Re: [PATCH] riscv: ftrace: Fix to pass correct ftrace_regs to ftrace_func_t functions
Hi,
Sorry please ignore this. I found that the arch/riscv doesn't support
HAVE_DYNAMIC_FTRACE_WITH_ARGS. Thus this might add a new feature support.
Let me update it.
Thank you,
On Sun, 15 Oct 2023 23:15:23 +0900
Masami Hiramatsu (Google) wrote:
> Hi,
>
> Gentry ping.
>
> I think this should be an important fix because if a fprobe handler without
> FTRACE_OPS_FL_SAVE_REGS tries to access any register via ftrace_regs, that
> will get a wrong value.
>
> Thank you,
>
> On Mon, 2 Oct 2023 21:50:34 +0900
> "Masami Hiramatsu (Google)" wrote:
>
> > From: Masami Hiramatsu (Google)
> >
> > Since ftrace_func_t requires to pass 'struct ftrace_regs *' as the 4th
> > argument even if FTRACE_OPS_FL_SAVE_REGS is not set, ftrace_caller must
> > pass 'struct ftrace_regs *', which is a partial pt_regs, on the stack
> > to the ftrace_func_t functions, so that the ftrace_func_t functions can
> > access some partial registers.
> >
> > Fix to allocate 'struct ftrace_regs' (which has the same size of 'struct
> > pt_regs') on the stack and save partial (argument) registers on it
> > instead of reduced size custom data structure.
> >
> > Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of
> > MCOUNT")
> > Signed-off-by: Masami Hiramatsu (Google)
> > ---
> > arch/riscv/kernel/mcount-dyn.S | 65
> > +---
> > 1 file changed, 28 insertions(+), 37 deletions(-)
> >
> > diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
> > index 669b8697aa38..84963680eff4 100644
> > --- a/arch/riscv/kernel/mcount-dyn.S
> > +++ b/arch/riscv/kernel/mcount-dyn.S
> > @@ -14,46 +14,37 @@
> > .text
> >
> > #define FENTRY_RA_OFFSET 8
> > -#define ABI_SIZE_ON_STACK 80
> > -#define ABI_A0 0
> > -#define ABI_A1 8
> > -#define ABI_A2 16
> > -#define ABI_A3 24
> > -#define ABI_A4 32
> > -#define ABI_A5 40
> > -#define ABI_A6 48
> > -#define ABI_A7 56
> > -#define ABI_T0 64
> > -#define ABI_RA 72
> >
> > .macro SAVE_ABI
> > - addisp, sp, -ABI_SIZE_ON_STACK
> > -
> > - REG_S a0, ABI_A0(sp)
> > - REG_S a1, ABI_A1(sp)
> > - REG_S a2, ABI_A2(sp)
> > - REG_S a3, ABI_A3(sp)
> > - REG_S a4, ABI_A4(sp)
> > - REG_S a5, ABI_A5(sp)
> > - REG_S a6, ABI_A6(sp)
> > - REG_S a7, ABI_A7(sp)
> > - REG_S t0, ABI_T0(sp)
> > - REG_S ra, ABI_RA(sp)
> > + addisp, sp, -PT_SIZE_ON_STACK
> > +
> > + /* Save t0 as epc for ftrace_regs_get_instruction_pointer() */
> > + REG_S t0, PT_EPC(sp)
> > + REG_S a0, PT_A0(sp)
> > + REG_S a1, PT_A1(sp)
> > + REG_S a2, PT_A2(sp)
> > + REG_S a3, PT_A3(sp)
> > + REG_S a4, PT_A4(sp)
> > + REG_S a5, PT_A5(sp)
> > + REG_S a6, PT_A6(sp)
> > + REG_S a7, PT_A7(sp)
> > + REG_S t0, PT_T0(sp)
> > + REG_S ra, PT_RA(sp)
> > .endm
> >
> > .macro RESTORE_ABI
> > - REG_L a0, ABI_A0(sp)
> > - REG_L a1, ABI_A1(sp)
> > - REG_L a2, ABI_A2(sp)
> > - REG_L a3, ABI_A3(sp)
> > - REG_L a4, ABI_A4(sp)
> > - REG_L a5, ABI_A5(sp)
> > - REG_L a6, ABI_A6(sp)
> > - REG_L a7, ABI_A7(sp)
> > - REG_L t0, ABI_T0(sp)
> > - REG_L ra, ABI_RA(sp)
> > -
> > - addisp, sp, ABI_SIZE_ON_STACK
> > + REG_L a0, PT_A0(sp)
> > + REG_L a1, PT_A1(sp)
> > + REG_L a2, PT_A2(sp)
> > + REG_L a3, PT_A3(sp)
> > + REG_L a4, PT_A4(sp)
> > + REG_L a5, PT_A5(sp)
> > + REG_L a6, PT_A6(sp)
> > + REG_L a7, PT_A7(sp)
> > + REG_L t0, PT_T0(sp)
> > + REG_L ra, PT_RA(sp)
> > +
> > + addisp, sp, PT_SIZE_ON_STACK
> > .endm
> >
> > #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> > @@ -96,8 +87,8 @@ ftrace_call:
> > callftrace_stub
> >
> > #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> > - addia0, sp, ABI_RA
> > - REG_L a1, ABI_T0(sp)
> > + addia0, sp, PT_RA
> > + REG_L a1, PT_T0(sp)
> > addia1, a1, -FENTRY_RA_OFFSET
> > #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
> > mv a2, s0
> >
> >
>
>
> --
> Masami Hiramatsu (Google)
--
Masami Hiramatsu (Google)
Re: [PATCH] riscv: ftrace: Fix to pass correct ftrace_regs to ftrace_func_t functions
Hi,
Gentry ping.
