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path: root/drivers/android/binder_alloc.c
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2024-01-25binder: fix unused alloc->free_async_spaceCarlos Llamas
commit c6d05e0762ab276102246d24affd1e116a46aa0c upstream. Each transaction is associated with a 'struct binder_buffer' that stores the metadata about its buffer area. Since commit 74310e06be4d ("android: binder: Move buffer out of area shared with user space") this struct is no longer embedded within the buffer itself but is instead allocated on the heap to prevent userspace access to this driver-exclusive info. Unfortunately, the space of this struct is still being accounted for in the total buffer size calculation, specifically for async transactions. This results in an additional 104 bytes added to every async buffer request, and this area is never used. This wasted space can be substantial. If we consider the maximum mmap buffer space of SZ_4M, the driver will reserve half of it for async transactions, or 0x200000. This area should, in theory, accommodate up to 262,144 buffers of the minimum 8-byte size. However, after adding the extra 'sizeof(struct binder_buffer)', the total number of buffers drops to only 18,724, which is a sad 7.14% of the actual capacity. This patch fixes the buffer size calculation to enable the utilization of the entire async buffer space. This is expected to reduce the number of -ENOSPC errors that are seen on the field. Fixes: 74310e06be4d ("android: binder: Move buffer out of area shared with user space") Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-6-cmllamas@google.com [cmllamas: fix trivial conflict with missing 261e7818f06e.] Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25binder: fix race between mmput() and do_exit()Carlos Llamas
commit 9a9ab0d963621d9d12199df9817e66982582d5a5 upstream. Task A calls binder_update_page_range() to allocate and insert pages on a remote address space from Task B. For this, Task A pins the remote mm via mmget_not_zero() first. This can race with Task B do_exit() and the final mmput() refcount decrement will come from Task A. Task A | Task B ------------------+------------------ mmget_not_zero() | | do_exit() | exit_mm() | mmput() mmput() | exit_mmap() | remove_vma() | fput() | In this case, the work of ____fput() from Task B is queued up in Task A as TWA_RESUME. So in theory, Task A returns to userspace and the cleanup work gets executed. However, Task A instead sleep, waiting for a reply from Task B that never comes (it's dead). This means the binder_deferred_release() is blocked until an unrelated binder event forces Task A to go back to userspace. All the associated death notifications will also be delayed until then. In order to fix this use mmput_async() that will schedule the work in the corresponding mm->async_put_work WQ instead of Task A. Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-4-cmllamas@google.com [cmllamas: fix trivial conflict with missing d8ed45c5dcd4.] Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25binder: fix use-after-free in shinker's callbackCarlos Llamas
commit 3f489c2067c5824528212b0fc18b28d51332d906 upstream. The mmap read lock is used during the shrinker's callback, which means that using alloc->vma pointer isn't safe as it can race with munmap(). As of commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") the mmap lock is downgraded after the vma has been isolated. I was able to reproduce this issue by manually adding some delays and triggering page reclaiming through the shrinker's debug sysfs. The following KASAN report confirms the UAF: ================================================================== BUG: KASAN: slab-use-after-free in zap_page_range_single+0x470/0x4b8 Read of size 8 at addr ffff356ed50e50f0 by task bash/478 CPU: 1 PID: 478 Comm: bash Not tainted 6.6.0-rc5-00055-g1c8b86a3799f-dirty #70 Hardware name: linux,dummy-virt (DT) Call trace: zap_page_range_single+0x470/0x4b8 binder_alloc_free_page+0x608/0xadc __list_lru_walk_one+0x130/0x3b0 list_lru_walk_node+0xc4/0x22c binder_shrink_scan+0x108/0x1dc shrinker_debugfs_scan_write+0x2b4/0x500 full_proxy_write+0xd4/0x140 vfs_write+0x1ac/0x758 ksys_write+0xf0/0x1dc __arm64_sys_write+0x6c/0x9c Allocated by task 492: kmem_cache_alloc+0x130/0x368 vm_area_alloc+0x2c/0x190 mmap_region+0x258/0x18bc do_mmap+0x694/0xa60 vm_mmap_pgoff+0x170/0x29c ksys_mmap_pgoff+0x290/0x3a0 __arm64_sys_mmap+0xcc/0x144 Freed by task 491: kmem_cache_free+0x17c/0x3c8 vm_area_free_rcu_cb+0x74/0x98 rcu_core+0xa38/0x26d4 rcu_core_si+0x10/0x1c __do_softirq+0x2fc/0xd24 Last potentially related work creation: __call_rcu_common.constprop.0+0x6c/0xba0 call_rcu+0x10/0x1c vm_area_free+0x18/0x24 remove_vma+0xe4/0x118 do_vmi_align_munmap.isra.0+0x718/0xb5c do_vmi_munmap+0xdc/0x1fc __vm_munmap+0x10c/0x278 __arm64_sys_munmap+0x58/0x7c Fix this issue by performing instead a vma_lookup() which will fail to find the vma that was isolated before the mmap lock downgrade. Note that this option has better performance than upgrading to a mmap write lock which would increase contention. Plus, mmap_write_trylock() has been recently removed anyway. Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Cc: stable@vger.kernel.org Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-3-cmllamas@google.com [cmllamas: use find_vma() instead of vma_lookup() as commit ce6d42f2e4a2 is missing in v5.4. This only works because we check the vma against our cached alloc->vma pointer. Also, unlock via up_read() instead of mmap_read_unlock() as commit d8ed45c5dcd4 is also missing in v5.4.] Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25binder: fix async space check for 0-sized buffersCarlos Llamas
commit 3091c21d3e9322428691ce0b7a0cfa9c0b239eeb upstream. Move the padding of 0-sized buffers to an earlier stage to account for this round up during the alloc->free_async_space check. Fixes: 74310e06be4d ("android: binder: Move buffer out of area shared with user space") Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-5-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25binder: fix comment on binder_alloc_new_buf() return valueCarlos Llamas
commit e1090371e02b601cbfcea175c2a6cc7c955fa830 upstream. Update the comments of binder_alloc_new_buf() to reflect that the return value of the function is now ERR_PTR(-errno) on failure. No functional changes in this patch. Cc: stable@vger.kernel.org Fixes: 57ada2fb2250 ("binder: add log information for binder transaction failures") Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-8-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-25binder: fix trivial typo of binder_free_buf_locked()Carlos Llamas
commit 122a3c1cb0ff304c2b8934584fcfea4edb2fe5e3 upstream. Fix minor misspelling of the function in the comment section. No functional changes in this patch. Cc: stable@vger.kernel.org Fixes: 0f966cba95c7 ("binder: add flag to clear buffer on txn complete") Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-7-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-16binder: fix memory leak in binder_init()Qi Zheng
commit adb9743d6a08778b78d62d16b4230346d3508986 upstream. In binder_init(), the destruction of binder_alloc_shrinker_init() is not performed in the wrong path, which will cause memory leaks. So this commit introduces binder_alloc_shrinker_exit() and calls it in the wrong path to fix that. Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Acked-by: Carlos Llamas <cmllamas@google.com> Fixes: f2517eb76f1f ("android: binder: Add global lru shrinker to binder") Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/20230625154937.64316-1-qi.zheng@linux.dev Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10binder: fix UAF of alloc->vma in race with munmap()Carlos Llamas
In commit 720c24192404 ("ANDROID: binder: change down_write to down_read") binder assumed the mmap read lock is sufficient to protect alloc->vma inside binder_update_page_range(). This used to be accurate until commit dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap"), which now downgrades the mmap_lock after detaching the vma from the rbtree in munmap(). Then it proceeds to teardown and free the vma with only the read lock held. This means that accesses to alloc->vma in binder_update_page_range() now will race with vm_area_free() in munmap() and can cause a UAF as shown in the following KASAN trace: ================================================================== BUG: KASAN: use-after-free in vm_insert_page+0x7c/0x1f0 Read of size 8 at addr ffff16204ad00600 by task server/558 CPU: 3 PID: 558 Comm: server Not tainted 5.10.150-00001-gdc8dcf942daa #1 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x2a0 show_stack+0x18/0x2c dump_stack+0xf8/0x164 print_address_description.constprop.0+0x9c/0x538 kasan_report+0x120/0x200 __asan_load8+0xa0/0xc4 vm_insert_page+0x7c/0x1f0 binder_update_page_range+0x278/0x50c binder_alloc_new_buf+0x3f0/0xba0 binder_transaction+0x64c/0x3040 binder_thread_write+0x924/0x2020 binder_ioctl+0x1610/0x2e5c __arm64_sys_ioctl+0xd4/0x120 el0_svc_common.constprop.0+0xac/0x270 do_el0_svc+0x38/0xa0 el0_svc+0x1c/0x2c el0_sync_handler+0xe8/0x114 el0_sync+0x180/0x1c0 Allocated by task 559: kasan_save_stack+0x38/0x6c __kasan_kmalloc.constprop.0+0xe4/0xf0 kasan_slab_alloc+0x18/0x2c kmem_cache_alloc+0x1b0/0x2d0 vm_area_alloc+0x28/0x94 mmap_region+0x378/0x920 