trace: riscv: Remove deprecated kprobe on ftrace support

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 <ruanjinjie@huawei.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240613111347.1745379-1-ruanjinjie@huawei.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 45eafb3306e979f858d689048a803211c11ade33..34ae39ecb89812761df783aa09a5940da749e270 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -154,7 +154,6 @@ 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 8265ff497977cffb5559f25a2bd6adcce2eb1a60..d2129f2c61b86bc3137da40cd833e23080bcd342 100644 (file)
--- 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 (file)
index a69dfa6..0000000
--- 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;
-}