diff options
| author | Todd Kjos <tkjos@android.com> | 2019-02-08 10:35:14 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 10:43:57 +0100 |
| commit | 1a7c3d9bb7a926e88d5f57643e75ad1abfc55013 (patch) | |
| tree | a64c869735ee00eded6f495cb250afefd96e1bba /drivers/android/binder.c | |
| parent | 6cffd79504ce040f460831030d3069fa1c99bb71 (diff) | |
binder: create userspace-to-binder-buffer copy function
The binder driver uses a vm_area to map the per-process
binder buffer space. For 32-bit android devices, this is
now taking too much vmalloc space. This patch removes
the use of vm_area when copying the transaction data
from the sender to the buffer space. Instead of using
copy_from_user() for multi-page copies, it now uses
binder_alloc_copy_user_to_buffer() which uses kmap()
and kunmap() to map each page, and uses copy_from_user()
for copying to that page.
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/android/binder.c')
| -rw-r--r-- | drivers/android/binder.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 01f80cbd2741..5ddb2a4d893e 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3078,8 +3078,12 @@ static void binder_transaction(struct binder_proc *proc, ALIGN(tr->data_size, sizeof(void *))); offp = off_start; - if (copy_from_user(t->buffer->data, (const void __user *)(uintptr_t) - tr->data.ptr.buffer, tr->data_size)) { + if (binder_alloc_copy_user_to_buffer( + &target_proc->alloc, + t->buffer, 0, + (const void __user *) + (uintptr_t)tr->data.ptr.buffer, + tr->data_size)) { binder_user_error("%d:%d got transaction with invalid data ptr\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; @@ -3087,8 +3091,13 @@ static void binder_transaction(struct binder_proc *proc, return_error_line = __LINE__; goto err_copy_data_failed; } - if (copy_from_user(offp, (const void __user *)(uintptr_t) - tr->data.ptr.offsets, tr->offsets_size)) { + if (binder_alloc_copy_user_to_buffer( + &target_proc->alloc, + t->buffer, + ALIGN(tr->data_size, sizeof(void *)), + (const void __user *) + (uintptr_t)tr->data.ptr.offsets, + tr->offsets_size)) { binder_user_error("%d:%d got transaction with invalid offsets ptr\n", proc->pid, thread->pid); return_error = BR_FAILED_REPLY; @@ -3217,6 +3226,8 @@ static void binder_transaction(struct binder_proc *proc, struct binder_buffer_object *bp = to_binder_buffer_object(hdr); size_t buf_left = sg_buf_end - sg_bufp; + binder_size_t sg_buf_offset = (uintptr_t)sg_bufp - + (uintptr_t)t->buffer->data; if (bp->length > buf_left) { binder_user_error("%d:%d got transaction with too large buffer\n", @@ -3226,9 +3237,13 @@ static void binder_transaction(struct binder_proc *proc, return_error_line = __LINE__; goto err_bad_offset; } - if (copy_from_user(sg_bufp, - (const void __user *)(uintptr_t) - bp->buffer, bp->length)) { + if (binder_alloc_copy_user_to_buffer( + &target_proc->alloc, + t->buffer, + sg_buf_offset, + (const void __user *) + (uintptr_t)bp->buffer, + bp->length)) { binder_user_error("%d:%d got transaction with invalid offsets ptr\n", proc->pid, thread->pid); return_error_param = -EFAULT; |