
+
+	.if \all == 1
+	REG_L x2,  PT_SP(sp)
+	REG_L x3,  PT_GP(sp)
+	REG_L x4,  PT_TP(sp)
+	REG_L x5,  PT_T0(sp)
+	REG_L x6,  PT_T1(sp)
+	REG_L x7,  PT_T2(sp)
+	REG_L x8,  PT_S0(sp)
+	REG_L x9,  PT_S1(sp)
 	REG_L x18, PT_S2(sp)
 	REG_L x19, PT_S3(sp)
 	REG_L x20, PT_S4(sp)
@@ -136,6 +205,11 @@
 	REG_L x30, PT_T5(sp)
 	REG_L x31, PT_T6(sp)
 
+	.else
+#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
+	REG_L x8,  PT_S0(sp)
+#endif
+	.endif
 	addi	sp, sp, PT_SIZE_ON_STACK
 	addi	sp, sp, SZREG
 	.endm
-- 
2.20.1


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v2 2/3] riscv/ftrace: SAVE_ALL supports lightweight save
  2022-11-16  3:13 ` [PATCH v2 2/3] riscv/ftrace: SAVE_ALL supports lightweight save Song Shuai
@ 2022-11-16  8:45   ` Andrew Jones
  2022-11-17  1:55     ` Guo Ren
  0 siblings, 1 reply; 9+ messages in thread
From: Andrew Jones @ 2022-11-16  8:45 UTC (permalink / raw)
  To: Song Shuai
  Cc: guoren, rostedt, mhiramat, mark.rutland, paul.walmsley, palmer,
	aou, linux-riscv, linux-kernel

On Wed, Nov 16, 2022 at 11:13:04AM +0800, Song Shuai wrote:
> In order to make the function graph use ftrace directly, ftrace_caller
> should be adjusted to save the necessary regs against the pt_regs layout
> so it can call ftrace_graph_func reasonably.
> 
> SAVE_ALL now saves all the regs according to the pt_regs struct. Here
> introduces a lightweight option for SAVE_ALL to save only the necessary
> regs for ftrace_caller.
> 
> For convenience, the original argument setup for the tracing function in
> ftrace_[regs]_caller is killed and appended to the tail of SAVE_ALL.
> 
> Signed-off-by: Song Shuai <suagrfillet@gmail.com>
> ---
>  arch/riscv/kernel/mcount-dyn.S | 110 +++++++++++++++++++++++++++------
>  1 file changed, 92 insertions(+), 18 deletions(-)
> 
> diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
> index d171eca623b6..2f0a280bd7a0 100644
> --- a/arch/riscv/kernel/mcount-dyn.S
> +++ b/arch/riscv/kernel/mcount-dyn.S
> @@ -56,7 +56,51 @@
>  	.endm
>  
>  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> -	.macro SAVE_ALL
> +
> +/**
> +* SAVE_ALL - save regs against the pt_regs struct
> +*
> +* @all: tell if saving all the regs

I find it odd to have a macro name that includes 'ALL' in it
to require a parameter 'all' to be set in order to actually save
all. I suggest renaming the macro to something like SAVE_REGS.

