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* binder: Convert binder_alloc selftests to KUnitTiffany Yang2025-07-161-345/+0
| | | | | | | | | | | | | | | Convert the existing binder_alloc_selftest tests into KUnit tests. These tests allocate and free an exhaustive combination of buffers with various sizes and alignments. This change allows them to be run without blocking or otherwise interfering with other processes in binder. This test is refactored into more meaningful cases in the subsequent patch. Signed-off-by: Tiffany Yang <[email protected]> Acked-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: Store lru freelist in binder_allocTiffany Yang2025-07-161-10/+49
| | | | | | | | | | | | | | | | | | | | | | | | | Store a pointer to the free pages list that the binder allocator should use for a process inside of struct binder_alloc. This change allows binder allocator code to be tested and debugged deterministically while a system is using binder; i.e., without interfering with other binder processes and independently of the shrinker. This is necessary to convert the current binder_alloc_selftest into a kunit test that does not rely on hijacking an existing binder_proc to run. A binder process's binder_alloc->freelist should not be changed after it is initialized. A sole exception is the process that runs the existing binder_alloc selftest. Its freelist can be temporarily replaced for the duration of the test because it runs as a single thread before any pages can be added to the global binder freelist, and the test frees every page it allocates before dropping the binder_selftest_lock. This exception allows the existing selftest to be used to check for regressions, but it will be dropped when the binder_alloc tests are converted to kunit in a subsequent patch in this series. Signed-off-by: Tiffany Yang <[email protected]> Acked-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: Fix selftest page indexingTiffany Yang2025-07-161-1/+1
| | | | | | | | | | | The binder allocator selftest was only checking the last page of buffers that ended on a page boundary. Correct the page indexing to account for buffers that are not page-aligned. Signed-off-by: Tiffany Yang <[email protected]> Acked-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: rename alloc->buffer to vm_startCarlos Llamas2024-12-241-1/+1
| | | | | | | | | | | | | | The alloc->buffer field in struct binder_alloc stores the starting address of the mapped vma, rename this field to alloc->vm_start to better reflect its purpose. It also avoids confusion with the binder buffer concept, e.g. transaction->buffer. No functional changes in this patch. Reviewed-by: Suren Baghdasaryan <[email protected]> Signed-off-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: replace alloc->vma with alloc->mappedCarlos Llamas2024-12-241-1/+1
| | | | | | | | | | | | | | | | | | | It is unsafe to use alloc->vma outside of the mmap_sem. Instead, add a new boolean alloc->mapped to save the vma state (mapped or unmmaped) and use this as a replacement for alloc->vma to validate several paths. Using the alloc->vma caused several performance and security issues in the past. Now that it has been replaced with either vm_lookup() or the alloc->mapped state, we can finally remove it. Cc: Minchan Kim <[email protected]> Cc: Liam R. Howlett <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Reviewed-by: Suren Baghdasaryan <[email protected]> Signed-off-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: store shrinker metadata under page->privateCarlos Llamas2024-12-241-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | Instead of pre-allocating an entire array of struct binder_lru_page in alloc->pages, install the shrinker metadata under page->private. This ensures the memory is allocated and released as needed alongside pages. By converting the alloc->pages[] into an array of struct page pointers, we can access these pages directly and only reference the shrinker metadata where it's being used (e.g. inside the shrinker's callback). Rename struct binder_lru_page to struct binder_shrinker_mdata to better reflect its purpose. Add convenience functions that wrap the allocation and freeing of pages along with their shrinker metadata. Note I've reworked this patch to avoid using page->lru and page->index directly, as Matthew pointed out that these are being removed [1]. Link: https://lore.kernel.org/all/[email protected]/ [1] Cc: Matthew Wilcox <[email protected]> Cc: Liam R. Howlett <[email protected]> Reviewed-by: Suren Baghdasaryan <[email protected]> Signed-off-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* android: binder: fix a kernel-doc enum warningRandy Dunlap2023-12-051-0/+4
| | | | | | | | | | | | | | | | | | | | Add kernel-doc notation for @LOOP_END to prevent a kernel-doc warning. binder_alloc_selftest.c:76: warning: Enum value 'LOOP_END' not described in enum 'buf_end_align_type' Signed-off-by: Randy Dunlap <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Arve Hjønnevåg <[email protected]> Cc: Todd Kjos <[email protected]> Cc: Martijn Coenen <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Carlos Llamas <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Acked-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: rename lru shrinker utilitiesCarlos Llamas2023-12-051-3/+3
| | | | | | | | | | | | | | Now that the page allocation step is done separately we should rename the binder_free_page_range() and binder_allocate_page_range() functions to provide a more accurate description of what they do. Lets borrow the freelist concept used in other parts of the kernel for this. No functional change here. Signed-off-by: Carlos Llamas <[email protected]> Reviewed-by: Alice Ryhl <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: remove pid param in binder_alloc_new_buf()Carlos Llamas2023-12-051-1/+1
| | | | | | | | | | | | | Binder attributes the buffer allocation to the current->tgid everytime. There is no need to pass this as a parameter so drop it. Also add a few touchups to follow the coding guidelines. No functional changes are introduced in this patch. Reviewed-by: Alice Ryhl <[email protected]> Signed-off-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: keep vma addresses type as unsigned longCarlos Llamas2023-12-051-3/+3
