Commit 3c77bf02 authored by Xin Li's avatar Xin Li Committed by Borislav Petkov (AMD)
Browse files

x86/ptrace: Add FRED additional information to the pt_regs structure 



FRED defines additional information in the upper 48 bits of cs/ss
fields. Therefore add the information definitions into the pt_regs
structure.

Specifically introduce a new structure fred_ss to denote the FRED flags
above SS selector, which avoids FRED_SSX_ macros and makes the code
simpler and easier to read.

Suggested-by: default avatarThomas Gleixner <tglx@linutronix.de>
Originally-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/20231205105030.8698-15-xin3.li@intel.com
parent ee63291a

arch/x86/include/asm/ptrace.h

+61 −5
Original line number Diff line number Diff line
@@ -56,6 +56,50 @@ struct pt_regs { 


#else /* __i386__ */



struct fred_cs {

		/* CS selector */

	u64	cs	: 16,

		/* Stack level at event time */

		sl	:  2,

		/* IBT in WAIT_FOR_ENDBRANCH state */

		wfe	:  1,

			: 45;

};



struct fred_ss {

		/* SS selector */

	u64	ss	: 16,

		/* STI state */

		sti	:  1,

		/* Set if syscall, sysenter or INT n */

		swevent	:  1,

		/* Event is NMI type */

		nmi	:  1,

			: 13,

		/* Event vector */

		vector	:  8,

			:  8,

		/* Event type */

		type	:  4,

			:  4,

		/* Event was incident to enclave execution */

		enclave	:  1,

		/* CPU was in long mode */

		lm	:  1,

		/*

		 * Nested exception during FRED delivery, not set

		 * for #DF.

		 */

		nested	:  1,

			:  1,

		/*

		 * The length of the instruction causing the event.

		 * Only set for INTO, INT1, INT3, INT n, SYSCALL

		 * and SYSENTER.  0 otherwise.

		 */

		insnlen	:  4;

};



struct pt_regs {

	/*

	 * C ABI says these regs are callee-preserved. They aren't saved on
@@ -85,6 +129,12 @@ struct pt_regs { 
	 * - the syscall number (syscall, sysenter, int80)

	 * - error_code stored by the CPU on traps and exceptions

	 * - the interrupt number for device interrupts

	 *

	 * A FRED stack frame starts here:

	 *   1) It _always_ includes an error code;

	 *

	 *   2) The return frame for ERET[US] starts here, but

	 *      the content of orig_ax is ignored.

	 */

	unsigned long orig_ax;
@@ -92,24 +142,30 @@ struct pt_regs { 
	unsigned long ip;



	union {

		/* The full 64-bit data slot containing CS */

		u64		csx;

		/* CS selector */

		u16		cs;

		/* The extended 64-bit data slot containing CS */

		u64		csx;

		/* The FRED CS extension */

		struct fred_cs	fred_cs;

	};



	unsigned long flags;

	unsigned long sp;



	union {

		/* The full 64-bit data slot containing SS */

		u64		ssx;

		/* SS selector */

		u16		ss;

		/* The extended 64-bit data slot containing SS */

		u64		ssx;

		/* The FRED SS extension */

		struct fred_ss	fred_ss;

	};



	/*

	 * Top of stack on IDT systems.

	 * Top of stack on IDT systems, while FRED systems have extra fields

	 * defined above for storing exception related information, e.g. CR2 or

	 * DR6.

	 */

};