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

   1 From f3978e548747dfe988016ef7c99fe50975da90df 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 108/196] 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 diff --git a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  12 index 2b5fa56..b3bdaa2 100644
  13 --- a/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  14 +++ b/drivers/misc/vc04_services/interface/vchiq_arm/vchiq_2835_arm.c
  15 @@ -374,6 +374,7 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
  16         unsigned int num_pages, offset, i;
  17         char *addr, *base_addr, *next_addr;
  18         int run, addridx, actual_pages;
  19 +        unsigned long *need_release;
  20
  21         offset = (unsigned int)buf & (PAGE_SIZE - 1);
  22         num_pages = (count + offset + PAGE_SIZE - 1) / PAGE_SIZE;
  23 @@ -384,9 +385,10 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
  24         ** list
  25         */
  26         pagelist = kmalloc(sizeof(PAGELIST_T) +
  27 -               (num_pages * sizeof(unsigned long)) +
  28 -               (num_pages * sizeof(pages[0])),
  29 -               GFP_KERNEL);
  30 +                           (num_pages * sizeof(unsigned long)) +
  31 +                           sizeof(unsigned long) +
  32 +                           (num_pages * sizeof(pages[0])),
  33 +                           GFP_KERNEL);
  34
  35         vchiq_log_trace(vchiq_arm_log_level,
  36                 "create_pagelist - %x", (unsigned int)pagelist);
  37 @@ -394,28 +396,44 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
  38                 return -ENOMEM;
  39
  40         addrs = pagelist->addrs;
  41 -       pages = (struct page **)(addrs + num_pages);
  42 +        need_release = (unsigned long *)(addrs + num_pages);
  43 +       pages = (struct page **)(addrs + num_pages + 1);
  44
  45 -       down_read(&task->mm->mmap_sem);
  46 -       actual_pages = get_user_pages(task, task->mm,
  47 -               (unsigned long)buf & ~(PAGE_SIZE - 1), num_pages,
  48 -               (type == PAGELIST_READ) /*Write */ , 0 /*Force */ ,
  49 -               pages, NULL /*vmas */);
  50 -       up_read(&task->mm->mmap_sem);
  51 -
  52 -   if (actual_pages != num_pages)
  53 -   {
  54 -      /* This is probably due to the process being killed */
  55 -      while (actual_pages > 0)
  56 -      {
  57 -         actual_pages--;
  58 -         page_cache_release(pages[actual_pages]);
  59 -      }
  60 -      kfree(pagelist);
  61 -      if (actual_pages == 0)
  62 -         actual_pages = -ENOMEM;
  63 -      return actual_pages;
  64 -   }
  65 +       if (is_vmalloc_addr(buf)) {
  66 +               for (actual_pages = 0; actual_pages < num_pages; actual_pages++) {
  67 +                       pages[actual_pages] = vmalloc_to_page(buf + (actual_pages * PAGE_SIZE));
  68 +               }
  69 +                *need_release = 0; /* do not try and release vmalloc pages */
  70 +       } else {
  71 +               down_read(&task->mm->mmap_sem);
  72 +               actual_pages = get_user_pages(task, task->mm,
  73 +                                         (unsigned long)buf & ~(PAGE_SIZE - 1),
  74 +                                         num_pages,
  75 +                                         (type == PAGELIST_READ) /*Write */ ,
  76 +                                         0 /*Force */ ,
  77 +                                         pages,
  78 +                                         NULL /*vmas */);
  79 +               up_read(&task->mm->mmap_sem);
  80 +
  81 +               if (actual_pages != num_pages) {
  82 +                       vchiq_log_info(vchiq_arm_log_level,
  83 +                                      "create_pagelist - only %d/%d pages locked",
  84 +                                      actual_pages,
  85 +                                      num_pages);
  86 +
  87 +                       /* This is probably due to the process being killed */
  88 +                       while (actual_pages > 0)
  89 +                       {
  90 +                               actual_pages--;
  91 +                               page_cache_release(pages[actual_pages]);
  92 +                       }
  93 +                       kfree(pagelist);
  94 +                       if (actual_pages == 0)
  95 +                               actual_pages = -ENOMEM;
  96 +                       return actual_pages;
  97 +               }
  98 +                *need_release = 1; /* release user pages */
  99 +       }
 100
 101         pagelist->length = count;
 102         pagelist->type = type;
 103 @@ -482,6 +500,7 @@ create_pagelist(char __user *buf, size_t count, unsigned short type,
 104  static void
 105  free_pagelist(PAGELIST_T *pagelist, int actual)
 106  {
 107 +        unsigned long *need_release;
 108         struct page **pages;
 109         unsigned int num_pages, i;
 110
 111 @@ -492,7 +511,8 @@ free_pagelist(PAGELIST_T *pagelist, int actual)
 112                 (pagelist->length + pagelist->offset + PAGE_SIZE - 1) /
 113                 PAGE_SIZE;
 114
 115 -       pages = (struct page **)(pagelist->addrs + num_pages);
 116 +        need_release = (unsigned long *)(pagelist->addrs + num_pages);
 117 +       pages = (struct page **)(pagelist->addrs + num_pages + 1);
 118
 119         /* Deal with any partial cache lines (fragments) */
 120         if (pagelist->type >= PAGELIST_READ_WITH_FRAGMENTS) {
 121 @@ -528,11 +548,14 @@ free_pagelist(PAGELIST_T *pagelist, int actual)
 122                 up(&g_free_fragments_sema);
 123         }
 124
 125 -       for (i = 0; i < num_pages; i++) {
 126 -               if (pagelist->type != PAGELIST_WRITE)
 127 -                       set_page_dirty(pages[i]);
 128 -               page_cache_release(pages[i]);
 129 -       }
 130 +        if (*need_release) {
 131 +               for (i = 0; i < num_pages; i++) {
 132 +                       if (pagelist->type != PAGELIST_WRITE)
 133 +                               set_page_dirty(pages[i]);
 134 +
 135 +                       page_cache_release(pages[i]);
 136 +               }
 137 +        }
 138
 139         kfree(pagelist);
 140  }
 141 --
 142 1.9.1
 143