This patch implements DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows
a traced function's arguments (and some other registers) to be captured
into a struct pt_regs, allowing these to be inspected and modified.
Co-developed-by: Jinyang He <[email protected]>
Signed-off-by: Jinyang He <[email protected]>
Signed-off-by: Qing Zhang <[email protected]>
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/ftrace.h | 3 +++
arch/loongarch/kernel/ftrace_dyn.c | 17 ++++++++++++++
arch/loongarch/kernel/mcount-dyn.S | 36 +++++++++++++++++++++++++++--
4 files changed, 55 insertions(+), 2 deletions(-)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 615ce62422b8..12e3e91a68ae 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -90,6 +90,7 @@ config LOONGARCH
select HAVE_DEBUG_STACKOVERFLOW
select HAVE_DMA_CONTIGUOUS
select HAVE_DYNAMIC_FTRACE
+ select HAVE_DYNAMIC_FTRACE_WITH_REGS
select HAVE_EBPF_JIT
select HAVE_EXIT_THREAD
select HAVE_FAST_GUP
diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
index 76ca58767f4d..a3f974a7a5ce 100644
--- a/arch/loongarch/include/asm/ftrace.h
+++ b/arch/loongarch/include/asm/ftrace.h
@@ -28,6 +28,9 @@ struct dyn_ftrace;
int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
#define ftrace_init_nop ftrace_init_nop
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+#define ARCH_SUPPORTS_FTRACE_OPS 1
+#endif
#endif /* CONFIG_DYNAMIC_FTRACE */
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */
diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c
index 3fe791b6783e..ec3d951be50c 100644
--- a/arch/loongarch/kernel/ftrace_dyn.c
+++ b/arch/loongarch/kernel/ftrace_dyn.c
@@ -99,6 +99,23 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
return ftrace_modify_code(pc, old, new, true);
}
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
+ unsigned long addr)
+{
+ unsigned long pc;
+ long offset;
+ u32 old, new;
+
+ pc = rec->ip + LOONGARCH_INSN_SIZE;
+
+ old = larch_insn_gen_bl(pc, old_addr);
+ new = larch_insn_gen_bl(pc, addr);
+
+ return ftrace_modify_code(pc, old, new, true);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
+
void arch_ftrace_update_code(int command)
{
command |= FTRACE_MAY_SLEEP;
diff --git a/arch/loongarch/kernel/mcount-dyn.S b/arch/loongarch/kernel/mcount-dyn.S
index 0c12cc108e6f..02835186b463 100644
--- a/arch/loongarch/kernel/mcount-dyn.S
+++ b/arch/loongarch/kernel/mcount-dyn.S
@@ -27,7 +27,7 @@
* follows the LoongArch psABI well.
*/
- .macro ftrace_regs_entry
+ .macro ftrace_regs_entry allregs=0
PTR_ADDI sp, sp, -PT_SIZE
/* Save trace function ra at PT_ERA */
PTR_S ra, sp, PT_ERA
@@ -43,16 +43,48 @@
PTR_S a7, sp, PT_R11
PTR_S fp, sp, PT_R22
+ .if \allregs
+ PTR_S t0, sp, PT_R12
+ PTR_S t1, sp, PT_R13
+ PTR_S t2, sp, PT_R14
+ PTR_S t3, sp, PT_R15
+ PTR_S t4, sp, PT_R16
+ PTR_S t5, sp, PT_R17
+ PTR_S t6, sp, PT_R18
+ PTR_S t7, sp, PT_R19
+ PTR_S t8, sp, PT_R20
+ PTR_S s0, sp, PT_R23
+ PTR_S s1, sp, PT_R24
+ PTR_S s2, sp, PT_R25
+ PTR_S s3, sp, PT_R26
+ PTR_S s4, sp, PT_R27
+ PTR_S s5, sp, PT_R28
+ PTR_S s6, sp, PT_R29
+ PTR_S s7, sp, PT_R30
+ PTR_S s8, sp, PT_R31
+ PTR_S tp, sp, PT_R2
+ /* Clear it for later use as a flag sometimes. */
+ PTR_S zero, sp, PT_R0
+ PTR_S $r21, sp, PT_R21
+ .endif
+
PTR_ADDI t8, sp, PT_SIZE
PTR_S t8, sp, PT_R3
.endm
SYM_CODE_START(ftrace_caller)
- ftrace_regs_entry
+ ftrace_regs_entry allregs=0
b ftrace_common
SYM_CODE_END(ftrace_caller)
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+SYM_CODE_START(ftrace_regs_caller)
+ ftrace_regs_entry allregs=1
+ b ftrace_common
+SYM_CODE_END(ftrace_regs_caller)
+#endif
+
SYM_CODE_START(ftrace_common)
PTR_ADDI a0, ra, -8 /* arg0: ip */
move a1, t0 /* arg1: parent_ip */
--
2.36.0
Hi, Qing,
Patch5 and Patch6 are small and related, maybe they can be combined
with a name "LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_{ARGS,REGS}
support"
Huacai
On Tue, Nov 15, 2022 at 10:55 AM Qing Zhang <[email protected]> wrote:
>
> This patch implements DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows
> a traced function's arguments (and some other registers) to be captured
> into a struct pt_regs, allowing these to be inspected and modified.
