[v2] LoongArch/rethook: Replace kretprobe with rethook on loongarch

[PATCH v2] LoongArch/rethook: Replace kretprobe with rethook on loongarch

Posted by jianghaoran 2 years, 8 months ago

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.

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@kylinos.cn>
---
v2:
Modified the patch format and commit message.
---
 arch/loongarch/Kconfig                        |  1 +
 arch/loongarch/include/asm/kprobes.h          |  3 ---
 arch/loongarch/kernel/Makefile                |  3 ++-
 arch/loongarch/kernel/kprobes.c               | 20 --------------
 arch/loongarch/kernel/rethook.c               | 27 +++++++++++++++++++
 arch/loongarch/kernel/rethook.h               |  8 ++++++
 ...obes_trampoline.S => rethook_trampoline.S} |  6 ++---
 7 files changed, 41 insertions(+), 27 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..33753a1ab0bb 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -113,6 +113,7 @@ config LOONGARCH
 	select HAVE_KPROBES
 	select HAVE_KPROBES_ON_FTRACE
 	select HAVE_KRETPROBES
+	select HAVE_RETHOOK
 	select HAVE_MOD_ARCH_SPECIFIC
 	select HAVE_NMI
 	select HAVE_PCI
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..e0d4d29a6f0f 100644
--- a/arch/loongarch/kernel/Makefile
+++ b/arch/loongarch/kernel/Makefile
@@ -52,6 +52,7 @@ 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..dbce23ba9970 100644
--- a/arch/loongarch/kernel/kprobes.c
+++ b/arch/loongarch/kernel/kprobes.c
@@ -378,26 +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)
 {
diff --git a/arch/loongarch/kernel/rethook.c b/arch/loongarch/kernel/rethook.c
new file mode 100644
index 000000000000..ac97b78daf55
--- /dev/null
+++ b/arch/loongarch/kernel/rethook.c
@@ -0,0 +1,27 @@
+// 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);
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

Re: [PATCH v2] LoongArch/rethook: Replace kretprobe with rethook on loongarch

Posted by Huacai Chen 2 years, 8 months ago

Hi, Haoran,

On Tue, Jun 13, 2023 at 9:20 AM jianghaoran <jianghaoran@kylinos.cn> wrote:
>
> 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.
>
> Replaces the kretprobe code with rethook on loongarch. With this patch,
> kretprobe on loongarch uses the rethook instead of kretprobe specific
> trampoline code.
Use LoongArch rather than loongarch in comments and commit messages.

>
> Signed-off-by: Haoran Jiang<jianghaoran@kylinos.cn>
The format is Haoran Jiang <jianghaoran@kylinos.cn>, pay attention to the space.

> ---
> v2:
> Modified the patch format and commit message.
> ---
>  arch/loongarch/Kconfig                        |  1 +
>  arch/loongarch/include/asm/kprobes.h          |  3 ---
>  arch/loongarch/kernel/Makefile                |  3 ++-
>  arch/loongarch/kernel/kprobes.c               | 20 --------------
>  arch/loongarch/kernel/rethook.c               | 27 +++++++++++++++++++
>  arch/loongarch/kernel/rethook.h               |  8 ++++++
>  ...obes_trampoline.S => rethook_trampoline.S} |  6 ++---
>  7 files changed, 41 insertions(+), 27 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..33753a1ab0bb 100644
> --- a/arch/loongarch/Kconfig
> +++ b/arch/loongarch/Kconfig
> @@ -113,6 +113,7 @@ config LOONGARCH
>         select HAVE_KPROBES
>         select HAVE_KPROBES_ON_FTRACE
>         select HAVE_KRETPROBES
> +       select HAVE_RETHOOK
>         select HAVE_MOD_ARCH_SPECIFIC
>         select HAVE_NMI
>         select HAVE_PCI
Use alpha-betical order for these symbols, though x86 and riscv don't
do this, s390 does.

> 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..e0d4d29a6f0f 100644
> --- a/arch/loongarch/kernel/Makefile
> +++ b/arch/loongarch/kernel/Makefile
> @@ -52,6 +52,7 @@ 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)
Please see commit 571a2a50a8fc546145ffd3bf673547e9 ("rethook, fprobe:
do not trace rethook related functions"), maybe we need to do some
additional modifications in Makefile.

> diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobes.c
> index 56c8c4b09a42..dbce23ba9970 100644
> --- a/arch/loongarch/kernel/kprobes.c
> +++ b/arch/loongarch/kernel/kprobes.c
> @@ -378,26 +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)
>  {
> diff --git a/arch/loongarch/kernel/rethook.c b/arch/loongarch/kernel/rethook.c
> new file mode 100644
> index 000000000000..ac97b78daf55
> --- /dev/null
> +++ b/arch/loongarch/kernel/rethook.c
> @@ -0,0 +1,27 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Generic return hook for loongarch.
Use LoongArch here.

> + */
> +
> +#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;
> +}
Whether the logic is correct here needs Tiezhu's review.

