2024-06-13 11:13:00

by Jinjie Ruan

[permalink] [raw]
Subject: [PATCH] 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 <[email protected]>
---
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