1 /* $NetBSD: frame_regs.h,v 1.8 2021/04/17 20:12:55 rillig Exp $ */ 2 3 #ifndef _AMD64_FRAME_REGS_H_ 4 #define _AMD64_FRAME_REGS_H_ 5 6 /* 7 * amd64 registers (and friends) ordered as in a trap/interrupt/syscall frame. 8 * Also the indexes into the 'general register state' (__greg_t) passed to 9 * userland. 10 * Historically they were in the same order, but the order in the frames 11 * has been changed to improve syscall efficiency. 12 * 13 * Notes: 14 * 1) gdb (amd64nbsd-tdep.c) has a lookup table that assumes the __greg_t 15 * ordering. 16 * 2) src/lib/libc/arch/x86_64/gen/makecontext.c assumes that the first 17 * 6 entries in the __greg_t array match the registers used to pass 18 * function arguments. 19 * 3) The 'struct reg' from machine/reg.h has to match __greg_t. 20 * Since they are both arrays and indexed with the same tokens this 21 * shouldn't be a problem, but is rather confusing. 22 * This assumption is made in a lot of places! 23 * 4) There might be other code out there that relies on the ordering. 24 * 25 * The first entries below match the registers used for syscall arguments 26 * (%rcx is destroyed by the syscall instruction, the libc system call 27 * stubs copy %rcx to %r10). 28 * arg6-arg9 are copied from the user stack for system calls with more 29 * than 6 args (SYS_MAXSYSARGS is 8, + 2 entries for SYS___SYSCALL). 30 */ 31 #define _FRAME_REG(greg, freg) \ 32 greg(rdi, RDI, 0) /* tf_rdi */ \ 33 greg(rsi, RSI, 1) /* tf_rsi */ \ 34 greg(rdx, RDX, 2) /* tf_rdx */ \ 35 greg(r10, R10, 6) /* tf_r10 */ \ 36 greg(r8, R8, 4) /* tf_r8 */ \ 37 greg(r9, R9, 5) /* tf_r9 */ \ 38 freg(arg6, @, @) /* tf_arg6: syscall arg from stack */ \ 39 freg(arg7, @, @) /* tf_arg7: syscall arg from stack */ \ 40 freg(arg8, @, @) /* tf_arg8: syscall arg from stack */ \ 41 freg(arg9, @, @) /* tf_arg9: syscall arg from stack */ \ 42 greg(rcx, RCX, 3) /* tf_rcx */ \ 43 greg(r11, R11, 7) /* tf_r11 */ \ 44 greg(r12, R12, 8) /* tf_r12 */ \ 45 greg(r13, R13, 9) /* tf_r13 */ \ 46 greg(r14, R14, 10) /* tf_r14 */ \ 47 greg(r15, R15, 11) /* tf_r15 */ \ 48 greg(rbp, RBP, 12) /* tf_rbp */ \ 49 greg(rbx, RBX, 13) /* tf_rbx */ \ 50 greg(rax, RAX, 14) /* tf_rax */ \ 51 greg(gs, GS, 15) /* tf_gs */ \ 52 greg(fs, FS, 16) /* tf_fs */ \ 53 greg(es, ES, 17) /* tf_es */ \ 54 greg(ds, DS, 18) /* tf_ds */ \ 55 greg(trapno, TRAPNO, /* tf_trapno */ \ 56 19) \ 57 /* Below portion defined in hardware */ \ 58 greg(err, ERR, 20) /* tf_err: Dummy inserted if not defined */ \ 59 greg(rip, RIP, 21) /* tf_rip */ \ 60 greg(cs, CS, 22) /* tf_cs */ \ 61 greg(rflags, RFLAGS, /* tf_rflags */ \ 62 23) \ 63 /* These are pushed unconditionally on the x86-64 */ \ 64 greg(rsp, RSP, 24) /* tf_rsp */ \ 65 greg(ss, SS, 25) /* tf_ss */ 66 67 #define _FRAME_NOREG(reg, REG, idx) 68 69 #define _FRAME_GREG(greg) _FRAME_REG(greg, _FRAME_NOREG) 70 71 #endif 72
Indexes created Fri Sep 26 08:10:20 GMT 2025