[Bug runtime/19990] New: on rawhide, the get_user_pages() function has changed

[Bug runtime/19990] New: on rawhide, the get_user_pages() function has changed

[dsmith at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=19990

            Bug ID: 19990
           Summary: on rawhide, the get_user_pages() function has changed
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: runtime
          Assignee: systemtap at sourceware dot org
          Reporter: dsmith at redhat dot com
  Target Milestone: ---

On rawhide (4.6.0-0.rc4.git3.1.fc25.x86_64), I'm getting the following compile
error:

====
stap nd_sys.stp -c ./preadv
In file included from /usr/local/share/systemtap/runtime/linux/runtime.h:209:0,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
/usr/local/share/systemtap/runtime/linux/access_process_vm.h: In function
‘__access_process_vm_’:
/usr/local/share/systemtap/runtime/linux/access_process_vm.h:35:29: error:
passing argument 1 of ‘get_user_pages’ makes integer from pointer without a
cast [-Werror=int-conversion]
       ret = get_user_pages (tsk, mm, addr, 1, write, 1, &page, &vma);
                             ^~~
In file included from include/linux/pid_namespace.h:6:0,
                 from include/linux/ptrace.h:8,
                 from include/linux/ftrace.h:13,
                 from include/linux/kprobes.h:42,
                 from /usr/local/share/systemtap/runtime/linux/runtime.h:21,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
include/linux/mm.h:1253:6: note: expected ‘long unsigned int’ but argument is
of type ‘struct task_struct *’
 long get_user_pages(unsigned long start, unsigned long nr_pages,
      ^~~~~~~~~~~~~~
In file included from /usr/local/share/systemtap/runtime/linux/runtime.h:209:0,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
/usr/local/share/systemtap/runtime/linux/access_process_vm.h:35:34: error:
passing argument 2 of ‘get_user_pages’ makes integer from pointer without a
cast [-Werror=int-conversion]
       ret = get_user_pages (tsk, mm, addr, 1, write, 1, &page, &vma);
                                  ^~
In file included from include/linux/pid_namespace.h:6:0,
                 from include/linux/ptrace.h:8,
                 from include/linux/ftrace.h:13,
                 from include/linux/kprobes.h:42,
                 from /usr/local/share/systemtap/runtime/linux/runtime.h:21,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
include/linux/mm.h:1253:6: note: expected ‘long unsigned int’ but argument is
of type ‘struct mm_struct *’
 long get_user_pages(unsigned long start, unsigned long nr_pages,
      ^~~~~~~~~~~~~~
In file included from /usr/local/share/systemtap/runtime/linux/runtime.h:209:0,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
/usr/local/share/systemtap/runtime/linux/access_process_vm.h:35:47: error:
passing argument 5 of ‘get_user_pages’ makes pointer from integer without a
cast [-Werror=int-conversion]
       ret = get_user_pages (tsk, mm, addr, 1, write, 1, &page, &vma);
                                               ^~~~~
In file included from include/linux/pid_namespace.h:6:0,
                 from include/linux/ptrace.h:8,
                 from include/linux/ftrace.h:13,
                 from include/linux/kprobes.h:42,
                 from /usr/local/share/systemtap/runtime/linux/runtime.h:21,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
include/linux/mm.h:1253:6: note: expected ‘struct page **’ but argument is of
type ‘int’
 long get_user_pages(unsigned long start, unsigned long nr_pages,
      ^~~~~~~~~~~~~~
In file included from /usr/local/share/systemtap/runtime/linux/runtime.h:209:0,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
/usr/local/share/systemtap/runtime/linux/access_process_vm.h:35:54: error:
passing argument 6 of ‘get_user_pages’ makes pointer from integer without a
cast [-Werror=int-conversion]
       ret = get_user_pages (tsk, mm, addr, 1, write, 1, &page, &vma);
                                                      ^
In file included from include/linux/pid_namespace.h:6:0,
                 from include/linux/ptrace.h:8,
                 from include/linux/ftrace.h:13,
                 from include/linux/kprobes.h:42,
                 from /usr/local/share/systemtap/runtime/linux/runtime.h:21,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
include/linux/mm.h:1253:6: note: expected ‘struct vm_area_struct **’ but
argument is of type ‘int’
 long get_user_pages(unsigned long start, unsigned long nr_pages,
      ^~~~~~~~~~~~~~
In file included from /usr/local/share/systemtap/runtime/linux/runtime.h:209:0,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
/usr/local/share/systemtap/runtime/linux/access_process_vm.h:35:13: error: too
many arguments to function ‘get_user_pages’
       ret = get_user_pages (tsk, mm, addr, 1, write, 1, &page, &vma);
             ^~~~~~~~~~~~~~
In file included from include/linux/pid_namespace.h:6:0,
                 from include/linux/ptrace.h:8,
                 from include/linux/ftrace.h:13,
                 from include/linux/kprobes.h:42,
                 from /usr/local/share/systemtap/runtime/linux/runtime.h:21,
                 from /usr/local/share/systemtap/runtime/runtime.h:24,
                 from
/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.c:25:
include/linux/mm.h:1253:6: note: declared here
 long get_user_pages(unsigned long start, unsigned long nr_pages,
      ^~~~~~~~~~~~~~

