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SubjectRe: [PATCH 11/13] tracing/kprobes: Add priv argument to fetch functions
(2013/08/09 17:45), Namhyung Kim wrote:
> From: Namhyung Kim <namhyung.kim@lge.com>
>
> This argument is for passing private data structure to each fetch
> function and will be used by uprobes.

OK, I just concern about overhead, but yeah, these fetch functions
are not optimized yet. that's another story. :)
I'd rather increase flexibility in this series.

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

Thank you!

> 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: Namhyung Kim <namhyung@kernel.org>
> ---
> kernel/trace/trace_kprobe.c | 32 ++++++++++++++++++--------------
> kernel/trace/trace_probe.c | 24 ++++++++++++------------
> kernel/trace/trace_probe.h | 19 ++++++++++---------
> kernel/trace/trace_uprobe.c | 8 ++++----
> 4 files changed, 44 insertions(+), 39 deletions(-)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index e3f798e41820..01bf5c879144 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -740,7 +740,7 @@ static const struct file_operations kprobe_profile_ops = {
> */
> #define DEFINE_FETCH_stack(type) \
> static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\
> - void *offset, void *dest) \
> + void *offset, void *dest, void *priv) \
> { \
> *(type *)dest = (type)regs_get_kernel_stack_nth(regs, \
> (unsigned int)((unsigned long)offset)); \
> @@ -752,7 +752,7 @@ DEFINE_BASIC_FETCH_FUNCS(stack)
>
> #define DEFINE_FETCH_memory(type) \
> static __kprobes void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,\
> - void *addr, void *dest) \
> + void *addr, void *dest, void *priv) \
> { \
> type retval; \
> if (probe_kernel_address(addr, retval)) \
> @@ -766,7 +766,7 @@ DEFINE_BASIC_FETCH_FUNCS(memory)
> * length and relative data location.
> */
> static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
> - void *addr, void *dest)
> + void *addr, void *dest, void *priv)
> {
> long ret;
> int maxlen = get_rloc_len(*(u32 *)dest);
> @@ -803,7 +803,7 @@ static __kprobes void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
>
> /* Return the length of string -- including null terminal byte */
> static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
> - void *addr, void *dest)
> + void *addr, void *dest, void *priv)
> {
> mm_segment_t old_fs;
> int ret, len = 0;
> @@ -874,11 +874,11 @@ struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
>
> #define DEFINE_FETCH_symbol(type) \
> __kprobes void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, \
> - void *data, void *dest) \
> + void *data, void *dest, void *priv) \
> { \
> struct symbol_cache *sc = data; \
> if (sc->addr) \
> - fetch_memory_##type(regs, (void *)sc->addr, dest); \
> + fetch_memory_##type(regs, (void *)sc->addr, dest, priv);\
> else \
> *(type *)dest = 0; \
> }
> @@ -924,7 +924,7 @@ __kprobe_trace_func(struct trace_kprobe *tp, struct pt_regs *regs,
> local_save_flags(irq_flags);
> pc = preempt_count();
>
> - dsize = __get_data_size(&tp->p, regs);
> + dsize = __get_data_size(&tp->p, regs, NULL);
> size = sizeof(*entry) + tp->p.size + dsize;
>
> event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
> @@ -935,7 +935,8 @@ __kprobe_trace_func(struct trace_kprobe *tp, struct pt_regs *regs,
>
> entry = ring_buffer_event_data(event);
> entry->ip = (unsigned long)tp->rp.kp.addr;
> - store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize);
> + store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize,
> + NULL);
>
> if (!filter_current_check_discard(buffer, call, entry, event))
> trace_buffer_unlock_commit_regs(buffer, event,
> @@ -972,7 +973,7 @@ __kretprobe_trace_func(struct trace_kprobe *tp, struct kretprobe_instance *ri,
> local_save_flags(irq_flags);
> pc = preempt_count();
>
> - dsize = __get_data_size(&tp->p, regs);
> + dsize = __get_data_size(&tp->p, regs, NULL);
> size = sizeof(*entry) + tp->p.size + dsize;
>
> event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
> @@ -984,7 +985,8 @@ __kretprobe_trace_func(struct trace_kprobe *tp, struct kretprobe_instance *ri,
> entry = ring_buffer_event_data(event);
> entry->func = (unsigned long)tp->rp.kp.addr;
> entry->ret_ip = (unsigned long)ri->ret_addr;
