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SubjectRe: [PATCH 04/13] tracing/kprobes: Add fetch{,_size} member into deref fetch method
(2013/08/09 17:45), Namhyung Kim wrote:
> From: Hyeoncheol Lee <cheol.lee@lge.com>
>
> The deref fetch methods access a memory region but it assumes that
> it's a kernel memory since uprobes does not support them.
>
> Add ->fetch and ->fetch_size member in order to provide a proper
> access methods for supporting uprobes.
>

Looks OK for me :)

Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>

> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
> Cc: Oleg Nesterov <oleg@redhat.com>
> Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
> Signed-off-by: Hyeoncheol Lee <cheol.lee@lge.com>
> [namhyung@kernel.org: Split original patch into pieces as requested]
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> kernel/trace/trace_probe.c | 22 ++++++++++++++++++++--
> 1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 41f654d24cd9..b7b8bda02d6e 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -97,6 +97,8 @@ DEFINE_BASIC_FETCH_FUNCS(retval)
> struct deref_fetch_param {
> struct fetch_param orig;
> long offset;
> + fetch_func_t fetch;
> + fetch_func_t fetch_size;
> };
>
> #define DEFINE_FETCH_deref(type) \
> @@ -108,13 +110,26 @@ __kprobes void FETCH_FUNC_NAME(deref, type)(struct pt_regs *regs, \
> call_fetch(&dprm->orig, regs, &addr); \
> if (addr) { \
> addr += dprm->offset; \
> - fetch_memory_##type(regs, (void *)addr, dest); \
> + dprm->fetch(regs, (void *)addr, dest); \
> } else \
> *(type *)dest = 0; \
> }
> DEFINE_BASIC_FETCH_FUNCS(deref)
> DEFINE_FETCH_deref(string)
> -DEFINE_FETCH_deref(string_size)
> +
> +__kprobes void FETCH_FUNC_NAME(deref, string_size)(struct pt_regs *regs,
> + void *data, void *dest)
> +{
> + struct deref_fetch_param *dprm = data;
> + unsigned long addr;
> +
> + call_fetch(&dprm->orig, regs, &addr);
> + if (addr && dprm->fetch_size) {
> + addr += dprm->offset;
> + dprm->fetch_size(regs, (void *)addr, dest);
> + } else
> + *(string_size *)dest = 0;
> +}
>
> static __kprobes void update_deref_fetch_param(struct deref_fetch_param *data)
> {
> @@ -394,6 +409,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
> return -ENOMEM;
>
> dprm->offset = offset;
> + dprm->fetch = t->fetch[FETCH_MTD_memory];
> + dprm->fetch_size = get_fetch_size_function(t,
> + dprm->fetch, ttbl);
> ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,
> is_kprobe);
> if (ret)
>


--
Masami HIRAMATSU
IT Management Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@hitachi.com




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