I think this should be an important fix because if a fprobe handler without
FTRACE_OPS_FL_SAVE_REGS tries to access any register via ftrace_regs, that
will get a wrong value.
Thank you,
On Mon, 2 Oct 2023 21:50:34 +0900
"Masami Hiramatsu (Google)" wrote:
> From: Masami Hiramatsu (Google)
>
> Since ftrace_func_t requires to pass 'struct ftrace_regs *' as the 4th
> argument even if FTRACE_OPS_FL_SAVE_REGS is not set, ftrace_caller must
> pass 'struct ftrace_regs *', which is a partial pt_regs, on the stack
> to the ftrace_func_t functions, so that the ftrace_func_t functions can
> access some partial registers.
>
> Fix to allocate 'struct ftrace_regs' (which has the same size of 'struct
> pt_regs') on the stack and save partial (argument) registers on it
> instead of reduced size custom data structure.
>
> Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of
> MCOUNT")
> Signed-off-by: Masami Hiramatsu (Google)
> ---
> arch/riscv/kernel/mcount-dyn.S | 65
> +---
> 1 file changed, 28 insertions(+), 37 deletions(-)
>
> diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
> index 669b8697aa38..84963680eff4 100644
> --- a/arch/riscv/kernel/mcount-dyn.S
> +++ b/arch/riscv/kernel/mcount-dyn.S
> @@ -14,46 +14,37 @@
> .text
>
> #define FENTRY_RA_OFFSET 8
> -#define ABI_SIZE_ON_STACK80
> -#define ABI_A0 0
> -#define ABI_A1 8
> -#define ABI_A2 16
> -#define ABI_A3 24
> -#define ABI_A4 32
> -#define ABI_A5 40
> -#define ABI_A6 48
> -#define ABI_A7 56
> -#define ABI_T0 64
> -#define ABI_RA 72
>
> .macro SAVE_ABI
> - addisp, sp, -ABI_SIZE_ON_STACK
> -
> - REG_S a0, ABI_A0(sp)
> - REG_S a1, ABI_A1(sp)
> - REG_S a2, ABI_A2(sp)
> - REG_S a3, ABI_A3(sp)
> - REG_S a4, ABI_A4(sp)
> - REG_S a5, ABI_A5(sp)
> - REG_S a6, ABI_A6(sp)
> - REG_S a7, ABI_A7(sp)
> - REG_S t0, ABI_T0(sp)
> - REG_S ra, ABI_RA(sp)
> + addisp, sp, -PT_SIZE_ON_STACK
> +
> + /* Save t0 as epc for ftrace_regs_get_instruction_pointer() */
> + REG_S t0, PT_EPC(sp)
> + REG_S a0, PT_A0(sp)
> + REG_S a1, PT_A1(sp)
> + REG_S a2, PT_A2(sp)
> + REG_S a3, PT_A3(sp)
> + REG_S a4, PT_A4(sp)
> + REG_S a5, PT_A5(sp)
> + REG_S a6, PT_A6(sp)
> + REG_S a7, PT_A7(sp)
> + REG_S t0, PT_T0(sp)
> + REG_S ra, PT_RA(sp)
> .endm
>
> .macro RESTORE_ABI
> - REG_L a0, ABI_A0(sp)
> - REG_L a1, ABI_A1(sp)
> - REG_L a2, ABI_A2(sp)
> - REG_L a3, ABI_A3(sp)
> - REG_L a4, ABI_A4(sp)
> - REG_L a5, ABI_A5(sp)
> - REG_L a6, ABI_A6(sp)
> - REG_L a7, ABI_A7(sp)
> - REG_L t0, ABI_T0(sp)
> - REG_L ra, ABI_RA(sp)
> -
> - addisp, sp, ABI_SIZE_ON_STACK
> + REG_L a0, PT_A0(sp)
> + REG_L a1, PT_A1(sp)
> + REG_L a2, PT_A2(sp)
> + REG_L a3, PT_A3(sp)
> + REG_L a4, PT_A4(sp)
> + REG_L a5, PT_A5(sp)
> + REG_L a6, PT_A6(sp)
> + REG_L a7, PT_A7(sp)
> + REG_L t0, PT_T0(sp)
> + REG_L ra, PT_RA(sp)
> +
> + addisp, sp, PT_SIZE_ON_STACK
> .endm
>
> #ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> @@ -96,8 +87,8 @@ ftrace_call:
> callftrace_stub
>
> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> - addia0, sp, ABI_RA
> - REG_L a1, ABI_T0(sp)
> + addia0, sp, PT_RA
> + REG_L a1, PT_T0(sp)
> addia1, a1, -FENTRY_RA_OFFSET
> #ifdef HAVE_FUNCTION_GRAPH_FP_TEST
> mv a2, s0
>
>
--
Masami Hiramatsu (Google)
[PATCH] riscv: ftrace: Fix to pass correct ftrace_regs to ftrace_func_t functions
From: Masami Hiramatsu (Google)
Since ftrace_func_t requires to pass 'struct ftrace_regs *' as the 4th
argument even if FTRACE_OPS_FL_SAVE_REGS is not set, ftrace_caller must
pass 'struct ftrace_regs *', which is a partial pt_regs, on the stack
to the ftrace_func_t functions, so that the ftrace_func_t functions can
access some partial registers.