>
> Co-developed-by: Jinyang He <[email protected]>
> Signed-off-by: Jinyang He <[email protected]>
> Signed-off-by: Qing Zhang <[email protected]>
> ---
> arch/loongarch/Kconfig | 1 +
> arch/loongarch/include/asm/ftrace.h | 3 +++
> arch/loongarch/kernel/ftrace_dyn.c | 17 ++++++++++++++
> arch/loongarch/kernel/mcount-dyn.S | 36 +++++++++++++++++++++++++++--
> 4 files changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> index 615ce62422b8..12e3e91a68ae 100644
> --- a/arch/loongarch/Kconfig
> +++ b/arch/loongarch/Kconfig
> @@ -90,6 +90,7 @@ config LOONGARCH
> select HAVE_DEBUG_STACKOVERFLOW
> select HAVE_DMA_CONTIGUOUS
> select HAVE_DYNAMIC_FTRACE
> + select HAVE_DYNAMIC_FTRACE_WITH_REGS
> select HAVE_EBPF_JIT
> select HAVE_EXIT_THREAD
> select HAVE_FAST_GUP
> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
> index 76ca58767f4d..a3f974a7a5ce 100644
> --- a/arch/loongarch/include/asm/ftrace.h
> +++ b/arch/loongarch/include/asm/ftrace.h
> @@ -28,6 +28,9 @@ struct dyn_ftrace;
> int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
> #define ftrace_init_nop ftrace_init_nop
>
> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> +#define ARCH_SUPPORTS_FTRACE_OPS 1
> +#endif
> #endif /* CONFIG_DYNAMIC_FTRACE */
> #endif /* __ASSEMBLY__ */
> #endif /* CONFIG_FUNCTION_TRACER */
> diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c
> index 3fe791b6783e..ec3d951be50c 100644
> --- a/arch/loongarch/kernel/ftrace_dyn.c
> +++ b/arch/loongarch/kernel/ftrace_dyn.c
> @@ -99,6 +99,23 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
> return ftrace_modify_code(pc, old, new, true);
> }
>
> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
> + unsigned long addr)
> +{
> + unsigned long pc;
> + long offset;
> + u32 old, new;
> +
> + pc = rec->ip + LOONGARCH_INSN_SIZE;
> +
> + old = larch_insn_gen_bl(pc, old_addr);
> + new = larch_insn_gen_bl(pc, addr);
> +
> + return ftrace_modify_code(pc, old, new, true);
> +}
> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> +
> void arch_ftrace_update_code(int command)
> {
> command |= FTRACE_MAY_SLEEP;
> diff --git a/arch/loongarch/kernel/mcount-dyn.S b/arch/loongarch/kernel/mcount-dyn.S
> index 0c12cc108e6f..02835186b463 100644
> --- a/arch/loongarch/kernel/mcount-dyn.S
> +++ b/arch/loongarch/kernel/mcount-dyn.S
> @@ -27,7 +27,7 @@
> * follows the LoongArch psABI well.
> */
>
> - .macro ftrace_regs_entry
> + .macro ftrace_regs_entry allregs=0
> PTR_ADDI sp, sp, -PT_SIZE
> /* Save trace function ra at PT_ERA */
> PTR_S ra, sp, PT_ERA
> @@ -43,16 +43,48 @@
> PTR_S a7, sp, PT_R11
> PTR_S fp, sp, PT_R22
>
> + .if \allregs
> + PTR_S t0, sp, PT_R12
> + PTR_S t1, sp, PT_R13
> + PTR_S t2, sp, PT_R14
> + PTR_S t3, sp, PT_R15
> + PTR_S t4, sp, PT_R16
> + PTR_S t5, sp, PT_R17
> + PTR_S t6, sp, PT_R18
> + PTR_S t7, sp, PT_R19
> + PTR_S t8, sp, PT_R20
> + PTR_S s0, sp, PT_R23
> + PTR_S s1, sp, PT_R24
> + PTR_S s2, sp, PT_R25
> + PTR_S s3, sp, PT_R26
> + PTR_S s4, sp, PT_R27
> + PTR_S s5, sp, PT_R28
> + PTR_S s6, sp, PT_R29
> + PTR_S s7, sp, PT_R30
> + PTR_S s8, sp, PT_R31
> + PTR_S tp, sp, PT_R2
> + /* Clear it for later use as a flag sometimes. */
> + PTR_S zero, sp, PT_R0
> + PTR_S $r21, sp, PT_R21
> + .endif
> +
> PTR_ADDI t8, sp, PT_SIZE
> PTR_S t8, sp, PT_R3
>
> .endm
>
> SYM_CODE_START(ftrace_caller)
> - ftrace_regs_entry
> + ftrace_regs_entry allregs=0
> b ftrace_common
> SYM_CODE_END(ftrace_caller)
>
> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> +SYM_CODE_START(ftrace_regs_caller)
> + ftrace_regs_entry allregs=1
> + b ftrace_common
> +SYM_CODE_END(ftrace_regs_caller)
> +#endif
> +
> SYM_CODE_START(ftrace_common)
> PTR_ADDI a0, ra, -8 /* arg0: ip */
> move a1, t0 /* arg1: parent_ip */
> --
> 2.36.0
>
>
On Tue, Nov 15, 2022 at 5:22 PM Qing Zhang <[email protected]> wrote:
>
> Hi, Huacai
>
> On 2022/11/15 下午4:41, Huacai Chen wrote:
> > Hi, Qing,
> >
> > Patch5 and Patch6 are small and related, maybe they can be combined
> > with a name "LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_{ARGS,REGS}
> > support"
> I think they should be independent due to different use scenarios.
