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* drivers/comedi: use standard array-copy-functionPhilipp Stanner2023-12-071-2/+2
| | | | | | | | | | | | | | | | | comedi_fops.c utilizes memdup_user() to copy a userspace array. The new function memdup_array_user() provides a standardized way to copy userspace-arrays. It makes it easier to see that an array is being copied and, additionally, performs a generic overflow-check which might help make the code more robust in case of changes in the future. Replace memdup_user() with memdup_array_user(). Suggested-by: Dave Airlie <airlied@redhat.com> Signed-off-by: Philipp Stanner <pstanner@redhat.com> Reviewed-by: Ian Abbott <abbotti@mev.co.uk> Link: https://lore.kernel.org/r/20231103112932.75795-2-pstanner@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* firmware: xilinx: Use proper indentation in kernel-docMichal Simek2023-12-071-2/+2
| | | | | | | | | | Use tab for zynqmp_pm_load_pdi() arguments doc indentation. No functional change. Signed-off-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com> Link: https://lore.kernel.org/r/1698645181-2874487-1-git-send-email-radhey.shyam.pandey@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* rootfs: Fix support for rootfstype= when root= is givenStefan Berger2023-12-071-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Documentation/filesystems/ramfs-rootfs-initramfs.rst states: If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by default. To force ramfs, add "rootfstype=ramfs" to the kernel command line. This currently does not work when root= is provided since then saved_root_name contains a string and rootfstype= is ignored. Therefore, ramfs is currently always chosen when root= is provided. The current behavior for rootfs's filesystem is: root= | rootfstype= | chosen rootfs filesystem ------------+-------------+-------------------------- unspecified | unspecified | tmpfs unspecified | tmpfs | tmpfs unspecified | ramfs | ramfs provided | ignored | ramfs rootfstype= should be respected regardless whether root= is given, as shown below: root= | rootfstype= | chosen rootfs filesystem ------------+-------------+-------------------------- unspecified | unspecified | tmpfs (as before) unspecified | tmpfs | tmpfs (as before) unspecified | ramfs | ramfs (as before) provided | unspecified | ramfs (compatibility with before) provided | tmpfs | tmpfs (new) provided | ramfs | ramfs (new) This table represents the new behavior. Fixes: 6e19eded3684 ("initmpfs: use initramfs if rootfstype= or root= specified") Cc: <stable@vger.kernel.org> Signed-off-by: Rob Landley <rob@landley.net> Link: https://lore.kernel.org/lkml/8244c75f-445e-b15b-9dbf-266e7ca666e2@landley.net/ Reviewed-and-Tested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com> Link: https://lore.kernel.org/r/20231120011248.396012-1-stefanb@linux.ibm.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* android: binder: fix a kernel-doc enum warningRandy Dunlap2023-12-061-0/+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 <rdunlap@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Arve Hjønnevåg <arve@android.com> Cc: Todd Kjos <tkjos@android.com> Cc: Martijn Coenen <maco@android.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Christian Brauner <christian@brauner.io> Cc: Carlos Llamas <cmllamas@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Acked-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231205225324.32362-1-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: switch alloc->mutex to spinlock_tCarlos Llamas2023-12-052-28/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The alloc->mutex is a highly contended lock that causes performance issues on Android devices. When a low-priority task is given this lock and it sleeps, it becomes difficult for the task to wake up and complete its work. This delays other tasks that are also waiting on the mutex. The problem gets worse when there is memory pressure in the system, because this increases the contention on the alloc->mutex while the shrinker reclaims binder pages. Switching to a spinlock helps to keep the waiters running and avoids the overhead of waking up tasks. This significantly improves the transaction latency when the problematic scenario occurs. The performance impact of this patchset was measured by stress-testing the binder alloc contention. In this test, several clients of different priorities send thousands of transactions of different sizes to a single server. In parallel, pages get reclaimed using the shinker's debugfs. The test was run on a Pixel 8, Pixel 6 and qemu machine. The results were similar on all three devices: after: | sched | prio | average | max | min | |--------+------+---------+-----------+---------| | fifo | 99 | 0.135ms | 1.197ms | 0.022ms | | fifo | 01 | 0.136ms | 5.232ms | 0.018ms | | other | -20 | 0.180ms | 7.403ms | 0.019ms | | other | 19 | 0.241ms | 58.094ms | 0.018ms | before: | sched | prio | average | max | min | |--------+------+---------+-----------+---------| | fifo | 99 | 0.350ms | 248.730ms | 0.020ms | | fifo | 01 | 0.357ms | 248.817ms | 0.024ms | | other | -20 | 0.399ms | 249.906ms | 0.020ms | | other | 19 | 0.477ms | 297.756ms | 0.022ms | The key metrics above are the average and max latencies (wall time). These improvements should roughly translate to p95-p99 latencies on real workloads. The response time is up to 200x faster in these scenarios and there is no penalty in the regular path. Note that it is only possible to convert this lock after a series of changes made by previous patches. These mainly include refactoring the sections that might_sleep() and changing the locking order with the mmap_lock amongst others. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-29-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: reverse locking order in shrinker callbackCarlos Llamas2023-12-051-24/+22
| | | | | | | | | | | | | | | | | The locking order currently requires the alloc->mutex to be acquired first followed by the mmap lock. However, the alloc->mutex is converted into a spinlock in subsequent commits so the order needs to be reversed to avoid nesting the sleeping mmap lock under the spinlock. The shrinker's callback binder_alloc_free_page() is the only place that needs to be reordered since other functions have been refactored and no longer nest these locks. Some minor cosmetic changes are also included in this patch. Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-28-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: avoid user addresses in debug logsCarlos Llamas2023-12-052-11/+8
| | | | | | | | | | | | Prefer logging vma offsets instead of addresses or simply drop the debug log altogether if not useful. Note this covers the instances affected by the switch to store addresses as unsigned long. However, there are other sections in the driver that could do the same. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-27-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: refactor binder_delete_free_buffer()Carlos Llamas2023-12-051-33/+11
| | | | | | | | | | Skip the freelist call immediately as needed, instead of continuing the pointless checks. Also, drop the debug logs that we don't really need. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-26-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: collapse print_binder_buffer() into callerCarlos Llamas2023-12-051-13/+9
| | | | | | | | | | | | The code in print_binder_buffer() is quite small so it can be collapsed into its single caller binder_alloc_print_allocated(). No functional change in this patch. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-25-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: document the final page calculationCarlos Llamas2023-12-051-7/+11
| | | | | | | | | | | | | | | | | | | | | | The code to determine the page range for binder_lru_freelist_del() is quite obscure. It leverages the buffer_size calculated before doing an oversized buffer split. This is used to figure out if the last page is being shared with another active buffer. If so, the page gets trimmed out of the range as it has been previously removed from the freelist. This would be equivalent to getting the start page of the next in-use buffer explicitly. However, the code for this is much larger as we can see in binder_free_buf_locked() routine. Instead, lets settle on documenting the tricky step and using better names for now. I believe an ideal solution would be to count the binder_page->users to determine when a page should be added or removed from the freelist. However, this is a much bigger change than what I'm willing to risk at this time. Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-24-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: rename lru shrinker utilitiesCarlos Llamas2023-12-053-25/+25
| | | | | | | | | | | | | | 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 <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-23-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: make oversized buffer code more readableCarlos Llamas2023-12-051-11/+10
| | | | | | | | | | | | | The sections in binder_alloc_new_buf_locked() dealing with oversized buffers are scattered which makes them difficult to read. Instead, consolidate this code into a single block to improve readability. No functional change here. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-22-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: remove redundant debug logCarlos Llamas2023-12-051-3/+0
| | | | | | | | | | The debug information in this statement is already logged earlier in the same function. We can get rid of this duplicate log. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-21-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: perform page installation outside of locksCarlos Llamas2023-12-051-28/+73
