Since kprobes events support an array argument, perf-probe can also support dumping array now. The syntax are
<array-var>[<range>] or <pointer-var>[<range>] where the <range> is <start>..<end>. e.g. array[0..5]. This can also be available with string type. In this case, the string array should be "char *array[]" or "char **array_ptr". Note that this feature is only available on the kernel which supports array type. Signed-off-by: Masami Hiramatsu <[email protected]> --- tools/perf/Documentation/perf-probe.txt | 2 - tools/perf/util/probe-event.c | 20 ++++++- tools/perf/util/probe-event.h | 2 + tools/perf/util/probe-file.c | 5 ++ tools/perf/util/probe-file.h | 1 tools/perf/util/probe-finder.c | 95 ++++++++++++++++++------------- 6 files changed, 84 insertions(+), 41 deletions(-) diff --git a/tools/perf/Documentation/perf-probe.txt b/tools/perf/Documentation/perf-probe.txt index b6866a05edd2..a68e423cac48 100644 --- a/tools/perf/Documentation/perf-probe.txt +++ b/tools/perf/Documentation/perf-probe.txt @@ -196,7 +196,7 @@ Each probe argument follows below syntax. [NAME=]LOCALVAR|$retval|%REG|@SYMBOL[:TYPE] -'NAME' specifies the name of this argument (optional). You can use the name of local variable, local data structure member (e.g. var->field, var.field2), local array with fixed index (e.g. array[1], var->array[0], var->pointer[2]), or kprobe-tracer argument format (e.g. $retval, %ax, etc). Note that the name of this argument will be set as the last member name if you specify a local data structure member (e.g. field2 for 'var->field1.field2'.) +'NAME' specifies the name of this argument (optional). You can use the name of local variable, local data structure member (e.g. var->field, var.field2), local array with fixed index (e.g. array[1], var->array[0], var->pointer[2]) or range (e.g. array[1..4], var->array[0..2]), or kprobe-tracer argument format (e.g. $retval, %ax, etc). Note that the name of this argument will be set as the last member name if you specify a local data structure member (e.g. field2 for 'var->field1.field2'.) '$vars' and '$params' special arguments are also available for NAME, '$vars' is expanded to the local variables (including function parameters) which can access at given probe point. '$params' is expanded to only the function parameters. 'TYPE' casts the type of this argument (optional). If omitted, perf probe automatically set the type based on debuginfo (*). Currently, basic types (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal integers (x/x8/x16/x32/x64), signedness casting (u/s), "string" and bitfield are supported. (see TYPES for detail) On x86 systems %REG is always the short form of the register: for example %AX. %RAX or %EAX is not valid. diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index e1dbc9821617..e07a1957c9cd 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -1570,6 +1570,7 @@ static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg) { char *tmp, *goodname; struct perf_probe_arg_field **fieldp; + long end; pr_debug("parsing arg: %s into ", str); @@ -1617,7 +1618,18 @@ static int parse_perf_probe_arg(char *str, struct perf_probe_arg *arg) str = tmp; (*fieldp)->index = strtol(str + 1, &tmp, 0); (*fieldp)->ref = true; - if (*tmp != ']' || tmp == str + 1) { + if (tmp[0] == '.' && tmp[1] == '.') { /* dump array */ + end = strtol(tmp + 2, &tmp, 0); + if (end < (*fieldp)->index || *tmp != ']') { + semantic_error("Invalid array range\n"); + return -EINVAL; + } + arg->length = end - (*fieldp)->index + 1; + if (tmp[1] != '\0') { + semantic_error("Array range must not follow anything."); + return -EINVAL; + } + } else if (*tmp != ']' || tmp == str + 1) { semantic_error("Array index must be a" " number.\n"); return -EINVAL; @@ -2022,6 +2034,12 @@ static int synthesize_probe_trace_arg(struct probe_trace_arg *arg, if (!err && arg->type) err = strbuf_addf(buf, ":%s", arg->type); + if (!err && arg->length) { + if (!arg->type) + return -EINVAL; + err = strbuf_addf(buf, "[%d]", arg->length); + } + return err; } diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index 45b14f020558..e5ca1bf33ee7 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -42,6 +42,7 @@ struct probe_trace_arg { char *name; /* Argument name */ char *value; /* Base value */ char *type; /* Type name */ + unsigned int length; /* Length of array */ struct probe_trace_arg_ref *ref; /* Referencing offset */ }; @@ -79,6 +80,7 @@ struct perf_probe_arg { char *name; /* Argument name */ char *var; /* Variable name */ char *type; /* Type name */ + unsigned int length; /* Length of array */ struct perf_probe_arg_field *field; /* Structure fields */ }; diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c index 4ae1123c6794..a879fe8eede3 100644 --- a/tools/perf/util/probe-file.c +++ b/tools/perf/util/probe-file.c @@ -999,6 +999,7 @@ int probe_cache__show_all_caches(struct strfilter *filter) enum ftrace_readme { FTRACE_README_PROBE_TYPE_X = 