| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20150723215836.GG3154@kernel.org>
Date: Thu, 23 Jul 2015 18:58:36 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Steven Rostedt <rostedt@...dmis.org>
Cc: David Ahern <dsahern@...il.com>,
Adrian Hunter <adrian.hunter@...el.com>,
Borislav Petkov <bp@...e.de>,
Frederic Weisbecker <fweisbec@...il.com>,
Jiri Olsa <jolsa@...hat.com>,
Namhyung Kim <namhyung@...nel.org>,
Stephane Eranian <eranian@...gle.com>,
Ingo Molnar <mingo@...nel.org>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [RFC PATCH] tools lib traceevent: Allow setting an alternative
symbol resolver
Em Thu, Jul 23, 2015 at 06:52:46PM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, Jul 23, 2015 at 05:35:24PM -0400, Steven Rostedt escreveu:
> > On Thu, 23 Jul 2015 18:25:36 -0300
> > Arnaldo Carvalho de Melo <acme@...nel.org> wrote:
> > > + if (resolver == NULL) {
> > > + errno = ENOMEM;
> >
> > Why set errno, wont a failed malloc set it for us?
>
> Humm, I thought about that, I've read malloc's man page and it doesn't
> mention that... in the return section, but later, in NOTES, it says
> UNIX98 requires that and glibc does it, so I'm ditching this...
> > Also I wonder if we should add a way to clear the resolver. That is,
> > you want to use the default resolver?
>
> I am adding a reset_function_resolver(pevent);
>
> > Not really a necessity, as I don't see any current programs using it,
> > but it would complete the interface.
One more try:
commit 212a2417baaa89168cbe3112fe7c8efaddee28b8
Author: Arnaldo Carvalho de Melo <acme@...hat.com>
Date: Wed Jul 22 12:36:55 2015 -0300
tools lib traceevent: Allow setting an alternative symbol resolver
The perf tools have a symbol resolver that includes solving kernel
symbols using either kallsyms or ELF symtabs, and it also is using
libtraceevent to format the trace events fields, including via
subsystem specific plugins, like the "timer" one.
To solve fields like "timer:hrtimer_start"'s "function", libtraceevent
needs a way to map from its value to a function name and addr.
This patch provides a way for tools that already have symbol resolving
facilities to ask libtraceevent to use it when needing to resolve
kernel symbols.
Acked-by: David Ahern <dsahern@...il.com>
Cc: Adrian Hunter <adrian.hunter@...el.com>
Cc: Borislav Petkov <bp@...e.de>
Cc: Frederic Weisbecker <fweisbec@...il.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Namhyung Kim <namhyung@...nel.org>
Cc: Stephane Eranian <eranian@...gle.com>
Cc: Steven Rostedt <rostedt@...dmis.org>
Link: http://lkml.kernel.org/n/tip-fdx1fazols17w5py26ia3bwh@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index cc25f059ab3d..fcd8a9e3d2e1 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -418,7 +418,7 @@ static int func_map_init(struct pevent *pevent)
}
static struct func_map *
-find_func(struct pevent *pevent, unsigned long long addr)
+__find_func(struct pevent *pevent, unsigned long long addr)
{
struct func_map *func;
struct func_map key;
@@ -434,6 +434,71 @@ find_func(struct pevent *pevent, unsigned long long addr)
return func;
}
+struct func_resolver {
+ pevent_func_resolver_t *func;
+ void *priv;
+ struct func_map map;
+};
+
+/**
+ * pevent_set_function_resolver - set an alternative function resolver
+ * @pevent: handle for the pevent
+ * @resolver: function to be used
+ * @priv: resolver function private state.
+ *
+ * Some tools may have already a way to resolve kernel functions, allow them to
+ * keep using it instead of duplicating all the entries inside
+ * pevent->funclist.
+ */
+int pevent_set_function_resolver(struct pevent *pevent,
+ pevent_func_resolver_t *func, void *priv)
+{
+ struct func_resolver *resolver = malloc(sizeof(*resolver));
+
+ if (resolver == NULL)
+ return -1;
+
+ resolver->func = func;
+ resolver->priv = priv;
+
+ free(pevent->func_resolver);
+ pevent->func_resolver = resolver;
+
+ return 0;
+}
+
+/**
+ * pevent_reset_function_resolver - reset alternative function resolver
+ * @pevent: handle for the pevent
+ *
+ * Stop using whatever alternative resolver was set, use the default
+ * one instead.
+ */
+void pevent_reset_function_resolver(struct pevent *pevent)
+{
+ free(pevent->func_resolver);
+ pevent->func_resolver = NULL;
+}
+
+static struct func_map *
+find_func(struct pevent *pevent, unsigned long long addr)
+{
+ struct func_map *map;
+
+ if (!pevent->func_resolver)
+ return __find_func(pevent, addr);
+
+ map = &pevent->func_resolver->map;
+ map->mod = NULL;
+ map->addr = addr;
+ map->func = pevent->func_resolver->func(pevent->func_resolver->priv,
+ &map->addr, &map->mod);
+ if (map->func == NULL)
+ return NULL;
+
+ return map;
+}
+
/**
* pevent_find_function - find a function by a given address
* @pevent: handle for the pevent
@@ -6564,6 +6629,7 @@ void pevent_free(struct pevent *pevent)
free(pevent->trace_clock);
free(pevent->events);
free(pevent->sort_events);
+ free(pevent->func_resolver);
free(pevent);
}
diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
index 063b1971eb35..204befb05a17 100644
--- a/tools/lib/traceevent/event-parse.h
+++ b/tools/lib/traceevent/event-parse.h
@@ -453,6 +453,10 @@ struct cmdline_list;
struct func_map;
struct func_list;
struct event_handler;
+struct func_resolver;
+
+typedef char *(pevent_func_resolver_t)(void *priv,
+ unsigned long long *addrp, char **modp);
struct pevent {
int ref_count;
@@ -481,6 +485,7 @@ struct pevent {
int cmdline_count;
struct func_map *func_map;
+ struct func_resolver *func_resolver;
struct func_list *funclist;
unsigned int func_count;
@@ -611,6 +616,9 @@ enum trace_flag_type {
TRACE_FLAG_SOFTIRQ = 0x10,
};
+int pevent_set_function_resolver(struct pevent *pevent,
+ pevent_func_resolver_t *func, void *priv);
+void pevent_reset_function_resolver(struct pevent *pevent);
int pevent_register_comm(struct pevent *pevent, const char *comm, int pid);
int pevent_register_trace_clock(struct pevent *pevent, const char *trace_clock);
int pevent_register_function(struct pevent *pevent, char *name,
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists