diff options
| author | Eric W. Biederman | 2020-07-13 12:06:48 -0500 |
|---|---|---|
| committer | Eric W. Biederman | 2020-07-21 08:24:52 -0500 |
| commit | be619f7f063a49c656f620a46af4f8ea3e759e91 (patch) | |
| tree | be0f257b8da82e9e2eb9bdaa2574a48221e7b516 /arch/x86 | |
| parent | d8b9cd549ecf0f3dc8da42ada5f0ce73e8ed5f1e (diff) | |
exec: Implement kernel_execve
To allow the kernel not to play games with set_fs to call exec
implement kernel_execve. The function kernel_execve takes pointers
into kernel memory and copies the values pointed to onto the new
userspace stack.
The calls with arguments from kernel space of do_execve are replaced
with calls to kernel_execve.
The calls do_execve and do_execveat are made static as there are now
no callers outside of exec.
The comments that mention do_execve are updated to refer to
kernel_execve or execve depending on the circumstances. In addition
to correcting the comments, this makes it easy to grep for do_execve
and verify it is not used.
Inspired-by: https://lkml.kernel.org/r/20200627072704.2447163-1-hch@lst.de
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/87wo365ikj.fsf@x220.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/entry/entry_32.S | 2 | ||||
| -rw-r--r-- | arch/x86/entry/entry_64.S | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/unwind_frame.c | 2 |
3 files changed, 3 insertions, 3 deletions
diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index 024d7d276cd4..8f4e085ee06d 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -854,7 +854,7 @@ SYM_CODE_START(ret_from_fork) CALL_NOSPEC ebx /* * A kernel thread is allowed to return here after successfully - * calling do_execve(). Exit to userspace to complete the execve() + * calling kernel_execve(). Exit to userspace to complete the execve() * syscall. */ movl $0, PT_EAX(%esp) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index d2a00c97e53f..73c7e255256b 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -293,7 +293,7 @@ SYM_CODE_START(ret_from_fork) CALL_NOSPEC rbx /* * A kernel thread is allowed to return here after successfully - * calling do_execve(). Exit to userspace to complete the execve() + * calling kernel_execve(). Exit to userspace to complete the execve() * syscall. */ movq $0, RAX(%rsp) diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index 722a85f3b2dd..e40b4942157f 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -275,7 +275,7 @@ bool unwind_next_frame(struct unwind_state *state) * This user_mode() check is slightly broader than a PF_KTHREAD * check because it also catches the awkward situation where a * newly forked kthread transitions into a user task by calling - * do_execve(), which eventually clears PF_KTHREAD. + * kernel_execve(), which eventually clears PF_KTHREAD. */ if (!user_mode(regs)) goto the_end; |