kernel-6.5-garbage-collect-all-references-to-get_user.patch

   1 From 6fe0c6bd4b3bbac5cf868b927973255961b28ff4 Mon Sep 17 00:00:00 2001
   2 From: Paolo Pisati <paolo.pisati@canonical.com>
   3 Date: Tue, 18 Jul 2023 12:14:47 +0000
   4 Subject: [PATCH 1/2] Linux 6.5: garbage collect all references to
   5  get_user_pages_remote()
   6
   7 Upstream commit ca5e863233e8f6acd1792fd85d6bc2729a1b2c10 "mm/gup: remove
   8 vmas parameter from get_user_pages_remote()" changed the API: since we
   9 reference get_user_pages_remote() (but don't use it anywhere), garbage
  10 collect all reference.
  11
  12 Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
  13 ---
  14  common/inc/nv-mm.h |  99 -------------
  15  conftest.sh        | 130 ------------------
  16  2 files changed, 229 deletions(-)
  17
  18 diff --git a/kernel/common/inc/nv-mm.h b/kernel/common/inc/nv-mm.h
  19 index aec55b0b..51d0df4a 100644
  20 --- a/kernel/common/inc/nv-mm.h
  21 +++ b/kernel/common/inc/nv-mm.h
  22 @@ -98,105 +98,6 @@ typedef int vm_fault_t;
  23      #endif
  24  #endif
  25
  26 -/*
  27 - * get_user_pages_remote() was added by commit 1e9877902dc7
  28 - * ("mm/gup: Introduce get_user_pages_remote()") in v4.6 (2016-02-12).
  29 - *
  30 - * The very next commit cde70140fed8 ("mm/gup: Overload get_user_pages()
  31 - * functions") deprecated the 8-argument version of get_user_pages for the
  32 - * non-remote case (calling get_user_pages with current and current->mm).
  33 - *
  34 - * The guidelines are: call NV_GET_USER_PAGES_REMOTE if you need the 8-argument
  35 - * version that uses something other than current and current->mm. Use
  36 - * NV_GET_USER_PAGES if you are refering to current and current->mm.
  37 - *
  38 - * Note that get_user_pages_remote() requires the caller to hold a reference on
  39 - * the task_struct (if non-NULL and if this API has tsk argument) and the mm_struct.
  40 - * This will always be true when using current and current->mm. If the kernel passes
  41 - * the driver a vma via driver callback, the kernel holds a reference on vma->vm_mm
  42 - * over that callback.
  43 - *
  44 - * get_user_pages_remote() write/force parameters were replaced
  45 - * with gup_flags by commit 9beae1ea8930 ("mm: replace get_user_pages_remote()
  46 - * write/force parameters with gup_flags") in v4.9 (2016-10-13).
  47 - *
  48 - * get_user_pages_remote() added 'locked' parameter by commit 5b56d49fc31d
  49 - * ("mm: add locked parameter to get_user_pages_remote()") in
  50 - * v4.10 (2016-12-14).
  51 - *
  52 - * get_user_pages_remote() removed 'tsk' parameter by
  53 - * commit 64019a2e467a ("mm/gup: remove task_struct pointer for
  54 - * all gup code") in v5.9-rc1 (2020-08-11).
