From 9178412ddf5a98feba0ad3986111c5ad10eb9e59 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 25 Apr 2018 21:19:01 +0900 Subject: tracing: probeevent: Return consumed bytes of dynamic area Cleanup string fetching routine so that returns the consumed bytes of dynamic area and store the string information as data_loc format instead of data_rloc. This simplifies the fetcharg loop. Link: http://lkml.kernel.org/r/152465874163.26224.12125143907501289031.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_probe_tmpl.h | 54 +++++++++++++++++++---------------------- 1 file changed, 25 insertions(+), 29 deletions(-) (limited to 'kernel/trace/trace_probe_tmpl.h') diff --git a/kernel/trace/trace_probe_tmpl.h b/kernel/trace/trace_probe_tmpl.h index c8a5272abf01..3b4aba6f84cc 100644 --- a/kernel/trace/trace_probe_tmpl.h +++ b/kernel/trace/trace_probe_tmpl.h @@ -48,24 +48,28 @@ fetch_apply_bitfield(struct fetch_insn *code, void *buf) } } -/* Define this for each callsite */ +/* + * This must be defined for each callsite. + * Return consumed dynamic data size (>= 0), or error (< 0). + * If dest is NULL, don't store result and return required dynamic data size. + */ static int process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, - void *dest, bool pre); + void *dest, void *base); /* Sum up total data length for dynamic arraies (strings) */ static nokprobe_inline int __get_data_size(struct trace_probe *tp, struct pt_regs *regs) { struct probe_arg *arg; - int i, ret = 0; - u32 len; + int i, len, ret = 0; for (i = 0; i < tp->nr_args; i++) { arg = tp->args + i; if (unlikely(arg->dynamic)) { - process_fetch_insn(arg->code, regs, &len, true); - ret += len; + len = process_fetch_insn(arg->code, regs, NULL, NULL); + if (len > 0) + ret += len; } } @@ -74,34 +78,26 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs) /* Store the value of each argument */ static nokprobe_inline void -store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs, - u8 *data, int maxlen) +store_trace_args(void *data, struct trace_probe *tp, struct pt_regs *regs, + int header_size, int maxlen) { struct probe_arg *arg; - u32 end = tp->size; - u32 *dl; /* Data (relative) location */ - int i; + void *base = data - header_size; + void *dyndata = data + tp->size; + u32 *dl; /* Data location */ + int ret, i; for (i = 0; i < tp->nr_args; i++) { arg = tp->args + i; - if (unlikely(arg->dynamic)) { - /* - * First, we set the relative location and - * maximum data length to *dl - */ - dl = (u32 *)(data + arg->offset); - *dl = make_data_rloc(maxlen, end - arg->offset); - /* Then try to fetch string or dynamic array data */ - process_fetch_insn(arg->code, regs, dl, false); - /* Reduce maximum length */ - end += get_rloc_len(*dl); - maxlen -= get_rloc_len(*dl); - /* Trick here, convert data_rloc to data_loc */ - *dl = convert_rloc_to_loc(*dl, ent_size + arg->offset); - } else - /* Just fetching data normally */ - process_fetch_insn(arg->code, regs, data + arg->offset, - false); + dl = data + arg->offset; + /* Point the dynamic data area if needed */ + if (unlikely(arg->dynamic)) + *dl = make_data_loc(maxlen, dyndata - base); + ret = process_fetch_insn(arg->code, regs, dl, base); + if (unlikely(ret < 0 && arg->dynamic)) + *dl = make_data_loc(0, dyndata - base); + else + dyndata += ret; } } -- cgit