> +*
> +* If all is set, all the regs will be saved, otherwise only ABI
> +* related regs (a0-a7,epc,ra and optional s0) will be saved.
> +*
> +* For convenience the argument setup for tracing function is appended here.
> +* Especially $sp is passed as the 4th argument of the tracing function.
> +*
> +* After the stack is established,
> +*
> +* 0(sp) stores the PC of the traced function which can be accessed
> +* by &(fregs)->regs->epc in tracing function. Note that the real
> +* function entry address should be computed with -FENTRY_RA_OFFSET.
> +*
> +* 8(sp) stores the function return address (i.e. parent IP) that
> +* can be accessed by &(fregs)->regs->ra in tracing function.
> +*
> +* The other regs are saved at the respective localtion and accessed
> +* by the respective pt_regs member.
> +*
> +* Here is the layout of stack for your reference.
> +*
> +*
> +*			=========
> +*			|  pip  |
> +* PT_SIZE_ON_STACK  ->  =========
> +*			+ ..... +
> +*			+ t3-t6 +
> +*			+ s2-s11+
> +*			+ a0-a7 + --++++-> ftrace_caller saved
> +*			+ s1    +   +
> +*			+ s0    + --+
> +*			+ t0-t2 +   +
> +*			+ tp    +   +
> +*			+ gp    +   +
> +*			+ sp    +   +
> +*			+ ra    + --+ // parent IP
> +*		sp  ->  + epc   + --+ // PC of the traced function
> +*			+++++++++
> +**/
> +	.macro SAVE_ALL, all=0
>  	addi	sp, sp, -SZREG
>  	addi	sp, sp, -PT_SIZE_ON_STACK
>  
> @@ -67,14 +111,8 @@
>  	REG_S x1,  PT_RA(sp)
>  	REG_L x1,  PT_EPC(sp)
>  
> -	REG_S x2,  PT_SP(sp)
> -	REG_S x3,  PT_GP(sp)
> -	REG_S x4,  PT_TP(sp)
> -	REG_S x5,  PT_T0(sp)
> -	REG_S x6,  PT_T1(sp)
> -	REG_S x7,  PT_T2(sp)
> -	REG_S x8,  PT_S0(sp)
> -	REG_S x9,  PT_S1(sp)
> +	/* always save the ABI regs */
> +
>  	REG_S x10, PT_A0(sp)
>  	REG_S x11, PT_A1(sp)
>  	REG_S x12, PT_A2(sp)
> @@ -83,6 +121,18 @@
>  	REG_S x15, PT_A5(sp)
>  	REG_S x16, PT_A6(sp)
>  	REG_S x17, PT_A7(sp)
> +
> +	/* save leftover regs for ftrace_regs_caller*/
> +
> +	.if \all == 1
> +	REG_S x2,  PT_SP(sp)
> +	REG_S x3,  PT_GP(sp)
> +	REG_S x4,  PT_TP(sp)
> +	REG_S x5,  PT_T0(sp)
> +	REG_S x6,  PT_T1(sp)
> +	REG_S x7,  PT_T2(sp)
> +	REG_S x8,  PT_S0(sp)
> +	REG_S x9,  PT_S1(sp)
>  	REG_S x18, PT_S2(sp)
>  	REG_S x19, PT_S3(sp)
>  	REG_S x20, PT_S4(sp)
> @@ -97,22 +147,31 @@
>  	REG_S x29, PT_T4(sp)
>  	REG_S x30, PT_T5(sp)
>  	REG_S x31, PT_T6(sp)
> +	.else
> +
> +	/* save s0 for ftrace_caller if FP_TEST defined */
> +
> +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
> +	REG_S x8,  PT_S0(sp)
> +#endif
> +	.endif
> +
> +	/* setup 4 args for tracing functions  */
> +
> +	addi	a0, ra, -FENTRY_RA_OFFSET // ip
> +	la	a1, function_trace_op
> +	REG_L	a2, 0(a1)		// op
> +	REG_L	a1, PT_SIZE_ON_STACK(sp) // parent_ip
> +	mv	a3, sp			// fregs

Please line up the comments.

>  	.endm
>  
> -	.macro RESTORE_ALL
> +	.macro RESTORE_ALL, all=0
>  	REG_L x1,  PT_RA(sp)
>  	addi	sp, sp, PT_SIZE_ON_STACK
>  	REG_S x1,  (sp)
>  	addi	sp, sp, -PT_SIZE_ON_STACK
>  	REG_L x1,  PT_EPC(sp)
> -	REG_L x2,  PT_SP(sp)
> -	REG_L x3,  PT_GP(sp)
> -	REG_L x4,  PT_TP(sp)
> -	REG_L x5,  PT_T0(sp)
> -	REG_L x6,  PT_T1(sp)
> -	REG_L x7,  PT_T2(sp)
> -	REG_L x8,  PT_S0(sp)
> -	REG_L x9,  PT_S1(sp)
> +
>  	REG_L x10, PT_A0(sp)
>  	REG_L x11, PT_A1(sp)
>  	REG_L x12, PT_A2(sp)
> @@ -121,6 +180,16 @@
>  	REG_L x15, PT_A5(sp)
>  	REG_L x16, PT_A6(sp)
>  	REG_L x17, PT_A7(sp)
> +
> +	.if \all == 1
> +	REG_L x2,  PT_SP(sp)
> +	REG_L x3,  PT_GP(sp)
> +	REG_L x4,  PT_TP(sp)
> +	REG_L x5,  PT_T0(sp)
> +	REG_L x6,  PT_T1(sp)
> +	REG_L x7,  PT_T2(sp)
> +	REG_L x8,  PT_S0(sp)
> +	REG_L x9,  PT_S1(sp)
>  	REG_L x18, PT_S2(sp)
>  	REG_L x19, PT_S3(sp)
>  	REG_L x20, PT_S4(sp)
> @@ -136,6 +205,11 @@
>  	REG_L x30, PT_T5(sp)
>  	REG_L x31, PT_T6(sp)
>  
> +	.else
> +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
> +	REG_L x8,  PT_S0(sp)
> +#endif
> +	.endif
>  	addi	sp, sp, PT_SIZE_ON_STACK
>  	addi	sp, sp, SZREG
>  	.endm
> -- 
> 2.20.1
> 
>

