From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Tue, 9 Jan 2024 15:33:13 +0000 (-0500)
Subject: Fix: prio context NULL pointer exception
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=1158b2706e58c2f94e6bd746e0504b989320c0a1;p=lttng-modules.git

Fix: prio context NULL pointer exception

A missing call to wrapper_task_prio_init() causes the function pointer
for task_prio to stay NULL, which triggers a OOPS when trying to use the
prio context.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I417e84cb8a07db624e682c7ec2c033fbc2a7b8e7
---

diff --git a/include/lttng/events-internal.h b/include/lttng/events-internal.h
index a727230f..181b7b45 100644
--- a/include/lttng/events-internal.h
+++ b/include/lttng/events-internal.h
@@ -649,6 +649,7 @@ int lttng_add_pid_to_ctx(struct lttng_kernel_ctx **ctx);
 int lttng_add_cpu_id_to_ctx(struct lttng_kernel_ctx **ctx);
 int lttng_add_procname_to_ctx(struct lttng_kernel_ctx **ctx);
 int lttng_add_prio_to_ctx(struct lttng_kernel_ctx **ctx);
+int wrapper_task_prio_init(void);
 int lttng_add_nice_to_ctx(struct lttng_kernel_ctx **ctx);
 int lttng_add_vpid_to_ctx(struct lttng_kernel_ctx **ctx);
 int lttng_add_tid_to_ctx(struct lttng_kernel_ctx **ctx);
diff --git a/src/lttng-context-prio.c b/src/lttng-context-prio.c
index a3034e4e..aac10a63 100644
--- a/src/lttng-context-prio.c
+++ b/src/lttng-context-prio.c
@@ -29,6 +29,7 @@ int wrapper_task_prio_init(void)
 	}
 	return 0;
 }
+EXPORT_SYMBOL_GPL(wrapper_task_prio_init);
 
 /*
  * Canary function to check for 'task_prio()' at compile time.
diff --git a/src/lttng-events.c b/src/lttng-events.c
index a0bd2322..08884410 100644
--- a/src/lttng-events.c
+++ b/src/lttng-events.c
@@ -4148,6 +4148,9 @@ static int __init lttng_events_init(void)
 	int ret;
 
 	ret = wrapper_get_pfnblock_flags_mask_init();
+	if (ret)
+		return ret;
+	ret = wrapper_task_prio_init();
 	if (ret)
 		return ret;
 	ret = lttng_probes_init();