From 73317b954041031249e8968d2e9023ff4e960d99 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 19 May 2010 15:57:35 -0400 Subject: perf probe: Support "string" type Support string type casting to event argument. If perf-probe finds an argument casted as string, it ensures the target variable is "(unsigned/signed) char *(or []). perf-probe also adds dereference if the target is a pointer. So, both of 'char buf[10];' and 'char *buf;' can be accessed by 'buf:string' Cc: Ingo Molnar Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Mike Galbraith Cc: Frederic Weisbecker LKML-Reference: <20100519195734.2885.1666.stgit@localhost6.localdomain6> Signed-off-by: Masami Hiramatsu Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-finder.c | 59 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 48 insertions(+), 11 deletions(-) (limited to 'tools/perf/util') diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index baf665383498..aaea16b1c60b 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -464,18 +464,61 @@ static int convert_location(Dwarf_Op *op, struct probe_finder *pf) } static int convert_variable_type(Dwarf_Die *vr_die, - struct kprobe_trace_arg *targ) + struct kprobe_trace_arg *tvar, + const char *cast) { + struct kprobe_trace_arg_ref **ref_ptr = &tvar->ref; Dwarf_Die type; char buf[16]; int ret; + /* TODO: check all types */ + if (cast && strcmp(cast, "string") != 0) { + /* Non string type is OK */ + tvar->type = strdup(cast); + return (tvar->type == NULL) ? -ENOMEM : 0; + } + if (die_get_real_type(vr_die, &type) == NULL) { pr_warning("Failed to get a type information of %s.\n", dwarf_diename(vr_die)); return -ENOENT; } + if (cast && strcmp(cast, "string") == 0) { /* String type */ + ret = dwarf_tag(&type); + if (ret != DW_TAG_pointer_type && + ret != DW_TAG_array_type) { + pr_warning("Failed to cast into string: " + "%s(%s) is not a pointer nor array.", + dwarf_diename(vr_die), dwarf_diename(&type)); + return -EINVAL; + } + if (ret == DW_TAG_pointer_type) { + if (die_get_real_type(&type, &type) == NULL) { + pr_warning("Failed to get a type information."); + return -ENOENT; + } + while (*ref_ptr) + ref_ptr = &(*ref_ptr)->next; + /* Add new reference with offset +0 */ + *ref_ptr = zalloc(sizeof(struct kprobe_trace_arg_ref)); + if (*ref_ptr == NULL) { + pr_warning("Out of memory error\n"); + return -ENOMEM; + } + } + if (die_compare_name(&type, "char") != 0 && + die_compare_name(&type, "unsigned char") != 0) { + pr_warning("Failed to cast into string: " + "%s is not (unsigned) char *.", + dwarf_diename(vr_die)); + return -EINVAL; + } + tvar->type = strdup(cast); + return (tvar->type == NULL) ? -ENOMEM : 0; + } + ret = die_get_byte_size(&type) * 8; if (ret) { /* Check the bitwidth */ @@ -495,8 +538,8 @@ static int convert_variable_type(Dwarf_Die *vr_die, strerror(-ret)); return ret; } - targ->type = strdup(buf); - if (targ->type == NULL) + tvar->type = strdup(buf); + if (tvar->type == NULL) return -ENOMEM; } return 0; @@ -606,14 +649,8 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) &die_mem); vr_die = &die_mem; } - if (ret == 0) { - if (pf->pvar->type) { - pf->tvar->type = strdup(pf->pvar->type); - if (pf->tvar->type == NULL) - ret = -ENOMEM; - } else - ret = convert_variable_type(vr_die, pf->tvar); - } + if (ret == 0) + ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type); /* *expr will be cached in libdw. Don't free it. */ return ret; error: -- cgit v1.2.3-59-g8ed1b