rtla: Replace magic number with MAX_PATH

The trace functions use a buffer to manipulate strings that will be
written to tracefs files. These buffers are defined with a magic number
of 1024, which is a common source of vulnerabilities.

Replace the magic number 1024 with the MAX_PATH macro to make the code
safer and more readable. While at it, replace other instances of the
magic number with ARRAY_SIZE() when the buffer is locally defined.

Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Link: https://lore.kernel.org/r/20260309195040.1019085-6-wander@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>

diff --git a/tools/tracing/rtla/src/osnoise.c b/tools/tracing/rtla/src/osnoise.c
index ec074cd53dd8447b7d35d6abd5d41c22a50c5e0d..9d1fd9981fe91345ca03c5644b77585b6bd13ca0 100644 (file)
--- a/tools/tracing/rtla/src/osnoise.c
+++ b/tools/tracing/rtla/src/osnoise.c
@@ -62,7 +62,7 @@ int osnoise_set_cpus(struct osnoise_context *context, char *cpus)
        if (!context->curr_cpus)
                return -1;
 
-       snprintf(buffer, 1024, "%s\n", cpus);
+       snprintf(buffer, ARRAY_SIZE(buffer), "%s\n", cpus);
 
        debug_msg("setting cpus to %s from %s", cpus, context->orig_cpus);
 

diff --git a/tools/tracing/rtla/src/timerlat_u.c b/tools/tracing/rtla/src/timerlat_u.c
index 03b4e68e8b1e68b59071762458eb990dc18c673f..c80edaf07b0090c7370901e2debae5c98abca14a 100644 (file)
--- a/tools/tracing/rtla/src/timerlat_u.c
+++ b/tools/tracing/rtla/src/timerlat_u.c
@@ -32,7 +32,7 @@
 static int timerlat_u_main(int cpu, struct timerlat_u_params *params)
 {
        struct sched_param sp = { .sched_priority = 95 };
-       char buffer[1024];
+       char buffer[MAX_PATH];
        int timerlat_fd;
        cpu_set_t set;
        int retval;
@@ -83,7 +83,7 @@ static int timerlat_u_main(int cpu, struct timerlat_u_params *params)
 
        /* add should continue with a signal handler */
        while (true) {
-               retval = read(timerlat_fd, buffer, 1024);
+               retval = read(timerlat_fd, buffer, ARRAY_SIZE(buffer));
                if (retval < 0)
                        break;
        }

diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c
index 211ca54b15b0e4cf2b6e225ece8d93ec8362a61a..e1af54f9531b87465b84f820416110e08a436aae 100644 (file)
--- a/tools/tracing/rtla/src/trace.c
+++ b/tools/tracing/rtla/src/trace.c
@@ -313,7 +313,7 @@ void trace_event_add_trigger(struct trace_events *event, char *trigger)
 static void trace_event_disable_filter(struct trace_instance *instance,
                                       struct trace_events *tevent)
 {
-       char filter[1024];
+       char filter[MAX_PATH];
        int retval;
 
        if (!tevent->filter)
@@ -325,7 +325,7 @@ static void trace_event_disable_filter(struct trace_instance *instance,
        debug_msg("Disabling %s:%s filter %s\n", tevent->system,
                  tevent->event ? : "*", tevent->filter);
 
-       snprintf(filter, 1024, "!%s\n", tevent->filter);
+       snprintf(filter, ARRAY_SIZE(filter), "!%s\n", tevent->filter);
 
        retval = tracefs_event_file_write(instance->inst, tevent->system,
                                          tevent->event, "filter", filter);
@@ -344,7 +344,7 @@ static void trace_event_save_hist(struct trace_instance *instance,
 {
        int retval, index, out_fd;
        mode_t mode = 0644;
-       char path[1024];
+       char path[MAX_PATH];
        char *hist;
 
        if (!tevent)
@@ -359,7 +359,7 @@ static void trace_event_save_hist(struct trace_instance *instance,
        if (retval)
                return;
 
-       snprintf(path, 1024, "%s_%s_hist.txt", tevent->system, tevent->event);
+       snprintf(path, ARRAY_SIZE(path), "%s_%s_hist.txt", tevent->system, tevent->event);
 
        printf("  Saving event %s:%s hist to %s\n", tevent->system, tevent->event, path);
 
@@ -391,7 +391,7 @@ out_close:
 static void trace_event_disable_trigger(struct trace_instance *instance,
                                        struct trace_events *tevent)
 {
-       char trigger[1024];
+       char trigger[MAX_PATH];
        int retval;
 
        if (!tevent->trigger)
@@ -405,7 +405,7 @@ static void trace_event_disable_trigger(struct trace_instance *instance,
 
        trace_event_save_hist(instance, tevent);
 
-       snprintf(trigger, 1024, "!%s\n", tevent->trigger);
+       snprintf(trigger, ARRAY_SIZE(trigger), "!%s\n", tevent->trigger);
 
        retval = tracefs_event_file_write(instance->inst, tevent->system,
                                          tevent->event, "trigger", trigger);
@@ -444,7 +444,7 @@ void trace_events_disable(struct trace_instance *instance,
 static int trace_event_enable_filter(struct trace_instance *instance,
                                     struct trace_events *tevent)
 {
-       char filter[1024];
+       char filter[MAX_PATH];
        int retval;
 
        if (!tevent->filter)
@@ -456,7 +456,7 @@ static int trace_event_enable_filter(struct trace_instance *instance,
                return 1;
        }
 
-       snprintf(filter, 1024, "%s\n", tevent->filter);
+       snprintf(filter, ARRAY_SIZE(filter), "%s\n", tevent->filter);
 
        debug_msg("Enabling %s:%s filter %s\n", tevent->system,
                  tevent->event ? : "*", tevent->filter);
@@ -479,7 +479,7 @@ static int trace_event_enable_filter(struct trace_instance *instance,
 static int trace_event_enable_trigger(struct trace_instance *instance,
                                      struct trace_events *tevent)
 {
-       char trigger[1024];
+       char trigger[MAX_PATH];
        int retval;
 
        if (!tevent->trigger)
@@ -491,7 +491,7 @@ static int trace_event_enable_trigger(struct trace_instance *instance,
                return 1;
        }
 
-       snprintf(trigger, 1024, "%s\n", tevent->trigger);
+       snprintf(trigger, ARRAY_SIZE(trigger), "%s\n", tevent->trigger);
 
        debug_msg("Enabling %s:%s trigger %s\n", tevent->system,
                  tevent->event ? : "*", tevent->trigger);