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 ARM platform.
We introduce a new structure called fgraph_ret_regs for the ARM 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 <[email protected]>
---
v10:
- Use CONFIG_FUNCTION_GRAPH_TRACER to control fgraph_ret_regs definition
v9:
- Fix stack pointer align issues
- Update the commit message
v8:
- Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
---
arch/arm/Kconfig | 1 +
arch/arm/include/asm/ftrace.h | 22 ++++++++++++++++++++++
arch/arm/kernel/asm-offsets.c | 8 +++++++-
arch/arm/kernel/entry-ftrace.S | 10 ++++++----
4 files changed, 36 insertions(+), 5 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e24a9820e12f..73061379855a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -98,6 +98,7 @@ config ARM
select HAVE_FAST_GUP if ARM_LPAE
select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
select HAVE_FUNCTION_ERROR_INJECTION
+ select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER if !XIP_KERNEL
select HAVE_GCC_PLUGINS
diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
index 7e9251ca29fe..3c457902b355 100644
--- a/arch/arm/include/asm/ftrace.h
+++ b/arch/arm/include/asm/ftrace.h
@@ -77,4 +77,26 @@ static inline bool arch_syscall_match_sym_name(const char *sym,
#endif /* ifndef __ASSEMBLY__ */
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+struct fgraph_ret_regs {
+ /* r0 - r3 */
+ unsigned long regs[4];
+
+ unsigned long fp;
+ unsigned long __unused;
+};
+
+static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
+{
+ return ret_regs->regs[0];
+}
+
+static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
+{
+ return ret_regs->fp;
+}
+#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
+#endif
+
#endif /* _ASM_ARM_FTRACE */
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 38121c59cbc2..18bb85115b21 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -23,6 +23,7 @@
#include <asm/suspend.h>
#include <asm/vdso_datapage.h>
#include <asm/hardware/cache-l2x0.h>
+#include <asm/ftrace.h>
#include <linux/kbuild.h>
#include <linux/arm-smccc.h>
#include "signal.h"
@@ -170,5 +171,10 @@ int main(void)
DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page));
DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type));
DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2));
- return 0;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ BLANK();
+ DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
+ BLANK();
+#endif
+ return 0;
}
diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
index 3e7bcaca5e07..d41a1676608c 100644
--- a/arch/arm/kernel/entry-ftrace.S
+++ b/arch/arm/kernel/entry-ftrace.S
@@ -257,11 +257,13 @@ ENDPROC(ftrace_graph_regs_caller)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
ENTRY(return_to_handler)
- stmdb sp!, {r0-r3}
- add r0, sp, #16 @ sp at exit of instrumented routine
+ mov ip, sp @ sp at exit of instrumented routine
+ stmdb sp!, {r0-r3, ip, lr} @ fill fgraph_ret_regs
+ mov r0, sp
bl ftrace_return_to_handler
- mov lr, r0 @ r0 has real ret addr
- ldmia sp!, {r0-r3}
+ mov lr, r0 @ r0 has real ret addr
+ ldmia sp, {r0-r3}
+ add sp, sp, #FGRET_REGS_SIZE @ restore stack pointer
ret lr
ENDPROC(return_to_handler)
#endif
--
2.25.1
On Sat, 8 Apr 2023 05:42:17 -0700
Donglin Peng <[email protected]> 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 ARM platform.
>
> We introduce a new structure called fgraph_ret_regs for the ARM 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 <[email protected]>
I really don't want to add this without an ack from an arm maintainer.
I have the patches queued (for testing), but I may remove the ones that do
not have the appropriate acks.