Thanks,
drew

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v2 2/3] riscv/ftrace: SAVE_ALL supports lightweight save
  2022-11-16  8:45   ` Andrew Jones
@ 2022-11-17  1:55     ` Guo Ren
  0 siblings, 0 replies; 9+ messages in thread
From: Guo Ren @ 2022-11-17  1:55 UTC (permalink / raw)
  To: Andrew Jones
  Cc: Song Shuai, rostedt, mhiramat, mark.rutland, paul.walmsley,
	palmer, aou, linux-riscv, linux-kernel

On Wed, Nov 16, 2022 at 4:45 PM Andrew Jones <ajones@ventanamicro.com> wrote:
>
> On Wed, Nov 16, 2022 at 11:13:04AM +0800, Song Shuai wrote:
> > In order to make the function graph use ftrace directly, ftrace_caller
> > should be adjusted to save the necessary regs against the pt_regs layout
> > so it can call ftrace_graph_func reasonably.
> >
> > SAVE_ALL now saves all the regs according to the pt_regs struct. Here
> > introduces a lightweight option for SAVE_ALL to save only the necessary
> > regs for ftrace_caller.
> >
> > For convenience, the original argument setup for the tracing function in
> > ftrace_[regs]_caller is killed and appended to the tail of SAVE_ALL.
> >
> > Signed-off-by: Song Shuai <suagrfillet@gmail.com>
> > ---
> >  arch/riscv/kernel/mcount-dyn.S | 110 +++++++++++++++++++++++++++------
> >  1 file changed, 92 insertions(+), 18 deletions(-)
> >
> > diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
> > index d171eca623b6..2f0a280bd7a0 100644
> > --- a/arch/riscv/kernel/mcount-dyn.S
> > +++ b/arch/riscv/kernel/mcount-dyn.S
> > @@ -56,7 +56,51 @@
> >       .endm
> >
> >  #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> > -     .macro SAVE_ALL
> > +
> > +/**
> > +* SAVE_ALL - save regs against the pt_regs struct
> > +*
> > +* @all: tell if saving all the regs
>
> I find it odd to have a macro name that includes 'ALL' in it
> to require a parameter 'all' to be set in order to actually save
> all. I suggest renaming the macro to something like SAVE_REGS.
SAVE_ABI_REGS <arg>
arg = 0 -> SAVE_ABI in pt_regs
arg = 1 -> SAVE_REGS

SAVE_ABI_REGS keeps the pt_regs layout and needs more stack space than SAVE_ABI.

