[PATCH] ftrace: let ftrace_enable_sysctl take a kernel pointer buffer

From: Tobias Klauser
Date: Mon Sep 07 2020 - 05:32:13 EST


Commit 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
changed ctl_table.proc_handler to take a kernel pointer. Adjust the
signature of ftrace_enable_sysctl to match ctl_table.proc_handler which
fixes the following sparse warning:

kernel/trace/ftrace.c:7544:43: warning: incorrect type in argument 3 (different address spaces)
kernel/trace/ftrace.c:7544:43: expected void *
kernel/trace/ftrace.c:7544:43: got void [noderef] __user *buffer

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Tobias Klauser <tklauser@xxxxxxxxxx>
---
include/linux/ftrace.h | 3 +--
kernel/trace/ftrace.c | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index ce2c06f72e86..e5c2d5cc6e6a 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -85,8 +85,7 @@ static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *val
extern int ftrace_enabled;
extern int
ftrace_enable_sysctl(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos);
+ void *buffer, size_t *lenp, loff_t *ppos);

struct ftrace_ops;

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 275441254bb5..e9fa580f3083 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -7531,8 +7531,7 @@ static bool is_permanent_ops_registered(void)

int
ftrace_enable_sysctl(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
+ void *buffer, size_t *lenp, loff_t *ppos)
{
int ret = -ENODEV;

--
2.27.0