do_mmap+0x3f0/0x600 vm_mmap_pgoff+0x150/0x17c ksys_mmap_pgoff+0x284/0x2dc __arm64_sys_mmap+0x84/0xa4 el0_svc_common.constprop.0+0xac/0x270 do_el0_svc+0x38/0xa0 el0_svc+0x1c/0x2c el0_sync_handler+0xe8/0x114 el0_sync+0x180/0x1c0 Freed by task 560: kasan_save_stack+0x38/0x6c kasan_set_track+0x28/0x40 kasan_set_free_info+0x24/0x4c __kasan_slab_free+0x100/0x164 kasan_slab_free+0x14/0x20 kmem_cache_free+0xc4/0x34c vm_area_free+0x1c/0x2c remove_vma+0x7c/0x94 __do_munmap+0x358/0x710 __vm_munmap+0xbc/0x130 __arm64_sys_munmap+0x4c/0x64 el0_svc_common.constprop.0+0xac/0x270 do_el0_svc+0x38/0xa0 el0_svc+0x1c/0x2c el0_sync_handler+0xe8/0x114 el0_sync+0x180/0x1c0 [...] ================================================================== To prevent the race above, revert back to taking the mmap write lock inside binder_update_page_range(). One might expect an increase of mmap lock contention. However, binder already serializes these calls via top level alloc->mutex. Also, there was no performance impact shown when running the binder benchmark tests. Note this patch is specific to stable branches 5.4 and 5.10. Since in newer kernel releases binder no longer caches a pointer to the vma. Instead, it has been refactored to use vma_lookup() which avoids the issue described here. This switch was introduced in commit a43cfc87caaf ("android: binder: stop saving a pointer to the VMA"). Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap") Reported-by: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> # 5.4.x Cc: Minchan Kim <minchan@kernel.org> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Liam Howlett <liam.howlett@oracle.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-05binder: fix async_free_space accounting for empty parcelsTodd Kjos
commit cfd0d84ba28c18b531648c9d4a35ecca89ad9901 upstream. In 4.13, commit 74310e06be4d ("android: binder: Move buffer out of area shared with user space") fixed a kernel structure visibility issue. As part of that patch, sizeof(void *) was used as the buffer size for 0-length data payloads so the driver could detect abusive clients sending 0-length asynchronous transactions to a server by enforcing limits on async_free_size. Unfortunately, on the "free" side, the accounting of async_free_space did not add the sizeof(void *) back. The result was that up to 8-bytes of async_free_space were leaked on every async transaction of 8-bytes or less. These small transactions are uncommon, so this accounting issue has gone undetected for several years. The fix is to use "buffer_size" (the allocated buffer size) instead of "size" (the logical buffer size) when updating the async_free_space during the free operation. These are the same except for this corner case of asynchronous transactions with payloads < 8 bytes. Fixes: 74310e06be4d ("android: binder: Move buffer out of area shared with user space") Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable@vger.kernel.org # 4.14+ Link: https://lore.kernel.org/r/20211220190150.2107077-1-tkjos@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30binder: add flag to clear buffer on txn completeTodd Kjos
commit 0f966cba95c78029f491b433ea95ff38f414a761 upstream. Add a per-transaction flag to indicate that the buffer must be cleared when the transaction is complete to prevent copies of sensitive data from being preserved in memory. Signed-off-by: Todd Kjos <tkjos@google.com> Link: https://lore.kernel.org/r/20201120233743.3617529-1-tkjos@google.com Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29binder: Don't use mmput() from shrinker function.Tetsuo Handa
commit f867c771f98891841c217fa8459244ed0dd28921 upstream. syzbot is reporting that mmput() from shrinker function has a risk of deadlock [1], for delayed_uprobe_add() from update_ref_ctr() calls kzalloc(GFP_KERNEL) with delayed_uprobe_lock held, and uprobe_clear_state() from __mmput() also holds delayed_uprobe_lock. Commit a1b2289cef92ef0e ("android: binder: drop lru lock in isolate callback") replaced mmput() with mmput_async() in order to avoid sleeping with spinlock held. But this patch replaces mmput() with mmput_async() in order not to start __mmput() from shrinker context. [1] https://syzkaller.appspot.com/bug?id=bc9e7303f537c41b2b0cc2dfcea3fc42964c2d45 Reported-by: syzbot <syzbot+1068f09c44d151250c33@syzkaller.appspotmail.com> Reported-by: syzbot <syzbot+e5344baa319c9a96edec@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Michal Hocko <mhocko@suse.com> Acked-by: Todd Kjos <tkjos@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: stable <stable@vger.kernel.org> Link: https://lore.kernel.org/r/4ba9adb2-43f5-2de0-22de-f6075c1fab50@i-love.sakura.ne.jp Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-13binder: Handle start==NULL in binder_update_page_range()Jann Horn
