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@xxxxxxxxx> AuthorDate: Tue, 05 Dec 2023 02:50:05 -08:00 Committer: Borislav Petkov (AMD) <bp@xxxxxxxxx> 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@xxxxxxxxx> Signed-off-by: Xin Li <xin3.li@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Borislav Petkov (AMD) <bp@xxxxxxxxx> Tested-by: Shan Kang <shan.kang@xxxxxxxxx> Link: https://lore.kernel.org/r/20231205105030.8698-17-xin3.li@xxxxxxxxx --- 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 /*
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