With CONFIG_INIT_STACK_ALL enabled, the local __wq_entry is initialized
twice. Because Clang is currently unable to optimize the automatic
initialization away (init_wait_entry() is defined in another translation
unit), remove it with the __no_initialize annotation.
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
---
v2:
- changed __do_not_initialize to __no_initialize as requested by Kees
Cook
---
drivers/android/binder.c | 4 ++--
include/linux/wait.h | 3 ++-
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index a59871532ff6b..66984e7c33094 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -4827,7 +4827,7 @@ static int binder_ioctl_write_read(struct file *filp,
struct binder_proc *proc = filp->private_data;
unsigned int size = _IOC_SIZE(cmd);
void __user *ubuf = (void __user *)arg;
- struct binder_write_read bwr __no_initialize;
+ struct binder_write_read bwr;
if (size != sizeof(struct binder_write_read)) {
ret = -EINVAL;
@@ -5026,7 +5026,7 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
goto err;
break;
case BINDER_SET_MAX_THREADS: {
- int max_threads;
+ int max_threads __no_initialize;
if (copy_from_user(&max_threads, ubuf,
sizeof(max_threads))) {
diff --git a/include/linux/wait.h b/include/linux/wait.h
index 3283c8d021377..b52a9bb2c7727 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -262,7 +262,8 @@ extern void init_wait_entry(struct wait_queue_entry *wq_entry, int flags);
#define ___wait_event(wq_head, condition, state, exclusive, ret, cmd) \
({ \
__label__ __out; \
- struct wait_queue_entry __wq_entry; \
+ /* Unconditionally initialized by init_wait_entry(). */ \
+ struct wait_queue_entry __wq_entry __no_initialize; \
long __ret = ret; /* explicit shadow */ \
\
init_wait_entry(&__wq_entry, exclusive ? WQ_FLAG_EXCLUSIVE : 0); \
--
2.25.0.265.gbab2e86ba0-goog
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