From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
This patch adds support for uprobes on csky architecture.
Just like kprobe, it support single-step and simulate instructions.
Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
arch/csky/Kconfig | 3 +
arch/csky/include/asm/thread_info.h | 2 +
arch/csky/include/asm/uprobes.h | 33 ++++++
arch/csky/kernel/entry.S | 2 +-
arch/csky/kernel/probes/Makefile | 1 +
arch/csky/kernel/probes/uprobes.c | 150 ++++++++++++++++++++++++++++
arch/csky/kernel/signal.c | 3 +
arch/csky/kernel/traps.c | 8 ++
8 files changed, 201 insertions(+), 1 deletion(-)
create mode 100644 arch/csky/include/asm/uprobes.h
create mode 100644 arch/csky/kernel/probes/uprobes.c
diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index f76c333758ca..94545d50d40f 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -75,6 +75,9 @@ config CSKY
config LOCKDEP_SUPPORT
def_bool y
+config ARCH_SUPPORTS_UPROBES
+ def_bool y if !CPU_CK610
+
config CPU_HAS_CACHEV2
bool
diff --git a/arch/csky/include/asm/thread_info.h b/arch/csky/include/asm/thread_info.h
index 0b546a55a8bf..442fedad0260 100644
--- a/arch/csky/include/asm/thread_info.h
+++ b/arch/csky/include/asm/thread_info.h
@@ -57,6 +57,7 @@ static inline struct thread_info *current_thread_info(void)
#define TIF_SYSCALL_TRACE 3 /* syscall trace active */
#define TIF_SYSCALL_TRACEPOINT 4 /* syscall tracepoint instrumentation */
#define TIF_SYSCALL_AUDIT 5 /* syscall auditing */
+#define TIF_UPROBE 6 /* uprobe breakpoint or singlestep */
#define TIF_POLLING_NRFLAG 16 /* poll_idle() is TIF_NEED_RESCHED */
#define TIF_MEMDIE 18 /* is terminating due to OOM killer */
#define TIF_RESTORE_SIGMASK 20 /* restore signal mask in do_signal() */
@@ -68,6 +69,7 @@ static inline struct thread_info *current_thread_info(void)
#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
#define _TIF_SYSCALL_TRACEPOINT (1 << TIF_SYSCALL_TRACEPOINT)
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
+#define _TIF_UPROBE (1 << TIF_UPROBE)
#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_MEMDIE (1 << TIF_MEMDIE)
#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
diff --git a/arch/csky/include/asm/uprobes.h b/arch/csky/include/asm/uprobes.h
new file mode 100644
index 000000000000..600388eb93c6
--- /dev/null
+++ b/arch/csky/include/asm/uprobes.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ASM_CSKY_UPROBES_H
+#define __ASM_CSKY_UPROBES_H
+
+#include <asm/probes.h>
+
+#define MAX_UINSN_BYTES 4
+
+#define UPROBE_SWBP_INSN USR_BKPT
+#define UPROBE_SWBP_INSN_SIZE 2
+#define UPROBE_XOL_SLOT_BYTES MAX_UINSN_BYTES
+
+typedef u32 uprobe_opcode_t;
+
+struct arch_uprobe_task {
+ unsigned long saved_trap_no;
+};
+
+struct arch_uprobe {
+ union {
+ u8 insn[MAX_UINSN_BYTES];
+ u8 ixol[MAX_UINSN_BYTES];
+ };
+ struct arch_probe_insn api;
+ unsigned long insn_size;
+ bool simulate;
+};
+
+int uprobe_breakpoint_handler(struct pt_regs *regs);
+int uprobe_single_step_handler(struct pt_regs *regs);
+
+#endif /* __ASM_CSKY_UPROBES_H */
diff --git a/arch/csky/kernel/entry.S b/arch/csky/kernel/entry.S
index 8b040a1b11d0..364819536f2e 100644
--- a/arch/csky/kernel/entry.S
+++ b/arch/csky/kernel/entry.S
@@ -221,7 +221,7 @@ ret_from_exception:
andn r9, r10
ldw r12, (r9, TINFO_FLAGS)
- andi r12, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED)
+ andi r12, (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | _TIF_UPROBE)
cmpnei r12, 0
bt exit_work
1:
diff --git a/arch/csky/kernel/probes/Makefile b/arch/csky/kernel/probes/Makefile
index 3a857d081958..1c7c6e6cb25b 100644
--- a/arch/csky/kernel/probes/Makefile
+++ b/arch/csky/kernel/probes/Makefile
@@ -2,5 +2,6 @@
obj-$(CONFIG_KPROBES) += kprobes.o decode-insn.o simulate-insn.o
obj-$(CONFIG_KPROBES) += kprobes_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)
diff --git a/arch/csky/kernel/probes/uprobes.c b/arch/csky/kernel/probes/uprobes.c
new file mode 100644
index 000000000000..b3a56c260e3e
--- /dev/null
+++ b/arch/csky/kernel/probes/uprobes.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2014-2016 Pratyush Anand <panand@xxxxxxxxxx>
+ */
+#include <linux/highmem.h>
+#include <linux/ptrace.h>
+#include <linux/uprobes.h>
+#include <asm/cacheflush.h>
+
+#include "decode-insn.h"
+
+#define UPROBE_TRAP_NR UINT_MAX
+
+unsigned long uprobe_get_swbp_addr(struct pt_regs *regs)
+{
+ return instruction_pointer(regs);
+}
+
+int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm,
+ unsigned long addr)
+{
+ probe_opcode_t insn;
+
+ insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+
+ auprobe->insn_size = is_insn32(insn) ? 4 : 2;
+
+ switch (csky_probe_decode_insn(&insn, &auprobe->api)) {
+ case INSN_REJECTED:
+ return -EINVAL;
+
+ case INSN_GOOD_NO_SLOT:
+ auprobe->simulate = true;
+ break;
+
+ default:
+ break;
+ }
+
+ return 0;
+}
+
+int arch_uprobe_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ utask->autask.saved_trap_no = current->thread.trap_no;
+ current->thread.trap_no = UPROBE_TRAP_NR;
+
+ instruction_pointer_set(regs, utask->xol_vaddr);
+
+ user_enable_single_step(current);
+
+ return 0;
+}
+
+int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ WARN_ON_ONCE(current->thread.trap_no != UPROBE_TRAP_NR);
+
+ instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size);
+
+ user_disable_single_step(current);
+
+ return 0;
+}
+
+bool arch_uprobe_xol_was_trapped(struct task_struct *t)
+{
+ if (t->thread.trap_no != UPROBE_TRAP_NR)
+ return true;
+
+ return false;
+}
+
+bool arch_uprobe_skip_sstep(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ probe_opcode_t insn;
+ unsigned long addr;
+
+ if (!auprobe->simulate)
+ return false;
+
+ insn = *(probe_opcode_t *)(&auprobe->insn[0]);
+ addr = instruction_pointer(regs);
+
+ if (auprobe->api.handler)
+ auprobe->api.handler(insn, addr, regs);
+
+ return true;
+}
+
+void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
+{
+ struct uprobe_task *utask = current->utask;
+
+ /*
+ * Task has received a fatal signal, so reset back to probbed
+ * address.
+ */
+ instruction_pointer_set(regs, utask->vaddr);
+
+ user_disable_single_step(current);
+}
+
+bool arch_uretprobe_is_alive(struct return_instance *ret, enum rp_check ctx,
+ struct pt_regs *regs)
+{
+ if (ctx == RP_CHECK_CHAIN_CALL)
+ return regs->usp <= ret->stack;
+ else
+ return regs->usp < ret->stack;
+}
+
+unsigned long
+arch_uretprobe_hijack_return_addr(unsigned long trampoline_vaddr,
+ struct pt_regs *regs)
+{
+ unsigned long ra;
+
+ ra = regs->lr;
+
+ regs->lr = trampoline_vaddr;
+
+ return ra;
+}
+
+int arch_uprobe_exception_notify(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ return NOTIFY_DONE;
+}
+
+int uprobe_breakpoint_handler(struct pt_regs *regs)
+{
+ if (uprobe_pre_sstep_notifier(regs))
+ return 1;
+
+ return 0;
+}
+
+int uprobe_single_step_handler(struct pt_regs *regs)
+{
+ if (uprobe_post_sstep_notifier(regs))
+ return 1;
+
+ return 0;
+}
diff --git a/arch/csky/kernel/signal.c b/arch/csky/kernel/signal.c
index 3d6b728cbb72..9452d6570b7e 100644
--- a/arch/csky/kernel/signal.c
+++ b/arch/csky/kernel/signal.c
@@ -253,6 +253,9 @@ static void do_signal(struct pt_regs *regs)
asmlinkage void do_notify_resume(struct pt_regs *regs,
unsigned long thread_info_flags)
{
+ if (thread_info_flags & _TIF_UPROBE)
+ uprobe_notify_resume(regs);
+
/* Handle pending signal delivery */
if (thread_info_flags & _TIF_SIGPENDING)
do_signal(regs);
diff --git a/arch/csky/kernel/traps.c b/arch/csky/kernel/traps.c
index c6a40806977f..fcc3a69831ad 100644
--- a/arch/csky/kernel/traps.c
+++ b/arch/csky/kernel/traps.c
@@ -129,6 +129,10 @@ asmlinkage void trap_c(struct pt_regs *regs)
#ifdef CONFIG_KPROBES
if (kprobe_single_step_handler(regs))
return;
+#endif
+#ifdef CONFIG_UPROBES
+ if (uprobe_single_step_handler(regs))
+ return;
#endif
info.si_code = TRAP_TRACE;
sig = SIGTRAP;
@@ -138,6 +142,10 @@ asmlinkage void trap_c(struct pt_regs *regs)
#ifdef CONFIG_KPROBES
if (kprobe_breakpoint_handler(regs))
return;
+#endif
+#ifdef CONFIG_UPROBES
+ if (uprobe_breakpoint_handler(regs))
+ return;
#endif
die_if_kernel("Kernel mode ILLEGAL", regs, vector);
#ifndef CONFIG_CPU_NO_USER_BKPT
--
2.17.0
