[PATCH -next V7 6/7] samples: ftrace: Add riscv support for SAMPLE_FTRACE_DIRECT[_MULTI]
Evgenii Shatokhin
e.shatokhin at yadro.com
Mon Jan 16 06:30:13 PST 2023
Hi,
On 12.01.2023 12:06, guoren at kernel.org wrote:
> From: Song Shuai <suagrfillet at gmail.com>
>
> select HAVE_SAMPLE_FTRACE_DIRECT and HAVE_SAMPLE_FTRACE_DIRECT_MULTI
> for ARCH_RV64I in arch/riscv/Kconfig. And add riscv asm code for
> the ftrace-direct*.c files in samples/ftrace/.
>
> Signed-off-by: Song Shuai <suagrfillet at gmail.com>
> Tested-by: Guo Ren <guoren at kernel.org>
> Signed-off-by: Guo Ren <guoren at kernel.org>
> ---
> arch/riscv/Kconfig | 2 ++
> samples/ftrace/ftrace-direct-modify.c | 33 ++++++++++++++++++
> samples/ftrace/ftrace-direct-multi-modify.c | 37 +++++++++++++++++++++
> samples/ftrace/ftrace-direct-multi.c | 22 ++++++++++++
> samples/ftrace/ftrace-direct-too.c | 26 +++++++++++++++
> samples/ftrace/ftrace-direct.c | 22 ++++++++++++
> 6 files changed, 142 insertions(+)
The samples were built OK now, but ftrace-direct-multi and
ftrace-direct-multi-modify report incorrect values of ip/pc it seems.
I ran 'insmod ftrace-direct-multi.ko', waited a little and then checked
the messages in the trace:
# TASK-PID CPU# ||||| TIMESTAMP FUNCTION
# | | | ||||| | |
migration/1-19 [001] ..... 3858.532131: my_direct_func1: my
direct func1 ip 0
migration/0-15 [000] d.s2. 3858.532136: my_direct_func1: my
direct func1 ip ff60000001ba9600
migration/0-15 [000] d..2. 3858.532204: my_direct_func1: my
direct func1 ip ff60000003334d00
migration/0-15 [000] ..... 3858.532232: my_direct_func1: my
direct func1 ip 0
rcu_sched-14 [001] ..... 3858.532257: my_direct_func1: my
direct func1 ip 0
insmod-415 [000] ..... 3858.532270: my_direct_func1: my
direct func1 ip 7fffffffffffffff
<idle>-0 [001] ..s1. 3858.539051: my_direct_func1: my
direct func1 ip ff60000001ba9600
<idle>-0 [001] dns2. 3858.539124: my_direct_func1: my
direct func1 ip ff60000001ba9600
rcu_sched-14 [001] ..... 3858.539208: my_direct_func1: my
direct func1 ip 0
[...]
If I understand it right, my_direct_func1() should print the address of
some location in the code, probably - at the beginning of the traced
functions.
The printed values (0x0, 0x7fffffffffffffff, ...) are not valid code
addresses.
The same issue is with ftrace-direct-multi-modify.ko.
Is anything missing here?
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 307a9f413edd..e944af44f681 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -112,6 +112,8 @@ config RISCV
> select HAVE_POSIX_CPU_TIMERS_TASK_WORK
> select HAVE_REGS_AND_STACK_ACCESS_API
> select HAVE_FUNCTION_ARG_ACCESS_API
> + select HAVE_SAMPLE_FTRACE_DIRECT
> + select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
> select HAVE_STACKPROTECTOR
> select HAVE_SYSCALL_TRACEPOINTS
> select HAVE_RSEQ
> diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
> index de5a0f67f320..be7bf472c3c7 100644
> --- a/samples/ftrace/ftrace-direct-modify.c
> +++ b/samples/ftrace/ftrace-direct-modify.c
> @@ -23,6 +23,39 @@ extern void my_tramp2(void *);
>
> static unsigned long my_ip = (unsigned long)schedule;
>
> +#ifdef CONFIG_RISCV
> +
> +asm (" .pushsection .text, \"ax\", @progbits\n"
> +" .type my_tramp1, @function\n"
> +" .globl my_tramp1\n"
> +" my_tramp1:\n"
> +" addi sp,sp,-16\n"
> +" sd t0,0(sp)\n"
> +" sd ra,8(sp)\n"
> +" call my_direct_func1\n"
> +" ld t0,0(sp)\n"
> +" ld ra,8(sp)\n"
> +" addi sp,sp,16\n"
> +" jr t0\n"
> +" .size my_tramp1, .-my_tramp1\n"
> +
> +" .type my_tramp2, @function\n"
> +" .globl my_tramp2\n"
> +" my_tramp2:\n"
> +" addi sp,sp,-16\n"
> +" sd t0,0(sp)\n"
> +" sd ra,8(sp)\n"
> +" call my_direct_func2\n"
> +" ld t0,0(sp)\n"
> +" ld ra,8(sp)\n"
> +" addi sp,sp,16\n"
> +" jr t0\n"
> +" .size my_tramp2, .-my_tramp2\n"
> +" .popsection\n"
> +);
> +
> +#endif /* CONFIG_RISCV */
> +
> #ifdef CONFIG_X86_64