-- Steve
> ---
> v10:
> - Use CONFIG_FUNCTION_GRAPH_TRACER to control fgraph_ret_regs definition
>
> v9:
> - Fix stack pointer align issues
> - Update the commit message
>
> v8:
> - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
> ---
> arch/arm/Kconfig | 1 +
> arch/arm/include/asm/ftrace.h | 22 ++++++++++++++++++++++
> arch/arm/kernel/asm-offsets.c | 8 +++++++-
> arch/arm/kernel/entry-ftrace.S | 10 ++++++----
> 4 files changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index e24a9820e12f..73061379855a 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -98,6 +98,7 @@ config ARM
> select HAVE_FAST_GUP if ARM_LPAE
> select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
> select HAVE_FUNCTION_ERROR_INJECTION
> + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
> select HAVE_FUNCTION_GRAPH_TRACER
> select HAVE_FUNCTION_TRACER if !XIP_KERNEL
> select HAVE_GCC_PLUGINS
> diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
> index 7e9251ca29fe..3c457902b355 100644
> --- a/arch/arm/include/asm/ftrace.h
> +++ b/arch/arm/include/asm/ftrace.h
> @@ -77,4 +77,26 @@ static inline bool arch_syscall_match_sym_name(const char *sym,
>
> #endif /* ifndef __ASSEMBLY__ */
>
> +#ifndef __ASSEMBLY__
> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> +struct fgraph_ret_regs {
> + /* r0 - r3 */
> + unsigned long regs[4];
> +
> + unsigned long fp;
> + unsigned long __unused;
> +};
> +
> +static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
> +{
> + return ret_regs->regs[0];
> +}
> +
> +static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
> +{
> + return ret_regs->fp;
> +}
> +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
> +#endif
> +
> #endif /* _ASM_ARM_FTRACE */
> diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
> index 38121c59cbc2..18bb85115b21 100644
> --- a/arch/arm/kernel/asm-offsets.c
> +++ b/arch/arm/kernel/asm-offsets.c
> @@ -23,6 +23,7 @@
> #include <asm/suspend.h>
> #include <asm/vdso_datapage.h>
> #include <asm/hardware/cache-l2x0.h>
> +#include <asm/ftrace.h>
> #include <linux/kbuild.h>
> #include <linux/arm-smccc.h>
> #include "signal.h"
> @@ -170,5 +171,10 @@ int main(void)
> DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page));
> DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type));
> DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2));
> - return 0;
> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> + BLANK();
> + DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
> + BLANK();
> +#endif
> + return 0;
> }
> diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
> index 3e7bcaca5e07..d41a1676608c 100644
> --- a/arch/arm/kernel/entry-ftrace.S
> +++ b/arch/arm/kernel/entry-ftrace.S
> @@ -257,11 +257,13 @@ ENDPROC(ftrace_graph_regs_caller)
>
> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> ENTRY(return_to_handler)
> - stmdb sp!, {r0-r3}
> - add r0, sp, #16 @ sp at exit of instrumented routine
> + mov ip, sp @ sp at exit of instrumented routine
> + stmdb sp!, {r0-r3, ip, lr} @ fill fgraph_ret_regs
> + mov r0, sp
> bl ftrace_return_to_handler
> - mov lr, r0 @ r0 has real ret addr
> - ldmia sp!, {r0-r3}
> + mov lr, r0 @ r0 has real ret addr
> + ldmia sp, {r0-r3}
> + add sp, sp, #FGRET_REGS_SIZE @ restore stack pointer
> ret lr
> ENDPROC(return_to_handler)
> #endif
On 2023/6/9 9:57, Steven Rostedt wrote:
> On Sat, 8 Apr 2023 05:42:17 -0700
> Donglin Peng <[email protected]> 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 ARM platform.
>>
>> We introduce a new structure called fgraph_ret_regs for the ARM 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 <[email protected]>
>
> I really don't want to add this without an ack from an arm maintainer.
>
> I have the patches queued (for testing), but I may remove the ones that do
> not have the appropriate acks.
>
> -- Steve
>
Hi Russell, can I get a ack for arm?