From the commit message it seems DYNAMIC_FTRACE_WITH_ARGS depend on
DYNAMIC_FTRACE_WITH_REGS.
Huacai
>
> Thanks,
> -Qing
> >
> > Huacai
> >
> > On Tue, Nov 15, 2022 at 10:55 AM Qing Zhang <[email protected]> wrote:
> >>
> >> This patch implements DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows
> >> a traced function's arguments (and some other registers) to be captured
> >> into a struct pt_regs, allowing these to be inspected and modified.
> >>
> >> Co-developed-by: Jinyang He <[email protected]>
> >> Signed-off-by: Jinyang He <[email protected]>
> >> Signed-off-by: Qing Zhang <[email protected]>
> >> ---
> >> arch/loongarch/Kconfig | 1 +
> >> arch/loongarch/include/asm/ftrace.h | 3 +++
> >> arch/loongarch/kernel/ftrace_dyn.c | 17 ++++++++++++++
> >> arch/loongarch/kernel/mcount-dyn.S | 36 +++++++++++++++++++++++++++--
> >> 4 files changed, 55 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> >> index 615ce62422b8..12e3e91a68ae 100644
> >> --- a/arch/loongarch/Kconfig
> >> +++ b/arch/loongarch/Kconfig
> >> @@ -90,6 +90,7 @@ config LOONGARCH
> >> select HAVE_DEBUG_STACKOVERFLOW
> >> select HAVE_DMA_CONTIGUOUS
> >> select HAVE_DYNAMIC_FTRACE
> >> + select HAVE_DYNAMIC_FTRACE_WITH_REGS
> >> select HAVE_EBPF_JIT
> >> select HAVE_EXIT_THREAD
> >> select HAVE_FAST_GUP
> >> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
> >> index 76ca58767f4d..a3f974a7a5ce 100644
> >> --- a/arch/loongarch/include/asm/ftrace.h
> >> +++ b/arch/loongarch/include/asm/ftrace.h
> >> @@ -28,6 +28,9 @@ struct dyn_ftrace;
> >> int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
> >> #define ftrace_init_nop ftrace_init_nop
> >>
> >> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> >> +#define ARCH_SUPPORTS_FTRACE_OPS 1
> >> +#endif
> >> #endif /* CONFIG_DYNAMIC_FTRACE */
> >> #endif /* __ASSEMBLY__ */
> >> #endif /* CONFIG_FUNCTION_TRACER */
> >> diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c
> >> index 3fe791b6783e..ec3d951be50c 100644
> >> --- a/arch/loongarch/kernel/ftrace_dyn.c
> >> +++ b/arch/loongarch/kernel/ftrace_dyn.c
> >> @@ -99,6 +99,23 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
> >> return ftrace_modify_code(pc, old, new, true);
> >> }
> >>
> >> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> >> +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
> >> + unsigned long addr)
> >> +{
> >> + unsigned long pc;
> >> + long offset;
> >> + u32 old, new;
> >> +
> >> + pc = rec->ip + LOONGARCH_INSN_SIZE;
> >> +
> >> + old = larch_insn_gen_bl(pc, old_addr);
> >> + new = larch_insn_gen_bl(pc, addr);
> >> +
> >> + return ftrace_modify_code(pc, old, new, true);
> >> +}
> >> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> >> +
> >> void arch_ftrace_update_code(int command)
> >> {
> >> command |= FTRACE_MAY_SLEEP;
> >> diff --git a/arch/loongarch/kernel/mcount-dyn.S b/arch/loongarch/kernel/mcount-dyn.S
> >> index 0c12cc108e6f..02835186b463 100644
> >> --- a/arch/loongarch/kernel/mcount-dyn.S
> >> +++ b/arch/loongarch/kernel/mcount-dyn.S
> >> @@ -27,7 +27,7 @@
> >> * follows the LoongArch psABI well.
