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trace: riscv: Remove deprecated kprobe on ftrace support

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Since commit 7caa976546 ("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>
This commit is contained in:
Jinjie Ruan 2024-06-13 19:13:47 +08:00 committed by Palmer Dabbelt
parent b9a603da42
commit 3308172276
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GPG Key ID: 2E1319F35FBB1889
3 changed files with 0 additions and 67 deletions
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1
arch/riscv/Kconfig
View File

@ -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

1
arch/riscv/kernel/probes/Makefile
View File

@ -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)

65
arch/riscv/kernel/probes/ftrace.c
View File

@ -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;
}