| | | | | | | | | | | | | | | | Split out the insertion of pages to be outside of the alloc->mutex in a separate binder_install_buffer_pages() routine. Since this is no longer serialized, we must look at the full range of pages used by the buffers. The installation is protected with mmap_sem in write mode since multiple tasks might race to install the same page. Besides avoiding unnecessary nested locking this helps in preparation of switching the alloc->mutex into a spinlock_t in subsequent patches. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-20-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: initialize lru pages in mmap callbackCarlos Llamas2023-12-051-5/+7
| | | | | | | | | | | Rather than repeatedly initializing some of the binder_lru_page members during binder_alloc_new_buf(), perform this initialization just once in binder_alloc_mmap_handler(), after the pages have been created. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-19-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: malloc new_buffer outside of locksCarlos Llamas2023-12-051-21/+23
| | | | | | | | | | | | | Preallocate new_buffer before acquiring the alloc->mutex and hand it down to binder_alloc_new_buf_locked(). The new buffer will be used in the vast majority of requests (measured at 98.2% in field data). The buffer is discarded otherwise. This change is required in preparation for transitioning alloc->mutex into a spinlock in subsequent commits. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-18-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: refactor page range allocationCarlos Llamas2023-12-051-60/+47
| | | | | | | | | | | Instead of looping through the page range twice to first determine if the mmap lock is required, simply do it per-page as needed. Split out all this logic into a separate binder_install_single_page() function. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-17-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: relocate binder_alloc_clear_buf()Carlos Llamas2023-12-051-63/+61
| | | | | | | | | | | | Move this function up along with binder_alloc_get_page() so that their prototypes aren't necessary. No functional change in this patch. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-16-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: relocate low space calculationCarlos Llamas2023-12-051-10/+11
| | | | | | | | | | | | | Move the low async space calculation to debug_low_async_space_locked(). This logic not only fits better here but also offloads some of the many tasks currently done in binder_alloc_new_buf_locked(). No functional change in this patch. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-15-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: separate the no-space debugging logicCarlos Llamas2023-12-051-31/+40
| | | | | | | | | | | | | Move the no-space debugging logic into a separate function. Lets also mark this branch as unlikely in binder_alloc_new_buf_locked() as most requests will fit without issue. Also add a few cosmetic changes and suggestions from checkpatch. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-14-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: remove pid param in binder_alloc_new_buf()Carlos Llamas2023-12-054-17/+12
| | | | | | | | | | | | | 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 <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-13-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: do unlocked work in binder_alloc_new_buf()Carlos Llamas2023-12-051-39/+56
| | | | | | | | | | | | | | Extract non-critical sections from binder_alloc_new_buf_locked() that don't require holding the alloc->mutex. While we are here, consolidate the checks for size overflow and zero-sized padding into a separate sanitized_size() helper function. Also add a few touchups to follow the coding guidelines. Signed-off-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-12-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: split up binder_update_page_range()Carlos Llamas2023-12-051-39/+40
| | | | | | | | | | | | | | | | The binder_update_page_range() function performs both allocation and freeing of binder pages. However, these two operations are unrelated and have no common logic. In fact, when a free operation is requested, the allocation logic is skipped entirely. This behavior makes the error path unnecessarily complex. To improve readability of the code, this patch splits the allocation and freeing operations into separate functions. No functional changes are introduced by this patch. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-11-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: keep vma addresses type as unsigned longCarlos Llamas2023-12-055-69/+57
| | | | | | | | | | | | | | | | | | | 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 <cmllamas@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-10-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: remove extern from function prototypesCarlos Llamas2023-12-051-19/+19
