[13/15] stackleak: let stack_erasing_sysctl take a kernel pointer buffer

Commit Message

Andrew Morton Sept. 19, 2020, 4:20 a.m. UTC

From: Tobias Klauser <[e-mail]>
Subject: 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

Link: https://lkml.kernel.org/r/[e-mail]
Fixes: 32927393dc1c ("sysctl: pass kernel pointers to ->proc_handler")
Signed-off-by: Tobias Klauser <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Al Viro <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 include/linux/stackleak.h |    2 +-
 kernel/stackleak.c        |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Patch

--- a/include/linux/stackleak.h~stackleak-let-stack_erasing_sysctl-take-a-kernel-pointer-buffer
+++ a/include/linux/stackleak.h
@@ -25,7 +25,7 @@  static inline void stackleak_task_init(s
 
 #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 */
--- a/kernel/stackleak.c~stackleak-let-stack_erasing_sysctl-take-a-kernel-pointer-buffer
+++ a/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);