> >> */
> >>
> >> - .macro ftrace_regs_entry
> >> + .macro ftrace_regs_entry allregs=0
> >> PTR_ADDI sp, sp, -PT_SIZE
> >> /* Save trace function ra at PT_ERA */
> >> PTR_S ra, sp, PT_ERA
> >> @@ -43,16 +43,48 @@
> >> PTR_S a7, sp, PT_R11
> >> PTR_S fp, sp, PT_R22
> >>
> >> + .if \allregs
> >> + PTR_S t0, sp, PT_R12
> >> + PTR_S t1, sp, PT_R13
> >> + PTR_S t2, sp, PT_R14
> >> + PTR_S t3, sp, PT_R15
> >> + PTR_S t4, sp, PT_R16
> >> + PTR_S t5, sp, PT_R17
> >> + PTR_S t6, sp, PT_R18
> >> + PTR_S t7, sp, PT_R19
> >> + PTR_S t8, sp, PT_R20
> >> + PTR_S s0, sp, PT_R23
> >> + PTR_S s1, sp, PT_R24
> >> + PTR_S s2, sp, PT_R25
> >> + PTR_S s3, sp, PT_R26
> >> + PTR_S s4, sp, PT_R27
> >> + PTR_S s5, sp, PT_R28
> >> + PTR_S s6, sp, PT_R29
> >> + PTR_S s7, sp, PT_R30
> >> + PTR_S s8, sp, PT_R31
> >> + PTR_S tp, sp, PT_R2
> >> + /* Clear it for later use as a flag sometimes. */
> >> + PTR_S zero, sp, PT_R0
> >> + PTR_S $r21, sp, PT_R21
> >> + .endif
> >> +
> >> PTR_ADDI t8, sp, PT_SIZE
> >> PTR_S t8, sp, PT_R3
> >>
> >> .endm
> >>
> >> SYM_CODE_START(ftrace_caller)
> >> - ftrace_regs_entry
> >> + ftrace_regs_entry allregs=0
> >> b ftrace_common
> >> SYM_CODE_END(ftrace_caller)
> >>
> >> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> >> +SYM_CODE_START(ftrace_regs_caller)
> >> + ftrace_regs_entry allregs=1
> >> + b ftrace_common
> >> +SYM_CODE_END(ftrace_regs_caller)
> >> +#endif
> >> +
> >> SYM_CODE_START(ftrace_common)
> >> PTR_ADDI a0, ra, -8 /* arg0: ip */
> >> move a1, t0 /* arg1: parent_ip */
> >> --
> >> 2.36.0
> >>
> >>
>
>
Hi, Huacai
On 2022/11/15 下午4:41, Huacai Chen wrote:
> Hi, Qing,
>
> Patch5 and Patch6 are small and related, maybe they can be combined
> with a name "LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_{ARGS,REGS}
> support"
I think they should be independent due to different use scenarios.
Thanks,
-Qing
>
> Huacai
>
> On Tue, Nov 15, 2022 at 10:55 AM Qing Zhang <[email protected]> wrote:
>>
>> This patch implements DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows
>> a traced function's arguments (and some other registers) to be captured
>> into a struct pt_regs, allowing these to be inspected and modified.
>>
>> Co-developed-by: Jinyang He <[email protected]>
>> Signed-off-by: Jinyang He <[email protected]>
>> Signed-off-by: Qing Zhang <[email protected]>
>> ---
>> arch/loongarch/Kconfig | 1 +
>> arch/loongarch/include/asm/ftrace.h | 3 +++
>> arch/loongarch/kernel/ftrace_dyn.c | 17 ++++++++++++++
>> arch/loongarch/kernel/mcount-dyn.S | 36 +++++++++++++++++++++++++++--
>> 4 files changed, 55 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
>> index 615ce62422b8..12e3e91a68ae 100644
>> --- a/arch/loongarch/Kconfig
>> +++ b/arch/loongarch/Kconfig
>> @@ -90,6 +90,7 @@ config LOONGARCH
>> select HAVE_DEBUG_STACKOVERFLOW
>> select HAVE_DMA_CONTIGUOUS
>> select HAVE_DYNAMIC_FTRACE
>> + select HAVE_DYNAMIC_FTRACE_WITH_REGS
>> select HAVE_EBPF_JIT
>> select HAVE_EXIT_THREAD
>> select HAVE_FAST_GUP
>> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
>> index 76ca58767f4d..a3f974a7a5ce 100644
>> --- a/arch/loongarch/include/asm/ftrace.h
>> +++ b/arch/loongarch/include/asm/ftrace.h
>> @@ -28,6 +28,9 @@ struct dyn_ftrace;
>> int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
>> #define ftrace_init_nop ftrace_init_nop
>>
>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>> +#define ARCH_SUPPORTS_FTRACE_OPS 1
>> +#endif
>> #endif /* CONFIG_DYNAMIC_FTRACE */
>> #endif /* __ASSEMBLY__ */
>> #endif /* CONFIG_FUNCTION_TRACER */
>> diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c
>> index 3fe791b6783e..ec3d951be50c 100644
>> --- a/arch/loongarch/kernel/ftrace_dyn.c
>> +++ b/arch/loongarch/kernel/ftrace_dyn.c
>> @@ -99,6 +99,23 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
>> return ftrace_modify_code(pc, old, new, true);
>> }
>>
>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>> +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
>> + unsigned long addr)
>> +{
>> + unsigned long pc;
>> + long offset;
>> + u32 old, new;
>> +
>> + pc = rec->ip + LOONGARCH_INSN_SIZE;
>> +
>> + old = larch_insn_gen_bl(pc, old_addr);
>> + new = larch_insn_gen_bl(pc, addr);
>> +
>> + return ftrace_modify_code(pc, old, new, true);
>> +}
>> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
>> +
>> void arch_ftrace_update_code(int command)
>> {
>> command |= FTRACE_MAY_SLEEP;
>> diff --git a/arch/loongarch/kernel/mcount-dyn.S b/arch/loongarch/kernel/mcount-dyn.S
>> index 0c12cc108e6f..02835186b463 100644
>> --- a/arch/loongarch/kernel/mcount-dyn.S
>> +++ b/arch/loongarch/kernel/mcount-dyn.S
>> @@ -27,7 +27,7 @@
>> * follows the LoongArch psABI well.