cc1: all warnings being treated as errors
scripts/Makefile.build:291: recipe for target
'/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.o' failed
make[1]: ***
[/tmp/stap1vHU9T/stap_0b3271e6957c26e6ec5ff4ce3462c458_1435718_src.o] Error 1
Makefile:1431: recipe for target '_module_/tmp/stap1vHU9T' failed
make: *** [_module_/tmp/stap1vHU9T] Error 2
WARNING: kbuild exited with status: 2
Pass 4: compilation failed.  [man error::pass4]
====

I believe this was caused by the following kernel commits:

====
commit a1f983174dd7e535e50ca850fcfb3b8d38149f39
Merge: 63a1281 c12d2da
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu Apr 14 19:31:34 2016 -0700

    Merge branch 'mm-urgent-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

    Pull mm gup cleanup from Ingo Molnar:
     "This removes the ugly get-user-pages API hack, now that all upstream
      code has been migrated to it"

    ("ugly" is putting it mildly. But it worked.. - Linus)

    * 'mm-urgent-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
      mm/gup: Remove the macro overload API migration helpers from the
get_user*() APIs

commit c12d2da56d0e07d230968ee2305aaa86b93a6832
Author: Ingo Molnar <mingo@kernel.org>
Date:   Mon Apr 4 10:24:58 2016 +0200

    mm/gup: Remove the macro overload API migration helpers from the
get_user*() APIs

    The pkeys changes brought about a truly hideous set of macros in:

      cde70140fed8 ("mm/gup: Overload get_user_pages() functions")

    ... which macros are (ab-)using the fact that __VA_ARGS__ can be used
    to shift parameter positions in macro arguments without breaking the
    build and so can be used to call separate C functions depending on
    the number of arguments of the macro.

    This allowed easy migration of these 3 GUP APIs, as both these variants
    worked at the C level:

      old:
        ret = get_user_pages(current, current->mm, address, 1, 1, 0, &page,
NULL);

      new:
        ret = get_user_pages(address, 1, 1, 0, &page, NULL);

    ... while we also generated a (functionally harmless but noticeable) build
    time warning if the old API was used. As there are over 300 uses of these
    APIs, this trick eased the migration of the API and avoided excessive
    migration pain in linux-next.

    Now, with its work done, get rid of all of that complication and ugliness:

        3 files changed, 16 insertions(+), 140 deletions(-)

    ... where the linecount of the migration hack was further inflated by the
    fact that there are NOMMU variants of these GUP APIs as well.

    Much of the conversion was done in linux-next over the past couple of
months,
    and Linus recently removed all remaining old API uses from the upstream
tree
    in the following upstrea commit:

      cb107161df3c ("Convert straggling drivers to new six-argument
get_user_pages()")

    There was one more old-API usage in mm/gup.c, in the
CONFIG_HAVE_GENERIC_RCU_GUP
    code path that ARM, ARM64 and PowerPC uses.

    After this commit any old API usage will break the build.

    [ Also fixed a PowerPC/HAVE_GENERIC_RCU_GUP warning reported by Stephen
Rothwell. ]
====

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[Bug runtime/19990] on rawhide, the get_user_pages() function has changed

[dsmith at redhat dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=19990

David Smith <dsmith at redhat dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |FIXED

--- Comment #1 from David Smith <dsmith at redhat dot com> ---
Fixed in commit e7c42c3.

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