On Thu, 13 Jun 2024 19:13:47 +0800
Jinjie Ruan <ruanjin...@huawei.com> wrote:
> Since commit 7caa9765465f60 ("ftrace: riscv: move from REGS to ARGS"),
> kprobe on ftrace is not supported by riscv, because riscv's support for
> FTRACE_WITH_REGS has been replaced with support for FTRACE_WITH_ARGS, and
> KPROBES_ON_FTRACE will be supplanted by FPROBES. So remove the deprecated
> kprobe on ftrace support, which is misunderstood.
>
> Signed-off-by: Jinjie Ruan <ruanjin...@huawei.com>
No problem, Now we have fprobe instead.
Anyway, this looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhira...@kernel.org>
Thank you,
> ---
> arch/riscv/Kconfig | 1 -
> arch/riscv/kernel/probes/Makefile | 1 -
> arch/riscv/kernel/probes/ftrace.c | 65 -------------------------------
> 3 files changed, 67 deletions(-)
> delete mode 100644 arch/riscv/kernel/probes/ftrace.c
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 0525ee2d63c7..a1f2d604c459 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -149,7 +149,6 @@ config RISCV
> select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT
> select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT
> select HAVE_KPROBES if !XIP_KERNEL
> - select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL
> select HAVE_KRETPROBES if !XIP_KERNEL
> # https://github.com/ClangBuiltLinux/linux/issues/1881
> select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD
> diff --git a/arch/riscv/kernel/probes/Makefile
> b/arch/riscv/kernel/probes/Makefile
> index 8265ff497977..d2129f2c61b8 100644
> --- a/arch/riscv/kernel/probes/Makefile
> +++ b/arch/riscv/kernel/probes/Makefile
> @@ -1,7 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o
> simulate-insn.o
> obj-$(CONFIG_RETHOOK) += rethook.o rethook_trampoline.o
> -obj-$(CONFIG_KPROBES_ON_FTRACE) += ftrace.o
> obj-$(CONFIG_UPROBES) += uprobes.o decode-insn.o
> simulate-insn.o
> CFLAGS_REMOVE_simulate-insn.o = $(CC_FLAGS_FTRACE)
> CFLAGS_REMOVE_rethook.o = $(CC_FLAGS_FTRACE)
> diff --git a/arch/riscv/kernel/probes/ftrace.c
> b/arch/riscv/kernel/probes/ftrace.c
> deleted file mode 100644
> index a69dfa610aa8..000000000000
> --- a/arch/riscv/kernel/probes/ftrace.c
> +++ /dev/null
> @@ -1,65 +0,0 @@
> -// SPDX-License-Identifier: GPL-2.0
> -
> -#include <linux/kprobes.h>
> -
> -/* Ftrace callback handler for kprobes -- called under preepmt disabled */
> -void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
> - struct ftrace_ops *ops, struct ftrace_regs *fregs)
> -{
> - struct kprobe *p;
> - struct pt_regs *regs;
> - struct kprobe_ctlblk *kcb;
> - int bit;
> -
> - if (unlikely(kprobe_ftrace_disabled))
> - return;
> -
> - bit = ftrace_test_recursion_trylock(ip, parent_ip);
> - if (bit < 0)
> - return;
> -
> - p = get_kprobe((kprobe_opcode_t *)ip);
> - if (unlikely(!p) || kprobe_disabled(p))
> - goto out;
> -
> - regs = ftrace_get_regs(fregs);
> - kcb = get_kprobe_ctlblk();
> - if (kprobe_running()) {
> - kprobes_inc_nmissed_count(p);
> - } else {
> - unsigned long orig_ip = instruction_pointer(regs);
> -
> - instruction_pointer_set(regs, ip);
> -
> - __this_cpu_write(current_kprobe, p);
> - kcb->kprobe_status = KPROBE_HIT_ACTIVE;
> - if (!p->pre_handler || !p->pre_handler(p, regs)) {
> - /*
> - * Emulate singlestep (and also recover regs->pc)
> - * as if there is a nop
> - */
> - instruction_pointer_set(regs,
> - (unsigned long)p->addr + MCOUNT_INSN_SIZE);
> - if (unlikely(p->post_handler)) {
> - kcb->kprobe_status = KPROBE_HIT_SSDONE;
> - p->post_handler(p, regs, 0);
> - }
> - instruction_pointer_set(regs, orig_ip);
> - }
> -
> - /*
> - * If pre_handler returns !0, it changes regs->pc. We have to
> - * skip emulating post_handler.
> - */
> - __this_cpu_write(current_kprobe, NULL);
> - }
> -out:
> - ftrace_test_recursion_unlock(bit);
> -}
> -NOKPROBE_SYMBOL(kprobe_ftrace_handler);
> -
> -int arch_prepare_kprobe_ftrace(struct kprobe *p)
> -{
> - p->ainsn.api.insn = NULL;
> - return 0;
> -}
> --
> 2.34.1
>
--
Masami Hiramatsu (Google) <mhira...@kernel.org>