>> */
>>
>> - .macro ftrace_regs_entry
>> + .macro ftrace_regs_entry allregs=0
>> PTR_ADDI sp, sp, -PT_SIZE
>> /* Save trace function ra at PT_ERA */
>> PTR_S ra, sp, PT_ERA
>> @@ -43,16 +43,48 @@
>> PTR_S a7, sp, PT_R11
>> PTR_S fp, sp, PT_R22
>>
>> + .if \allregs
>> + PTR_S t0, sp, PT_R12
>> + PTR_S t1, sp, PT_R13
>> + PTR_S t2, sp, PT_R14
>> + PTR_S t3, sp, PT_R15
>> + PTR_S t4, sp, PT_R16
>> + PTR_S t5, sp, PT_R17
>> + PTR_S t6, sp, PT_R18
>> + PTR_S t7, sp, PT_R19
>> + PTR_S t8, sp, PT_R20
>> + PTR_S s0, sp, PT_R23
>> + PTR_S s1, sp, PT_R24
>> + PTR_S s2, sp, PT_R25
>> + PTR_S s3, sp, PT_R26
>> + PTR_S s4, sp, PT_R27
>> + PTR_S s5, sp, PT_R28
>> + PTR_S s6, sp, PT_R29
>> + PTR_S s7, sp, PT_R30
>> + PTR_S s8, sp, PT_R31
>> + PTR_S tp, sp, PT_R2
>> + /* Clear it for later use as a flag sometimes. */
>> + PTR_S zero, sp, PT_R0
>> + PTR_S $r21, sp, PT_R21
>> + .endif
>> +
>> PTR_ADDI t8, sp, PT_SIZE
>> PTR_S t8, sp, PT_R3
>>
>> .endm
>>
>> SYM_CODE_START(ftrace_caller)
>> - ftrace_regs_entry
>> + ftrace_regs_entry allregs=0
>> b ftrace_common
>> SYM_CODE_END(ftrace_caller)
>>
>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>> +SYM_CODE_START(ftrace_regs_caller)
>> + ftrace_regs_entry allregs=1
>> + b ftrace_common
>> +SYM_CODE_END(ftrace_regs_caller)
>> +#endif
>> +
>> SYM_CODE_START(ftrace_common)
>> PTR_ADDI a0, ra, -8 /* arg0: ip */
>> move a1, t0 /* arg1: parent_ip */
>> --
>> 2.36.0
>>
>>
Hi, huacai
On 2022/11/15 下午5:24, Huacai Chen wrote:
> On Tue, Nov 15, 2022 at 5:22 PM Qing Zhang <[email protected]> wrote:
>>
>> Hi, Huacai
>>
>> On 2022/11/15 下午4:41, Huacai Chen wrote:
>>> Hi, Qing,
>>>
>>> Patch5 and Patch6 are small and related, maybe they can be combined
>>> with a name "LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_{ARGS,REGS}
>>> support"
>> I think they should be independent due to different use scenarios.
> From the commit message it seems DYNAMIC_FTRACE_WITH_ARGS depend on
> DYNAMIC_FTRACE_WITH_REGS.
DYNAMIC_FTRACE_WITH_REGS : which allows trace function saved registers,
It means that these registers can be modified, eg: Kprobe、Livepatch.
DYNAMIC_FTRACE_WITH_ARGS: uses pt_regs as a parameter for get sp,
which means it can be used to access registers on the stack, and
use graph_ops::func to install return_hooker to replace the special
hook, eg: Livepatch.
From the following Kconfig, they are reasonable as separate patches.
config LIVEPATCH
bool "Kernel Live Patching"
depends on DYNAMIC_FTRACE_WITH_REGS || DYNAMIC_FTRACE_WITH_ARGS
Thanks
- Qing
>
> Huacai
>>
>> Thanks,
>> -Qing
>>>
>>> Huacai
>>>
>>> On Tue, Nov 15, 2022 at 10:55 AM Qing Zhang <[email protected]> wrote:
>>>>
>>>> This patch implements DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows
>>>> a traced function's arguments (and some other registers) to be captured
>>>> into a struct pt_regs, allowing these to be inspected and modified.