commit 2a9edd056ed4fbf9d2e797c3fc06335af35bccc4 upstream. The old loop wouldn't stop when reaching `start` if `start==NULL`, instead continuing backwards to index -1 and crashing. Luckily you need to be highly privileged to map things at NULL, so it's not a big problem. Fix it by adjusting the loop so that the loop variable is always in bounds. This patch is deliberately minimal to simplify backporting, but IMO this function could use a refactor. The jump labels in the second loop body are horrible (the error gotos should be jumping to free_range instead), and both loops would look nicer if they just iterated upwards through indices. And the up_read()+mmput() shouldn't be duplicated like that. Cc: stable@vger.kernel.org Fixes: 457b9a6f09f0 ("Staging: android: add binder driver") Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20191018205631.248274-3-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-13binder: Prevent repeated use of ->mmap() via NULL mappingJann Horn
commit a7a74d7ff55a0c657bc46238b050460b9eacea95 upstream. binder_alloc_mmap_handler() attempts to detect the use of ->mmap() on a binder_proc whose binder_alloc has already been initialized by checking whether alloc->buffer is non-zero. Before commit 880211667b20 ("binder: remove kernel vm_area for buffer space"), alloc->buffer was a kernel mapping address, which is always non-zero, but since that commit, it is a userspace mapping address. A sufficiently privileged user can map /dev/binder at NULL, tricking binder_alloc_mmap_handler() into assuming that the binder_proc has not been mapped yet. This leads to memory unsafety. Luckily, no context on Android has such privileges, and on a typical Linux desktop system, you need to be root to do that. Fix it by using the mapping size instead of the mapping address to distinguish the mapped case. A valid VMA can't have size zero. Fixes: 880211667b20 ("binder: remove kernel vm_area for buffer space") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20191018205631.248274-2-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-13binder: Fix race between mmap() and binder_alloc_print_pages()Jann Horn
commit 8eb52a1ee37aafd9b796713aa0b3ab9cbc455be3 upstream. binder_alloc_print_pages() iterates over alloc->pages[0..alloc->buffer_size-1] under alloc->mutex. binder_alloc_mmap_handler() writes alloc->pages and alloc->buffer_size without holding that lock, and even writes them before the last bailout point. Unfortunately we can't take the alloc->mutex in the ->mmap() handler because mmap_sem can be taken while alloc->mutex is held. So instead, we have to locklessly check whether the binder_alloc has been fully initialized with binder_alloc_get_vma(), like in binder_alloc_new_buf_locked(). Fixes: 8ef4665aa129 ("android: binder: Add page usage in binder stats") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20191018205631.248274-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-17binder: Don't modify VMA bounds in ->mmap handlerJann Horn
binder_mmap() tries to prevent the creation of overly big binder mappings by silently truncating the size of the VMA to 4MiB. However, this violates the API contract of mmap(). If userspace attempts to create a large binder VMA, and later attempts to unmap that VMA, it will call munmap() on a range beyond the end of the VMA, which may have been allocated to another VMA in the meantime. This can lead to userspace memory corruption. The following sequence of calls leads to a segfault without this commit: int main(void) { int binder_fd = open("/dev/binder", O_RDWR); if (binder_fd == -1) err(1, "open binder"); void *binder_mapping = mmap(NULL, 0x800000UL, PROT_READ, MAP_SHARED, binder_fd, 0); if (binder_mapping == MAP_FAILED) err(1, "mmap binder"); void *data_mapping = mmap(NULL, 0x400000UL, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); if (data_mapping == MAP_FAILED) err(1, "mmap data"); munmap(binder_mapping, 0x800000UL); *(char*)data_mapping = 1; return 0; } Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Todd Kjos <tkjos@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20191016150119.154756-1-jannh@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-10-10binder: Fix comment headers on binder_alloc_prepare_to_free()Joel Fernandes (Google)
binder_alloc_buffer_lookup() doesn't exist and is named "binder_alloc_prepare_to_free()". Correct the code comments to reflect this. Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com> Link: https://lore.kernel.org/r/20190930201250.139554-1-joel@joelfernandes.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-01binder: return errors from buffer copy functionsTodd Kjos
