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Commit 3925f4a5 authored by Hyeoncheol Lee's avatar Hyeoncheol Lee Committed by Steven Rostedt
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tracing/probes: Add fetch{,_size} member into deref fetch method 



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.

Acked-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: default avatarHyeoncheol Lee <cheol.lee@lge.com>
[namhyung@kernel.org: Split original patch into pieces as requested]
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 1301a44e

kernel/trace/trace_probe.c

+20 −2
Original line number Diff line number Diff line
@@ -184,6 +184,8 @@ __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, 
struct deref_fetch_param {

	struct fetch_param	orig;

	long			offset;

	fetch_func_t		fetch;

	fetch_func_t		fetch_size;

};



#define DEFINE_FETCH_deref(type)					\
@@ -195,13 +197,26 @@ __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)

{
@@ -477,6 +492,9 @@ 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, ftbl);

			ret = parse_probe_arg(arg, t2, &dprm->orig, is_return,

							is_kprobe);

			if (ret)