| | | | | | | | | | | | | The kernel coding style does not require 'extern' in function prototypes in .h files, so remove them from drivers/android/binder_alloc.h as they are not needed. No functional changes in this patch. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-9-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: fix comment on binder_alloc_new_buf() return valueCarlos Llamas2023-12-051-1/+1
| | | | | | | | | | | | | | 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>
* binder: fix trivial typo of binder_free_buf_locked()Carlos Llamas2023-12-051-1/+1
| | | | | | | | | | | | | 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>
* binder: fix unused alloc->free_async_spaceCarlos Llamas2023-12-051-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: fix async space check for 0-sized buffersCarlos Llamas2023-12-051-3/+4
| | | | | | | | | | | 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>
* binder: fix race between mmput() and do_exit()Carlos Llamas2023-12-051-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: fix use-after-free in shinker's callbackCarlos Llamas2023-12-051-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* binder: use EPOLLERR from eventpoll.hCarlos Llamas2023-12-051-1/+1
| | | | | | | | | | | | | | | | | Use EPOLLERR instead of POLLERR to make sure it is cast to the correct __poll_t type. This fixes the following sparse issue: drivers/android/binder.c:5030:24: warning: incorrect type in return expression (different base types) drivers/android/binder.c:5030:24: expected restricted __poll_t drivers/android/binder.c:5030:24: got int Fixes: f88982679f54 ("binder: check for binder_thread allocation failure in binder_poll()") Cc: stable@vger.kernel.org Cc: Eric Biggers <ebiggers@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Carlos Llamas <cmllamas@google.com> Link: https://lore.kernel.org/r/20231201172212.1813387-2-cmllamas@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vmgenid: emit uevent when VMGENID updatesBabis Chalios2023-11-301-0/+2
| | | | | | | | | | | | | We receive an ACPI notification every time the VM Generation ID changes and use the new ID as fresh randomness added to the entropy pool. This commits emits a uevent every time we receive the ACPI notification, as a means to notify the user space that it now is in a new VM. Signed-off-by: Babis Chalios <bchalios@amazon.es> Reviewed-by: Alexander Graf <graf@amazon.com> Reviewed-by: Lennart Poettering <mzxreary@0pointer.de> Link: https://lore.kernel.org/r/20230531095119.11202-2-bchalios@amazon.es Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: Add Nitro Secure Module driverAlexander Graf2023-11-285-0/+560
| | | | | | | | | | | | | | | | | | | | | | When running Linux inside a Nitro Enclave, the hypervisor provides a special virtio device called "Nitro Security Module" (NSM). This device has 3 main functions: 1) Provide attestation reports 2) Modify PCR state 3) Provide entropy This patch adds a driver for NSM that exposes a /dev/nsm device node which user space can issue an ioctl on this device with raw NSM CBOR formatted commands to request attestation documents, influence PCR states, read entropy and enumerate status of the device. In addition, the driver implements a hwrng backend. Originally-by: Petre Eftime <petre.eftime@gmail.com> Signed-off-by: Alexander Graf <graf@amazon.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20231011213522.51781-1-graf@amazon.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* vgacon: drop IA64 reference in VGA_CONSOLE dependency listLukas Bulwahn2023-11-281-1/+1
| | | | | | | | | | | | | | | | | Commit e9e3300b6e77 ("vgacon: rework Kconfig dependencies") turns the dependencies into a positive list of supported architectures, which includes the IA64 architecture, but in the meantime, this architecture is removed in commit cf8e8658100d ("arch: Remove Itanium (IA-64) architecture"). Drop the reference to IA64 architecture in the dependency list of the VGA_CONSOLE config definition. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Link: https://lore.kernel.org/r/20231110114400.30882-1-lukas.bulwahn@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* platform/goldfish: goldfish_pipe: Convert to platform remove callback ↵Uwe Kleine-König2023-11-281-3/+2
| | | | | | | | | | | | | | | | | | | | | returning void The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231112000029.151117-2-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: ocxl: main: Remove unnecessary ‘0’ values from rcLi kunyu2023-11-271-1/+1
| | | | | | | | | rc is assigned first, so it does not need to initialize the assignment. Signed-off-by: Li kunyu <kunyu@nfschina.com> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> Link: https://lore.kernel.org/r/20231113015229.12074-1-kunyu@nfschina.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: ocxl: link: Remove unnecessary (void*) conversionsLi zeming2023-11-271-7/+7
| | | | | | | | | | The link pointer does not need to cast the type. Signed-off-by: Li zeming <zeming@nfschina.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> Link: https://lore.kernel.org/r/20231113014533.11064-1-zeming@nfschina.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: ocxl: afu_irq: Remove unnecessary (void*) conversionsLi zeming2023-11-271-1/+1
| | | | | | | | | | The irq pointer does not need to cast the type. Signed-off-by: Li zeming <zeming@nfschina.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> Link: https://lore.kernel.org/r/20231113012202.7887-1-zeming@nfschina.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* misc: ocxl: context: Remove unnecessary (void*) conversionsLi zeming2023-11-271-1/+1
| | | | | | | | | | The ctx pointer does not need to cast the type. Signed-off-by: Li zeming <zeming@nfschina.com> Acked-by: Frederic Barrat <fbarrat@linux.ibm.com> Acked-by: Andrew Donnellan <ajd@linux.ibm.com> Link: https://lore.kernel.org/r/20231113011543.6940-1-zeming@nfschina.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Linux 6.7-rc3v6.7-rc3Linus Torvalds2023-11-261-1/+1
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* Merge tag 'trace-v6.7-rc2' of ↵Linus Torvalds2023-11-263-48/+31
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt:: "Eventfs fixes: - With the usage of simple_recursive_remove() recommended by Al Viro, the code should not be calling "d_invalidate()" itself. Doing so is causing crashes. The code was calling d_invalidate() on the race of trying to look up a file while the parent was being deleted. This was detected, and the added dentry was having d_invalidate() called on it, but the deletion of the directory was also calling d_invalidate() on that same dentry. - A fix to not free the eventfs_inode (ei) until the last dput() was called on its ei->dentry made the ei->dentry exist even after it was marked for free by setting the ei->is_freed. But code elsewhere still was checking if ei->dentry was NULL if ei->is_freed is set and would trigger WARN_ON if that was the case. That's no longer true and there should not be any warnings when it is true. - Use GFP_NOFS for allocations done under eventfs_mutex. The eventfs_mutex can be taken on file system reclaim, make sure that allocations done under that mutex do not trigger file system reclaim. - Clean up code by moving the taking of inode_lock out of the helper functions and into where they are needed, and not use the parameter to know to take it or not. It must always be held but some callers of the helper function have it taken when they were called. - Warn if the inode_lock is not held in the helper functions. - Warn if eventfs_start_creating() is called without a parent. As eventfs is underneath tracefs, all files created will have a parent (the top one will have a tracefs parent). Tracing update: - Add Mathieu Desnoyers as an official reviewer of the tracing subsystem" * tag 'trace-v6.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: MAINTAINERS: TRACING: Add Mathieu Desnoyers as Reviewer eventfs: Make sure that parent->d_inode is locked in creating files/dirs eventfs: Do not allow NULL parent to eventfs_start_creating() eventfs: Move taking of inode_lock into dcache_dir_open_wrapper() eventfs: Use GFP_NOFS for allocation when eventfs_mutex is held eventfs: Do not invalidate dentry in create_file/dir_dentry() eventfs: Remove expectation that ei->is_freed means ei->dentry == NULL
| * MAINTAINERS: TRACING: Add Mathieu Desnoyers as ReviewerMathieu Desnoyers2023-11-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | In order to make sure I get CC'd on tracing changes for which my input would be relevant, add my name as reviewer of the TRACING subsystem. Link: https://lore.kernel.org/linux-trace-kernel/20231115155018.8236-1-mathieu.desnoyers@efficios.com Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * eventfs: Make sure that parent->d_inode is locked in creating files/dirsSteven Rostedt (Google)2023-11-221-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the locking of the parent->d_inode has been moved outside the creation of the files and directories (as it use to be locked via a conditional), add a WARN_ON_ONCE() to the case that it's not locked. Link: https://lkml.kernel.org/r/20231121231112.853962542@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * eventfs: Do not allow NULL parent to eventfs_start_creating()Steven Rostedt (Google)2023-11-221-9/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The eventfs directory is dynamically created via the meta data supplied by the existing trace events. All files and directories in eventfs has a parent. Do not allow NULL to be passed into eventfs_start_creating() as the parent because that should never happen. Warn if it does. Link: https://lkml.kernel.org/r/20231121231112.693841807@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * eventfs: Move taking of inode_lock into