[PATCH v4] LoongArch/rethook: Replace kretprobe with rethook on LoongArch
From: Haoran Jiang
Date: Tue Jun 13 2023 - 07:24:26 EST
That's an adaptation of commit f3a112c0c40d ("x86,rethook,kprobes:
Replace kretprobe with rethook on x86")and commit b57c2f124098
("riscv: add riscv rethook implementation") to LoongArch.
Mainly refer to this commit
b57c2f124098 ("riscv: add riscv rethook implementation").
Replaces the kretprobe code with rethook on LoongArch. With this patch,
kretprobe on LoongArch uses the rethook instead of kretprobe specific
trampoline code.
Signed-off-by: Haoran Jiang <jianghaoran@xxxxxxxxxx>
---
v4:
1,remove some blank lines
2,add NOKPROBE_SYMBOL(arch_rethook_trampoline)
3,Move CFLAGS_REMOVE_rethook.o = $(CC_FLAGS_FTRACE) and
CFLAGS_REMOVE_rethook_trampoline.o = $(CC_FLAGS_FTRACE)
to below CFLAGS_REMOVE_perf_event.o = $(CC_FLAGS_FTRACE)
v3:
1,Fixed some format and spelling issues
2,According to this commit 571a2a50a8fc
(rethook, fprobe: do not trace rethook related functions),
the problem described in this commit Should be modified on LoongArch.
v2:
Modified the patch format and commit message.
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/kprobes.h | 3 --
arch/loongarch/kernel/Makefile | 5 +++-
arch/loongarch/kernel/kprobes.c | 21 --------------
arch/loongarch/kernel/rethook.c | 28 +++++++++++++++++++
arch/loongarch/kernel/rethook.h | 8 ++++++
...obes_trampoline.S => rethook_trampoline.S} | 6 ++--
7 files changed, 44 insertions(+), 28 deletions(-)
create mode 100644 arch/loongarch/kernel/rethook.c
create mode 100644 arch/loongarch/kernel/rethook.h
rename arch/loongarch/kernel/{kprobes_trampoline.S => rethook_trampoline.S} (93%)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index d38b066fc931..5800aa52c82f 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -120,6 +120,7 @@ config LOONGARCH
select HAVE_PERF_REGS
select HAVE_PERF_USER_STACK_DUMP
select HAVE_REGS_AND_STACK_ACCESS_API
+ select HAVE_RETHOOK
select HAVE_RSEQ
select HAVE_SAMPLE_FTRACE_DIRECT
select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
diff --git a/arch/loongarch/include/asm/kprobes.h b/arch/loongarch/include/asm/kprobes.h
index 798020ae02c6..7b9fc3ed71c3 100644
--- a/arch/loongarch/include/asm/kprobes.h
+++ b/arch/loongarch/include/asm/kprobes.h
@@ -49,9 +49,6 @@ bool kprobe_fault_handler(struct pt_regs *regs, int trapnr);
bool kprobe_breakpoint_handler(struct pt_regs *regs);
bool kprobe_singlestep_handler(struct pt_regs *regs);
-void __kretprobe_trampoline(void);
-void *trampoline_probe_handler(struct pt_regs *regs);
-
#else /* !CONFIG_KPROBES */
static inline bool kprobe_breakpoint_handler(struct pt_regs *regs) { return false; }
diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile
index 9a72d91cd104..b30b1459f513 100644
--- a/arch/loongarch/kernel/Makefile
+++ b/arch/loongarch/kernel/Makefile
@@ -28,6 +28,8 @@ ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_inst.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_time.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_perf_event.o = $(CC_FLAGS_FTRACE)
+ CFLAGS_REMOVE_rethook.o = $(CC_FLAGS_FTRACE)
+ CFLAGS_REMOVE_rethook_trampoline.o = $(CC_FLAGS_FTRACE)
endif
obj-$(CONFIG_MODULES) += module.o module-sections.o
@@ -52,6 +54,7 @@ obj-$(CONFIG_UNWINDER_PROLOGUE) += unwind_prologue.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o perf_regs.o
obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
-obj-$(CONFIG_KPROBES) += kprobes.o kprobes_trampoline.o
+obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_RETHOOK) += rethook.o rethook_trampoline.o
CPPFLAGS_vmlinux.lds := $(KBUILD_CFLAGS)
diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobes.c
index 56c8c4b09a42..83467232ca3c 100644
--- a/arch/loongarch/kernel/kprobes.c
+++ b/arch/loongarch/kernel/kprobes.c
@@ -378,27 +378,6 @@ int __init arch_init_kprobes(void)
return 0;
}
-/* ASM function that handles the kretprobes must not be probed */
-NOKPROBE_SYMBOL(__kretprobe_trampoline);
-
-/* Called from __kretprobe_trampoline */
-void __used *trampoline_probe_handler(struct pt_regs *regs)
-{
- return (void *)kretprobe_trampoline_handler(regs, NULL);
-}
-NOKPROBE_SYMBOL(trampoline_probe_handler);
-
-void arch_prepare_kretprobe(struct kretprobe_instance *ri,
- struct pt_regs *regs)
-{
- ri->ret_addr = (kprobe_opcode_t *)regs->regs[1];
- ri->fp = NULL;
-
- /* Replace the return addr with trampoline addr */
- regs->regs[1] = (unsigned long)&__kretprobe_trampoline;
-}
-NOKPROBE_SYMBOL(arch_prepare_kretprobe);
-
int arch_trampoline_kprobe(struct kprobe *p)
{
return 0;
diff --git a/arch/loongarch/kernel/rethook.c b/arch/loongarch/kernel/rethook.c
new file mode 100644
index 000000000000..69966af30d4f
--- /dev/null
+++ b/arch/loongarch/kernel/rethook.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic return hook for LoongArch.
+ */
+
+#include <linux/kprobes.h>
+#include <linux/rethook.h>
+#include "rethook.h"
+
+/* This is called from arch_rethook_trampoline() */
+unsigned long __used arch_rethook_trampoline_callback(struct pt_regs *regs)
+{
+ return rethook_trampoline_handler(regs, 0);
+}
+NOKPROBE_SYMBOL(arch_rethook_trampoline_callback);
+
+void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount)
+{
+ rhn->ret_addr = regs->regs[1];
+ rhn->frame = 0;
+
+ /* replace return addr with trampoline */
+ regs->regs[1] = (unsigned long)arch_rethook_trampoline;
+}
+NOKPROBE_SYMBOL(arch_rethook_prepare);
+
+/* assembler function that handles the rethook must not be probed itself */
+NOKPROBE_SYMBOL(arch_rethook_trampoline);
diff --git a/arch/loongarch/kernel/rethook.h b/arch/loongarch/kernel/rethook.h
new file mode 100644
index 000000000000..3f1c1edf0d0b
--- /dev/null
+++ b/arch/loongarch/kernel/rethook.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LOONGARCH_RETHOOK_H
+#define __LOONGARCH_RETHOOK_H
+
+unsigned long arch_rethook_trampoline_callback(struct pt_regs *regs);
+void arch_rethook_prepare(struct rethook_node *rhn, struct pt_regs *regs, bool mcount);
+
+#endif
diff --git a/arch/loongarch/kernel/kprobes_trampoline.S b/arch/loongarch/kernel/rethook_trampoline.S
similarity index 93%
rename from arch/loongarch/kernel/kprobes_trampoline.S
rename to arch/loongarch/kernel/rethook_trampoline.S
index af94b0d213fa..bd5772c96338 100644
--- a/arch/loongarch/kernel/kprobes_trampoline.S
+++ b/arch/loongarch/kernel/rethook_trampoline.S
@@ -75,7 +75,7 @@
csrxchg t0, t1, LOONGARCH_CSR_CRMD
.endm
-SYM_CODE_START(__kretprobe_trampoline)
+SYM_CODE_START(arch_rethook_trampoline)
addi.d sp, sp, -PT_SIZE
save_all_base_regs
@@ -84,7 +84,7 @@ SYM_CODE_START(__kretprobe_trampoline)
move a0, sp /* pt_regs */
- bl trampoline_probe_handler
+ bl arch_rethook_trampoline_callback
/* use the result as the return-address */
move ra, a0
@@ -93,4 +93,4 @@ SYM_CODE_START(__kretprobe_trampoline)
addi.d sp, sp, PT_SIZE
jr ra
-SYM_CODE_END(__kretprobe_trampoline)
+SYM_CODE_END(arch_rethook_trampoline)
--
2.27.0