The buffer copy functions assumed the caller would ensure correct alignment and that the memory to be copied was completely within the binder buffer. There have been a few cases discovered by syzkallar where a malformed transaction created by a user could violated the assumptions and resulted in a BUG_ON. The fix is to remove the BUG_ON and always return the error to be handled appropriately by the caller. Acked-by: Martijn Coenen <maco@android.com> Reported-by: syzbot+3ae18325f96190606754@syzkaller.appspotmail.com Fixes: bde4a19fc04f ("binder: use userspace pointer as base of buffer space") Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282Thomas Gleixner
Based on 1 normalized pattern(s): this software is licensed under the terms of the gnu general public license version 2 as published by the free software foundation and may be copied distributed and modified under those terms this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 285 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25binder: take read mode of mmap_sem in binder_alloc_free_page()Tyler Hicks
Restore the behavior of locking mmap_sem for reading in binder_alloc_free_page(), as was first done in commit 3013bf62b67a ("binder: reduce mmap_sem write-side lock"). That change was inadvertently reverted by commit 5cec2d2e5839 ("binder: fix race between munmap() and direct reclaim"). In addition, change the name of the label for the error path to accurately reflect that we're taking the lock for reading. Backporting note: This fix is only needed when *both* of the commits mentioned above are applied. That's an unlikely situation since they both landed during the development of v5.1 but only one of them is targeted for stable. Fixes: 5cec2d2e5839 ("binder: fix race between munmap() and direct reclaim") Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Todd Kjos <tkjos@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-21binder: fix race between munmap() and direct reclaimTodd Kjos
An munmap() on a binder device causes binder_vma_close() to be called which clears the alloc->vma pointer. If direct reclaim causes binder_alloc_free_page() to be called, there is a race where alloc->vma is read into a local vma pointer and then used later after the mm->mmap_sem is acquired. This can result in calling zap_page_range() with an invalid vma which manifests as a use-after-free in zap_page_range(). The fix is to check alloc->vma after acquiring the mmap_sem (which we were acquiring anyway) and skip zap_page_range() if it has changed to NULL. Signed-off-by: Todd Kjos <tkjos@google.com> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-19binder: reduce mmap_sem write-side lockMinchan Kim
binder has used write-side mmap_sem semaphore to release memory mapped at address space of the process. However, right lock to release pages is down_read, not down_write because page table lock already protects the race for parallel freeing. Please do not use mmap_sem write-side lock which is well known contented lock. Cc: Todd Kjos <tkjos@google.com> Cc: Martijn Coenen <maco@android.com> Cc: Arve Hjønnevåg <arve@android.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: use userspace pointer as base of buffer spaceTodd Kjos
Now that alloc->buffer points to the userspace vm_area rename buffer->data to buffer->user_data and rename local pointers that hold user addresses. Also use the "__user" tag to annotate all user pointers so sparse can flag cases where user pointer vaues are copied to kernel pointers. Refactor code to use offsets instead of user pointers. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: remove user_buffer_offsetTodd Kjos
Remove user_buffer_offset since there is no kernel buffer pointer anymore. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: remove kernel vm_area for buffer spaceTodd Kjos
Remove the kernel's vm_area and the code that maps buffer pages into it. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: add functions to copy to/from binder buffersTodd Kjos
Avoid vm_area when copying to or from binder buffers. Instead, new copy functions are added that copy from kernel space to binder buffer space. These use kmap_atomic() and kunmap_atomic() to create temporary mappings and then memcpy() is used to copy within that page. Also, kmap_atomic() / kunmap_atomic() use the appropriate cache flushing to support VIVT cache architectures. Allow binder to build if CPU_CACHE_VIVT is defined. Several uses of the new functions are added here. More to follow in subsequent patches. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12binder: create userspace-to-binder-buffer copy functionTodd Kjos
