target/linux/brcm2708/patches-3.10/0108-vchiq-create_pagelist-copes-with-vmalloc-memory.patch

   1 From 974102eef65cd2576157b089db47386c5b29dee6 Mon Sep 17 00:00:00 2001
   2 From: Vincent Sanders <vincent.sanders@collabora.co.uk>
   3 Date: Mon, 2 Sep 2013 16:44:57 +0100
   4 Subject: [PATCH 108/174] vchiq: create_pagelist copes with vmalloc memory
   5
   6 Signed-off-by: Daniel Stone <daniels@collabora.com>
   7 ---
   8  .../interface/vchiq_arm/vchiq_2835_arm.c           | 83 ++++++++++++++--------
   9  1 file changed, 53 insertions(+), 30 deletions(-)
  10
  11 --- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  12 +++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  13 @@ -374,6 +374,7 @@ create_pagelist(char __user *buf, size_t
  14         unsigned int num_pages, offset, i;
  15         char *addr, *base_addr, *next_addr;
  16         int run, addridx, actual_pages;
  17 +        unsigned long *need_release;
  18
  19         offset = (unsigned int)buf & (PAGE_SIZE - 1);
  20         num_pages = (count + offset + PAGE_SIZE - 1) / PAGE_SIZE;
  21 @@ -384,9 +385,10 @@ create_pagelist(char __user *buf, size_t
  22         ** list
  23         */
  24         pagelist = kmalloc(sizeof(PAGELIST_T) +
  25 -               (num_pages * sizeof(unsigned long)) +
  26 -               (num_pages * sizeof(pages[0])),
  27 -               GFP_KERNEL);
  28 +                           (num_pages * sizeof(unsigned long)) +
  29 +                           sizeof(unsigned long) +
  30 +                           (num_pages * sizeof(pages[0])),
  31 +                           GFP_KERNEL);
  32
  33         vchiq_log_trace(vchiq_arm_log_level,
  34                 "create_pagelist - %x", (unsigned int)pagelist);
  35 @@ -394,28 +396,44 @@ create_pagelist(char __user *buf, size_t
  36                 return -ENOMEM;
  37
  38         addrs = pagelist->addrs;
  39 -       pages = (struct page **)(addrs + num_pages);
  40 +        need_release = (unsigned long *)(addrs + num_pages);
  41 +       pages = (struct page **)(addrs + num_pages + 1);
  42
  43 -       down_read(&task->mm->mmap_sem);
  44 -       actual_pages = get_user_pages(task, task->mm,
  45 -               (unsigned long)buf & ~(PAGE_SIZE - 1), num_pages,
  46 -               (type == PAGELIST_READ) /*Write */ , 0 /*Force */ ,
  47 -               pages, NULL /*vmas */);
  48 -       up_read(&task->mm->mmap_sem);
  49 -
  50 -   if (actual_pages != num_pages)
  51 -   {
  52 -      /* This is probably due to the process being killed */
  53 -      while (actual_pages > 0)
  54 -      {
  55 -         actual_pages--;
  56 -         page_cache_release(pages[actual_pages]);
  57 -      }
  58 -      kfree(pagelist);
  59 -      if (actual_pages == 0)
  60 -         actual_pages = -ENOMEM;
  61 -      return actual_pages;
  62 -   }
  63 +       if (is_vmalloc_addr(buf)) {
  64 +               for (actual_pages = 0; actual_pages < num_pages; actual_pages++) {
  65 +                       pages[actual_pages] = vmalloc_to_page(buf + (actual_pages * PAGE_SIZE));
  66 +               }
  67 +                *need_release = 0; /* do not try and release vmalloc pages */
  68 +       } else {
  69 +               down_read(&task->mm->mmap_sem);
  70 +               actual_pages = get_user_pages(task, task->mm,
  71 +                                         (unsigned long)buf & ~(PAGE_SIZE - 1),
  72 +                                         num_pages,
  73 +                                         (type == PAGELIST_READ) /*Write */ ,
  74 +                                         0 /*Force */ ,
  75 +                                         pages,
  76 +                                         NULL /*vmas */);
  77 +               up_read(&task->mm->mmap_sem);
  78 +
  79 +               if (actual_pages != num_pages) {
  80 +                       vchiq_log_info(vchiq_arm_log_level,
  81 +                                      "create_pagelist - only %d/%d pages locked",
  82 +                                      actual_pages,
  83 +                                      num_pages);
  84 +
  85 +                       /* This is probably due to the process being killed */
  86 +                       while (actual_pages > 0)
  87 +                       {
  88 +                               actual_pages--;
  89 +                               page_cache_release(pages[actual_pages]);
  90 +                       }
  91 +                       kfree(pagelist);
  92 +                       if (actual_pages == 0)
  93 +                               actual_pages = -ENOMEM;
  94 +                       return actual_pages;
  95 +               }
  96 +                *need_release = 1; /* release user pages */
  97 +       }
  98
  99         pagelist->length = count;
 100         pagelist->type = type;
 101 @@ -482,6 +500,7 @@ create_pagelist(char __user *buf, size_t
 102  static void
 103  free_pagelist(PAGELIST_T *pagelist, int actual)
 104  {
 105 +        unsigned long *need_release;
 106         struct page **pages;
 107         unsigned int num_pages, i;
 108
 109 @@ -492,7 +511,8 @@ free_pagelist(PAGELIST_T *pagelist, int
 110                 (pagelist->length + pagelist->offset + PAGE_SIZE - 1) /
 111                 PAGE_SIZE;
 112
 113 -       pages = (struct page **)(pagelist->addrs + num_pages);
 114 +        need_release = (unsigned long *)(pagelist->addrs + num_pages);
 115 +       pages = (struct page **)(pagelist->addrs + num_pages + 1);
 116
 117         /* Deal with any partial cache lines (fragments) */
 118         if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
 119 @@ -528,11 +548,14 @@ free_pagelist(PAGELIST_T *pagelist, int
 120                 up(&g_free_fragments_sema);
 121         }
 122
 123 -       for (i = 0; i < num_pages; i++) {
 124 -               if (pagelist->type != PAGELIST_WRITE)
 125 -                       set_page_dirty(pages[i]);
 126 -               page_cache_release(pages[i]);
 127 -       }
 128 +        if (*need_release) {
 129 +               for (i = 0; i < num_pages; i++) {
 130 +                       if (pagelist->type != PAGELIST_WRITE)
 131 +                               set_page_dirty(pages[i]);
 132 +
 133 +                       page_cache_release(pages[i]);
 134 +               }
 135 +        }
 136
 137         kfree(pagelist);
 138  }