From f4c72c70308897bd26f2918979d06b429916fd0e Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Fri, 27 Feb 2015 20:44:21 +0300 Subject: [PATCH] android: binder: fix binder mmap failures binder_update_page_range() initializes only addr and size fields in 'struct vm_struct tmp_area;' and passes it to map_vm_area(). Before 71394fe50146 ("mm: vmalloc: add flag preventing guard hole allocation") this was because map_vm_area() didn't use any other fields in vm_struct except addr and size. Now get_vm_area_size() (used in map_vm_area()) reads vm_struct's flags to determine whether vm area has guard hole or not. binder_update_page_range() don't initialize flags field, so this causes following binder mmap failures: -----------[ cut here ]------------ WARNING: CPU: 0 PID: 1971 at mm/vmalloc.c:130 vmap_page_range_noflush+0x119/0x144() CPU: 0 PID: 1971 Comm: healthd Not tainted 4.0.0-rc1-00399-g7da3fdc-dirty #157 Hardware name: ARM-Versatile Express [] (unwind_backtrace) from [] (show_stack+0x11/0x14) [] (show_stack) from [] (dump_stack+0x59/0x7c) [] (dump_stack) from [] (warn_slowpath_common+0x55/0x84) [] (warn_slowpath_common) from [] (warn_slowpath_null+0x17/0x1c) [] (warn_slowpath_null) from [] (vmap_page_range_noflush+0x119/0x144) [] (vmap_page_range_noflush) from [] (map_vm_area+0x27/0x48) [] (map_vm_area) from [] (binder_update_page_range+0x12f/0x27c) [] (binder_update_page_range) from [] (binder_mmap+0xbf/0x1ac) [] (binder_mmap) from [] (mmap_region+0x2eb/0x4d4) [] (mmap_region) from [] (do_mmap_pgoff+0x1e7/0x250) [] (do_mmap_pgoff) from [] (vm_mmap_pgoff+0x45/0x60) [] (vm_mmap_pgoff) from [] (SyS_mmap_pgoff+0x5d/0x80) [] (SyS_mmap_pgoff) from [] (ret_fast_syscall+0x1/0x5c) ---[ end trace 48c2c4b9a1349e54 ]--- binder: 1982: binder_alloc_buf failed to map page at f0e00000 in kernel binder: binder_mmap: 1982 b6bde000-b6cdc000 alloc small buf failed -12 Use map_kernel_range_noflush() instead of map_vm_area() as this is better API for binder's purposes and it allows to get rid of 'vm_struct tmp_area' at all. Fixes: 71394fe50146 ("mm: vmalloc: add flag preventing guard hole allocation") Signed-off-by: Andrey Ryabinin Reported-by: Amit Pundir Tested-by: Amit Pundir Acked-by: David Rientjes Tested-by: John Stultz Signed-off-by: Greg Kroah-Hartman --- drivers/android/binder.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 33b09b6568a4..6607f3c6ace1 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -551,7 +551,6 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate, { void *page_addr; unsigned long user_page_addr; - struct vm_struct tmp_area; struct page **page; struct mm_struct *mm; @@ -600,10 +599,11 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate, proc->pid, page_addr); goto err_alloc_page_failed; } - tmp_area.addr = page_addr; - tmp_area.size = PAGE_SIZE + PAGE_SIZE /* guard page? */; - ret = map_vm_area(&tmp_area, PAGE_KERNEL, page); - if (ret) { + ret = map_kernel_range_noflush((unsigned long)page_addr, + PAGE_SIZE, PAGE_KERNEL, page); + flush_cache_vmap((unsigned long)page_addr, + (unsigned long)page_addr + PAGE_SIZE); + if (ret != 1) { pr_err("%d: binder_alloc_buf failed to map page at %p in kernel\n", proc->pid, page_addr); goto err_map_kernel_failed; -- 2.20.1