for longterm v4.4.283, the code has checked if (!page) https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/staging/android/ion/ion_system_heap.c?h=v4.4.283 static struct page *alloc_buffer_page(struct ion_system_heap *heap, struct ion_buffer *buffer, unsigned long order) { ... if (!cached) { page = ion_page_pool_alloc(pool); } else { ... page = alloc_pages(gfp_flags | __GFP_COMP, order); if (!page) <--- return NULL; <--- ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order, ... } ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ for longterm v4.14.246, has no ion_pages_sync_for_device after ion_page_pool_alloc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/staging/android/ion/ion_system_heap.c?h=v4.14.246 static struct page *alloc_buffer_page(struct ion_system_heap *heap, struct ion_buffer *buffer, unsigned long order) { ... if (!cached) pool = heap->uncached_pools[order_to_index(order)]; else pool = heap->cached_pools[order_to_index(order)]; page = ion_page_pool_alloc(pool); return page; } ---------------------------------------------------------------------------------------------------------------------------------------------------------- after longterm v4.19.206(include), static struct page *alloc_buffer_page(struct ion_system_heap *heap, struct ion_buffer *buffer, unsigned long order) { struct ion_page_pool *pool = heap->pools[order_to_index(order)]; return ion_page_pool_alloc(pool); } On Sat, Sep 11, 2021 at 7:54 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Sat, Sep 11, 2021 at 07:21:15PM +0800, Cheng Chao wrote: > > kernel panic is here: > > > > Unable to handle kernel paging request at virtual address b0380000 > > pgd = d9d94000 > > [b0380000] *pgd=00000000 > > Internal error: Oops: 2805 [#1] PREEMPT SMP ARM > > ... > > task: daa2dd00 task.stack: da194000 > > PC is at v7_dma_clean_range+0x1c/0x34 > > LR is at arm_dma_sync_single_for_device+0x44/0x58 > > pc : [<c011aa0c>] lr : [<c011645c>] psr: 200f0013 > > sp : da195da0 ip : dc1f9000 fp : c1043dc4 > > r10: 00000000 r9 : c16f1f58 r8 : 00000001 > > r7 : c1621f94 r6 : c0116418 r5 : 00000000 r4 : c011aa58 > > r3 : 0000003f r2 : 00000040 r1 : b0480000 r0 : b0380000 > > Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none > > Control: 10c5383d Table: 19d9406a DAC: 00000051 > > ... > > [<c011aa0c>] (v7_dma_clean_range) from [<c011645c>] (arm_dma_sync_single_for_device+0x44/0x58) > > [<c011645c>] (arm_dma_sync_single_for_device) from [<c0117088>] (arm_dma_sync_sg_for_device+0x50/0x7c) > > [<c0117088>] (arm_dma_sync_sg_for_device) from [<c0c033c4>] (ion_pages_sync_for_device+0xb0/0xec) > > [<c0c033c4>] (ion_pages_sync_for_device) from [<c0c054ac>] (ion_system_heap_allocate+0x2a0/0x2e0) > > [<c0c054ac>] (ion_system_heap_allocate) from [<c0c02c78>] (ion_alloc+0x12c/0x494) > > [<c0c02c78>] (ion_alloc) from [<c0c03eac>] (ion_ioctl+0x510/0x63c) > > [<c0c03eac>] (ion_ioctl) from [<c027c4b0>] (do_vfs_ioctl+0xa8/0x9b4) > > [<c027c4b0>] (do_vfs_ioctl) from [<c027ce28>] (SyS_ioctl+0x6c/0x7c) > > [<c027ce28>] (SyS_ioctl) from [<c0108a40>] (ret_fast_syscall+0x0/0x48) > > Code: e3a02004 e1a02312 e2423001 e1c00003 (ee070f3a) > > ---[ end trace 89278304932c0e87 ]--- > > Kernel panic - not syncing: Fatal exception > > > > Signed-off-by: Cheng Chao <cs.os.kernel@xxxxxxxxx> > > --- > > drivers/staging/android/ion/ion_system_heap.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c > > index 22c481f2ae4f..2a35b99cf628 100644 > > --- a/drivers/staging/android/ion/ion_system_heap.c > > +++ b/drivers/staging/android/ion/ion_system_heap.c > > @@ -75,7 +75,7 @@ static struct page *alloc_buffer_page(struct ion_system_heap *heap, > > > > page = ion_page_pool_alloc(pool); > > > > - if (cached) > > + if (page && cached) > > ion_pages_sync_for_device(NULL, page, PAGE_SIZE << order, > > DMA_BIDIRECTIONAL); > > return page; > > -- > > 2.26.3 > > > > Why is this just a 4.9 patch? Ion didn't get removed until 5.11, so > wouldn't this be an issue for anything 5.10 and older? > > thanks, > > greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
