From fbc1963d2c1c4eb4651132a2c5c9d6111ada17d3 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 17 Apr 2014 17:18:00 +0900 Subject: 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 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') 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; -- cgit v1.2.3-59-g8ed1b From 3da0f18007e5b87b573cf6ae8c445d59e757d274 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 17 Apr 2014 17:18:28 +0900 Subject: kprobes, ftrace: Use NOKPROBE_SYMBOL macro in ftrace Use NOKPROBE_SYMBOL macro to protect functions from kprobes instead of __kprobes annotation in ftrace. This applies nokprobe_inline annotation for some cases, because NOKPROBE_SYMBOL() will inhibit inlining by referring the symbol address. Signed-off-by: Masami Hiramatsu Cc: Frederic Weisbecker Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20140417081828.26341.55152.stgit@ltc230.yrl.intra.hitachi.co.jp Signed-off-by: Ingo Molnar --- kernel/trace/trace_event_perf.c | 5 ++-- kernel/trace/trace_kprobe.c | 66 ++++++++++++++++++++++++----------------- kernel/trace/trace_probe.c | 61 ++++++++++++++++++++----------------- kernel/trace/trace_probe.h | 15 +++++----- 4 files changed, 82 insertions(+), 65 deletions(-) (limited to 'kernel/trace/trace_kprobe.c') diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index c894614de14d..5d12bb407b44 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -248,8 +248,8 @@ void perf_trace_del(struct perf_event *p_event, int flags) tp_event->class->reg(tp_event, TRACE_REG_PERF_DEL, p_event); } -__kprobes void *perf_trace_buf_prepare(int size, unsigned short type, - struct pt_regs *regs, int *rctxp) +void *perf_trace_buf_prepare(int size, unsigned short type, + struct pt_regs *regs, int *rctxp) { struct trace_entry *entry; unsigned long flags; @@ -281,6 +281,7 @@ __kprobes void *perf_trace_buf_prepare(int size, unsigned short type, return raw_data; } EXPORT_SYMBOL_GPL(perf_trace_buf_prepare); +NOKPROBE_SYMBOL(perf_trace_buf_prepare); #ifdef CONFIG_FUNCTION_TRACER static void diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index aa5f0bfcdf7b..242e4ec97d94 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -40,27 +40,27 @@ struct trace_kprobe { (sizeof(struct probe_arg) * (n))) -static __kprobes bool trace_kprobe_is_return(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk) { return tk->rp.handler != NULL; } -static __kprobes const char *trace_kprobe_symbol(struct trace_kprobe *tk) +static nokprobe_inline const char *trace_kprobe_symbol(struct trace_kprobe *tk) { return tk->symbol ? tk->symbol : "unknown"; } -static __kprobes unsigned long trace_kprobe_offset(struct trace_kprobe *tk) +static nokprobe_inline unsigned long trace_kprobe_offset(struct trace_kprobe *tk) { return tk->rp.kp.offset; } -static __kprobes bool trace_kprobe_has_gone(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) { return !!(kprobe_gone(&tk->rp.kp)); } -static __kprobes bool trace_kprobe_within_module(struct trace_kprobe *tk, +static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, struct module *mod) { int len = strlen(mod->name); @@ -68,7 +68,7 @@ static __kprobes bool trace_kprobe_within_module(struct trace_kprobe *tk, return strncmp(mod->name, name, len) == 0 && name[len] == ':'; } -static __kprobes bool trace_kprobe_is_on_module(struct trace_kprobe *tk) +static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk) { return !!strchr(trace_kprobe_symbol(tk), ':'); } @@ -132,19 +132,21 @@ struct symbol_cache *alloc_symbol_cache(const char *sym, long offset) * Kprobes-specific fetch functions */ #define DEFINE_FETCH_stack(type) \ -static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\ +static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs, \ void *offset, void *dest) \ { \ *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \ (unsigned int)((unsigned long)offset)); \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type)); + DEFINE_BASIC_FETCH_FUNCS(stack) /* No string on the stack entry */ #define fetch_stack_string NULL #define fetch_stack_string_size NULL #define DEFINE_FETCH_memory(type) \ -static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ +static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs, \ void *addr, void *dest) \ { \ type retval; \ @@ -152,14 +154,16 @@ static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\ *(type *)dest = 0; \ else \ *(type *)dest = retval; \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type)); + 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; int maxlen = get_rloc_len(*(u32 *)dest); @@ -193,10 +197,11 @@ static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs, get_rloc_offs(*(u32 *)dest)); } } +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string)); /* Return the length of string -- including null terminal byte */ -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) { mm_segment_t old_fs; int ret, len = 0; @@ -219,17 +224,19 @@ static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, else *(u32 *)dest = len; } +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size)); #define DEFINE_FETCH_symbol(type) \ -__kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \ - void *data, void *dest) \ +void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\ { \ struct symbol_cache *sc = data; \ if (sc->addr) \ fetch_memory_##type(regs, (void *)sc->addr, dest); \ else \ *(type *)dest = 