  55 - *
  56 - */
  57 -
  58 -#if defined(NV_GET_USER_PAGES_REMOTE_PRESENT)
  59 -    #if defined(NV_GET_USER_PAGES_REMOTE_HAS_WRITE_AND_FORCE_ARGS)
  60 -        #define NV_GET_USER_PAGES_REMOTE    get_user_pages_remote
  61 -    #else
  62 -        static inline long NV_GET_USER_PAGES_REMOTE(struct task_struct *tsk,
  63 -                                                    struct mm_struct *mm,
  64 -                                                    unsigned long start,
  65 -                                                    unsigned long nr_pages,
  66 -                                                    int write,
  67 -                                                    int force,
  68 -                                                    struct page **pages,
  69 -                                                    struct vm_area_struct **vmas)
  70 -        {
  71 -            unsigned int flags = 0;
  72 -
  73 -            if (write)
  74 -                flags |= FOLL_WRITE;
  75 -            if (force)
  76 -                flags |= FOLL_FORCE;
  77 -
  78 -        #if defined(NV_GET_USER_PAGES_REMOTE_HAS_LOCKED_ARG)
  79 -            #if defined (NV_GET_USER_PAGES_REMOTE_HAS_TSK_ARG)
  80 -               return get_user_pages_remote(tsk, mm, start, nr_pages, flags,
  81 -                                            pages, vmas, NULL);
  82 -            #else
  83 -               return get_user_pages_remote(mm, start, nr_pages, flags,
  84 -                                            pages, vmas, NULL);
  85 -            #endif
  86 -
  87 -        #else
  88 -
  89 -               return get_user_pages_remote(tsk, mm, start, nr_pages, flags,
  90 -                                            pages, vmas);
  91 -
  92 -        #endif
  93 -
  94 -        }
  95 -    #endif
  96 -#else
  97 -    #if defined(NV_GET_USER_PAGES_HAS_WRITE_AND_FORCE_ARGS)
  98 -        #define NV_GET_USER_PAGES_REMOTE    NV_GET_USER_PAGES
  99 -    #else
 100 -        #include <linux/mm.h>
 101 -        #include <linux/sched.h>
 102 -
 103 -        static inline long NV_GET_USER_PAGES_REMOTE(struct task_struct *tsk,
 104 -                                                    struct mm_struct *mm,
 105 -                                                    unsigned long start,
 106 -                                                    unsigned long nr_pages,
 107 -                                                    int write,
 108 -                                                    int force,
 109 -                                                    struct page **pages,
 110 -                                                    struct vm_area_struct **vmas)
 111 -        {
 112 -            unsigned int flags = 0;
 113 -
 114 -            if (write)
 115 -                flags |= FOLL_WRITE;
 116 -            if (force)
 117 -                flags |= FOLL_FORCE;
 118 -
 119 -            return get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas);
 120 -        }
 121 -    #endif
 122 -#endif
 123 -
 124 -
 125  /*
 126   * The .virtual_address field was effectively renamed to .address, by these
 127   * two commits:
 128 diff --git a/kernel/conftest.sh b/kernel/conftest.sh
 129 index 24daa850..abe435ff 100755
 130 --- a/kernel/conftest.sh
 131 +++ b/kernel/conftest.sh
 132 @@ -3081,136 +3081,6 @@ compile_test() {
 133              return
 134          ;;
 135
 136 -        get_user_pages_remote)
 137 -            #
 138 -            # Determine if the function get_user_pages_remote() is
 139 -            # present and has write/force/locked/tsk parameters.
 140 -            #
 141 -            # get_user_pages_remote() was added by:
 142 -            #   2016 Feb 12: 1e9877902dc7e11d2be038371c6fbf2dfcd469d7
 143 -            #
 144 -            # get_user_pages[_remote]() write/force parameters
 145 -            # replaced with gup_flags:
 146 -            #   2016 Oct 12: 768ae309a96103ed02eb1e111e838c87854d8b51
 147 -            #   2016 Oct 12: 9beae1ea89305a9667ceaab6d0bf46a045ad71e7
 148 -            #
 149 -            # get_user_pages_remote() added 'locked' parameter
 150 -            #   2016 Dec 14:5b56d49fc31dbb0487e14ead790fc81ca9fb2c99
 151 -            #
 152 -            # get_user_pages_remote() removed 'tsk' parameter by
 153 -            # commit 64019a2e467a ("mm/gup: remove task_struct pointer for
 154 -            # all gup code") in v5.9-rc1 (2020-08-11).
 155 -            #
 156 -            # conftest #1: check if get_user_pages_remote() is available
 157 -            # return if not available.
 158 -            # Fall through to conftest #2 if it is present
 159 -
 160 -            echo "$CONFTEST_PREAMBLE
 161 -            #include <linux/mm.h>
 162 -            void conftest_get_user_pages_remote(void) {
 163 -                get_user_pages_remote();
 164 -            }" > conftest$$.c
 165 -
 166 -            $CC $CFLAGS -c conftest$$.c > /dev/null 2>&1
 167 -            rm -f conftest$$.c
 168 -
 169 -            if [ -f conftest$$.o ]; then
 170 -                echo "#undef NV_GET_USER_PAGES_REMOTE_PRESENT" | append_conftest "functions"
 171 -                echo "#undef NV_GET_USER_PAGES_REMOTE_HAS_TSK_ARG" | append_conftest "functions"
 172 -                echo "#undef NV_GET_USER_PAGES_REMOTE_HAS_WRITE_AND_FORCE_ARGS" | append_conftest "functions"
 173 -                echo "#undef NV_GET_USER_PAGES_REMOTE_HAS_LOCKED_ARG" | append_conftest "functions"
 174 -                rm -f conftest$$.o
 175 -                return
 176 -            fi
 177 -
 178 -            # conftest #2: check if get_user_pages_remote() has write and
 179 -            # force arguments. Return if these arguments are present
 180 -            # Fall through to conftest #3 if these args are absent.
