Quoting Cyrill Gorcunov ([email protected]): > Instead of taking mm->mmap_sem inside prctl_set_mm_exe_file move > it out of and rename the helper to prctl_set_mm_exe_file_locked. > This will allow to reuse this function in a next patch. > > Signed-off-by: Cyrill Gorcunov <[email protected]> > Cc: Kees Cook <[email protected]> > Cc: Tejun Heo <[email protected]> > Cc: Andrew Morton <[email protected]> > Cc: Andrew Vagin <[email protected]> > Cc: Eric W. Biederman <[email protected]> > Cc: H. Peter Anvin <[email protected]> > Cc: Serge Hallyn <[email protected]>
Acked-by: Serge Hallyn <[email protected]> > Cc: Pavel Emelyanov <[email protected]> > Cc: Vasiliy Kulikov <[email protected]> > Cc: KAMEZAWA Hiroyuki <[email protected]> > Cc: Michael Kerrisk <[email protected]> > Cc: Julien Tinnes <[email protected]> > --- > kernel/sys.c | 21 +++++++++++---------- > 1 file changed, 11 insertions(+), 10 deletions(-) > > Index: linux-2.6.git/kernel/sys.c > =================================================================== > --- linux-2.6.git.orig/kernel/sys.c > +++ linux-2.6.git/kernel/sys.c > @@ -1628,12 +1628,14 @@ SYSCALL_DEFINE1(umask, int, mask) > return mask; > } > > -static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) > +static int prctl_set_mm_exe_file_locked(struct mm_struct *mm, unsigned int > fd) > { > struct fd exe; > struct inode *inode; > int err; > > + VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem)); > + > exe = fdget(fd); > if (!exe.file) > return -EBADF; > @@ -1654,8 +1656,6 @@ static int prctl_set_mm_exe_file(struct > if (err) > goto exit; > > - down_write(&mm->mmap_sem); > - > /* > * Forbid mm->exe_file change if old file still mapped. > */ > @@ -1667,7 +1667,7 @@ static int prctl_set_mm_exe_file(struct > if (vma->vm_file && > path_equal(&vma->vm_file->f_path, > &mm->exe_file->f_path)) > - goto exit_unlock; > + goto exit; > } > > /* > @@ -1678,13 +1678,10 @@ static int prctl_set_mm_exe_file(struct > */ > err = -EPERM; > if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) > - goto exit_unlock; > + goto exit; > > err = 0; > set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */ > -exit_unlock: > - up_write(&mm->mmap_sem); > - > exit: > fdput(exe); > return err; > @@ -1703,8 +1700,12 @@ static int prctl_set_mm(int opt, unsigne > if (!capable(CAP_SYS_RESOURCE)) > return -EPERM; > > - if (opt == PR_SET_MM_EXE_FILE) > - return prctl_set_mm_exe_file(mm, (unsigned int)addr); > + if (opt == PR_SET_MM_EXE_FILE) { > + down_write(&mm->mmap_sem); > + error = prctl_set_mm_exe_file_locked(mm, (unsigned int)addr); > + up_write(&mm->mmap_sem); > + return error; > + } > > if (addr >= TASK_SIZE || addr < mmap_min_addr) > return -EINVAL; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
