From fbc1963d2c1c4eb4651132a2c5c9d6111ada17d3 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 17 Apr 2014 17:18:00 +0900 Subject: [PATCH] kprobes, ftrace: Allow probing on some functions There is no need to prohibit probing on the functions used for preparation and uprobe only fetch functions. Those are safely probed because those are not invoked from kprobe's breakpoint/fault/debug handlers. So there is no chance to cause recursive exceptions. Following functions are now removed from the kprobes blacklist: update_bitfield_fetch_param free_bitfield_fetch_param kprobe_register FETCH_FUNC_NAME(stack, type) in trace_uprobe.c FETCH_FUNC_NAME(memory, type) in trace_uprobe.c FETCH_FUNC_NAME(memory, string) in trace_uprobe.c FETCH_FUNC_NAME(memory, string_size) in trace_uprobe.c FETCH_FUNC_NAME(file_offset, type) in trace_uprobe.c Signed-off-by: Masami Hiramatsu Cc: Frederic Weisbecker Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20140417081800.26341.56504.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar --- kernel/trace/trace_kprobe.c | 5 ++--- kernel/trace/trace_probe.c | 4 ++-- kernel/trace/trace_uprobe.c | 20 ++++++++++---------- 3 files changed, 14 insertions(+), 15 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 903ae28962be..aa5f0bfcdf7b 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1196,9 +1196,8 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, * kprobe_trace_self_tests_init() does enable_trace_probe/disable_trace_probe * lockless, but we can't race with this __init function. */ -static __kprobes -int kprobe_register(struct ftrace_event_call *event, - enum trace_reg type, void *data) +static int kprobe_register(struct ftrace_event_call *event, + enum trace_reg type, void *data) { struct trace_kprobe *tk = (struct trace_kprobe *)event->data; struct ftrace_event_file *file = data; diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 8364a421b4df..d3a91e40a659 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -183,7 +183,7 @@ DEFINE_BASIC_FETCH_FUNCS(bitfield) #define fetch_bitfield_string NULL #define fetch_bitfield_string_size NULL -static __kprobes void +static void update_bitfield_fetch_param(struct bitfield_fetch_param *data) { /* @@ -196,7 +196,7 @@ update_bitfield_fetch_param(struct bitfield_fetch_param *data) update_symbol_cache(data->orig.data); } -static __kprobes void +static void free_bitfield_fetch_param(struct bitfield_fetch_param *data) { /* diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index c082a7441345..991e3b7c4edb 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -108,8 +108,8 @@ static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) * Uprobes-specific fetch functions */ #define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ +static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ + void *offset, void *dest) \ { \ *(type *)dest = (type)get_user_stack_nth(regs, \ ((unsigned long)offset)); \ @@ -120,8 +120,8 @@ DEFINE_BASIC_FETCH_FUNCS(stack) #define fetch_stack_string_size NULL #define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ - void *addr, void *dest) \ +static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ + void *addr, void *dest) \ { \ type retval; \ void __user *vaddr = (void __force __user *) addr; \ @@ -136,8 +136,8 @@ DEFINE_BASIC_FETCH_FUNCS(memory) * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max * length and relative data location. */ -static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, - void *addr, void *dest) +static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, + void *addr, void *dest) { long ret; u32 rloc = *(u32 *)dest; @@ -158,8 +158,8 @@ static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, } } -static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, - void *addr, void *dest) +static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, + void *addr, void *dest) { int len; void __user *vaddr = (void __force __user *) addr; @@ -184,8 +184,8 @@ static unsigned long translate_user_vaddr(void *file_offset) } #define DEFINE_FETCH_file_offset(type) \ -static __kprobes void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs,\ - void *offset, void *dest) \ +static void FETCH_FUNC_NAME(file_offset, type)(struct pt_regs *regs, \ + void *offset, void *dest)\ { \ void *vaddr = (void *)translate_user_vaddr(offset); \ \ -- 2.30.2