>
>> ---
>> v10:
>> - Use CONFIG_FUNCTION_GRAPH_TRACER to control fgraph_ret_regs definition
>>
>> v9:
>> - Fix stack pointer align issues
>> - Update the commit message
>>
>> v8:
>> - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
>> ---
>> arch/arm/Kconfig | 1 +
>> arch/arm/include/asm/ftrace.h | 22 ++++++++++++++++++++++
>> arch/arm/kernel/asm-offsets.c | 8 +++++++-
>> arch/arm/kernel/entry-ftrace.S | 10 ++++++----
>> 4 files changed, 36 insertions(+), 5 deletions(-)
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index e24a9820e12f..73061379855a 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -98,6 +98,7 @@ config ARM
>> select HAVE_FAST_GUP if ARM_LPAE
>> select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
>> select HAVE_FUNCTION_ERROR_INJECTION
>> + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
>> select HAVE_FUNCTION_GRAPH_TRACER
>> select HAVE_FUNCTION_TRACER if !XIP_KERNEL
>> select HAVE_GCC_PLUGINS
>> diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
>> index 7e9251ca29fe..3c457902b355 100644
>> --- a/arch/arm/include/asm/ftrace.h
>> +++ b/arch/arm/include/asm/ftrace.h
>> @@ -77,4 +77,26 @@ static inline bool arch_syscall_match_sym_name(const char *sym,
>>
>> #endif /* ifndef __ASSEMBLY__ */
>>
>> +#ifndef __ASSEMBLY__
>> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> +struct fgraph_ret_regs {
>> + /* r0 - r3 */
>> + unsigned long regs[4];
>> +
>> + unsigned long fp;
>> + unsigned long __unused;
>> +};
>> +
>> +static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
>> +{
>> + return ret_regs->regs[0];
>> +}
>> +
>> +static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
>> +{
>> + return ret_regs->fp;
>> +}
>> +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
>> +#endif
>> +
>> #endif /* _ASM_ARM_FTRACE */
>> diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
>> index 38121c59cbc2..18bb85115b21 100644
>> --- a/arch/arm/kernel/asm-offsets.c
>> +++ b/arch/arm/kernel/asm-offsets.c
>> @@ -23,6 +23,7 @@
>> #include <asm/suspend.h>
>> #include <asm/vdso_datapage.h>
>> #include <asm/hardware/cache-l2x0.h>
>> +#include <asm/ftrace.h>
>> #include <linux/kbuild.h>
>> #include <linux/arm-smccc.h>
>> #include "signal.h"
>> @@ -170,5 +171,10 @@ int main(void)
>> DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page));
>> DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type));
>> DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2));
>> - return 0;
>> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> + BLANK();
>> + DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
>> + BLANK();
>> +#endif
>> + return 0;
>> }
>> diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
>> index 3e7bcaca5e07..d41a1676608c 100644
>> --- a/arch/arm/kernel/entry-ftrace.S
>> +++ b/arch/arm/kernel/entry-ftrace.S
>> @@ -257,11 +257,13 @@ ENDPROC(ftrace_graph_regs_caller)
>>
>> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> ENTRY(return_to_handler)
>> - stmdb sp!, {r0-r3}
>> - add r0, sp, #16 @ sp at exit of instrumented routine
>> + mov ip, sp @ sp at exit of instrumented routine
>> + stmdb sp!, {r0-r3, ip, lr} @ fill fgraph_ret_regs
>> + mov r0, sp
>> bl ftrace_return_to_handler
>> - mov lr, r0 @ r0 has real ret addr
>> - ldmia sp!, {r0-r3}
>> + mov lr, r0 @ r0 has real ret addr
>> + ldmia sp, {r0-r3}
>> + add sp, sp, #FGRET_REGS_SIZE @ restore stack pointer
>> ret lr
>> ENDPROC(return_to_handler)
>> #endif
>
Hi Russell,
I noticed that this patch set only went to the linux-arm-kernel mailing
list but did not include you in the Cc.
Could you give an ack to this patch, and I can take it through my tree?
The full patch set went to linux-arm-kernel where I'm sure you have access
to.
Thanks!
-- Steve
On Sat, 8 Apr 2023 05:42:17 -0700
Donglin Peng <[email protected]> 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 ARM platform.