> - store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize);
> + store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize,
> + NULL);
>
> if (!filter_current_check_discard(buffer, call, entry, event))
> trace_buffer_unlock_commit_regs(buffer, event,
> @@ -1144,7 +1146,7 @@ kprobe_perf_func(struct trace_kprobe *tp, struct pt_regs *regs)
> if (hlist_empty(head))
> return;
>
> - dsize = __get_data_size(&tp->p, regs);
> + dsize = __get_data_size(&tp->p, regs, NULL);
> __size = sizeof(*entry) + tp->p.size + dsize;
> size = ALIGN(__size + sizeof(u32), sizeof(u64));
> size -= sizeof(u32);
> @@ -1155,7 +1157,8 @@ kprobe_perf_func(struct trace_kprobe *tp, struct pt_regs *regs)
>
> entry->ip = (unsigned long)tp->rp.kp.addr;
> memset(&entry[1], 0, dsize);
> - store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize);
> + store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize,
> + NULL);
> perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
> }
>
> @@ -1174,7 +1177,7 @@ kretprobe_perf_func(struct trace_kprobe *tp, struct kretprobe_instance *ri,
> if (hlist_empty(head))
> return;
>
> - dsize = __get_data_size(&tp->p, regs);
> + dsize = __get_data_size(&tp->p, regs, NULL);
> __size = sizeof(*entry) + tp->p.size + dsize;
> size = ALIGN(__size + sizeof(u32), sizeof(u64));
> size -= sizeof(u32);
> @@ -1185,7 +1188,8 @@ kretprobe_perf_func(struct trace_kprobe *tp, struct kretprobe_instance *ri,
>
> entry->func = (unsigned long)tp->rp.kp.addr;
> entry->ret_ip = (unsigned long)ri->ret_addr;
> - store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize);
> + store_trace_args(sizeof(*entry), &tp->p, regs, (u8 *)&entry[1], dsize,
> + NULL);
> perf_trace_buf_submit(entry, size, rctx, 0, 1, regs, head, NULL);
> }
> #endif /* CONFIG_PERF_EVENTS */
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 1ab83d4c7775..eaee44d5d9d1 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -78,7 +78,7 @@ 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 *offset, void *dest, void *priv) \
> { \
> *(type *)dest = (type)regs_get_register(regs, \
> (unsigned int)((unsigned long)offset)); \
> @@ -87,7 +87,7 @@ DEFINE_BASIC_FETCH_FUNCS(reg)
>
> #define DEFINE_FETCH_retval(type) \
> __kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs, \
> - void *dummy, void *dest) \
> + void *dummy, void *dest, void *priv) \
> { \
> *(type *)dest = (type)regs_return_value(regs); \
> }
> @@ -103,14 +103,14 @@ 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 *data, void *dest, void *priv) \
> { \
> struct deref_fetch_param *dprm = data; \
> unsigned long addr; \
> - call_fetch(&dprm->orig, regs, &addr); \
> + call_fetch(&dprm->orig, regs, &addr, priv); \
> if (addr) { \
> addr += dprm->offset; \
> - dprm->fetch(regs, (void *)addr, dest); \
> + dprm->fetch(regs, (void *)addr, dest, priv); \
> } else \
> *(type *)dest = 0; \
> }
> @@ -118,15 +118,15 @@ 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 *data, void *dest, void *priv)
> {
> struct deref_fetch_param *dprm = data;
> unsigned long addr;
>
> - call_fetch(&dprm->orig, regs, &addr);
> + call_fetch(&dprm->orig, regs, &addr, priv);
> if (addr && dprm->fetch_size) {
> addr += dprm->offset;
> - dprm->fetch_size(regs, (void *)addr, dest);
> + dprm->fetch_size(regs, (void *)addr, dest, priv);
> } else
> *(string_size *)dest = 0;
> }
> @@ -156,12 +156,12 @@ struct bitfield_fetch_param {
> };
>
> #define DEFINE_FETCH_bitfield(type) \
> -__kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs,\
> - void *data, void *dest) \
> +__kprobes void FETCH_FUNC_NAME(bitfield, type)(struct pt_regs *regs, \
> + void *data, void *dest, void *priv) \
> { \
> struct bitfield_fetch_param *bprm = data; \
> type buf = 0; \
> - call_fetch(&bprm->orig, regs, &buf); \
> + call_fetch(&bprm->orig, regs, &buf, priv); \
> if (buf) { \
> buf <<= bprm->hi_shift; \
> buf >>= bprm->low_shift; \
> @@ -249,7 +249,7 @@ fail:
>
> /* Special function : only accept unsigned long */
> static __kprobes void fetch_stack_address(struct pt_regs *regs,
> - void *dummy, void *dest)
> + void *dummy, void *dest, void *priv)
> {
> *(unsigned long *)dest = kernel_stack_pointer(regs);
> }
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 325989f24dbf..fc7edf3749ef 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -98,7 +98,7 @@ typedef u32 string;