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>
2018-12-03Merge 4.20-rc5 into char-misc-nextGreg Kroah-Hartman
We need the fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-26binder: fix sparse warnings on locking contextTodd Kjos
Add __acquire()/__release() annnotations to fix warnings in sparse context checking There is one case where the warning was due to a lack of a "default:" case in a switch statement where a lock was being released in each of the cases, so the default case was added. Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-26binder: fix race that allows malicious free of live bufferTodd Kjos
Malicious code can attempt to free buffers using the BC_FREE_BUFFER ioctl to binder. There are protections against a user freeing a buffer while in use by the kernel, however there was a window where BC_FREE_BUFFER could be used to free a recently allocated buffer that was not completely initialized. This resulted in a use-after-free detected by KASAN with a malicious test program. This window is closed by setting the buffer's allow_user_free attribute to 0 when the buffer is allocated or when the user has previously freed it instead of waiting for the caller to set it. The problem was that when the struct buffer was recycled, allow_user_free was stale and set to 1 allowing a free to go through. Signed-off-by: Todd Kjos <tkjos@google.com> Acked-by: Arve Hjønnevåg <arve@android.com> Cc: stable <stable@vger.kernel.org> # 4.14 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-12android: binder: fix the race mmap and alloc_new_buf_lockedMinchan Kim
There is RaceFuzzer report like below because we have no lock to close below the race between binder_mmap and binder_alloc_new_buf_locked. To close the race, let's use memory barrier so that if someone see alloc->vma is not NULL, alloc->vma_vm_mm should be never NULL. (I didn't add stable mark intentionallybecause standard android userspace libraries that interact with binder (libbinder & libhwbinder) prevent the mmap/ioctl race. - from Todd) " Thread interleaving: CPU0 (binder_alloc_mmap_handler) CPU1 (binder_alloc_new_buf_locked) ===== ===== // drivers/android/binder_alloc.c // #L718 (v4.18-rc3) alloc->vma = vma; // drivers/android/binder_alloc.c // #L346 (v4.18-rc3) if (alloc->vma == NULL) { ... // alloc->vma is not NULL at this point return ERR_PTR(-ESRCH); } ... // #L438 binder_update_page_range(alloc, 0, (void *)PAGE_ALIGN((uintptr_t)buffer->data), end_page_addr); // In binder_update_page_range() #L218 // But still alloc->vma_vm_mm is NULL here if (need_mm && mmget_not_zero(alloc->vma_vm_mm)) alloc->vma_vm_mm = vma->vm_mm; Crash Log: ================================================================== BUG: KASAN: null-ptr-deref in __atomic_add_unless include/asm-generic/atomic-instrumented.h:89 [inline] BUG: KASAN: null-ptr-deref in atomic_add_unless include/linux/atomic.h:533 [inline] BUG: KASAN: null-ptr-deref in mmget_not_zero include/linux/sched/mm.h:75 [inline] BUG: KASAN: null-ptr-deref in binder_update_page_range+0xece/0x18e0 drivers/android/binder_alloc.c:218 Write of size 4 at addr 0000000000000058 by task syz-executor0/11184 CPU: 1 PID: 11184 Comm: syz-executor0 Not tainted 4.18.0-rc3 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.8.2-0-g33fbe13 by qemu-project.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x16e/0x22c lib/dump_stack.c:113 kasan_report_error mm/kasan/report.c:352 [inline] kasan_report+0x163/0x380 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x140/0x1a0 mm/kasan/kasan.c:267 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278 __atomic_add_unless include/asm-generic/atomic-instrumented.h:89 [inline] atomic_add_unless include/linux/atomic.h:533 [inline] mmget_not_zero include/linux/sched/mm.h:75 [inline] binder_update_page_range+0xece/0x18e0 drivers/android/binder_alloc.c:218 binder_alloc_new_buf_locked drivers/android/binder_alloc.c:443 [inline] binder_alloc_new_buf+0x467/0xc30 drivers/android/binder_alloc.c:513 binder_transaction+0x125b/0x4fb0 drivers/android/binder.c:2957 binder_thread_write+0xc08/0x2770 drivers/android/binder.c:3528 binder_ioctl_write_read.isra.39+0x24f/0x8e0 drivers/android/binder.c:4456 binder_ioctl+0xa86/0xf34 drivers/android/binder.c:4596 vfs_ioctl fs/ioctl.c:46 [inline] do_vfs_ioctl+0x154/0xd40 fs/ioctl.c:686 ksys_ioctl+0x94/0xb0 fs/ioctl.c:701 __do_sys_ioctl fs/ioctl.c:708 [inline] __se_sys_ioctl fs/ioctl.c:706 [inline] __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:706 do_syscall_64+0x167/0x4b0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe " Signed-off-by: Todd Kjos <tkjos@google.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Martijn Coenen <maco@android.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-08-08android: binder: Rate-limit debug and userspace triggered err msgsSherry Yang