>
> #include <asm/ibt.h>
> diff --git a/samples/ftrace/ftrace-direct-multi-modify.c b/samples/ftrace/ftrace-direct-multi-modify.c
> index d52370cad0b6..10884bf418f7 100644
> --- a/samples/ftrace/ftrace-direct-multi-modify.c
> +++ b/samples/ftrace/ftrace-direct-multi-modify.c
> @@ -21,6 +21,43 @@ void my_direct_func2(unsigned long ip)
> extern void my_tramp1(void *);
> extern void my_tramp2(void *);
>
> +#ifdef CONFIG_RISCV
> +
> +asm (" .pushsection .text, \"ax\", @progbits\n"
> +" .type my_tramp1, @function\n"
> +" .globl my_tramp1\n"
> +" my_tramp1:\n"
> +" addi sp,sp,-24\n"
> +" sd a0,0(sp)\n"
> +" sd t0,8(sp)\n"
> +" sd ra,16(sp)\n"
> +" call my_direct_func1\n"
> +" ld a0,0(sp)\n"
> +" ld t0,8(sp)\n"
> +" ld ra,16(sp)\n"
> +" addi sp,sp,24\n"
> +" jr t0\n"
> +" .size my_tramp1, .-my_tramp1\n"
> +
> +" .type my_tramp2, @function\n"
> +" .globl my_tramp2\n"
> +" my_tramp2:\n"
> +" addi sp,sp,-24\n"
> +" sd a0,0(sp)\n"
> +" sd t0,8(sp)\n"
> +" sd ra,16(sp)\n"
> +" call my_direct_func2\n"
> +" ld a0,0(sp)\n"
> +" ld t0,8(sp)\n"
> +" ld ra,16(sp)\n"
> +" addi sp,sp,24\n"
> +" jr t0\n"
> +" .size my_tramp2, .-my_tramp2\n"
> +" .popsection\n"
> +);
> +
> +#endif /* CONFIG_RISCV */
> +
> #ifdef CONFIG_X86_64
>
> #include <asm/ibt.h>
> diff --git a/samples/ftrace/ftrace-direct-multi.c b/samples/ftrace/ftrace-direct-multi.c
> index ec1088922517..a35bf43bf6d7 100644
> --- a/samples/ftrace/ftrace-direct-multi.c
> +++ b/samples/ftrace/ftrace-direct-multi.c
> @@ -16,6 +16,28 @@ void my_direct_func(unsigned long ip)
>
> extern void my_tramp(void *);
>
> +#ifdef CONFIG_RISCV
> +
> +asm (" .pushsection .text, \"ax\", @progbits\n"
> +" .type my_tramp, @function\n"
> +" .globl my_tramp\n"
> +" my_tramp:\n"
> +" addi sp,sp,-24\n"
> +" sd a0,0(sp)\n"
> +" sd t0,8(sp)\n"
> +" sd ra,16(sp)\n"
> +" call my_direct_func\n"
> +" ld a0,0(sp)\n"
> +" ld t0,8(sp)\n"
> +" ld ra,16(sp)\n"
> +" addi sp,sp,24\n"
> +" jr t0\n"
> +" .size my_tramp, .-my_tramp\n"
> +" .popsection\n"
> +);
> +
> +#endif /* CONFIG_RISCV */
> +
> #ifdef CONFIG_X86_64
>
> #include <asm/ibt.h>
> diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c
> index e13fb59a2b47..3b62e33c2e6d 100644
> --- a/samples/ftrace/ftrace-direct-too.c
> +++ b/samples/ftrace/ftrace-direct-too.c
> @@ -18,6 +18,32 @@ void my_direct_func(struct vm_area_struct *vma,
>
> extern void my_tramp(void *);
>
> +#ifdef CONFIG_RISCV
> +
> +asm (" .pushsection .text, \"ax\", @progbits\n"
> +" .type my_tramp, @function\n"
> +" .globl my_tramp\n"
> +" my_tramp:\n"
> +" addi sp,sp,-40\n"
> +" sd a0,0(sp)\n"
> +" sd a1,8(sp)\n"
> +" sd a2,16(sp)\n"
> +" sd t0,24(sp)\n"
> +" sd ra,32(sp)\n"
> +" call my_direct_func\n"
> +" ld a0,0(sp)\n"
> +" ld a1,8(sp)\n"
> +" ld a2,16(sp)\n"
> +" ld t0,24(sp)\n"
> +" ld ra,32(sp)\n"
> +" addi sp,sp,40\n"
> +" jr t0\n"
> +" .size my_tramp, .-my_tramp\n"
> +" .popsection\n"
> +);
> +
> +#endif /* CONFIG_RISCV */
> +
> #ifdef CONFIG_X86_64
>
> #include <asm/ibt.h>
> diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c
> index 1f769d0db20f..2cfe5a7d2d70 100644
> --- a/samples/ftrace/ftrace-direct.c
> +++ b/samples/ftrace/ftrace-direct.c
> @@ -15,6 +15,28 @@ void my_direct_func(struct task_struct *p)
>
> extern void my_tramp(void *);
>
> +#ifdef CONFIG_RISCV
> +
> +asm (" .pushsection .text, \"ax\", @progbits\n"
> +" .type my_tramp, @function\n"
> +" .globl my_tramp\n"
> +" my_tramp:\n"
> +" addi sp,sp,-24\n"
> +" sd a0,0(sp)\n"
> +" sd t0,8(sp)\n"
> +" sd ra,16(sp)\n"
> +" call my_direct_func\n"
> +" ld a0,0(sp)\n"
> +" ld t0,8(sp)\n"
> +" ld ra,16(sp)\n"
> +" addi sp,sp,24\n"
> +" jr t0\n"
> +" .size my_tramp, .-my_tramp\n"
> +" .popsection\n"
> +);
> +
> +#endif /* CONFIG_RISCV */
> +
> #ifdef CONFIG_X86_64
>
> #include <asm/ibt.h>
> --
> 2.36.1
>
>
Regards,
Evgenii
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