>
> > +*
> > +* If all is set, all the regs will be saved, otherwise only ABI
> > +* related regs (a0-a7,epc,ra and optional s0) will be saved.
> > +*
> > +* For convenience the argument setup for tracing function is appended here.
> > +* Especially $sp is passed as the 4th argument of the tracing function.
> > +*
> > +* After the stack is established,
> > +*
> > +* 0(sp) stores the PC of the traced function which can be accessed
> > +* by &(fregs)->regs->epc in tracing function. Note that the real
> > +* function entry address should be computed with -FENTRY_RA_OFFSET.
> > +*
> > +* 8(sp) stores the function return address (i.e. parent IP) that
> > +* can be accessed by &(fregs)->regs->ra in tracing function.
> > +*
> > +* The other regs are saved at the respective localtion and accessed
> > +* by the respective pt_regs member.
> > +*
> > +* Here is the layout of stack for your reference.
> > +*
> > +*
> > +*                    =========
> > +*                    |  pip  |
> > +* PT_SIZE_ON_STACK  ->  =========
> > +*                    + ..... +
> > +*                    + t3-t6 +
> > +*                    + s2-s11+
> > +*                    + a0-a7 + --++++-> ftrace_caller saved
> > +*                    + s1    +   +
> > +*                    + s0    + --+
> > +*                    + t0-t2 +   +
> > +*                    + tp    +   +
> > +*                    + gp    +   +
> > +*                    + sp    +   +
> > +*                    + ra    + --+ // parent IP
> > +*            sp  ->  + epc   + --+ // PC of the traced function
> > +*                    +++++++++
> > +**/
> > +     .macro SAVE_ALL, all=0
> >       addi    sp, sp, -SZREG
> >       addi    sp, sp, -PT_SIZE_ON_STACK
> >
> > @@ -67,14 +111,8 @@
> >       REG_S x1,  PT_RA(sp)
> >       REG_L x1,  PT_EPC(sp)
> >
> > -     REG_S x2,  PT_SP(sp)
> > -     REG_S x3,  PT_GP(sp)
> > -     REG_S x4,  PT_TP(sp)
> > -     REG_S x5,  PT_T0(sp)
> > -     REG_S x6,  PT_T1(sp)
> > -     REG_S x7,  PT_T2(sp)
> > -     REG_S x8,  PT_S0(sp)
> > -     REG_S x9,  PT_S1(sp)
> > +     /* always save the ABI regs */
> > +
> >       REG_S x10, PT_A0(sp)
> >       REG_S x11, PT_A1(sp)
> >       REG_S x12, PT_A2(sp)
> > @@ -83,6 +121,18 @@
> >       REG_S x15, PT_A5(sp)
> >       REG_S x16, PT_A6(sp)
> >       REG_S x17, PT_A7(sp)
> > +
> > +     /* save leftover regs for ftrace_regs_caller*/
> > +
> > +     .if \all == 1
> > +     REG_S x2,  PT_SP(sp)
> > +     REG_S x3,  PT_GP(sp)
> > +     REG_S x4,  PT_TP(sp)
> > +     REG_S x5,  PT_T0(sp)
> > +     REG_S x6,  PT_T1(sp)
> > +     REG_S x7,  PT_T2(sp)
> > +     REG_S x8,  PT_S0(sp)
> > +     REG_S x9,  PT_S1(sp)
> >       REG_S x18, PT_S2(sp)
> >       REG_S x19, PT_S3(sp)
> >       REG_S x20, PT_S4(sp)
> > @@ -97,22 +147,31 @@
> >       REG_S x29, PT_T4(sp)
> >       REG_S x30, PT_T5(sp)
> >       REG_S x31, PT_T6(sp)
> > +     .else
> > +
> > +     /* save s0 for ftrace_caller if FP_TEST defined */
> > +
> > +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
> > +     REG_S x8,  PT_S0(sp)
> > +#endif
> > +     .endif
> > +
> > +     /* setup 4 args for tracing functions  */
> > +
> > +     addi    a0, ra, -FENTRY_RA_OFFSET // ip
> > +     la      a1, function_trace_op
> > +     REG_L   a2, 0(a1)               // op
> > +     REG_L   a1, PT_SIZE_ON_STACK(sp) // parent_ip
> > +     mv      a3, sp                  // fregs
>
> Please line up the comments.
>
> >       .endm
> >
> > -     .macro RESTORE_ALL
> > +     .macro RESTORE_ALL, all=0
> >       REG_L x1,  PT_RA(sp)
> >       addi    sp, sp, PT_SIZE_ON_STACK
> >       REG_S x1,  (sp)
> >       addi    sp, sp, -PT_SIZE_ON_STACK
> >       REG_L x1,  PT_EPC(sp)
> > -     REG_L x2,  PT_SP(sp)
> > -     REG_L x3,  PT_GP(sp)
> > -     REG_L x4,  PT_TP(sp)
> > -     REG_L x5,  PT_T0(sp)
> > -     REG_L x6,  PT_T1(sp)
> > -     REG_L x7,  PT_T2(sp)
> > -     REG_L x8,  PT_S0(sp)
> > -     REG_L x9,  PT_S1(sp)
> > +
> >       REG_L x10, PT_A0(sp)
> >       REG_L x11, PT_A1(sp)
> >       REG_L x12, PT_A2(sp)
> > @@ -121,6 +180,16 @@
> >       REG_L x15, PT_A5(sp)
> >       REG_L x16, PT_A6(sp)
> >       REG_L x17, PT_A7(sp)
> > +
> > +     .if \all == 1
> > +     REG_L x2,  PT_SP(sp)
> > +     REG_L x3,  PT_GP(sp)
> > +     REG_L x4,  PT_TP(sp)
> > +     REG_L x5,  PT_T0(sp)
> > +     REG_L x6,  PT_T1(sp)
> > +     REG_L x7,  PT_T2(sp)
> > +     REG_L x8,  PT_S0(sp)
> > +     REG_L x9,  PT_S1(sp)
> >       REG_L x18, PT_S2(sp)
> >       REG_L x19, PT_S3(sp)
> >       REG_L x20, PT_S4(sp)
> > @@ -136,6 +205,11 @@
> >       REG_L x30, PT_T5(sp)
> >       REG_L x31, PT_T6(sp)
> >
> > +     .else
> > +#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
> > +     REG_L x8,  PT_S0(sp)
> > +#endif
> > +     .endif
> >       addi    sp, sp, PT_SIZE_ON_STACK
> >       addi    sp, sp, SZREG
> >       .endm
> > --
> > 2.20.1
> >
> >
>
> Thanks,
> drew



-- 
Best Regards
 Guo Ren

^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v2 3/3] riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller
  2022-11-16  3:13 [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Song Shuai
  2022-11-16  3:13 ` [PATCH v2 1/3] riscv/ftrace: add ftrace_graph_func Song Shuai
  2022-11-16  3:13 ` [PATCH v2 2/3] riscv/ftrace: SAVE_ALL supports lightweight save Song Shuai
@ 2022-11-16  3:13 ` Song Shuai
  2022-11-17  1:49   ` Guo Ren
  2022-11-17  1:45 ` [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Guo Ren
  3 siblings, 1 reply; 9+ messages in thread
From: Song Shuai @ 2022-11-16  3:13 UTC (permalink / raw)
  To: guoren, rostedt, mhiramat, mark.rutland, paul.walmsley, palmer, aou
  Cc: linux-riscv, linux-kernel, Song Shuai

ftrace_caller and ftrace_regs_caller save their regs with the respective
option of SAVE_ALL, then call the tracing function, especially graph_ops's
ftrace_graph_func. So the ftrace_graph_[regs]_call labels aren't needed
anymore if FTRACE_WITH_REGS is defined.