> typedef u32 string_size;
>
> /* Data fetch function type */
> -typedef void (*fetch_func_t)(struct pt_regs *, void *, void *);
> +typedef void (*fetch_func_t)(struct pt_regs *, void *, void *, void *);
> /* Printing function type */
> typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
>
> @@ -182,7 +182,8 @@ static inline bool trace_probe_is_registered(struct trace_probe *tp)
> #define FETCH_FUNC_NAME(method, type) fetch_##method##_##type
>
> #define DECLARE_FETCH_FUNC(method, type) \
> -extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *, void *, void *)
> +extern void FETCH_FUNC_NAME(method, type)(struct pt_regs *, void *, \
> + void *, void *)
>
> #define DECLARE_BASIC_FETCH_FUNCS(method) \
> DECLARE_FETCH_FUNC(method, u8); \
> @@ -264,9 +265,9 @@ ASSIGN_FETCH_FUNC(bitfield, ftype), \
> extern const struct fetch_type kprobes_fetch_type_table[];
>
> static inline __kprobes void call_fetch(struct fetch_param *fprm,
> - struct pt_regs *regs, void *dest)
> + struct pt_regs *regs, void *dest, void *priv)
> {
> - return fprm->fn(regs, fprm->data, dest);
> + return fprm->fn(regs, fprm->data, dest, priv);
> }
>
> struct symbol_cache;
> @@ -305,14 +306,14 @@ extern int traceprobe_command(const char *buf, int (*createfn)(int, char**));
>
> /* Sum up total data length for dynamic arraies (strings) */
> static inline __kprobes int
> -__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
> +__get_data_size(struct trace_probe *tp, struct pt_regs *regs, void *priv)
> {
> int i, ret = 0;
> u32 len;
>
> for (i = 0; i < tp->nr_args; i++)
> if (unlikely(tp->args[i].fetch_size.fn)) {
> - call_fetch(&tp->args[i].fetch_size, regs, &len);
> + call_fetch(&tp->args[i].fetch_size, regs, &len, priv);
> ret += len;
> }
>
> @@ -322,7 +323,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
> /* Store the value of each argument */
> static inline __kprobes void
> store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
> - u8 *data, int maxlen)
> + u8 *data, int maxlen, void *priv)
> {
> int i;
> u32 end = tp->size;
> @@ -337,7 +338,7 @@ store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
> dl = (u32 *)(data + tp->args[i].offset);
> *dl = make_data_rloc(maxlen, end - tp->args[i].offset);
> /* Then try to fetch string or dynamic array data */
> - call_fetch(&tp->args[i].fetch, regs, dl);
> + call_fetch(&tp->args[i].fetch, regs, dl, priv);
> /* Reduce maximum length */
> end += get_rloc_len(*dl);
> maxlen -= get_rloc_len(*dl);
> @@ -347,7 +348,7 @@ store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
> } else
> /* Just fetching data normally */
> call_fetch(&tp->args[i].fetch, regs,
> - data + tp->args[i].offset);
> + data + tp->args[i].offset, priv);
> }
> }
>
> diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
> index 2888b95b063f..2c1c648e75bb 100644
> --- a/kernel/trace/trace_uprobe.c
> +++ b/kernel/trace/trace_uprobe.c
> @@ -520,7 +520,7 @@ static void uprobe_trace_print(struct trace_uprobe *tu,
> int size, dsize, esize;
> struct ftrace_event_call *call = &tu->p.call;
>
> - dsize = __get_data_size(&tu->p, regs);
> + dsize = __get_data_size(&tu->p, regs, NULL);
> esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
>
> /*
> @@ -532,7 +532,7 @@ static void uprobe_trace_print(struct trace_uprobe *tu,
> if (tmp == NULL)
> return;
>
> - store_trace_args(esize, &tu->p, regs, tmp, dsize);
> + store_trace_args(esize, &tu->p, regs, tmp, dsize, NULL);
>
> size = esize + tu->p.size + dsize;
> event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
> @@ -775,7 +775,7 @@ static void uprobe_perf_print(struct trace_uprobe *tu,
> int size, dsize, esize;
> int rctx;
>
> - dsize = __get_data_size(&tu->p, regs);
> + dsize = __get_data_size(&tu->p, regs, NULL);
> esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
>
> /*
> @@ -787,7 +787,7 @@ static void uprobe_perf_print(struct trace_uprobe *tu,
> if (tmp == NULL)
> return;
>
> - store_trace_args(esize, &tu->p, regs, tmp, dsize);
> + store_trace_args(esize, &tu->p, regs, tmp, dsize, NULL);
>
> size = esize + tu->p.size + dsize;
> size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32);
>


--
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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