Thanks,
Huacai

> +
> +NOKPROBE_SYMBOL(arch_rethook_prepare);
> 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
>

[PATCH v3] LoongArch/rethook: Replace kretprobe with rethook on LoongArch

Posted by Haoran Jiang 2 years, 8 months ago

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@kylinos.cn>

---
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                |  7 ++++-
 arch/loongarch/kernel/kprobes.c               | 20 --------------
 arch/loongarch/kernel/rethook.c               | 27 +++++++++++++++++++
 arch/loongarch/kernel/rethook.h               |  8 ++++++
 ...obes_trampoline.S => rethook_trampoline.S} |  6 ++---
 7 files changed, 45 insertions(+), 27 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..7106ca996e55 100644
--- a/arch/loongarch/kernel/Makefile
+++ b/arch/loongarch/kernel/Makefile
@@ -52,6 +52,11 @@ 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
+
+CFLAGS_REMOVE_rethook.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_rethook_trampoline.o = $(CC_FLAGS_FTRACE)
+
 
 CPPFLAGS_vmlinux.lds		:= $(KBUILD_CFLAGS)
diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobes.c
index 56c8c4b09a42..dbce23ba9970 100644
--- a/arch/loongarch/kernel/kprobes.c
+++ b/arch/loongarch/kernel/kprobes.c
@@ -378,26 +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)
 {
diff --git a/arch/loongarch/kernel/rethook.c b/arch/loongarch/kernel/rethook.c
new file mode 100644
index 000000000000..b5e7f62f7dea
--- /dev/null
+++ b/arch/loongarch/kernel/rethook.c
@@ -0,0 +1,27 @@
+// 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);
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

Re: [PATCH v3] LoongArch/rethook: Replace kretprobe with rethook on LoongArch

Posted by Huacai Chen 2 years, 8 months ago

On Tue, Jun 13, 2023 at 2:09 PM Haoran Jiang <jianghaoran@kylinos.cn> wrote:
>
> 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@kylinos.cn>
>
> ---
> 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                |  7 ++++-
>  arch/loongarch/kernel/kprobes.c               | 20 --------------
>  arch/loongarch/kernel/rethook.c               | 27 +++++++++++++++++++
>  arch/loongarch/kernel/rethook.h               |  8 ++++++
>  ...obes_trampoline.S => rethook_trampoline.S} |  6 ++---
>  7 files changed, 45 insertions(+), 27 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..7106ca996e55 100644
> --- a/arch/loongarch/kernel/Makefile
> +++ b/arch/loongarch/kernel/Makefile
> @@ -52,6 +52,11 @@ 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
> +
> +CFLAGS_REMOVE_rethook.o = $(CC_FLAGS_FTRACE)
> +CFLAGS_REMOVE_rethook_trampoline.o = $(CC_FLAGS_FTRACE)
Move them to below CFLAGS_REMOVE_perf_event.o = $(CC_FLAGS_FTRACE), thanks.

Huacai
> +
>
>  CPPFLAGS_vmlinux.lds           := $(KBUILD_CFLAGS)
> diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobes.c
> index 56c8c4b09a42..dbce23ba9970 100644
> --- a/arch/loongarch/kernel/kprobes.c
> +++ b/arch/loongarch/kernel/kprobes.c
> @@ -378,26 +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)
>  {
> diff --git a/arch/loongarch/kernel/rethook.c b/arch/loongarch/kernel/rethook.c
> new file mode 100644
> index 000000000000..b5e7f62f7dea
> --- /dev/null
> +++ b/arch/loongarch/kernel/rethook.c
> @@ -0,0 +1,27 @@
> +// 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);
> 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
>

Re: [PATCH v3] LoongArch/rethook: Replace kretprobe with rethook on LoongArch

Posted by Tiezhu Yang 2 years, 8 months ago


On 06/13/2023 02:03 PM, Haoran Jiang wrote:
> 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.

Maybe Huacai can refine the commit message.

>
> Signed-off-by: Haoran Jiang <jianghaoran@kylinos.cn>

...

> diff --git a/arch/loongarch/kernel/kprobes.c b/arch/loongarch/kernel/kprobes.c
> index 56c8c4b09a42..dbce23ba9970 100644
> --- a/arch/loongarch/kernel/kprobes.c
> +++ b/arch/loongarch/kernel/kprobes.c
> @@ -378,26 +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);
>

Please remove the blank line.

>  int arch_trampoline_kprobe(struct kprobe *p)
>  {
> diff --git a/arch/loongarch/kernel/rethook.c b/arch/loongarch/kernel/rethook.c
> new file mode 100644
> index 000000000000..b5e7f62f7dea
> --- /dev/null
> +++ b/arch/loongarch/kernel/rethook.c
> @@ -0,0 +1,27 @@
> +// 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);
> +}
> +

Ditto

> +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;
> +}
> +

Ditto

> +NOKPROBE_SYMBOL(arch_rethook_prepare);

Like s390 and x86, please add:

/* 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

...

> -SYM_CODE_END(__kretprobe_trampoline)
> +SYM_CODE_END(arch_rethook_trampoline)

Thanks,
Tiezhu