master
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