Commit 65c9cc9e authored by H. Peter Anvin (Intel)'s avatar H. Peter Anvin (Intel) Committed by Borislav Petkov (AMD)
Browse files

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: default avatarH. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: default avatarXin Li <xin3.li@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Tested-by: default avatarShan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20231205105030.8698-17-xin3.li@intel.com
parent 32b09c23

arch/x86/include/asm/thread_info.h

+9 −3
Original line number Diff line number Diff line
@@ -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
@@ -39,9 +41,13 @@ 
# else

#  define TOP_OF_KERNEL_STACK_PADDING 8

# endif

#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



/*

 * low level task data that entry.S needs immediate access to