Received-SPF: pass (google.com: domain of linux-kernel+bounces-47136-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Date: Wed, 31 Jan 2024 21:14:50 -0000
From: "tip-bot2 for H. Peter Anvin (Intel)" <tip-bot2@linutronix.de>
Sender: tip-bot2@linutronix.de
Reply-to: linux-kernel@vger.kernel.org
To: linux-tip-commits@vger.kernel.org
Subject: [tip: x86/fred] x86/fred: Reserve space for the FRED stack frame
Cc: "H. Peter Anvin (Intel)" <hpa@zytor.com>, Xin Li <xin3.li@intel.com>,
 Thomas Gleixner <tglx@linutronix.de>, "Borislav Petkov (AMD)" <bp@alien8.de>,
 Shan Kang <shan.kang@intel.com>, x86@kernel.org, linux-kernel@vger.kernel.org
In-Reply-To: <20231205105030.8698-17-xin3.li@intel.com>
References: <20231205105030.8698-17-xin3.li@intel.com>
Precedence: bulk
MIME-Version: 1.0
Message-ID: <170673569050.398.6147585182118522399.tip-bot2@tip-bot2>
Robot-ID: <tip-bot2@linutronix.de>
Robot-Unsubscribe:
 Contact <mailto:tglx@linutronix.de> to get blacklisted from these emails
Precedence: bulk
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit

The following commit has been merged into the x86/fred branch of tip:

Commit-ID:     65c9cc9e2c14602d98f1ca61c51ac954e9529303
Gitweb:        https://git.kernel.org/tip/65c9cc9e2c14602d98f1ca61c51ac954e9529303
Author:        H. Peter Anvin (Intel) <hpa@zytor.com>
AuthorDate:    Tue, 05 Dec 2023 02:50:05 -08:00
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Wed, 31 Jan 2024 22:01:31 +01:00

x86/fred: Reserve space for the FRED stack frame

When using FRED, reserve space at the top of the stack frame, just
like i386 does.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-17-xin3.li@intel.com
---
 arch/x86/include/asm/thread_info.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h
index d63b029..12da7df 100644
--- a/arch/x86/include/asm/thread_info.h
+++ b/arch/x86/include/asm/thread_info.h
@@ -31,7 +31,9 @@
  * In vm86 mode, the hardware frame is much longer still, so add 16
  * bytes to make room for the real-mode segments.
  *
- * x86_64 has a fixed-length stack frame.
+ * x86-64 has a fixed-length stack frame, but it depends on whether
+ * or not FRED is enabled. Future versions of FRED might make this
+ * dynamic, but for now it is always 2 words longer.
  */
 #ifdef CONFIG_X86_32
 # ifdef CONFIG_VM86
@@ -39,8 +41,12 @@
 # else
 #  define TOP_OF_KERNEL_STACK_PADDING 8
 # endif
-#else
-# define TOP_OF_KERNEL_STACK_PADDING 0
+#else /* x86-64 */
+# ifdef CONFIG_X86_FRED
+#  define TOP_OF_KERNEL_STACK_PADDING (2 * 8)
+# else
+#  define TOP_OF_KERNEL_STACK_PADDING 0
+# endif
 #endif
 
 /*