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authorGuo Ren <guoren@linux.alibaba.com>2020-04-02 19:52:27 +0800
committerGuo Ren <guoren@linux.alibaba.com>2020-04-03 11:37:51 +0800
commit8f6bb793b2be82f1f73bfb416486f156f70b4314 (patch)
tree783eef0d08ebaa652b335db205f99e970d4a2c0d /arch/csky/kernel/probes
parent33e53ae1ce413a081254e686d9b27cc1b3585e2f (diff)
downloadlinux-sh-8f6bb793b2be82f1f73bfb416486f156f70b4314.tar.gz
csky: Add uprobes support
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@linux.alibaba.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/csky/kernel/probes')
-rw-r--r--arch/csky/kernel/probes/Makefile1
-rw-r--r--arch/csky/kernel/probes/uprobes.c150
2 files changed, 151 insertions, 0 deletions
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@redhat.com>
+ */
+#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;
+}