Use rate-limited debug messages where userspace can trigger excessive log spams. Acked-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-24android: binder_alloc: Include asm/cacheflush.h after linux/ include filesGuenter Roeck
If asm/cacheflush.h is included first, the following build warnings are seen with sparc32 builds. In file included from ./arch/sparc/include/asm/cacheflush.h:11:0, from drivers/android/binder_alloc.c:20: ./arch/sparc/include/asm/cacheflush_32.h:40:37: warning: 'struct page' declared inside parameter list Moving the asm/ include after linux/ includes fixes the problem. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-12treewide: kzalloc() -> kcalloc()Kees Cook
The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-05-14ANDROID: binder: change down_write to down_readMinchan Kim
binder_update_page_range needs down_write of mmap_sem because vm_insert_page need to change vma->vm_flags to VM_MIXEDMAP unless it is set. However, when I profile binder working, it seems every binder buffers should be mapped in advance by binder_mmap. It means we could set VM_MIXEDMAP in binder_mmap time which is already hold a mmap_sem as down_write so binder_update_page_range doesn't need to hold a mmap_sem as down_write. Please use proper API down_read. It would help mmap_sem contention problem as well as fixing down_write abuse. Ganesh Mahendran tested app launching and binder throughput test and he said he couldn't find any problem and I did binder latency test per Greg KH request(Thanks Martijn to teach me how I can do) I cannot find any problem, too. Cc: Ganesh Mahendran <opensource.ganesh@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Arve Hjønnevåg <arve@android.com> Cc: Todd Kjos <tkjos@google.com> Reviewed-by: Martijn Coenen <maco@android.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-25android: binder: use VM_ALLOC to get vm areaGanesh Mahendran
VM_IOREMAP is used to access hardware through a mechanism called I/O mapped memory. Android binder is a IPC machanism which will not access I/O memory. And VM_IOREMAP has alignment requiement which may not needed in binder. __get_vm_area_node() { ... if (flags & VM_IOREMAP) align = 1ul << clamp_t(int, fls_long(size), PAGE_SHIFT, IOREMAP_MAX_ORDER); ... } This patch will save some kernel vm area, especially for 32bit os. In 32bit OS, kernel vm area is only 240MB. We may got below error when launching a app: <3>[ 4482.440053] binder_alloc: binder_alloc_mmap_handler: 15728 8ce67000-8cf65000 get_vm_area failed -12 <3>[ 4483.218817] binder_alloc: binder_alloc_mmap_handler: 15745 8ce67000-8cf65000 get_vm_area failed -12 Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Acked-by: Martijn Coenen <maco@android.com> Acked-by: Todd Kjos <tkjos@google.com> Cc: stable <stable@vger.kernel.org> ---- V3: update comments V2: update comments Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-19ANDROID: binder: make binder_alloc_new_buf_locked static and indent its ↵Xiongwei Song
arguments The function binder_alloc_new_buf_locked() is only used in this file, so make it static. Also clean up sparse warning: drivers/android/binder_alloc.c:330:23: warning: no previous prototype for ‘binder_alloc_new_buf_locked’ [-Wmissing-prototypes] In addition, the line of the function name exceeds 80 characters when add static for this function, hence indent its arguments anew. Signed-off-by: Xiongwei Song <sxwjean@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-18android: binder: Check for errors in binder_alloc_shrinker_init().Tetsuo Handa
Both list_lru_init() and register_shrinker() might return an error. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Sherry Yang <sherryy@android.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-28ANDROID: binder: show high watermark of alloc->pages.Martijn Coenen
Show the high watermark of the index into the alloc->pages array, to facilitate sizing the buffer on a per-process basis. Signed-off-by: Martijn Coenen <maco@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-23Merge 4.14-rc6 into char-misc-nextGreg Kroah-Hartman
We want the driver fixes in here and this resolves a merge issue with the binder driver. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21android: binder: Fix null ptr dereference in debug msgSherry Yang
Don't access next->data in kernel debug message when the next buffer is null. Acked-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-21android: binder: Don't get mm from taskSherry Yang
