On Sun, Jan 24, 2021, Greg KH wrote:
On Sun, Jan 24, 2021 at 02:29:07PM +0800, Tianjia Zhang wrote:
In this scenario, there is no case where va_page is NULL, and the error has been checked. The if condition statement here is redundant, so remove the condition detection.
Signed-off-by: Tianjia Zhang tianjia.zhang@linux.alibaba.com
arch/x86/kernel/cpu/sgx/ioctl.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index 1c6ecf9fbeff..b0b829f1b761 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -66,9 +66,11 @@ static int sgx_encl_create(struct sgx_encl *encl, struct sgx_secs *secs) va_page = sgx_encl_grow(encl); if (IS_ERR(va_page)) return PTR_ERR(va_page);
- else if (va_page)
list_add(&va_page->list, &encl->va_pages);- /* else the tail page of the VA page list had free slots. */
- if (WARN_ONCE(!va_page, "non-empty VA page list before ECREATE"))
return -EIO;So you just crashed machines that have panic-on-warn enabled. Don't do that for no reason, just handle the error and move on.
The WARN will only fire if someone introduces a kernel bug. It's one part documentation, two parts helping detect future breakage. Even if the VA page management is significantly reworked, I'm having a hard time envisioning a scenario where adding VA pages before ECREATE would be anything but a kernel bug.