From 3fd996a29515df23b3f20c36d69788a3707254a9 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Tue, 26 Nov 2013 15:21:04 +0900 Subject: [PATCH] tracing/probes: Implement 'stack' fetch method for uprobes Use separate method to fetch from stack. Move existing functions to trace_kprobe.c and make them static. Also add new stack fetch implementation for uprobes. Acked-by: Oleg Nesterov Cc: Masami Hiramatsu Cc: Srikar Dronamraju Cc: zhangwei(Jovi) Cc: Arnaldo Carvalho de Melo Signed-off-by: Namhyung Kim --- kernel/trace/trace_kprobe.c | 15 +++++++++++++++ kernel/trace/trace_probe.c | 22 ---------------------- kernel/trace/trace_probe.h | 14 ++++++++++---- kernel/trace/trace_uprobe.c | 41 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 66 insertions(+), 26 deletions(-) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index fe3f00c..389f9e4 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -88,6 +88,21 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); static int kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs); +/* + * Kprobes-specific fetch functions + */ +#define DEFINE_FETCH_stack(type) \ +static __kprobes 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)); \ +} +DEFINE_BASIC_FETCH_FUNCS(stack) +/* No string on the stack entry */ +#define fetch_stack_string NULL +#define fetch_stack_string_size NULL + /* Fetch type information table */ const struct fetch_type kprobes_fetch_type_table[] = { /* Special types */ diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 541036e..77aa7d1 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -70,16 +70,6 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\""; -/* - * Define macro for basic types - we don't need to define s* types, because - * we have to care only about bitwidth at recording time. - */ -#define DEFINE_BASIC_FETCH_FUNCS(method) \ -DEFINE_FETCH_##method(u8) \ -DEFINE_FETCH_##method(u16) \ -DEFINE_FETCH_##method(u32) \ -DEFINE_FETCH_##method(u64) - #define CHECK_FETCH_FUNCS(method, fn) \ (((FETCH_FUNC_NAME(method, u8) == fn) || \ (FETCH_FUNC_NAME(method, u16) == fn) || \ @@ -102,18 +92,6 @@ DEFINE_BASIC_FETCH_FUNCS(reg) #define fetch_reg_string NULL #define fetch_reg_string_size NULL -#define DEFINE_FETCH_stack(type) \ -__kprobes 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)); \ -} -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_retval(type) \ __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \ void *dummy, void *dest) \ diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 5b77798..8211dd6 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -167,10 +167,6 @@ DECLARE_BASIC_FETCH_FUNCS(reg); #define fetch_reg_string NULL #define fetch_reg_string_size NULL -DECLARE_BASIC_FETCH_FUNCS(stack); -#define fetch_stack_string NULL -#define fetch_stack_string_size NULL - DECLARE_BASIC_FETCH_FUNCS(retval); #define fetch_retval_string NULL #define fetch_retval_string_size NULL @@ -191,6 +187,16 @@ DECLARE_BASIC_FETCH_FUNCS(bitfield); #define fetch_bitfield_string NULL #define fetch_bitfield_string_size NULL +/* + * Define macro for basic types - we don't need to define s* types, because + * we have to care only about bitwidth at recording time. + */ +#define DEFINE_BASIC_FETCH_FUNCS(method) \ +DEFINE_FETCH_##method(u8) \ +DEFINE_FETCH_##method(u16) \ +DEFINE_FETCH_##method(u32) \ +DEFINE_FETCH_##method(u64) + /* Default (unsigned long) fetch type */ #define __DEFAULT_FETCH_TYPE(t) u##t #define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 2c60925..5395d37 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -74,6 +74,47 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); static int uretprobe_dispatcher(struct uprobe_consumer *con, unsigned long func, struct pt_regs *regs); +#ifdef CONFIG_STACK_GROWSUP +static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) +{ + return addr - (n * sizeof(long)); +} +#else +static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n) +{ + return addr + (n * sizeof(long)); +} +#endif + +static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n) +{ + unsigned long ret; + unsigned long addr = user_stack_pointer(regs); + + addr = adjust_stack_addr(addr, n); + + if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret))) + return 0; + + return ret; +} + +/* + * 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) \ +{ \ + *(type *)dest = (type)get_user_stack_nth(regs, \ + ((unsigned long)offset)); \ +} +DEFINE_BASIC_FETCH_FUNCS(stack) +/* No string on the stack entry */ +#define fetch_stack_string NULL +#define fetch_stack_string_size NULL + + /* Fetch type information table */ const struct fetch_type uprobes_fetch_type_table[] = { /* Special types */ -- 2.7.4