 181 -            echo "#define NV_GET_USER_PAGES_REMOTE_PRESENT" | append_conftest "functions"
 182 -            echo "$CONFTEST_PREAMBLE
 183 -            #include <linux/mm.h>
 184 -            long get_user_pages_remote(struct task_struct *tsk,
 185 -                                       struct mm_struct *mm,
 186 -                                       unsigned long start,
 187 -                                       unsigned long nr_pages,
 188 -                                       int write,
 189 -                                       int force,
 190 -                                       struct page **pages,
 191 -                                       struct vm_area_struct **vmas) {
 192 -                return 0;
 193 -            }" > conftest$$.c
 194 -
 195 -            $CC $CFLAGS -c conftest$$.c > /dev/null 2>&1
 196 -            rm -f conftest$$.c
 197 -
 198 -            if [ -f conftest$$.o ]; then
 199 -                echo "#define NV_GET_USER_PAGES_REMOTE_HAS_TSK_ARG" | append_conftest "functions"
 200 -                echo "#define NV_GET_USER_PAGES_REMOTE_HAS_WRITE_AND_FORCE_ARGS" | append_conftest "functions"
 201 -                echo "#undef NV_GET_USER_PAGES_REMOTE_HAS_LOCKED_ARG" | append_conftest "functions"
 202 -                rm -f conftest$$.o
 203 -                return
 204 -            fi
 205 -
 206 -            echo "#undef NV_GET_USER_PAGES_REMOTE_HAS_WRITE_AND_FORCE_ARGS" | append_conftest "functions"
 207 -
 208 -            #
 209 -            # conftest #3: check if get_user_pages_remote() has locked argument
 210 -            # Return if these arguments are present. Fall through to conftest #4
 211 -            # if these args are absent.
 212 -            #
 213 -            echo "$CONFTEST_PREAMBLE
 214 -            #include <linux/mm.h>
 215 -            long get_user_pages_remote(struct task_struct *tsk,
 216 -                                       struct mm_struct *mm,
 217 -                                       unsigned long start,
 218 -                                       unsigned long nr_pages,
 219 -                                       unsigned int gup_flags,
 220 -                                       struct page **pages,
 221 -                                       struct vm_area_struct **vmas,
 222 -                                       int *locked) {
 223 -                return 0;
 224 -            }" > conftest$$.c
 225 -
 226 -            $CC $CFLAGS -c conftest$$.c > /dev/null 2>&1
 227 -            rm -f conftest$$.c
 228 -
 229 -            if [ -f conftest$$.o ]; then
 230 -                echo "#define NV_GET_USER_PAGES_REMOTE_HAS_TSK_ARG" | append_conftest "functions"
 231 -                echo "#define NV_GET_USER_PAGES_REMOTE_HAS_LOCKED_ARG" | append_conftest "functions"
 232 -                rm -f conftest$$.o
 233 -                return
 234 -            fi
 235 -
 236 -            #
 237 -            # conftest #4: check if get_user_pages_remote() does not take
 238 -            # tsk argument.
 239 -            #
 240 -            echo "$CONFTEST_PREAMBLE
 241 -            #include <linux/mm.h>
 242 -            long get_user_pages_remote(struct mm_struct *mm,
 243 -                                       unsigned long start,
 244 -                                       unsigned long nr_pages,
 245 -                                       unsigned int gup_flags,
 246 -                                       struct page **pages,
 247 -                                       struct vm_area_struct **vmas,
 248 -                                       int *locked) {
 249 -                return 0;
 250 -            }" > conftest$$.c
 251 -
 252 -            $CC $CFLAGS -c conftest$$.c > /dev/null 2>&1
 253 -            rm -f conftest$$.c
 254 -
 255 -            if [ -f conftest$$.o ]; then
 256 -                echo "#undef NV_GET_USER_PAGES_REMOTE_HAS_TSK_ARG" | append_conftest "functions"
 257 -                echo "#define NV_GET_USER_PAGES_REMOTE_HAS_LOCKED_ARG" | append_conftest "functions"
 258 -                rm -f conftest$$.o
 259 -            else
 260 -
 261 -                echo "#define NV_GET_USER_PAGES_REMOTE_HAS_TSK_ARG" | append_conftest "functions"
 262 -                echo "#undef NV_GET_USER_PAGES_REMOTE_HAS_LOCKED_ARG" | append_conftest "functions"
 263 -            fi
 264 -        ;;
 265 -
 266          usleep_range)
 267              #
 268              # Determine if the function usleep_range() is present.
 269 --
 270 2.40.1
 271