Messages in this thread Patch in this message |  | | From | Jeremy Linton <> | Subject | [RFC/PATCH] perf: Add sizeof operator support | Date | Tue, 14 Jun 2016 11:38:32 -0500 |
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There are a fair number of tracepoints in the kernel making use of the sizeof operator. Allow perf to understand some of those cases, and report a more informative error message for the ones it cannot understand.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> ---
So this is as much a RFC as a patch because the use of sizeof seems to extend to structures, pointers, etc that aren't easy to deduce from userspace. I'm not sure what the correct solution should be in those cases.
tools/lib/traceevent/event-parse.c | 46 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+)
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c index a8b6357..5813248 100644 --- a/tools/lib/traceevent/event-parse.c +++ b/tools/lib/traceevent/event-parse.c @@ -31,6 +31,8 @@ #include <errno.h> #include <stdint.h> #include <limits.h> +#include <linux/kernel.h> +#include <linux/types.h> #include <netinet/ip6.h> #include "event-parse.h" @@ -2868,6 +2870,46 @@ process_str(struct event_format *event __maybe_unused, struct print_arg *arg, } static enum event_type +process_sizeof(struct event_format *event __maybe_unused, struct print_arg *arg, + char **tok) +{ + char *token; + char *atom; + + if (process_paren(event, arg, &token) < 0) + goto out_free; + + atom = arg->atom.atom; + if (arg->type != PRINT_ATOM) { + do_warning_event(event, "didn't understand %s for sizeof\n", + token); + goto out_free_atom; + } + + if (strcmp(token, "__u64") == 0) { + if (asprintf(&arg->atom.atom, "%zd", sizeof(__u64)) < 0) + goto out_free_atom; + } else if (strcmp(token, "__u32") == 0) { + if (asprintf(&arg->atom.atom, "%zd", sizeof(__u32)) < 0) + goto out_free_atom; + } else { + do_warning_event(event, "unknown sizeof %s\n", token); + goto out_free_atom; + } + + free(atom); + *tok = token; + return EVENT_DELIM; + + out_free_atom: + free_token(atom); + out_free: + free_token(token); + *tok = NULL; + return EVENT_ERROR; +} + +static enum event_type process_bitmask(struct event_format *event __maybe_unused, struct print_arg *arg, char **tok) { @@ -3026,6 +3068,10 @@ process_function(struct event_format *event, struct print_arg *arg, free_token(token); return process_dynamic_array_len(event, arg, tok); } + if (strcmp(token, "sizeof") == 0) { + free_token(token); + return process_sizeof(event, arg, tok); + } func = find_func_handler(event->pevent, token); if (func) { -- 2.5.5
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