>
> We introduce a new structure called fgraph_ret_regs for the ARM 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 <[email protected]>
> ---
> v10:
> - Use CONFIG_FUNCTION_GRAPH_TRACER to control fgraph_ret_regs definition
>
> v9:
> - Fix stack pointer align issues
> - Update the commit message
>
> v8:
> - Modify the control range of CONFIG_HAVE_FUNCTION_GRAPH_RETVAL
> ---
> arch/arm/Kconfig | 1 +
> arch/arm/include/asm/ftrace.h | 22 ++++++++++++++++++++++
> arch/arm/kernel/asm-offsets.c | 8 +++++++-
> arch/arm/kernel/entry-ftrace.S | 10 ++++++----
> 4 files changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index e24a9820e12f..73061379855a 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -98,6 +98,7 @@ config ARM
> select HAVE_FAST_GUP if ARM_LPAE
> select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
> select HAVE_FUNCTION_ERROR_INJECTION
> + select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER
> select HAVE_FUNCTION_GRAPH_TRACER
> select HAVE_FUNCTION_TRACER if !XIP_KERNEL
> select HAVE_GCC_PLUGINS
> diff --git a/arch/arm/include/asm/ftrace.h b/arch/arm/include/asm/ftrace.h
> index 7e9251ca29fe..3c457902b355 100644
> --- a/arch/arm/include/asm/ftrace.h
> +++ b/arch/arm/include/asm/ftrace.h
> @@ -77,4 +77,26 @@ static inline bool arch_syscall_match_sym_name(const char *sym,
>
> #endif /* ifndef __ASSEMBLY__ */
>
> +#ifndef __ASSEMBLY__
> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> +struct fgraph_ret_regs {
> + /* r0 - r3 */
> + unsigned long regs[4];
> +
> + unsigned long fp;
> + unsigned long __unused;
> +};
> +
> +static inline unsigned long fgraph_ret_regs_return_value(struct fgraph_ret_regs *ret_regs)
> +{
> + return ret_regs->regs[0];
> +}
> +
> +static inline unsigned long fgraph_ret_regs_frame_pointer(struct fgraph_ret_regs *ret_regs)
> +{
> + return ret_regs->fp;
> +}
> +#endif /* ifdef CONFIG_FUNCTION_GRAPH_TRACER */
> +#endif
> +
> #endif /* _ASM_ARM_FTRACE */
> diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
> index 38121c59cbc2..18bb85115b21 100644
> --- a/arch/arm/kernel/asm-offsets.c
> +++ b/arch/arm/kernel/asm-offsets.c
> @@ -23,6 +23,7 @@
> #include <asm/suspend.h>
> #include <asm/vdso_datapage.h>
> #include <asm/hardware/cache-l2x0.h>
> +#include <asm/ftrace.h>
> #include <linux/kbuild.h>
> #include <linux/arm-smccc.h>
> #include "signal.h"
> @@ -170,5 +171,10 @@ int main(void)
> DEFINE(KEXEC_INDIR_PAGE, offsetof(struct kexec_relocate_data, kexec_indirection_page));
> DEFINE(KEXEC_MACH_TYPE, offsetof(struct kexec_relocate_data, kexec_mach_type));
> DEFINE(KEXEC_R2, offsetof(struct kexec_relocate_data, kexec_r2));
> - return 0;
> +#ifdef CONFIG_FUNCTION_GRAPH_TRACER
> + BLANK();
> + DEFINE(FGRET_REGS_SIZE, sizeof(struct fgraph_ret_regs));
> + BLANK();
> +#endif
> + return 0;
> }
> diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
> index 3e7bcaca5e07..d41a1676608c 100644
> --- a/arch/arm/kernel/entry-ftrace.S
> +++ b/arch/arm/kernel/entry-ftrace.S
> @@ -257,11 +257,13 @@ ENDPROC(ftrace_graph_regs_caller)
>
> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
> ENTRY(return_to_handler)
> - stmdb sp!, {r0-r3}
> - add r0, sp, #16 @ sp at exit of instrumented routine
> + mov ip, sp @ sp at exit of instrumented routine
> + stmdb sp!, {r0-r3, ip, lr} @ fill fgraph_ret_regs
> + mov r0, sp
> bl ftrace_return_to_handler
> - mov lr, r0 @ r0 has real ret addr
> - ldmia sp!, {r0-r3}
> + mov lr, r0 @ r0 has real ret addr
> + ldmia sp, {r0-r3}
> + add sp, sp, #FGRET_REGS_SIZE @ restore stack pointer
> ret lr
> ENDPROC(return_to_handler)
> #endif