If FTRACE_WITH_REGS isn't defined, the !FTRACE_WITH_REGS version
ftrace_caller remains with the ftrace_graph_call. So the enable/disable
helpers are revised for serving only this ftrace_graph_call.

Signed-off-by: Song Shuai <suagrfillet@gmail.com>
---
 arch/riscv/kernel/ftrace.c     | 19 ++----------------
 arch/riscv/kernel/mcount-dyn.S | 35 +++++++++++++++-------------------
 2 files changed, 17 insertions(+), 37 deletions(-)

diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
index 148a5480076b..2f0bcedc6a2d 100644
--- a/arch/riscv/kernel/ftrace.c
+++ b/arch/riscv/kernel/ftrace.c
@@ -211,30 +211,15 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
 #else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
 
 extern void ftrace_graph_call(void);
-extern void ftrace_graph_regs_call(void);
 int ftrace_enable_ftrace_graph_caller(void)
 {
-	int ret;
-
-	ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
-				    (unsigned long)&prepare_ftrace_return, true);
-	if (ret)
-		return ret;
-
-	return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
+	return  __ftrace_modify_call((unsigned long)&ftrace_graph_call,
 				    (unsigned long)&prepare_ftrace_return, true);
 }
 
 int ftrace_disable_ftrace_graph_caller(void)
 {
-	int ret;
-
-	ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
-				    (unsigned long)&prepare_ftrace_return, false);
-	if (ret)
-		return ret;
-
-	return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
+	return  __ftrace_modify_call((unsigned long)&ftrace_graph_call,
 				    (unsigned long)&prepare_ftrace_return, false);
 }
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index 2f0a280bd7a0..9e4097c6793d 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -215,6 +215,7 @@
 	.endm
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
 
+#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
 ENTRY(ftrace_caller)
 	SAVE_ABI
 
@@ -243,33 +244,27 @@ ftrace_graph_call:
 	ret
 ENDPROC(ftrace_caller)
 
-#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
 ENTRY(ftrace_regs_caller)
-	SAVE_ALL
-
-	addi	a0, ra, -FENTRY_RA_OFFSET
-	la	a1, function_trace_op
-	REG_L	a2, 0(a1)
-	REG_L	a1, PT_SIZE_ON_STACK(sp)
-	mv	a3, sp
+	SAVE_ALL 1
 
 ftrace_regs_call:
 	.global ftrace_regs_call
 	call	ftrace_stub
 
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-	addi	a0, sp, PT_RA
-	REG_L	a1, PT_EPC(sp)
-	addi	a1, a1, -FENTRY_RA_OFFSET
-#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
-	mv	a2, s0
-#endif
-ftrace_graph_regs_call:
-	.global ftrace_graph_regs_call
-	call	ftrace_stub
-#endif
 
-	RESTORE_ALL
+	RESTORE_ALL 1
 	ret
 ENDPROC(ftrace_regs_caller)
+
+ENTRY(ftrace_caller)
+	SAVE_ALL 0
+
+ftrace_call:
+	.global ftrace_call
+	call	ftrace_stub
+
+	RESTORE_ALL 0
+	ret
+ENDPROC(ftrace_caller)
 #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
-- 
2.20.1


^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v2 3/3] riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller
  2022-11-16  3:13 ` [PATCH v2 3/3] riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller Song Shuai
@ 2022-11-17  1:49   ` Guo Ren
  0 siblings, 0 replies; 9+ messages in thread
From: Guo Ren @ 2022-11-17  1:49 UTC (permalink / raw)
  To: Song Shuai
  Cc: rostedt, mhiramat, mark.rutland, paul.walmsley, palmer, aou,
	linux-riscv, linux-kernel