0; \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type)); + DEFINE_BASIC_FETCH_FUNCS(symbol) DEFINE_FETCH_symbol(string) DEFINE_FETCH_symbol(string_size) @@ -907,7 +914,7 @@ static const struct file_operations kprobe_profile_ops = { }; /* Kprobe handler */ -static __kprobes void +static nokprobe_inline void __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, struct ftrace_event_file *ftrace_file) { @@ -943,7 +950,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs, entry, irq_flags, pc, regs); } -static __kprobes void +static void kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) { struct event_file_link *link; @@ -951,9 +958,10 @@ kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs) list_for_each_entry_rcu(link, &tk->tp.files, list) __kprobe_trace_func(tk, regs, link->file); } +NOKPROBE_SYMBOL(kprobe_trace_func); /* Kretprobe handler */ -static __kprobes void +static nokprobe_inline void __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct pt_regs *regs, struct ftrace_event_file *ftrace_file) @@ -991,7 +999,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, entry, irq_flags, pc, regs); } -static __kprobes void +static void kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct pt_regs *regs) { @@ -1000,6 +1008,7 @@ kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, list_for_each_entry_rcu(link, &tk->tp.files, list) __kretprobe_trace_func(tk, ri, regs, link->file); } +NOKPROBE_SYMBOL(kretprobe_trace_func); /* Event entry printers */ static enum print_line_t @@ -1131,7 +1140,7 @@ static int kretprobe_event_define_fields(struct ftrace_event_call *event_call) #ifdef CONFIG_PERF_EVENTS /* Kprobe profile handler */ -static __kprobes void +static void kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) { struct ftrace_event_call *call = &tk->tp.call; @@ -1158,9 +1167,10 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); } +NOKPROBE_SYMBOL(kprobe_perf_func); /* Kretprobe profile handler */ -static __kprobes void +static void kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, struct pt_regs *regs) { @@ -1188,6 +1198,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize); perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL); } +NOKPROBE_SYMBOL(kretprobe_perf_func); #endif /* CONFIG_PERF_EVENTS */ /* @@ -1223,8 +1234,7 @@ static int kprobe_register(struct ftrace_event_call *event, return 0; } -static __kprobes -int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) +static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) { struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); @@ -1238,9 +1248,10 @@ int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) #endif return 0; /* We don't tweek kernel, so just return 0 */ } +NOKPROBE_SYMBOL(kprobe_dispatcher); -static __kprobes -int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) +static int +kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) { struct trace_kprobe *tk = container_of(ri->rp, struct trace_kprobe, rp); @@ -1254,6 +1265,7 @@ int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) #endif return 0; /* We don't tweek kernel, so just return 0 */ } +NOKPROBE_SYMBOL(kretprobe_dispatcher); static struct trace_event_functions kretprobe_funcs = { .trace = print_kretprobe_event diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index d3a91e40a659..d4b9fc22cd27 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -37,13 +37,13 @@ const char *reserved_field_names[] = { /* Printing in basic type function template */ #define DEFINE_BASIC_PRINT_TYPE_FUNC(type, fmt) \ -__kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent) \ +int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ + void *data, void *ent) \ { \ return trace_seq_printf(s, " %s=" fmt, name, *(type *)data); \ } \ -const char PRINT_TYPE_FMT_NAME(type)[] = fmt; +const char PRINT_TYPE_FMT_NAME(type)[] = fmt; \ +NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(type)); DEFINE_BASIC_PRINT_TYPE_FUNC(u8 , "0x%x") DEFINE_BASIC_PRINT_TYPE_FUNC(u16, "0x%x") @@ -55,9 +55,8 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(s32, "%d") DEFINE_BASIC_PRINT_TYPE_FUNC(s64, "%Ld") /* Print type function for string type */ -__kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, - const char *name, - void *data, void *ent) +int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name, + void *data, void *ent) { int len = *(u32 *)data >> 16; @@ -67,6 +66,7 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, return trace_seq_printf(s, " %s=\"%s\"", name, (const char *)get_loc_data(data, ent)); } +NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string)); const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; @@ -81,23 +81,24 @@ const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; /* Data fetch function templates */ #define DEFINE_FETCH_reg(type) \ -__kprobes void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, \ - void *offset, void *dest) \ +void FETCH_FUNC_NAME(reg, type)(struct pt_regs *regs, void *offset, void *dest) \ { \ *(type *)dest = (type)regs_get_register(regs, \ (unsigned int)((unsigned long)offset)); \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(reg, type)); DEFINE_BASIC_FETCH_FUNCS(reg) /* No string on the register */ #define fetch_reg_string NULL #define fetch_reg_string_size NULL #define DEFINE_FETCH_retval(type) \ -__kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ - void *dummy, void *dest) \ +void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ + void *dummy, void *dest) \ { \ *(type *)dest = (type)regs_return_value(regs); \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(retval, type)); DEFINE_BASIC_FETCH_FUNCS(retval) /* No string on the retval */ #define fetch_retval_string NULL @@ -112,8 +113,8 @@ struct deref_fetch_param { }; #define DEFINE_FETCH_deref(type) \ -__kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ - void *data, void *dest) \ +void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ + void *data, void *dest) \ { \ struct deref_fetch_param *dprm = data; \ unsigned long addr; \ @@ -123,12 +124,13 @@ __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \ dprm->fetch(regs, (void *)addr, dest); \ } else \ *(type *)dest = 0; \ -} +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, type)); DEFINE_BASIC_FETCH_FUNCS(deref) DEFINE_FETCH_deref(string) -__kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, - void *data, void *dest) +void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, + void *data, void *dest) { struct deref_fetch_param *dprm = data; unsigned long addr; @@ -140,16 +142,18 @@ __kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs, } else *(string_size *)dest = 0; } +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(deref, string_size)); -static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data) +static void update_deref_fetch_param(struct deref_fetch_param *data) { if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) update_deref_fetch_param(data->orig.data); else if (CHECK_FETCH_FUNCS(symbol, data->orig.fn)) update_symbol_cache(data->orig.data); } +NOKPROBE_SYMBOL(update_deref_fetch_param); -static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) +static void free_deref_fetch_param(struct deref_fetch_param *data) { if (CHECK_FETCH_FUNCS(deref, data->orig.fn)) free_deref_fetch_param(data->orig.data); @@ -157,6 +161,7 @@ static __kprobes void free_deref_fetch_param(struct deref_fetch_param *data) free_symbol_cache(data->orig.data); kfree(data); } +NOKPROBE_SYMBOL(free_deref_fetch_param); /* Bitfield fetch function */ struct bitfield_fetch_param { @@ -166,8 +171,8 @@ struct bitfield_fetch_param { }; #define DEFINE_FETCH_bitfield(type) \ -__kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ - void *data, void *dest) \ +void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ + void *data, void *dest) \ { \ struct bitfield_fetch_param *bprm = data; \ type buf = 0; \ @@ -177,8 +182,8 @@ __kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \ buf >>= bprm->low_shift; \ } \ *(type *)dest = buf; \ -} - +} \ +NOKPROBE_SYMBOL(FETCH_FUNC_NAME(bitfield, type)); DEFINE_BASIC_FETCH_FUNCS(bitfield) #define fetch_bitfield_string NULL #define fetch_bitfield_string_size NULL @@ -255,17 +260,17 @@ fail: } /* Special function : only accept unsigned long */ -static __kprobes void fetch_kernel_stack_address(struct pt_regs *regs, - void *dummy, void *dest) +static void fetch_kernel_stack_address(struct pt_regs *regs, void *dummy, void *dest) { *(unsigned long *)dest = kernel_stack_pointer(regs); } +NOKPROBE_SYMBOL(fetch_kernel_stack_address); -static __kprobes void fetch_user_stack_address(struct pt_regs *regs, - void *dummy, void *dest) +static void fetch_user_stack_address(struct pt_regs *regs, void *dummy, void *dest) { *(unsigned long *)dest = user_stack_pointer(regs); } +NOKPROBE_SYMBOL(fetch_user_stack_address); static fetch_func_t get_fetch_size_function(const struct fetch_type *type, fetch_func_t orig_fn, diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index fb1ab5dfbd42..4f815fbce16d 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -81,13 +81,13 @@ */ #define convert_rloc_to_loc(dl, offs) ((u32)(dl) + (offs)) -static inline void *get_rloc_data(u32 *dl) +static nokprobe_inline void *get_rloc_data(u32 *dl) { return (u8 *)dl + get_rloc_offs(*dl); } /* For data_loc conversion */ -static inline void *get_loc_data(u32 *dl, void *ent) +static nokprobe_inline void *get_loc_data(u32 *dl, void *ent) { return (u8 *)ent + get_rloc_offs(*dl); } @@ -136,9 +136,8 @@ typedef u32 string_size; /* Printing in basic type function template */ #define DECLARE_BASIC_PRINT_TYPE_FUNC(type) \ -__kprobes int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, \ - const char *name, \ - void *data, void *ent); \ +int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name, \ + void *data, void *ent); \ extern const char PRINT_TYPE_FMT_NAME(type)[] DECLARE_BASIC_PRINT_TYPE_FUNC(u8); @@ -303,7 +302,7 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp) return !!(tp->flags & TP_FLAG_REGISTERED); } -static inline __kprobes void call_fetch(struct fetch_param *fprm, +static nokprobe_inline void call_fetch(struct fetch_param *fprm, struct pt_regs *regs, void *dest) { return fprm->fn(regs, fprm->data, dest); @@ -351,7 +350,7 @@ extern ssize_t traceprobe_probes_write(struct file *file, extern int traceprobe_command(const char *buf, int (*createfn)(int, char**)); /* Sum up total data length for dynamic arraies (strings) */ -static inline __kprobes int +static nokprobe_inline int __get_data_size(struct trace_probe *tp, struct pt_regs *regs) { int i, ret = 0; @@ -367,7 +366,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs) } /* Store the value of each argument */ -static inline __kprobes void +static nokprobe_inline void store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, u8 *data, int maxlen) { -- cgit v1.2.3-59-g8ed1b