Re: [Minios-devel] [UNIKRAFT PATCH] lib/vfscore: Populate exportsyms.uk

[Felipe Huici <Felipe.Huici@xxxxxxxxx>]

Hi Simon,

When building this against newlib I get a number of linker errors:

  CC      libuknetdev: netdev.o
  LD      libuknetdev.ld.o
  OBJCOPY libuknetdev.o
  LD      helloworld_kvm-x86_64.ld.o
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libvfscore.o: 
In function `fchown':
/root/workspace/gitlab/unikraft/upstreaming/unikraft/lib/vfscore/main.c:1963: 
multiple definition of `fchown'
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libnewlibglue.o:/root/workspace/gitlab/unikraft/upstreaming/libs/newlib/file.c:100:
 first defined here
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libvfscore.o: 
In function `lchown':
/root/workspace/gitlab/unikraft/upstreaming/unikraft/lib/vfscore/main.c:1976: 
multiple definition of `lchown'
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libnewlibglue.o:/root/workspace/gitlab/unikraft/upstreaming/libs/newlib/file.c:106:
 first defined here
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libvfscore.o: 
In function `rename':
/root/workspace/gitlab/unikraft/upstreaming/unikraft/lib/vfscore/main.c:909: 
multiple definition of `rename'
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libnewlibc.o:/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libnewlibc/origin/newlib-2.5.0.20170922/newlib/libc/stdio/rename.c:66:
 first defined here
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libvfscore.o: 
In function `umask':
/root/workspace/gitlab/unikraft/upstreaming/unikraft/lib/vfscore/main.c:2063: 
multiple definition of `umask'
/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/libnewlibglue.o:/root/workspace/gitlab/unikraft/upstreaming/libs/newlib/file.c:58:
 first defined here
collect2: error: ld returned 1 exit status
/root/workspace/gitlab/unikraft/upstreaming/unikraft/plat/kvm/Linker.uk:21: 
recipe for target 
'/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/helloworld_kvm-x86_64.dbg'
 failed
make[1]: *** 
[/root/workspace/gitlab/unikraft/upstreaming/apps/helloworld/build/helloworld_kvm-x86_64.dbg]
 Error 1
make[1]: Leaving directory 
'/root/workspace/gitlab/unikraft/upstreaming/unikraft'
Makefile:21: recipe for target 'all' failed
make: *** [all] Error 2

fchown, lchown, and umask are stubs in the newlib glue code, so it'd fine to 
just remove them.

rename is an actual implementation, but since vfscore now provides and exposes 
one, you can just remove newlib's rename.c from Makefile.uk .

If you agree and submit these fixes to newlib I can then upstream this vfscore 
patch.

-- Felipe

Reviewed-by: Felipe Huici <felipe.huici@xxxxxxxxx>

On 18.09.19, 12:18, "Simon Kuenzer" <simon.kuenzer@xxxxxxxxx> wrote:

    In order to avoid surprising linking errors, we further populate the
    `exportsyms.uk` file with symbols that are being expected to be publicly
    provided by vfscore.
    Duplicates of entries are removed with this commit, too (e.g., read, write)
    
    Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
    ---
     lib/vfscore/exportsyms.uk | 38 +++++++++++++++++++++++++++++++++-----
     1 file changed, 33 insertions(+), 5 deletions(-)
    
    diff --git a/lib/vfscore/exportsyms.uk b/lib/vfscore/exportsyms.uk
    index e2627c03..46156098 100644
    --- a/lib/vfscore/exportsyms.uk
    +++ b/lib/vfscore/exportsyms.uk
    @@ -3,9 +3,6 @@ vfscore_put_fd
     vfscore_install_fd
     vfscore_get_file
     vfscore_put_file
    -close
    -write
    -read
     mount
     vfscore_nullop
     vfscore_release_mp_dentries
    @@ -24,15 +21,17 @@ mkdir
     fsync
     fstat
     flock
    -lseek
    +fhold
    +fdrop
    +fget
     ftruncate
     stat
     chmod
     fchmod
    +fchown
     dup
     dup2
     dup3
    -vfscore_uiomove
     sync
     vfscore_mount_dump
     umount
    @@ -41,13 +40,16 @@ link
     unlink
     getcwd
     chown
    +chroot
     chdir
     fstatat
     statfs
     lstat
    +lchown
     openat
     opendir
     readdir
    +readdir64
     closedir
     pread
     pwrite
    @@ -75,9 +77,35 @@ readlink
     fallocate
     lseek
     uk_syscall_writev
    +umask
     dentry_alloc
    +dentry_init
    +dentry_lookup
    +dentry_move
    +dentry_remove
     drele
     vrele
    +vput
    +vref
    +vflush
    +dref
     fcntl
     readdir_r
    +readdir64_r
     fstatfs
    +eaccess
    +euidaccess
    +rename
    +__xmknod
    +__xstat
    +__lxstat
    +vn_access
    +vn_add_name
    +vn_del_name
    +vn_lock
    +vn_lookup
    +vn_setmode
    +vn_settimes
    +vn_stat
    +vn_unlock
    +vfs_busy
    -- 
    2.20.1
    
    

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