| | | | | | | | | | | | | | | | | | | The vma addresses in binder are currently stored as void __user *. This requires casting back and forth between the mm/ api which uses unsigned long. Since we also do internal arithmetic on these addresses we end up having to cast them _again_ to an integer type. Lets stop all the unnecessary casting which kills code readability and store the virtual addresses as the native unsigned long from mm/. Note that this approach is preferred over uintptr_t as Linus explains in [1]. Opportunistically add a few cosmetic touchups. Link: https://lore.kernel.org/all/CAHk-=wj2OHy-5e+srG1fy+ZU00TmZ1NFp6kFLbVLMXHe7A1d-g@mail.gmail.com/ [1] Signed-off-by: Carlos Llamas <[email protected]> Reviewed-by: Alice Ryhl <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* Revert "android: binder: stop saving a pointer to the VMA"Carlos Llamas2023-05-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit a43cfc87caaf46710c8027a8c23b8a55f1078f19. This patch fixed an issue reported by syzkaller in [1]. However, this turned out to be only a band-aid in binder. The root cause, as bisected by syzkaller, was fixed by commit 5789151e48ac ("mm/mmap: undo ->mmap() when mas_preallocate() fails"). We no longer need the patch for binder. Reverting such patch allows us to have a lockless access to alloc->vma in specific cases where the mmap_lock is not required. This approach avoids the contention that caused a performance regression. [1] https://lore.kernel.org/all/[email protected] [cmllamas: resolved conflicts with rework of alloc->mm and removal of binder_alloc_set_vma() also fixed comment section] Fixes: a43cfc87caaf ("android: binder: stop saving a pointer to the VMA") Cc: Liam Howlett <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: [email protected] Signed-off-by: Carlos Llamas <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* android: binder: stop saving a pointer to the VMALiam R. Howlett2022-07-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not record a pointer to a VMA outside of the mmap_lock for later use. This is unsafe and there are a number of failure paths *after* the recorded VMA pointer may be freed during setup. There is no callback to the driver to clear the saved pointer from generic mm code. Furthermore, the VMA pointer may become stale if any number of VMA operations end up freeing the VMA so saving it was fragile to being with. Instead, change the binder_alloc struct to record the start address of the VMA and use vma_lookup() to get the vma when needed. Add lockdep mmap_lock checks on updates to the vma pointer to ensure the lock is held and depend on that lock for synchronization of readers and writers - which was already the case anyways, so the smp_wmb()/smp_rmb() was not necessary. [[email protected]: fix drivers/android/binder_alloc_selftest.c] Link: https://lkml.kernel.org/r/20220621140212.vpkio64idahetbyf@revolver Fixes: da1b9564e85b ("android: binder: fix the race mmap and alloc_new_buf_locked") Reported-by: [email protected] Signed-off-by: Liam R. Howlett <[email protected]> Cc: Minchan Kim <[email protected]> Cc: Christian Brauner (Microsoft) <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Hridya Valsaraju <[email protected]> Cc: Joel Fernandes <[email protected]> Cc: Martijn Coenen <[email protected]> Cc: Suren Baghdasaryan <[email protected]> Cc: Todd Kjos <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
* binder: print warnings when detecting oneway spamming.Martijn Coenen2020-09-031-1/+1
| | | | | | | | | | | | | | | | | | The most common cause of the binder transaction buffer filling up is a client rapidly firing oneway transactions into a process, before it has a chance to handle them. Yet the root cause of this is often hard to debug, because either the system or the app will stop, and by that time binder debug information we dump in bugreports is no longer relevant. This change warns as soon as a process dips below 80% of its oneway space (less than 100kB available in the configuration), when any one process is responsible for either more than 50 transactions, or more than 50% of the oneway space. Signed-off-by: Martijn Coenen <[email protected]> Acked-by: Todd Kjos <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282Thomas Gleixner2019-06-051-10/+1
| | | | | | | | | | | | | | | | | | | | | | | | | 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 <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: fix sparse issue in binder_alloc_selftest.cTodd Kjos2019-02-141-2/+3
| | | | | | | | | | | | | | | | | | | Fixes sparse issues reported by the kbuild test robot running on https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git char-misc-testing: bde4a19fc04f5 ("binder: use userspace pointer as base of buffer space") Error output (drivers/android/binder_alloc_selftest.c): sparse: warning: incorrect type in assignment (different address spaces) sparse: expected void *page_addr sparse: got void [noderef] <asn:1> *user_data sparse: error: subtraction of different types can't work Fixed by adding necessary "__user" tags. Reported-by: kbuild test robot <[email protected]> Signed-off-by: Todd Kjos <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* binder: use userspace pointer as base of buffer spaceTodd Kjos2019-02-121-2/+2
| | | | | | | | | | | | | 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 <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* android: binder: Add global lru shrinker to binderSherry Yang2017-08-281-14/+54
| | | | | | | | | | | | | | | | | | | | | | | | | 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 <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* android: binder: Move buffer out of area shared with user spaceSherry Yang2017-08-281-6/+5
| | | | | | | | | | | 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 <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
* android: binder: Add allocator selftestSherry Yang2017-08-281-0/+271
binder_alloc_selftest tests that alloc_new_buf handles page allocation and deallocation properly when allocate and free buffers. The test allocates 5 buffers of various sizes to cover all possible page alignment cases, and frees the buffers using a list of exhaustive freeing order. Test: boot the device with ANDROID_BINDER_IPC_SELFTEST config option enabled. Allocator selftest passes. Signed-off-by: Sherry Yang <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>