stackleak: let stack_erasing_sysctl take a kernel pointer buffer

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

kernel/stackleak.c:31:50: warning: incorrect type in argument 3 (different address spaces)
kernel/stackleak.c:31:50:    expected void *
kernel/stackleak.c:31:50:    got void [noderef] __user *buffer

Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: https://lkml.kernel.org/r/20200907093253.13656-1-tklauser@distanz.ch
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/stackleak.h b/include/linux/stackleak.h
index 3d5c327..a59db2f 100644 (file)
--- a/include/linux/stackleak.h
+++ b/include/linux/stackleak.h
@@ -25,7 +25,7 @@ static inline void stackleak_task_init(struct task_struct *t)
 
 #ifdef CONFIG_STACKLEAK_RUNTIME_DISABLE
 int stack_erasing_sysctl(struct ctl_table *table, int write,
-                       void __user *buffer, size_t *lenp, loff_t *ppos);
+                       void *buffer, size_t *lenp, loff_t *ppos);
 #endif
 
 #else /* !CONFIG_GCC_PLUGIN_STACKLEAK */

diff --git a/kernel/stackleak.c b/kernel/stackleak.c
index a8fc9ae..ce161a8 100644 (file)
--- a/kernel/stackleak.c
+++ b/kernel/stackleak.c
@@ -20,7 +20,7 @@
 static DEFINE_STATIC_KEY_FALSE(stack_erasing_bypass);
 
 int stack_erasing_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 = 0;
        int state = !static_branch_unlikely(&stack_erasing_bypass);