Use binder_alloc struct's mm_struct rather than getting a reference to the mm struct through get_task_mm to avoid a potential deadlock between lru lock, task lock and dentry lock, since a thread can be holding the task lock and the dentry lock while trying to acquire the lru lock. Acked-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-20android: binder: Change binder_shrinker to staticSherry Yang
binder_shrinker struct is not used anywhere outside of binder_alloc.c and should be static. Acked-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-20android: binder: Remove unused vma argumentSherry Yang
The vma argument in update_page_range is no longer used after 74310e06 ("android: binder: Move buffer out of area shared with user space"), since mmap_handler no longer calls update_page_range with a vma. Acked-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-03android: binder: drop lru lock in isolate callbackSherry Yang
Drop the global lru lock in isolate callback before calling zap_page_range which calls cond_resched, and re-acquire the global lru lock before returning. Also change return code to LRU_REMOVED_RETRY. Use mmput_async when fail to acquire mmap sem in an atomic context. Fix "BUG: sleeping function called from invalid context" errors when CONFIG_DEBUG_ATOMIC_SLEEP is enabled. Also restore mmput_async, which was initially introduced in commit ec8d7c14ea14 ("mm, oom_reaper: do not mmput synchronously from the oom reaper context"), and was removed in commit 212925802454 ("mm: oom: let oom_reap_task and exit_mmap run concurrently"). Link: http://lkml.kernel.org/r/20170914182231.90908-1-sherryy@android.com Fixes: f2517eb76f1f2 ("android: binder: Add global lru shrinker to binder") Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reported-by: Kyle Yan <kyan@codeaurora.org> Acked-by: Arve Hjønnevåg <arve@android.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Martijn Coenen <maco@google.com> Cc: Todd Kjos <tkjos@google.com> Cc: Riley Andrews <riandrews@android.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Hillf Danton <hdanton@sina.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hoeun Ryu <hoeun.ryu@gmail.com> Cc: Christopher Lameter <cl@linux.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-01android: binder: Add page usage in binder statsSherry Yang
Add the number of active, lru, and free pages for each binder process in binder stats Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-01android: binder: fixup crash introduced by moving buffer hdrSherry Yang
Fix crash introduced by 74310e06be4d74dcf67cd108366710dee5c576d5 (android: binder: Move buffer out of area shared with user space) when close is called after open without mmap in between. Reported-by: kernel test robot <fengguang.wu@intel.com> Fixes: 74310e06be4d ("android: binder: Move buffer out of area shared with user space") Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28android: binder: Add shrinker tracepointsSherry Yang
Add tracepoints in binder transaction allocator to record lru hits and alloc/free page. Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28android: binder: Add global lru shrinker to binderSherry Yang
Hold on to the pages allocated and mapped for transaction buffers until the system is under memory pressure. When that happens, use linux shrinker to free pages. Without using shrinker, patch "android: binder: Move buffer out of area shared with user space" will cause a significant slow down for small transactions that fit into the first page because free list buffer header used to be inlined with buffer data. In addition to prevent the performance regression for small transactions, this patch improves the performance for transactions that take up more than one page. Modify alloc selftest to work with the shrinker change. Test: Run memory intensive applications (Chrome and Camera) to trigger shrinker callbacks. Binder frees memory as expected. Test: Run binderThroughputTest with high memory pressure option enabled. Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28android: binder: Move buffer out of area shared with user spaceSherry Yang
Binder driver allocates buffer meta data in a region that is mapped in user space. These meta data contain pointers in the kernel. This patch allocates buffer meta data on the kernel heap that is not mapped in user space, and uses a pointer to refer to the data mapped. Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-28android: binder: Refactor prev and next buffer into a helper functionSherry Yang
Use helper functions buffer_next and buffer_prev instead of list_entry to get the next and previous buffers. Signed-off-by: Sherry Yang <sherryy@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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