Messages in this thread Patch in this message | | | From | Wang Nan <> | Subject | [RFC PATCH v2 22/26] early kprobes: introduce arch_fix_ftrace_early_kprobe(). | Date | Thu, 12 Feb 2015 20:21:15 +0800 |
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Gives arch code a chance to fix ftrace entry.
Signed-off-by: Wang Nan <wangnan0@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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