Gives arch code a chance to fix ftrace entry.
Signed-off-by: Wang Nan <wangn...@huawei.com>
---
arch/x86/kernel/kprobes/opt.c | 31 +++++++++++++++++++++++++++++++
include/linux/kprobes.h | 6 +++++-
kernel/kprobes.c | 6 ++++++
3 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 21847ab..f3ea954 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -456,3 +456,34 @@ int setup_detour_execution(struct kprobe *p, struct
pt_regs *regs, int reenter)
return 0;
}
NOKPROBE_SYMBOL(setup_detour_execution);
+
+#ifdef CONFIG_EARLY_KPROBES
+void arch_fix_ftrace_early_kprobe(struct optimized_kprobe *op)
+{
+ const unsigned char *correct_nop5 = ideal_nops[NOP_ATOMIC5];
+ struct kprobe *list_p;
+
+ u32 mask = KPROBE_FLAG_EARLY |
+ KPROBE_FLAG_OPTIMIZED |
+ KPROBE_FLAG_FTRACE;
+
+ if ((op->kp.flags & mask) != mask)
+ return;
+
+ /*
+ * For early kprobe on ftrace, use right nop instruction.
+ * See x86 ftrace_make_nop and ftrace_nop_replace. Note that
+ * ideal_nops used by ftrace_nop_replace is setupt after early
+ * kprobe registration.
+ */
+
+ memcpy(&op->kp.opcode, correct_nop5, sizeof(kprobe_opcode_t));
+ memcpy(op->optinsn.copied_insn, correct_nop5 + INT3_SIZE,
+ RELATIVE_ADDR_SIZE);
+
+ /* Fix all kprobes connected to it */
+ list_for_each_entry_rcu(list_p, &op->kp.list, list)
+ memcpy(&list_p->opcode, correct_nop5, sizeof(kprobe_opcode_t));
+
+}
+#endif
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 0c64df8..990d04b 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -330,7 +330,6 @@ extern kprobe_opcode_t __early_kprobes_code_area_start[];
extern kprobe_opcode_t __early_kprobes_code_area_end[];
extern kprobe_opcode_t __early_kprobes_insn_slot_start[];
extern kprobe_opcode_t __early_kprobes_insn_slot_end[];
-
#else
#define __DEFINE_EKPROBE_ALLOC_OPS(__t, __name)
\
static inline __t *__ek_alloc_##__name(__t *__s, __t *__e, unsigned long *__b)\
@@ -459,6 +458,11 @@ struct early_kprobe_slot {
extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *ops, struct pt_regs *regs);
extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
+
+#ifdef CONFIG_EARLY_KPROBES
+extern void arch_fix_ftrace_early_kprobe(struct optimized_kprobe *p);
+#endif
+
#endif
int arch_check_ftrace_location(struct kprobe *p);
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 131a71a..0bbb510 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -2536,6 +2536,12 @@ EXPORT_SYMBOL_GPL(jprobe_return);
#ifdef CONFIG_EARLY_KPROBES
+#ifdef CONFIG_KPROBES_ON_FTRACE
+void __weak arch_fix_ftrace_early_kprobe(struct optimized_kprobe *p)
+{
+}
+#endif
+
static int register_early_kprobe(struct kprobe *p)
{
struct early_kprobe_slot *slot;
--
1.8.4
--
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