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_probe.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/trace/trace_probe.c') 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) { /* -- cgit v1.2.1 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_probe.c | 61 +++++++++++++++++++++++++--------------------- 1 file changed, 33 insertions(+), 28 deletions(-) (limited to 'kernel/trace/trace_probe.c') 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, -- cgit v1.2.1