On Wed, Nov 16, 2022 at 11:13 AM Song Shuai <suagrfillet@gmail.com> wrote:
>
> ftrace_caller and ftrace_regs_caller save their regs with the respective
> option of SAVE_ALL, then call the tracing function, especially graph_ops's
> ftrace_graph_func. So the ftrace_graph_[regs]_call labels aren't needed
> anymore if FTRACE_WITH_REGS is defined.
>
> If FTRACE_WITH_REGS isn't defined, the !FTRACE_WITH_REGS version
> ftrace_caller remains with the ftrace_graph_call. So the enable/disable
> helpers are revised for serving only this ftrace_graph_call.
>
> Signed-off-by: Song Shuai <suagrfillet@gmail.com>
> ---
>  arch/riscv/kernel/ftrace.c     | 19 ++----------------
>  arch/riscv/kernel/mcount-dyn.S | 35 +++++++++++++++-------------------
>  2 files changed, 17 insertions(+), 37 deletions(-)
>
> diff --git a/arch/riscv/kernel/ftrace.c b/arch/riscv/kernel/ftrace.c
> index 148a5480076b..2f0bcedc6a2d 100644
> --- a/arch/riscv/kernel/ftrace.c
> +++ b/arch/riscv/kernel/ftrace.c
> @@ -211,30 +211,15 @@ void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
>  #else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
>
>  extern void ftrace_graph_call(void);
> -extern void ftrace_graph_regs_call(void);
>  int ftrace_enable_ftrace_graph_caller(void)
>  {
> -       int ret;
> -
> -       ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
> -                                   (unsigned long)&prepare_ftrace_return, true);
> -       if (ret)
> -               return ret;
> -
> -       return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
> +       return  __ftrace_modify_call((unsigned long)&ftrace_graph_call,
>                                     (unsigned long)&prepare_ftrace_return, true);
>  }
>
>  int ftrace_disable_ftrace_graph_caller(void)
>  {
> -       int ret;
> -
> -       ret = __ftrace_modify_call((unsigned long)&ftrace_graph_call,
> -                                   (unsigned long)&prepare_ftrace_return, false);
> -       if (ret)
> -               return ret;
> -
> -       return __ftrace_modify_call((unsigned long)&ftrace_graph_regs_call,
> +       return  __ftrace_modify_call((unsigned long)&ftrace_graph_call,
>                                     (unsigned long)&prepare_ftrace_return, false);
>  }
>  #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
> index 2f0a280bd7a0..9e4097c6793d 100644
> --- a/arch/riscv/kernel/mcount-dyn.S
> +++ b/arch/riscv/kernel/mcount-dyn.S
> @@ -215,6 +215,7 @@
>         .endm
>  #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
>
> +#ifndef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>  ENTRY(ftrace_caller)
>         SAVE_ABI
>
> @@ -243,33 +244,27 @@ ftrace_graph_call:
>         ret
>  ENDPROC(ftrace_caller)
>
> -#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> +#else /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
>  ENTRY(ftrace_regs_caller)
> -       SAVE_ALL
> -
> -       addi    a0, ra, -FENTRY_RA_OFFSET
> -       la      a1, function_trace_op
> -       REG_L   a2, 0(a1)
> -       REG_L   a1, PT_SIZE_ON_STACK(sp)
> -       mv      a3, sp
> +       SAVE_ALL 1
I think the patch is broken, we shouldn't split mcount-dyn.S
modification from the patch.

>
>  ftrace_regs_call:
>         .global ftrace_regs_call
>         call    ftrace_stub
>
> -#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> -       addi    a0, sp, PT_RA
> -       REG_L   a1, PT_EPC(sp)
> -       addi    a1, a1, -FENTRY_RA_OFFSET
> -#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
> -       mv      a2, s0
> -#endif
> -ftrace_graph_regs_call:
> -       .global ftrace_graph_regs_call
> -       call    ftrace_stub
> -#endif
>
> -       RESTORE_ALL
> +       RESTORE_ALL 1
>         ret
>  ENDPROC(ftrace_regs_caller)
> +
> +ENTRY(ftrace_caller)
> +       SAVE_ALL 0
> +
> +ftrace_call:
> +       .global ftrace_call
> +       call    ftrace_stub
> +
> +       RESTORE_ALL 0
> +       ret
> +ENDPROC(ftrace_caller)
>  #endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> --
> 2.20.1
>


--
Best Regards
 Guo Ren

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly
  2022-11-16  3:13 [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Song Shuai
                   ` (2 preceding siblings ...)
  2022-11-16  3:13 ` [PATCH v2 3/3] riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller Song Shuai
@ 2022-11-17  1:45 ` Guo Ren
  2022-11-18 10:10   ` Song Shuai
  3 siblings, 1 reply; 9+ messages in thread
From: Guo Ren @ 2022-11-17  1:45 UTC (permalink / raw)
  To: Song Shuai
  Cc: rostedt, mhiramat, mark.rutland, paul.walmsley, palmer, aou,
	linux-riscv, linux-kernel

I hope this series could base on the following:
https://lore.kernel.org/linux-riscv/20220921034910.3142465-4-guoren@kernel.org/

They all modified the mcount-dyn.S.