0, FTRACE_README_KRETPROBE_OFFSET, + FTRACE_README_ARRAY_TYPE, FTRACE_README_END, }; @@ -1010,6 +1011,8 @@ static struct { [idx] = {.pattern = pat, .avail = false} DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"), DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"), + DEFINE_TYPE(FTRACE_README_ARRAY_TYPE, + "*<type>\\\\\\[<array-size>\\\\\\]*"), }; static bool scan_ftrace_readme(enum ftrace_readme type) @@ -1057,6 +1060,8 @@ bool probe_type_is_available(enum probe_type type) return false; else if (type == PROBE_TYPE_X) return scan_ftrace_readme(FTRACE_README_PROBE_TYPE_X); + else if (type == PROBE_TYPE_ARRAY) + return scan_ftrace_readme(FTRACE_README_ARRAY_TYPE); return true; } diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h index 63f29b1d22c1..654290b2fd9c 100644 --- a/tools/perf/util/probe-file.h +++ b/tools/perf/util/probe-file.h @@ -27,6 +27,7 @@ enum probe_type { PROBE_TYPE_X, PROBE_TYPE_STRING, PROBE_TYPE_BITFIELD, + PROBE_TYPE_ARRAY, PROBE_TYPE_END, }; diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c index c37fbef1711d..a1df7926edfc 100644 --- a/tools/perf/util/probe-finder.c +++ b/tools/perf/util/probe-finder.c @@ -290,13 +290,52 @@ static int convert_variable_location(Dwarf_Die *vr_die, Dwarf_Addr addr, return ret2; } +static int convert_variable_string_type(Dwarf_Die *vr_die, Dwarf_Die *type, + struct probe_trace_arg *tvar) +{ + struct probe_trace_arg_ref **ref_ptr = &tvar->ref; + int ret; + + 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.\n", + dwarf_diename(vr_die), dwarf_diename(type)); + return -EINVAL; + } + if (ret == DW_TAG_pointer_type && tvar->length == 0) { + while (*ref_ptr) + ref_ptr = &(*ref_ptr)->next; + /* Add new reference with offset +0 */ + *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref)); + if (*ref_ptr == NULL) { + pr_warning("Out of memory error\n"); + return -ENOMEM; + } + } + if (die_get_real_type(type, type) == NULL) { + pr_warning("Failed to get a type" + " information.\n"); + return -ENOENT; + } + if (!die_compare_name(type, "char") && + !die_compare_name(type, "unsigned char")) { + pr_warning("Failed to cast into string: " + "%s is not (unsigned) char *.\n", + dwarf_diename(vr_die)); + return -EINVAL; + } + tvar->type = strdup("string"); + return (tvar->type == NULL) ? -ENOMEM : 0; +} + #define BYTES_TO_BITS(nb) ((nb) * BITS_PER_LONG / sizeof(long)) static int convert_variable_type(Dwarf_Die *vr_die, struct probe_trace_arg *tvar, - const char *cast) + struct perf_probe_arg *pvar) { - struct probe_trace_arg_ref **ref_ptr = &tvar->ref; + const char *cast = pvar->type; Dwarf_Die type; char buf[16]; char sbuf[STRERR_BUFSIZE]; @@ -304,6 +343,12 @@ static int convert_variable_type(Dwarf_Die *vr_die, int ret; char prefix; + tvar->length = pvar->length; + if (tvar->length && !probe_type_is_available(PROBE_TYPE_ARRAY)) { + pr_warning("This kerneld doesn't support array type.\n"); + return -ENOTSUP; + } + /* TODO: check all types */ if (cast && strcmp(cast, "string") != 0 && strcmp(cast, "x") != 0 && strcmp(cast, "s") != 0 && strcmp(cast, "u") != 0) { @@ -334,40 +379,8 @@ static int convert_variable_type(Dwarf_Die *vr_die, pr_debug("%s type is %s.\n", dwarf_diename(vr_die), dwarf_diename(&type)); - 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.\n", - dwarf_diename(vr_die), dwarf_diename(&type)); - return -EINVAL; - } - if (die_get_real_type(&type, &type) == NULL) { - pr_warning("Failed to get a type" - " information.\n"); - return -ENOENT; - } - if (ret == DW_TAG_pointer_type) { - while (*ref_ptr) - ref_ptr = &(*ref_ptr)->next; - /* Add new reference with offset +0 */ - *ref_ptr = zalloc(sizeof(struct probe_trace_arg_ref)); - if (*ref_ptr == NULL) { - pr_warning("Out of memory error\n"); - return -ENOMEM; - } - } - if (!die_compare_name(&type, "char") && - !die_compare_name(&type, "unsigned char")) { - pr_warning("Failed to cast into string: " - "%s is not (unsigned) char *.\n", - dwarf_diename(vr_die)); - return -EINVAL; - } - tvar->type = strdup(cast); - return (tvar->type == NULL) ? -ENOMEM : 0; - } + if (cast && strcmp(cast, "string") == 0) /* String type */ + return convert_variable_string_type(vr_die, &type, tvar); if (cast && (strcmp(cast, "u") == 0)) prefix = 'u'; @@ -381,9 +394,13 @@ static int convert_variable_type(Dwarf_Die *vr_die, probe_type_is_available(PROBE_TYPE_X) ? 'x' : 'u'; ret = dwarf_bytesize(&type); - if (ret <= 0) - /* No size ... try to use default type */ + if (ret <= 0) { /* No size ... try to use default type */ + if (tvar->length) { /* But array can not be dumped */ + pr_warning("Failed to convert array with unsupported type\n"); + return -EINVAL; + } return 0; + } ret = BYTES_TO_BITS(ret); /* Check the bitwidth */ @@ -559,7 +576,7 @@ static int convert_variable(Dwarf_Die *vr_die, struct probe_finder *pf) vr_die = &die_mem; } if (ret == 0) - ret = convert_variable_type(vr_die, pf->tvar, pf->pvar->type); + ret = convert_variable_type(vr_die, pf->tvar, pf->pvar); /* *expr will be cached in libdw. Don't free it. */ return ret; }