>>>>
>>>> Co-developed-by: Jinyang He <[email protected]>
>>>> Signed-off-by: Jinyang He <[email protected]>
>>>> Signed-off-by: Qing Zhang <[email protected]>
>>>> ---
>>>> arch/loongarch/Kconfig | 1 +
>>>> arch/loongarch/include/asm/ftrace.h | 3 +++
>>>> arch/loongarch/kernel/ftrace_dyn.c | 17 ++++++++++++++
>>>> arch/loongarch/kernel/mcount-dyn.S | 36 +++++++++++++++++++++++++++--
>>>> 4 files changed, 55 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
>>>> index 615ce62422b8..12e3e91a68ae 100644
>>>> --- a/arch/loongarch/Kconfig
>>>> +++ b/arch/loongarch/Kconfig
>>>> @@ -90,6 +90,7 @@ config LOONGARCH
>>>> select HAVE_DEBUG_STACKOVERFLOW
>>>> select HAVE_DMA_CONTIGUOUS
>>>> select HAVE_DYNAMIC_FTRACE
>>>> + select HAVE_DYNAMIC_FTRACE_WITH_REGS
>>>> select HAVE_EBPF_JIT
>>>> select HAVE_EXIT_THREAD
>>>> select HAVE_FAST_GUP
>>>> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
>>>> index 76ca58767f4d..a3f974a7a5ce 100644
>>>> --- a/arch/loongarch/include/asm/ftrace.h
>>>> +++ b/arch/loongarch/include/asm/ftrace.h
>>>> @@ -28,6 +28,9 @@ struct dyn_ftrace;
>>>> int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
>>>> #define ftrace_init_nop ftrace_init_nop
>>>>
>>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>>> +#define ARCH_SUPPORTS_FTRACE_OPS 1
>>>> +#endif
>>>> #endif /* CONFIG_DYNAMIC_FTRACE */
>>>> #endif /* __ASSEMBLY__ */
>>>> #endif /* CONFIG_FUNCTION_TRACER */
>>>> diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c
>>>> index 3fe791b6783e..ec3d951be50c 100644
>>>> --- a/arch/loongarch/kernel/ftrace_dyn.c
>>>> +++ b/arch/loongarch/kernel/ftrace_dyn.c
>>>> @@ -99,6 +99,23 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
>>>> return ftrace_modify_code(pc, old, new, true);
>>>> }
>>>>
>>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>>> +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
>>>> + unsigned long addr)
>>>> +{
>>>> + unsigned long pc;
>>>> + long offset;
>>>> + u32 old, new;
>>>> +
>>>> + pc = rec->ip + LOONGARCH_INSN_SIZE;
>>>> +
>>>> + old = larch_insn_gen_bl(pc, old_addr);
>>>> + new = larch_insn_gen_bl(pc, addr);
>>>> +
>>>> + return ftrace_modify_code(pc, old, new, true);
>>>> +}
>>>> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
>>>> +
>>>> void arch_ftrace_update_code(int command)
>>>> {
>>>> command |= FTRACE_MAY_SLEEP;
>>>> diff --git a/arch/loongarch/kernel/mcount-dyn.S b/arch/loongarch/kernel/mcount-dyn.S
>>>> index 0c12cc108e6f..02835186b463 100644
>>>> --- a/arch/loongarch/kernel/mcount-dyn.S
>>>> +++ b/arch/loongarch/kernel/mcount-dyn.S
>>>> @@ -27,7 +27,7 @@
>>>> * follows the LoongArch psABI well.
>>>> */
>>>>
>>>> - .macro ftrace_regs_entry
>>>> + .macro ftrace_regs_entry allregs=0
>>>> PTR_ADDI sp, sp, -PT_SIZE
>>>> /* Save trace function ra at PT_ERA */
>>>> PTR_S ra, sp, PT_ERA
>>>> @@ -43,16 +43,48 @@
>>>> PTR_S a7, sp, PT_R11
>>>> PTR_S fp, sp, PT_R22
>>>>
>>>> + .if \allregs
>>>> + PTR_S t0, sp, PT_R12
>>>> + PTR_S t1, sp, PT_R13
>>>> + PTR_S t2, sp, PT_R14
>>>> + PTR_S t3, sp, PT_R15
>>>> + PTR_S t4, sp, PT_R16
>>>> + PTR_S t5, sp, PT_R17
>>>> + PTR_S t6, sp, PT_R18
>>>> + PTR_S t7, sp, PT_R19
>>>> + PTR_S t8, sp, PT_R20
>>>> + PTR_S s0, sp, PT_R23
>>>> + PTR_S s1, sp, PT_R24
>>>> + PTR_S s2, sp, PT_R25
>>>> + PTR_S s3, sp, PT_R26
>>>> + PTR_S s4, sp, PT_R27
>>>> + PTR_S s5, sp, PT_R28
>>>> + PTR_S s6, sp, PT_R29
>>>> + PTR_S s7, sp, PT_R30
>>>> + PTR_S s8, sp, PT_R31
>>>> + PTR_S tp, sp, PT_R2
