Re: [PATCH 10/17] tracing/probes: Move 'symbol' fetch method to kprobes
From: Masami Hiramatsu
Date: Mon Dec 16 2013 - 03:23:38 EST
(2013/12/16 13:32), Namhyung Kim wrote:
> From: Namhyung Kim <namhyung.kim@xxxxxxx>
>
> Move existing functions to trace_kprobe.c and add NULL entries to the
> uprobes fetch type table. I don't make them static since some generic
> routines like update/free_XXX_fetch_param() require pointers to the
> functions.
>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
> Cc: Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx>
> Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
> Cc: zhangwei(Jovi) <jovi.zhangwei@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
This looks good for me :)
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
And now all of this series has been reviewed/acked by me!
Thank you!
> ---
> kernel/trace/trace_kprobe.c | 59 +++++++++++++++++++++++++++++++++++++++++++++
> kernel/trace/trace_probe.c | 59 ---------------------------------------------
> kernel/trace/trace_probe.h | 24 ++++++++++++++++++
> kernel/trace/trace_uprobe.c | 8 ++++++
> 4 files changed, 91 insertions(+), 59 deletions(-)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 11478020f76c..1c38f3f47d0d 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -88,6 +88,51 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
> static int kretprobe_dispatcher(struct kretprobe_instance *ri,
> struct pt_regs *regs);
>
> +/* Memory fetching by symbol */
> +struct symbol_cache {
> + char *symbol;
> + long offset;
> + unsigned long addr;
> +};
> +
> +unsigned long update_symbol_cache(struct symbol_cache *sc)
> +{
> + sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
> +
> + if (sc->addr)
> + sc->addr += sc->offset;
> +
> + return sc->addr;
> +}
> +
> +void free_symbol_cache(struct symbol_cache *sc)
> +{
> + kfree(sc->symbol);
> + kfree(sc);
> +}
> +
> +struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
> +{
> + struct symbol_cache *sc;
> +
> + if (!sym || strlen(sym) == 0)
> + return NULL;
> +
> + sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
> + if (!sc)
> + return NULL;
> +
> + sc->symbol = kstrdup(sym, GFP_KERNEL);
> + if (!sc->symbol) {
> + kfree(sc);
> + return NULL;
> + }
> + sc->offset = offset;
> + update_symbol_cache(sc);
> +
> + return sc;
> +}
> +
> /*
> * Kprobes-specific fetch functions
> */
> @@ -103,6 +148,20 @@ DEFINE_BASIC_FETCH_FUNCS(stack)
> #define fetch_stack_string NULL
> #define fetch_stack_string_size NULL
>
> +#define DEFINE_FETCH_symbol(type) \
> +__kprobes 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; \
> +}
> +DEFINE_BASIC_FETCH_FUNCS(symbol)
> +DEFINE_FETCH_symbol(string)
> +DEFINE_FETCH_symbol(string_size)
> +
> /* 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 77aa7d18821e..a31ad478b7f6 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -180,65 +180,6 @@ __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
> *(u32 *)dest = len;
> }
>
> -/* Memory fetching by symbol */
> -struct symbol_cache {
> - char *symbol;
> - long offset;
> - unsigned long addr;
> -};
> -
> -static unsigned long update_symbol_cache(struct symbol_cache *sc)
> -{
> - sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
> -
> - if (sc->addr)
> - sc->addr += sc->offset;
> -
> - return sc->addr;
> -}
> -
> -static void free_symbol_cache(struct symbol_cache *sc)
> -{
> - kfree(sc->symbol);
> - kfree(sc);
> -}
> -
> -static struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
> -{
> - struct symbol_cache *sc;
> -
> - if (!sym || strlen(sym) == 0)
> - return NULL;
> -
> - sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
> - if (!sc)
> - return NULL;
> -
> - sc->symbol = kstrdup(sym, GFP_KERNEL);
> - if (!sc->symbol) {
> - kfree(sc);
> - return NULL;
> - }
> - sc->offset = offset;
> - update_symbol_cache(sc);
> -
> - return sc;
> -}
> -
> -#define DEFINE_FETCH_symbol(type) \
> -__kprobes 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; \
> -}
> -DEFINE_BASIC_FETCH_FUNCS(symbol)
> -DEFINE_FETCH_symbol(string)
> -DEFINE_FETCH_symbol(string_size)
> -
> /* Dereference memory access function */
> struct deref_fetch_param {
> struct fetch_param orig;
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 8211dd674ab6..8be84550ceb3 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -239,6 +239,30 @@ ASSIGN_FETCH_FUNC(bitfield, ftype), \
> extern __weak const struct fetch_type kprobes_fetch_type_table[];
> extern __weak const struct fetch_type uprobes_fetch_type_table[];
>
> +#ifdef CONFIG_KPROBE_EVENT
> +struct symbol_cache;
> +unsigned long update_symbol_cache(struct symbol_cache *sc);
> +void free_symbol_cache(struct symbol_cache *sc);
> +struct symbol_cache *alloc_symbol_cache(const char *sym, long offset);
> +#else
> +struct symbol_cache {
> +};
> +static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc)
> +{
> + return 0;
> +}
> +
> +static inline void __used free_symbol_cache(struct symbol_cache *sc)
> +{
> +}
> +
> +static inline struct symbol_cache * __used
> +alloc_symbol_cache(const char *sym, long offset)
> +{
> + return NULL;
> +}
> +#endif /* CONFIG_KPROBE_EVENT */
> +
> struct probe_arg {
> struct fetch_param fetch;
> struct fetch_param fetch_size;
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index 5395d37e5e72..adc9ac70fd3c 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -115,6 +115,14 @@ DEFINE_BASIC_FETCH_FUNCS(stack)
> #define fetch_stack_string_size NULL
>
>
> +/* uprobes don't support symbol fetch methods */
> +#define fetch_symbol_u8 NULL
> +#define fetch_symbol_u16 NULL
> +#define fetch_symbol_u32 NULL
> +#define fetch_symbol_u64 NULL
> +#define fetch_symbol_string NULL
> +#define fetch_symbol_string_size NULL
> +
> /* Fetch type information table */
> const struct fetch_type uprobes_fetch_type_table[] = {
> /* Special types */
>
--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/