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| 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_alloc.h | |
| parent | 6cffd79504ce040f460831030d3069fa1c99bb71 (diff) | |
| download | lwn-1a7c3d9bb7a926e88d5f57643e75ad1abfc55013.tar.gz lwn-1a7c3d9bb7a926e88d5f57643e75ad1abfc55013.zip | |
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_alloc.h')
| -rw-r--r-- | drivers/android/binder_alloc.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h index c0aadbbf7f19..995155f31dbd 100644 --- a/drivers/android/binder_alloc.h +++ b/drivers/android/binder_alloc.h @@ -22,6 +22,7 @@ #include <linux/vmalloc.h> #include <linux/slab.h> #include <linux/list_lru.h> +#include <uapi/linux/android/binder.h> extern struct list_lru binder_alloc_lru; struct binder_transaction; @@ -183,5 +184,12 @@ binder_alloc_get_user_buffer_offset(struct binder_alloc *alloc) return alloc->user_buffer_offset; } +unsigned long +binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc, + struct binder_buffer *buffer, + binder_size_t buffer_offset, + const void __user *from, + size_t bytes); + #endif /* _LINUX_BINDER_ALLOC_H */ |