public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Dave Hansen <dave.hansen@intel.com>
To: linux-kernel@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Jarkko Sakkinen <jarkko@kernel.org>,
	Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, linux-sgx@vger.kernel.org
Subject: [PATCH] x86/sgx: fix uninitialized 'nid' variable
Date: Thu, 18 Mar 2021 14:49:33 -0700	[thread overview]
Message-ID: <20210318214933.29341-1-dave.hansen@intel.com> (raw)
In-Reply-To: <202103190514.xH7IrKMe-lkp@intel.com>

The NUMA fallback in __sgx_alloc_epc_page() recently grew an
additional 'nid' variable to prevent extra trips through the
fallback loop in case where the thread is migrated around.

But, the new copy is not properly initialized.  Fix it.

This was found by some fancy clang that 0day runs.  My gcc
does not detect it.

Fixes: 5b8719504e3a ("x86/sgx: Add a basic NUMA allocation scheme to sgx_alloc_epc_page()")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: linux-sgx@vger.kernel.org
---
 arch/x86/kernel/cpu/sgx/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c
index 2a0031e4a4dc..1b4d8a0e0915 100644
--- a/arch/x86/kernel/cpu/sgx/main.c
+++ b/arch/x86/kernel/cpu/sgx/main.c
@@ -489,7 +489,7 @@ struct sgx_epc_page *__sgx_alloc_epc_page(void)
 {
 	struct sgx_epc_page *page;
 	int nid_of_current = numa_node_id();
-	int nid;
+	int nid = nid_of_current;
 
 	if (node_isset(nid_of_current, sgx_numa_mask)) {
 		page = __sgx_alloc_epc_page_from_node(nid_of_current);
-- 
2.19.1


  reply	other threads:[~2021-03-18 21:52 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-18 21:03 [tip:x86/sgx 2/2] arch/x86/kernel/cpu/sgx/main.c:496:7: warning: variable 'nid' is used uninitialized whenever 'if' condition is false kernel test robot
2021-03-18 21:49 ` Dave Hansen [this message]
2021-03-19  5:38   ` [PATCH] x86/sgx: fix uninitialized 'nid' variable Jarkko Sakkinen
2021-03-19  8:57   ` [tip: x86/sgx] x86/sgx: Fix " tip-bot2 for Dave Hansen

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210318214933.29341-1-dave.hansen@intel.com \
    --to=dave.hansen@intel.com \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=jarkko@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sgx@vger.kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox