From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Fri, 6 Sep 2019 01:01:47 +0000 (-0400)
Subject: Fix: gcc-9.1 stack frame size warning
X-Git-Tag: v2.9.14~1
X-Git-Url: http://git.liburcu.org/?p=lttng-modules.git;a=commitdiff_plain;h=78c597c7e02868d6bf3c0b5c6005afade2a8ad70

Fix: gcc-9.1 stack frame size warning

gcc-9.1.0 warns about lttng_session_ioctl taking a too large frame size.

lttng-modules/lttng-abi.c:622:1: warning: the frame size of 2240 bytes
is larger than 2048 bytes [-Wframe-larger-than=]

Combine the variables used in the various case of the switch so they are
not duplicated on the stack by the compiler.

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

diff --git a/lttng-abi.c b/lttng-abi.c
index bee4255d..1f00a0e5 100644
--- a/lttng-abi.c
+++ b/lttng-abi.c
@@ -490,13 +490,12 @@ static
 long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct lttng_session *session = file->private_data;
+	struct lttng_kernel_channel chan_param;
+	struct lttng_kernel_old_channel old_chan_param;
 
 	switch (cmd) {
 	case LTTNG_KERNEL_OLD_CHANNEL:
 	{
-		struct lttng_kernel_channel chan_param;
-		struct lttng_kernel_old_channel old_chan_param;
-
 		if (copy_from_user(&old_chan_param,
 				(struct lttng_kernel_old_channel __user *) arg,
 				sizeof(struct lttng_kernel_old_channel)))
@@ -513,8 +512,6 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	}
 	case LTTNG_KERNEL_CHANNEL:
 	{
-		struct lttng_kernel_channel chan_param;
-
 		if (copy_from_user(&chan_param,
 				(struct lttng_kernel_channel __user *) arg,
 				sizeof(struct lttng_kernel_channel)))
@@ -534,9 +531,6 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		return lttng_session_disable(session);
 	case LTTNG_KERNEL_OLD_METADATA:
 	{
-		struct lttng_kernel_channel chan_param;
-		struct lttng_kernel_old_channel old_chan_param;
-
 		if (copy_from_user(&old_chan_param,
 				(struct lttng_kernel_old_channel __user *) arg,
 				sizeof(struct lttng_kernel_old_channel)))
@@ -553,8 +547,6 @@ long lttng_session_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	}
 	case LTTNG_KERNEL_METADATA:
 	{
-		struct lttng_kernel_channel chan_param;
-
 		if (copy_from_user(&chan_param,
 					(struct lttng_kernel_channel __user *) arg,
 					sizeof(struct lttng_kernel_channel)))