/*
* get_throw_trampoline:
*
* Generate a call to mono_amd64_throw_exception/
* mono_amd64_throw_corlib_exception.
*/
static gpointer
get_throw_trampoline (MonoTrampInfo **info, gboolean rethrow, gboolean corlib, gboolean llvm_abs, gboolean resume_unwind, const char *tramp_name, gboolean aot)
{
guint8* start;
guint8 *code;
MonoJumpInfo *ji = NULL;
GSList *unwind_ops = NULL;
int i, stack_size, arg_offsets [16], ctx_offset, regs_offset, dummy_stack_space;
const guint kMaxCodeSize = NACL_SIZE (256, 512);
#ifdef TARGET_WIN32
dummy_stack_space = 6 * sizeof(mgreg_t); /* Windows expects stack space allocated for all 6 dummy args. */
#else
dummy_stack_space = 0;
#endif
start = code = (guint8 *)mono_global_codeman_reserve (kMaxCodeSize);
/* The stack is unaligned on entry */
stack_size = ALIGN_TO (sizeof (MonoContext) + 64 + dummy_stack_space, MONO_ARCH_FRAME_ALIGNMENT) + 8;
code = start;
if (info)
unwind_ops = mono_arch_get_cie_program ();
/* Alloc frame */
amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, stack_size);
if (info)
mono_add_unwind_op_def_cfa_offset (unwind_ops, code, start, stack_size + 8);
/*
* To hide linux/windows calling convention differences, we pass all arguments on
* the stack by passing 6 dummy values in registers.
*/
arg_offsets [0] = dummy_stack_space + 0;
arg_offsets [1] = dummy_stack_space + sizeof(mgreg_t);
arg_offsets [2] = dummy_stack_space + sizeof(mgreg_t) * 2;
ctx_offset = dummy_stack_space + sizeof(mgreg_t) * 4;
regs_offset = ctx_offset + MONO_STRUCT_OFFSET (MonoContext, gregs);
/* Save registers */
for (i = 0; i < AMD64_NREG; ++i)
if (i != AMD64_RSP)
amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (i * sizeof(mgreg_t)), i, sizeof(mgreg_t));
/* Save RSP */
amd64_lea_membase (code, AMD64_RAX, AMD64_RSP, stack_size + sizeof(mgreg_t));
amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (AMD64_RSP * sizeof(mgreg_t)), X86_EAX, sizeof(mgreg_t));
/* Save IP */
if (llvm_abs)
amd64_alu_reg_reg (code, X86_XOR, AMD64_RAX, AMD64_RAX);
else
amd64_mov_reg_membase (code, AMD64_RAX, AMD64_RSP, stack_size, sizeof(mgreg_t));
amd64_mov_membase_reg (code, AMD64_RSP, regs_offset + (AMD64_RIP * sizeof(mgreg_t)), AMD64_RAX, sizeof(mgreg_t));
/* Set arg1 == ctx */
amd64_lea_membase (code, AMD64_RAX, AMD64_RSP, ctx_offset);
amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [0], AMD64_RAX, sizeof(mgreg_t));
/* Set arg2 == exc/ex_token_index */
if (resume_unwind)
amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [1], 0, sizeof(mgreg_t));
else
amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [1], AMD64_ARG_REG1, sizeof(mgreg_t));
/* Set arg3 == rethrow/pc offset */
if (resume_unwind) {
amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [2], 0, sizeof(mgreg_t));
} else if (corlib) {
amd64_mov_membase_reg (code, AMD64_RSP, arg_offsets [2], AMD64_ARG_REG2, sizeof(mgreg_t));
if (llvm_abs)
/*
* The caller is LLVM code which passes the absolute address not a pc offset,
* so compensate by passing 0 as 'rip' and passing the negated abs address as
* the pc offset.