>>>> + /* Clear it for later use as a flag sometimes. */
>>>> + PTR_S zero, sp, PT_R0
>>>> + PTR_S $r21, sp, PT_R21
>>>> + .endif
>>>> +
>>>> PTR_ADDI t8, sp, PT_SIZE
>>>> PTR_S t8, sp, PT_R3
>>>>
>>>> .endm
>>>>
>>>> SYM_CODE_START(ftrace_caller)
>>>> - ftrace_regs_entry
>>>> + ftrace_regs_entry allregs=0
>>>> b ftrace_common
>>>> SYM_CODE_END(ftrace_caller)
>>>>
>>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
>>>> +SYM_CODE_START(ftrace_regs_caller)
>>>> + ftrace_regs_entry allregs=1
>>>> + b ftrace_common
>>>> +SYM_CODE_END(ftrace_regs_caller)
>>>> +#endif
>>>> +
>>>> SYM_CODE_START(ftrace_common)
>>>> PTR_ADDI a0, ra, -8 /* arg0: ip */
>>>> move a1, t0 /* arg1: parent_ip */
>>>> --
>>>> 2.36.0
>>>>
>>>>
>>
>>
On Tue, Nov 15, 2022 at 6:44 PM Qing Zhang <[email protected]> wrote:
>
>
> Hi, huacai
> On 2022/11/15 下午5:24, Huacai Chen wrote:
> > On Tue, Nov 15, 2022 at 5:22 PM Qing Zhang <[email protected]> wrote:
> >>
> >> Hi, Huacai
> >>
> >> On 2022/11/15 下午4:41, Huacai Chen wrote:
> >>> Hi, Qing,
> >>>
> >>> Patch5 and Patch6 are small and related, maybe they can be combined
> >>> with a name "LoongArch/ftrace: Add DYNAMIC_FTRACE_WITH_{ARGS,REGS}
> >>> support"
> >> I think they should be independent due to different use scenarios.
> > From the commit message it seems DYNAMIC_FTRACE_WITH_ARGS depend on
> > DYNAMIC_FTRACE_WITH_REGS.
>
> DYNAMIC_FTRACE_WITH_REGS : which allows trace function saved registers,
> It means that these registers can be modified, eg: Kprobe、Livepatch.
>
> DYNAMIC_FTRACE_WITH_ARGS: uses pt_regs as a parameter for get sp,
> which means it can be used to access registers on the stack, and
> use graph_ops::func to install return_hooker to replace the special
> hook, eg: Livepatch.
>
> From the following Kconfig, they are reasonable as separate patches.
> config LIVEPATCH
> bool "Kernel Live Patching"
> depends on DYNAMIC_FTRACE_WITH_REGS || DYNAMIC_FTRACE_WITH_ARGS
>
OK, then keeping them separately is reasonable.
Huacai
> Thanks
> - Qing
> >
> > Huacai
> >>
> >> Thanks,
> >> -Qing
> >>>
> >>> Huacai
> >>>
> >>> On Tue, Nov 15, 2022 at 10:55 AM Qing Zhang <[email protected]> wrote:
> >>>>
> >>>> This patch implements DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows
> >>>> a traced function's arguments (and some other registers) to be captured
> >>>> into a struct pt_regs, allowing these to be inspected and modified.
> >>>>
> >>>> Co-developed-by: Jinyang He <[email protected]>
> >>>> Signed-off-by: Jinyang He <[email protected]>
> >>>> Signed-off-by: Qing Zhang <[email protected]>
> >>>> ---
> >>>> arch/loongarch/Kconfig | 1 +
> >>>> arch/loongarch/include/asm/ftrace.h | 3 +++
> >>>> arch/loongarch/kernel/ftrace_dyn.c | 17 ++++++++++++++
> >>>> arch/loongarch/kernel/mcount-dyn.S | 36 +++++++++++++++++++++++++++--
> >>>> 4 files changed, 55 insertions(+), 2 deletions(-)
> >>>>
> >>>> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> >>>> index 615ce62422b8..12e3e91a68ae 100644
> >>>> --- a/arch/loongarch/Kconfig
> >>>> +++ b/arch/loongarch/Kconfig
> >>>> @@ -90,6 +90,7 @@ config LOONGARCH
> >>>> select HAVE_DEBUG_STACKOVERFLOW
> >>>> select HAVE_DMA_CONTIGUOUS
> >>>> select HAVE_DYNAMIC_FTRACE
> >>>> + select HAVE_DYNAMIC_FTRACE_WITH_REGS
> >>>> select HAVE_EBPF_JIT
> >>>> select HAVE_EXIT_THREAD
> >>>> select HAVE_FAST_GUP
> >>>> diff --git a/arch/loongarch/include/asm/ftrace.h b/arch/loongarch/include/asm/ftrace.h
> >>>> index 76ca58767f4d..a3f974a7a5ce 100644
