The current idiom for the callers is: flush_old_exec(bprm); set_personality(...); setup_new_exec(bprm); In 2010 Linus split flush_old_exec into flush_old_exec and setup_new_exec. With the intention that setup_new_exec be what is called after the processes new personality is set. Move the code that doesn't depend upon the personality from setup_new_exec into flush_old_exec. This is to facilitate future changes by having as much code together in one function as possible. Ref: 221af7f87b97 ("Split 'flush_old_exec' into two functions") Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> --- fs/exec.c | 85 ++++++++++++++++++++++++++++--------------------------- 1 file changed, 44 insertions(+), 41 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 8c3abafb9bb1..0eff20558735 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1359,39 +1359,7 @@ int flush_old_exec(struct linux_binprm * bprm) * undergoing exec(2). */ do_close_on_exec(me->files); - return 0; - -out_unlock: - mutex_unlock(&me->signal->exec_update_mutex); -out: - return retval; -} -EXPORT_SYMBOL(flush_old_exec); - -void would_dump(struct linux_binprm *bprm, struct file *file) -{ - struct inode *inode = file_inode(file); - if (inode_permission(inode, MAY_READ) < 0) { - struct user_namespace *old, *user_ns; - bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; - - /* Ensure mm->user_ns contains the executable */ - user_ns = old = bprm->mm->user_ns; - while ((user_ns != &init_user_ns) && - !privileged_wrt_inode_uidgid(user_ns, inode)) - user_ns = user_ns->parent; - if (old != user_ns) { - bprm->mm->user_ns = get_user_ns(user_ns); - put_user_ns(old); - } - } -} -EXPORT_SYMBOL(would_dump); - -void setup_new_exec(struct linux_binprm * bprm) -{ - struct task_struct *me = current; /* * Once here, prepare_binrpm() will not be called any more, so * the final state of setuid/setgid/fscaps can be merged into the @@ -1414,8 +1382,6 @@ void setup_new_exec(struct linux_binprm * bprm) bprm->rlim_stack.rlim_cur = _STK_LIM; } - arch_pick_mmap_layout(me->mm, &bprm->rlim_stack); - me->sas_ss_sp = me->sas_ss_size = 0; /* @@ -1430,16 +1396,9 @@ void setup_new_exec(struct linux_binprm * bprm) else set_dumpable(current->mm, SUID_DUMP_USER); - arch_setup_new_exec(); perf_event_exec(); __set_task_comm(me, kbasename(bprm->filename), true); - /* Set the new mm task size. We have to do that late because it may - * depend on TIF_32BIT which is only updated in flush_thread() on - * some architectures like powerpc - */ - me->mm->task_size = TASK_SIZE; - /* An exec changes our domain. We are no longer part of the thread group */ WRITE_ONCE(me->self_exec_id, me->self_exec_id + 1); @@ -1467,6 +1426,50 @@ void setup_new_exec(struct linux_binprm * bprm) * credentials; any time after this it may be unlocked. */ security_bprm_committed_creds(bprm); + return 0; + +out_unlock: + mutex_unlock(&me->signal->exec_update_mutex); +out: + return retval; +} +EXPORT_SYMBOL(flush_old_exec); + +void would_dump(struct linux_binprm *bprm, struct file *file) +{ + struct inode *inode = file_inode(file); + if (inode_permission(inode, MAY_READ) < 0) { + struct user_namespace *old, *user_ns; + bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP; + + /* Ensure mm->user_ns contains the executable */ + user_ns = old = bprm->mm->user_ns; + while ((user_ns != &init_user_ns) && + !privileged_wrt_inode_uidgid(user_ns, inode)) + user_ns = user_ns->parent; + + if (old != user_ns) { + bprm->mm->user_ns = get_user_ns(user_ns); + put_user_ns(old); + } + } +} +EXPORT_SYMBOL(would_dump); + +void setup_new_exec(struct linux_binprm * bprm) +{ + /* Setup things that can depend upon the personality */ + struct task_struct *me = current; + + arch_pick_mmap_layout(me->mm, &bprm->rlim_stack); + + arch_setup_new_exec(); + + /* Set the new mm task size. We have to do that late because it may + * depend on TIF_32BIT which is only updated in flush_thread() on + * some architectures like powerpc + */ + me->mm->task_size = TASK_SIZE; mutex_unlock(&me->signal->exec_update_mutex); mutex_unlock(&me->signal->cred_guard_mutex); } -- 2.20.1