diff options
| author | Jiazi.Li <jqqlijiazi@gmail.com> | 2022-11-15 20:03:51 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-19 17:13:56 +0100 |
| commit | 7feb35bc16203c06362c31b95d0d2f291c0212d5 (patch) | |
| tree | 9e0ad08bc50782f905b0a18f080e58c80a6a41c6 /drivers/android/binder.c | |
| parent | 5dc4c995db9eb45f6373a956eb1f69460e69e6d4 (diff) | |
binder: remove unneeded size check code
In binder_ioctl function, the legitimacy check of cmd size has been
done in switch-case code:
switch (cmd) {
case BINDER_WRITE_READ;//BINDER_WRITE_READ contains size info
So unneeded do size check in binder_ioctl and binder_ioctl_write_read
again.
In the following version of Google GKI:
Linux version 5.10.110-android12-9-00011-g2c814f559132-ab8969555
It seems that the compiler has made optimization and has not passed
cmd parameters to binder_ioctl_write_read:
<binder_ioctl+628>: mov w8, #0x6201 // #25089
<binder_ioctl+632>: movk w8, #0xc030, lsl #16
<binder_ioctl+636>: cmp w20, w8
<binder_ioctl+640>: b.ne 0xffffffda8aa97880 <binder_ioctl+3168>
<binder_ioctl+644>: mov x0, x23 //filp
<binder_ioctl+648>: mov x1, x27 //arg
<binder_ioctl+652>: mov x2, x22 //thread
<binder_ioctl+656>: bl 0xffffffda8aa9e6e4 <binder_ioctl_write_read>
<binder_ioctl+660>: mov w26, w0
Signed-off-by: Jiazi.Li <jiazi.li@transsion.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Link: https://lore.kernel.org/r/20221115120351.2769-1-jiazi.li@transsion.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/android/binder.c')
| -rw-r--r-- | drivers/android/binder.c | 15 |
1 files changed, 2 insertions, 13 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 880224ec6abb..48e5a3531282 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -5006,20 +5006,14 @@ static __poll_t binder_poll(struct file *filp, return 0; } -static int binder_ioctl_write_read(struct file *filp, - unsigned int cmd, unsigned long arg, +static int binder_ioctl_write_read(struct file *filp, unsigned long arg, struct binder_thread *thread) { int ret = 0; struct binder_proc *proc = filp->private_data; - unsigned int size = _IOC_SIZE(cmd); void __user *ubuf = (void __user *)arg; struct binder_write_read bwr; - if (size != sizeof(struct binder_write_read)) { - ret = -EINVAL; - goto out; - } if (copy_from_user(&bwr, ubuf, sizeof(bwr))) { ret = -EFAULT; goto out; @@ -5296,7 +5290,6 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) int ret; struct binder_proc *proc = filp->private_data; struct binder_thread *thread; - unsigned int size = _IOC_SIZE(cmd); void __user *ubuf = (void __user *)arg; /*pr_info("binder_ioctl: %d:%d %x %lx\n", @@ -5318,7 +5311,7 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) switch (cmd) { case BINDER_WRITE_READ: - ret = binder_ioctl_write_read(filp, cmd, arg, thread); + ret = binder_ioctl_write_read(filp, arg, thread); if (ret) goto err; break; @@ -5361,10 +5354,6 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) case BINDER_VERSION: { struct binder_version __user *ver = ubuf; - if (size != sizeof(struct binder_version)) { - ret = -EINVAL; - goto err; - } if (put_user(BINDER_CURRENT_PROTOCOL_VERSION, &ver->protocol_version)) { ret = -EINVAL; |