> >>>> --- a/arch/loongarch/include/asm/ftrace.h
> >>>> +++ b/arch/loongarch/include/asm/ftrace.h
> >>>> @@ -28,6 +28,9 @@ struct dyn_ftrace;
> >>>> int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
> >>>> #define ftrace_init_nop ftrace_init_nop
> >>>>
> >>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> >>>> +#define ARCH_SUPPORTS_FTRACE_OPS 1
> >>>> +#endif
> >>>> #endif /* CONFIG_DYNAMIC_FTRACE */
> >>>> #endif /* __ASSEMBLY__ */
> >>>> #endif /* CONFIG_FUNCTION_TRACER */
> >>>> diff --git a/arch/loongarch/kernel/ftrace_dyn.c b/arch/loongarch/kernel/ftrace_dyn.c
> >>>> index 3fe791b6783e..ec3d951be50c 100644
> >>>> --- a/arch/loongarch/kernel/ftrace_dyn.c
> >>>> +++ b/arch/loongarch/kernel/ftrace_dyn.c
> >>>> @@ -99,6 +99,23 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
> >>>> return ftrace_modify_code(pc, old, new, true);
> >>>> }
> >>>>
> >>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> >>>> +int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
> >>>> + unsigned long addr)
> >>>> +{
> >>>> + unsigned long pc;
> >>>> + long offset;
> >>>> + u32 old, new;
> >>>> +
> >>>> + pc = rec->ip + LOONGARCH_INSN_SIZE;
> >>>> +
> >>>> + old = larch_insn_gen_bl(pc, old_addr);
> >>>> + new = larch_insn_gen_bl(pc, addr);
> >>>> +
> >>>> + return ftrace_modify_code(pc, old, new, true);
> >>>> +}
> >>>> +#endif /* CONFIG_DYNAMIC_FTRACE_WITH_REGS */
> >>>> +
> >>>> void arch_ftrace_update_code(int command)
> >>>> {
> >>>> command |= FTRACE_MAY_SLEEP;
> >>>> diff --git a/arch/loongarch/kernel/mcount-dyn.S b/arch/loongarch/kernel/mcount-dyn.S
> >>>> index 0c12cc108e6f..02835186b463 100644
> >>>> --- a/arch/loongarch/kernel/mcount-dyn.S
> >>>> +++ b/arch/loongarch/kernel/mcount-dyn.S
> >>>> @@ -27,7 +27,7 @@
> >>>> * follows the LoongArch psABI well.
> >>>> */
> >>>>
> >>>> - .macro ftrace_regs_entry
> >>>> + .macro ftrace_regs_entry allregs=0
> >>>> PTR_ADDI sp, sp, -PT_SIZE
> >>>> /* Save trace function ra at PT_ERA */
> >>>> PTR_S ra, sp, PT_ERA
> >>>> @@ -43,16 +43,48 @@
> >>>> PTR_S a7, sp, PT_R11
> >>>> PTR_S fp, sp, PT_R22
> >>>>
> >>>> + .if \allregs
> >>>> + PTR_S t0, sp, PT_R12
> >>>> + PTR_S t1, sp, PT_R13
> >>>> + PTR_S t2, sp, PT_R14
> >>>> + PTR_S t3, sp, PT_R15
> >>>> + PTR_S t4, sp, PT_R16
> >>>> + PTR_S t5, sp, PT_R17
> >>>> + PTR_S t6, sp, PT_R18
> >>>> + PTR_S t7, sp, PT_R19
> >>>> + PTR_S t8, sp, PT_R20
> >>>> + PTR_S s0, sp, PT_R23
> >>>> + PTR_S s1, sp, PT_R24
> >>>> + PTR_S s2, sp, PT_R25
> >>>> + PTR_S s3, sp, PT_R26
> >>>> + PTR_S s4, sp, PT_R27
> >>>> + PTR_S s5, sp, PT_R28
> >>>> + PTR_S s6, sp, PT_R29
> >>>> + PTR_S s7, sp, PT_R30
> >>>> + PTR_S s8, sp, PT_R31
> >>>> + PTR_S tp, sp, PT_R2
> >>>> + /* Clear it for later use as a flag sometimes. */
> >>>> + PTR_S zero, sp, PT_R0
> >>>> + PTR_S $r21, sp, PT_R21
> >>>> + .endif
> >>>> +
> >>>> PTR_ADDI t8, sp, PT_SIZE
> >>>> PTR_S t8, sp, PT_R3
> >>>>
> >>>> .endm
> >>>>
> >>>> SYM_CODE_START(ftrace_caller)
> >>>> - ftrace_regs_entry
> >>>> + ftrace_regs_entry allregs=0
> >>>> b ftrace_common
> >>>> SYM_CODE_END(ftrace_caller)
> >>>>
> >>>> +#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
> >>>> +SYM_CODE_START(ftrace_regs_caller)
> >>>> + ftrace_regs_entry allregs=1
> >>>> + b ftrace_common
> >>>> +SYM_CODE_END(ftrace_regs_caller)
> >>>> +#endif
> >>>> +
> >>>> SYM_CODE_START(ftrace_common)
> >>>> PTR_ADDI a0, ra, -8 /* arg0: ip */
> >>>> move a1, t0 /* arg1: parent_ip */
> >>>> --
> >>>> 2.36.0
> >>>>
> >>>>
> >>
> >>
>
>