On Wed, Nov 16, 2022 at 11:13 AM Song Shuai <suagrfillet@gmail.com> wrote:
>
> In RISC-V architecture, when we enable the ftrace_graph tracer on some
> functions, the function tracings on other functions will suffer extra
> graph tracing work. In essence, graph_ops isn't limited by its func_hash
> due to the global ftrace_graph_[regs]_call label. That should be corrected.
>
> What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function
> graph use ftrace directly") that uses graph_ops::func function to install
> return_hooker and makes the function called against its func_hash.
>
> This series of patches makes function graph use ftrace directly for riscv.
>
> If FTRACE_WITH_REGS isn't defined, ftrace_caller keeps ftrace_graph_call
> so that it can be replaced with the calling of prepare_ftrace_return by
> the enable/disable helper.
>
> As for defining FTRACE_WITH_REGS, ftrace_caller is adjusted to save the
> necessary regs against the pt_regs layout, so it can reasonably call the
> graph_ops::func function - ftrace_graph_func. And ftrace_graph_[regs]_call
> and its enable/disable helper aren't needed.
>
> The tests generated by CONFIG_FTRACE_STARTUP_TEST have passed in the local
> qemu-system-riscv64 virt machine. The following is the log during startup.
>
> ```
> Nov 15 03:07:13 stage4 kernel: Testing tracer function: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #1:
> Nov 15 03:07:13 stage4 kernel: (1 0 1 0 0)
> Nov 15 03:07:13 stage4 kernel: (1 1 2 0 0)
> Nov 15 03:07:13 stage4 kernel: (2 1 3 0 365)
> Nov 15 03:07:13 stage4 kernel: (2 2 4 0 399)
> Nov 15 03:07:13 stage4 kernel: (3 2 4 0 146071)
> Nov 15 03:07:13 stage4 kernel: (3 3 5 0 146105) PASSED
> Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #2:
> Nov 15 03:07:13 stage4 kernel: (1 0 1 589 0)
> Nov 15 03:07:13 stage4 kernel: (1 1 2 635 0)
> Nov 15 03:07:13 stage4 kernel: (2 1 3 1 2)
> Nov 15 03:07:13 stage4 kernel: (2 2 4 125 126)
> Nov 15 03:07:13 stage4 kernel: (3 2 4 146001 146078)
> Nov 15 03:07:13 stage4 kernel: (3 3 5 146035 146112) PASSED
> Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion safe: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing ftrace regs: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing tracer nop: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing tracer irqsoff: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup:
> Nov 15 03:07:13 stage4 kernel: sched: DL replenish lagged too much
> Nov 15 03:07:13 stage4 kernel: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_rt: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_dl: PASSED
> Nov 15 03:07:13 stage4 kernel: Testing tracer function_graph: PASSED
> ```
>
> Note that the changes of mcount-dyn.S conflicts with this unmerged
> commit (riscv: entry: consolidate general regs saving/restoring).
> https://lore.kernel.org/linux-riscv/20221103075047.1634923-15-guoren@kernel.org
>
> Changes since v1
> -  fixed the checkpatch warnings in patch 1
> Link: https://lore.kernel.org/linux-riscv/20221115061525.112757-1-suagrfillet@gmail.com
>
> Song Shuai (3):
>   riscv/ftrace: add ftrace_graph_func
>   riscv/ftrace: SAVE_ALL supports lightweight save
>   riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller
>
>  arch/riscv/include/asm/ftrace.h |  13 ++-
>  arch/riscv/kernel/ftrace.c      |  35 ++++----
>  arch/riscv/kernel/mcount-dyn.S  | 145 +++++++++++++++++++++++---------
>  3 files changed, 136 insertions(+), 57 deletions(-)
>
> --
> 2.20.1
>


--
Best Regards
 Guo Ren

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly
  2022-11-17  1:45 ` [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Guo Ren
@ 2022-11-18 10:10   ` Song Shuai
  0 siblings, 0 replies; 9+ messages in thread
From: Song Shuai @ 2022-11-18 10:10 UTC (permalink / raw)
  To: Guo Ren
  Cc: rostedt, mhiramat, mark.rutland, paul.walmsley, palmer, aou,
	linux-riscv, linux-kernel