Fix to allocate 'struct ftrace_regs' (which has the same size of 'struct
pt_regs') on the stack and save partial (argument) registers on it
instead of reduced size custom data structure.
Fixes: afc76b8b8011 ("riscv: Using PATCHABLE_FUNCTION_ENTRY instead of MCOUNT")
Signed-off-by: Masami Hiramatsu (Google)
---
arch/riscv/kernel/mcount-dyn.S | 65 +---
1 file changed, 28 insertions(+), 37 deletions(-)
diff --git a/arch/riscv/kernel/mcount-dyn.S b/arch/riscv/kernel/mcount-dyn.S
index 669b8697aa38..84963680eff4 100644
--- a/arch/riscv/kernel/mcount-dyn.S
+++ b/arch/riscv/kernel/mcount-dyn.S
@@ -14,46 +14,37 @@
.text
#define FENTRY_RA_OFFSET 8
-#define ABI_SIZE_ON_STACK 80
-#define ABI_A0 0
-#define ABI_A1 8
-#define ABI_A2 16
-#define ABI_A3 24
-#define ABI_A4 32
-#define ABI_A5 40
-#define ABI_A6 48
-#define ABI_A7 56
-#define ABI_T0 64
-#define ABI_RA 72
.macro SAVE_ABI
- addisp, sp, -ABI_SIZE_ON_STACK
-
- REG_S a0, ABI_A0(sp)
- REG_S a1, ABI_A1(sp)
- REG_S a2, ABI_A2(sp)
- REG_S a3, ABI_A3(sp)
- REG_S a4, ABI_A4(sp)
- REG_S a5, ABI_A5(sp)
- REG_S a6, ABI_A6(sp)
- REG_S a7, ABI_A7(sp)
- REG_S t0, ABI_T0(sp)
- REG_S ra, ABI_RA(sp)
+ addisp, sp, -PT_SIZE_ON_STACK
+
+ /* Save t0 as epc for ftrace_regs_get_instruction_pointer() */
+ REG_S t0, PT_EPC(sp)
+ REG_S a0, PT_A0(sp)
+ REG_S a1, PT_A1(sp)
+ REG_S a2, PT_A2(sp)
+ REG_S a3, PT_A3(sp)
+ REG_S a4, PT_A4(sp)
+ REG_S a5, PT_A5(sp)
+ REG_S a6, PT_A6(sp)
+ REG_S a7, PT_A7(sp)
+ REG_S t0, PT_T0(sp)
+ REG_S ra, PT_RA(sp)
.endm
.macro RESTORE_ABI
- REG_L a0, ABI_A0(sp)
- REG_L a1, ABI_A1(sp)
- REG_L a2, ABI_A2(sp)
- REG_L a3, ABI_A3(sp)
- REG_L a4, ABI_A4(sp)
- REG_L a5, ABI_A5(sp)
- REG_L a6, ABI_A6(sp)
- REG_L a7, ABI_A7(sp)
- REG_L t0, ABI_T0(sp)
- REG_L ra, ABI_RA(sp)
-
- addisp, sp, ABI_SIZE_ON_STACK
+ REG_L a0, PT_A0(sp)
+ REG_L a1, PT_A1(sp)
+ REG_L a2, PT_A2(sp)
+ REG_L a3, PT_A3(sp)
+ REG_L a4, PT_A4(sp)
+ REG_L a5, PT_A5(sp)
+ REG_L a6, PT_A6(sp)
+ REG_L a7, PT_A7(sp)
+ REG_L t0, PT_T0(sp)
+ REG_L ra, PT_RA(sp)
+
+ addisp, sp, PT_SIZE_ON_STACK
.endm
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
@@ -96,8 +87,8 @@ ftrace_call:
callftrace_stub
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
- addia0, sp, ABI_RA
- REG_L a1, ABI_T0(sp)
+ addia0, sp, PT_RA
+ REG_L a1, PT_T0(sp)
addia1, a1, -FENTRY_RA_OFFSET
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
mv a2, s0
