FRED defines additional information in the upper 48 bits of cs/ss fields. Therefore add the information definitions into the pt_regs structure. Specially 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. Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx> Tested-by: Shan Kang <shan.kang@xxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Xin Li <xin3.li@xxxxxxxxx> --- Changes since v9: * 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 (Thomas Gleixner). * Use type u64 to define FRED bit fields instead of type unsigned int (Thomas Gleixner). Changes since v8: * Reflect stack frame definition changes from FRED spec 3.0 to 5.0. * Use __packed instead of __attribute__((__packed__)) (Borislav Petkov). * Put all comments above the members, like the rest of the file does (Borislav Petkov). Changes since v3: * Rename csl/ssl of the pt_regs structure to csx/ssx (x for extended) (Andrew Cooper). --- arch/x86/include/asm/ptrace.h | 51 +++++++++++++++++++++++++++++++---- 1 file changed, 46 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h index f08ea073edd6..5786c8ca5f4c 100644 --- a/arch/x86/include/asm/ptrace.h +++ b/arch/x86/include/asm/ptrace.h @@ -56,6 +56,25 @@ struct pt_regs { #else /* __i386__ */ +struct fred_ss { + u64 ss : 16, // SS selector + sti : 1, // STI state + swevent : 1, // Set if syscall, sysenter or INT n + nmi : 1, // Event is NMI type + : 13, + vector : 8, // Event vector + : 8, + type : 4, // Event type + : 4, + enclave : 1, // Event was incident to enclave execution + lm : 1, // CPU was in long mode + nested : 1, // Nested exception during FRED delivery + // not set for #DF + : 1, + insnlen : 4; // The length of the instruction causing the event + // Only set for INT0, INT1, INT3, INT n, SYSCALL +}; // and SYSENTER. 0 otherwise. + struct pt_regs { /* * C ABI says these regs are callee-preserved. They aren't saved on @@ -85,6 +104,12 @@ 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; @@ -92,20 +117,36 @@ struct pt_regs { unsigned long ip; union { - u64 csx; // The full 64-bit data slot containing CS - u16 cs; // CS selector + u64 csx; // The full data for FRED + /* + * The 'cs' member should be defined as a 16-bit bit-field + * along with the 'sl' and 'wfe' members, which however + * breaks compiling REG_OFFSET_NAME(cs), because compilers + * disallow calculating the address of a bit-field. + * + * Therefore 'cs" is defined as an individual member with + * type u16. + */ + u16 cs; // CS selector + u64 : 16, + sl : 2, // Stack level at event time + wfe : 1, // IBT is in WAIT_FOR_BRANCH_STATE + : 45; }; unsigned long flags; unsigned long sp; union { - u64 ssx; // The full 64-bit data slot containing SS - u16 ss; // SS selector + u64 ssx; // The full data for FRED + u16 ss; // SS selector + struct fred_ss fred_ss; // The fred extension }; /* - * 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. */ }; -- 2.34.1