Guo Ren <guoren@kernel.org> 于2022年11月17日周四 01:46写道：
>
> I hope this series could base on the following:
> https://lore.kernel.org/linux-riscv/20220921034910.3142465-4-guoren@kernel.org/
>
> They all modified the mcount-dyn.S.
Ok, I'll adapt these patches based on the series you mentioned.
>
>
> On Wed, Nov 16, 2022 at 11:13 AM Song Shuai <suagrfillet@gmail.com> wrote:
> >
> > In RISC-V architecture, when we enable the ftrace_graph tracer on some
> > functions, the function tracings on other functions will suffer extra
> > graph tracing work. In essence, graph_ops isn't limited by its func_hash
> > due to the global ftrace_graph_[regs]_call label. That should be corrected.
> >
> > What inspires me is the commit 0c0593b45c9b ("x86/ftrace: Make function
> > graph use ftrace directly") that uses graph_ops::func function to install
> > return_hooker and makes the function called against its func_hash.
> >
> > This series of patches makes function graph use ftrace directly for riscv.
> >
> > If FTRACE_WITH_REGS isn't defined, ftrace_caller keeps ftrace_graph_call
> > so that it can be replaced with the calling of prepare_ftrace_return by
> > the enable/disable helper.
> >
> > As for defining FTRACE_WITH_REGS, ftrace_caller is adjusted to save the
> > necessary regs against the pt_regs layout, so it can reasonably call the
> > graph_ops::func function - ftrace_graph_func. And ftrace_graph_[regs]_call
> > and its enable/disable helper aren't needed.
> >
> > The tests generated by CONFIG_FTRACE_STARTUP_TEST have passed in the local
> > qemu-system-riscv64 virt machine. The following is the log during startup.
> >
> > ```
> > Nov 15 03:07:13 stage4 kernel: Testing tracer function: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #1:
> > Nov 15 03:07:13 stage4 kernel: (1 0 1 0 0)
> > Nov 15 03:07:13 stage4 kernel: (1 1 2 0 0)
> > Nov 15 03:07:13 stage4 kernel: (2 1 3 0 365)
> > Nov 15 03:07:13 stage4 kernel: (2 2 4 0 399)
> > Nov 15 03:07:13 stage4 kernel: (3 2 4 0 146071)
> > Nov 15 03:07:13 stage4 kernel: (3 3 5 0 146105) PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing dynamic ftrace ops #2:
> > Nov 15 03:07:13 stage4 kernel: (1 0 1 589 0)
> > Nov 15 03:07:13 stage4 kernel: (1 1 2 635 0)
> > Nov 15 03:07:13 stage4 kernel: (2 1 3 1 2)
> > Nov 15 03:07:13 stage4 kernel: (2 2 4 125 126)
> > Nov 15 03:07:13 stage4 kernel: (3 2 4 146001 146078)
> > Nov 15 03:07:13 stage4 kernel: (3 3 5 146035 146112) PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing ftrace recursion safe: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing ftrace regs: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing tracer nop: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing tracer irqsoff: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup:
> > Nov 15 03:07:13 stage4 kernel: sched: DL replenish lagged too much
> > Nov 15 03:07:13 stage4 kernel: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_rt: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing tracer wakeup_dl: PASSED
> > Nov 15 03:07:13 stage4 kernel: Testing tracer function_graph: PASSED
> > ```
> >
> > Note that the changes of mcount-dyn.S conflicts with this unmerged
> > commit (riscv: entry: consolidate general regs saving/restoring).
> > https://lore.kernel.org/linux-riscv/20221103075047.1634923-15-guoren@kernel.org
> >
> > Changes since v1
> > -  fixed the checkpatch warnings in patch 1
> > Link: https://lore.kernel.org/linux-riscv/20221115061525.112757-1-suagrfillet@gmail.com
> >
> > Song Shuai (3):
> >   riscv/ftrace: add ftrace_graph_func
> >   riscv/ftrace: SAVE_ALL supports lightweight save
> >   riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller
> >
> >  arch/riscv/include/asm/ftrace.h |  13 ++-
> >  arch/riscv/kernel/ftrace.c      |  35 ++++----
> >  arch/riscv/kernel/mcount-dyn.S  | 145 +++++++++++++++++++++++---------
> >  3 files changed, 136 insertions(+), 57 deletions(-)
> >
> > --
> > 2.20.1
> >
>
>
> --
> Best Regards
>  Guo Ren

Thanks,
Song

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2022-11-18 10:11 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-11-16  3:13 [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Song Shuai
2022-11-16  3:13 ` [PATCH v2 1/3] riscv/ftrace: add ftrace_graph_func Song Shuai
2022-11-16  3:13 ` [PATCH v2 2/3] riscv/ftrace: SAVE_ALL supports lightweight save Song Shuai
2022-11-16  8:45   ` Andrew Jones
2022-11-17  1:55     ` Guo Ren
2022-11-16  3:13 ` [PATCH v2 3/3] riscv/ftrace: cleanup ftrace_caller and ftrace_regs_caller Song Shuai
2022-11-17  1:49   ` Guo Ren
2022-11-17  1:45 ` [PATCH v2 0/3] riscv/ftrace: make function graph use ftrace directly Guo Ren
2022-11-18 10:10   ` Song Shuai

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