dcache_dir_open_wrapper()Steven Rostedt (Google)2023-11-221-14/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The both create_file_dentry() and create_dir_dentry() takes a boolean parameter "lookup", as on lookup the inode_lock should already be taken, but for dcache_dir_open_wrapper() it is not taken. There's no reason that the dcache_dir_open_wrapper() can't take the inode_lock before calling these functions. In fact, it's better if it does, as the lock can be held throughout both directory and file creations. This also simplifies the code, and possibly prevents unexpected race conditions when the lock is released. Link: https://lkml.kernel.org/r/20231121231112.528544825@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * eventfs: Use GFP_NOFS for allocation when eventfs_mutex is heldSteven Rostedt (Google)2023-11-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If memory reclaim happens, it can reclaim file system pages. The file system pages from eventfs may take the eventfs_mutex on reclaim. This means that allocation while holding the eventfs_mutex must not call into filesystem reclaim. A lockdep splat uncovered this. Link: https://lkml.kernel.org/r/20231121231112.373501894@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 28e12c09f5aa0 ("eventfs: Save ownership and mode") Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Reported-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * eventfs: Do not invalidate dentry in create_file/dir_dentry()Steven Rostedt (Google)2023-11-201-13/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the call to simple_recursive_removal() on the entire eventfs sub system when the directory is removed, it performs the d_invalidate on all the dentries when it is removed. There's no need to do clean ups when a dentry is being created while the directory is being deleted. As dentries are cleaned up by the simpler_recursive_removal(), trying to do d_invalidate() in these functions will cause the dentry to be invalidated twice, and crash the kernel. Link: https://lore.kernel.org/all/20231116123016.140576-1-naresh.kamboju@linaro.org/ Link: https://lkml.kernel.org/r/20231120235154.422970988@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 407c6726ca71 ("eventfs: Use simple_recursive_removal() to clean up dentries") Reported-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * eventfs: Remove expectation that ei->is_freed means ei->dentry == NULLSteven Rostedt (Google)2023-11-201-10/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The logic to free the eventfs_inode (ei) use to set is_freed and clear the "dentry" field under the eventfs_mutex. But that changed when a race was found where the ei->dentry needed to be cleared when the last dput() was called on it. But there was still logic that checked if ei->dentry was not NULL and is_freed is set, and would warn if it was. But since that situation was changed and the ei->dentry isn't cleared until the last dput() is called on it while the ei->is_freed is set, do not test for that condition anymore, and change the comments to reflect that. Link: https://lkml.kernel.org/r/20231120235154.265826243@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 020010fbfa20 ("eventfs: Delete eventfs_inode when the last dentry is freed") Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
* | Merge tag 'parisc-for-6.7-rc3' of ↵Linus Torvalds2023-11-2611-34/+43
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc architecture fixes from Helge Deller: "This patchset fixes and enforces correct section alignments for the ex_table, altinstructions, parisc_unwind, jump_table and bug_table which are created by inline assembly. Due to not being correctly aligned at link & load time they can trigger unnecessarily the kernel unaligned exception handler at runtime. While at it, I switched the bug table to use relative addresses which reduces the size of the table by half on 64-bit. We still had the ENOSYM and EREMOTERELEASE errno symbols as left-overs from HP-UX, which now trigger build-issues with glibc. We can simply remove them. Most of the patches are tagged for stable kernel series. Summary: - Drop HP-UX ENOSYM and EREMOTERELEASE return codes to avoid glibc build issues - Fix section alignments for ex_table, altinstructions, parisc unwind table, jump_table and bug_table - Reduce size of bug_table on 64-bit kernel by using relative pointers" * tag 'parisc-for-6.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Reduce size of the bug_table on 64-bit kernel by half parisc: Drop the HP-UX ENOSYM and EREMOTERELEASE error codes parisc: Use natural CPU alignment for bug_table parisc: Ensure 32-bit alignment on parisc unwind section parisc: Mark lock_aligned variables 16-byte aligned on SMP parisc: Mark jump_table naturally aligned parisc: Mark altinstructions read-only and 32-bit aligned parisc: Mark ex_table entries 32-bit aligned in uaccess.h parisc: Mark ex_table entries 32-bit aligned in assembly.h