*/
amd64_neg_membase (code, AMD64_RSP, arg_offsets [2]);
} else {
amd64_mov_membase_imm (code, AMD64_RSP, arg_offsets [2], rethrow, sizeof(mgreg_t));
}
if (aot) {
const char *icall_name;
if (resume_unwind)
icall_name = "mono_amd64_resume_unwind";
else if (corlib)
icall_name = "mono_amd64_throw_corlib_exception";
else
icall_name = "mono_amd64_throw_exception";
ji = mono_patch_info_list_prepend (ji, code - start, MONO_PATCH_INFO_JIT_ICALL_ADDR, icall_name);
amd64_mov_reg_membase (code, AMD64_R11, AMD64_RIP, 0, 8);
} else {
amd64_mov_reg_imm (code, AMD64_R11, resume_unwind ? ((gpointer)mono_amd64_resume_unwind) : (corlib ? (gpointer)mono_amd64_throw_corlib_exception : (gpointer)mono_amd64_throw_exception));
}
amd64_call_reg (code, AMD64_R11);
amd64_breakpoint (code);
mono_arch_flush_icache (start, code - start);
g_assert ((code - start) < kMaxCodeSize);
nacl_global_codeman_validate(&start, kMaxCodeSize, &code);
mono_profiler_code_buffer_new (start, code - start, MONO_PROFILER_CODE_BUFFER_EXCEPTION_HANDLING, NULL);
if (info)
*info = mono_tramp_info_create (tramp_name, start, code - start, ji, unwind_ops);
return start;
}
gpointer
mono_arch_get_gsharedvt_trampoline (MonoTrampInfo **info, gboolean aot)
{
guint8 *code, *buf;
int buf_len, cfa_offset;
GSList *unwind_ops = NULL;
MonoJumpInfo *ji = NULL;
int n_arg_regs, n_arg_fregs, framesize, i;
int info_offset, offset, rgctx_arg_reg_offset;
int caller_reg_area_offset, callee_reg_area_offset, callee_stack_area_offset;
guint8 *br_out, *br [64], *br_ret [64];
int b_ret_index;
int reg_area_size;
buf_len = 2048;
buf = code = mono_global_codeman_reserve (buf_len + MONO_MAX_TRAMPOLINE_UNWINDINFO_SIZE);
/*
* We are being called by an gsharedvt arg trampoline, the info argument is in AMD64_RAX.
*/
n_arg_regs = PARAM_REGS;
n_arg_fregs = FLOAT_PARAM_REGS;
/* Compute stack frame size and offsets */
offset = 0;
/* info reg */
info_offset = offset;
offset += 8;
/* rgctx reg */
rgctx_arg_reg_offset = offset;
offset += 8;
/*callconv in regs */
caller_reg_area_offset = offset;
reg_area_size = ALIGN_TO ((n_arg_regs + n_arg_fregs) * 8, MONO_ARCH_FRAME_ALIGNMENT);
offset += reg_area_size;
framesize = offset;
g_assert (framesize % MONO_ARCH_FRAME_ALIGNMENT == 0);
g_assert (reg_area_size % MONO_ARCH_FRAME_ALIGNMENT == 0);
/* unwind markers 1/3 */
cfa_offset = sizeof (gpointer);
mono_add_unwind_op_def_cfa (unwind_ops, code, buf, AMD64_RSP, cfa_offset);
mono_add_unwind_op_offset (unwind_ops, code, buf, AMD64_RIP, -cfa_offset);
/* save the old frame pointer */
amd64_push_reg (code, AMD64_RBP);
/* unwind markers 2/3 */
cfa_offset += sizeof (gpointer);
mono_add_unwind_op_def_cfa_offset (unwind_ops, code, buf, cfa_offset);
mono_add_unwind_op_offset (unwind_ops, code, buf, AMD64_RBP, - cfa_offset);
/* set it as the new frame pointer */
amd64_mov_reg_reg (code, AMD64_RBP, AMD64_RSP, sizeof(mgreg_t));
/* unwind markers 3/3 */
mono_add_unwind_op_def_cfa_reg (unwind_ops, code, buf, AMD64_RBP);
mono_add_unwind_op_fp_alloc (unwind_ops, code, buf, AMD64_RBP, 0);
/* setup the frame */
amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, framesize);
/* save stuff */
/* save info */
amd64_mov_membase_reg (code, AMD64_RSP, info_offset, AMD64_RAX, sizeof (mgreg_t));
/* save rgctx */
amd64_mov_membase_reg (code, AMD64_RSP, rgctx_arg_reg_offset, MONO_ARCH_RGCTX_REG, sizeof (mgreg_t));
for (i = 0; i < n_arg_regs; ++i)
amd64_mov_membase_reg (code, AMD64_RSP, caller_reg_area_offset + i * 8, param_regs [i], sizeof (mgreg_t));
for (i = 0; i < n_arg_fregs; ++i)
amd64_sse_movsd_membase_reg (code, AMD64_RSP, caller_reg_area_offset + (i + n_arg_regs) * 8, i);
/* TODO Allocate stack area used to pass arguments to the method */
/* Allocate callee register area just below the caller area so it can be accessed from start_gsharedvt_call using negative offsets */
/* XXX figure out alignment */
callee_reg_area_offset = reg_area_size - ((n_arg_regs + n_arg_fregs) * 8); /* Ensure alignment */
callee_stack_area_offset = callee_reg_area_offset + reg_area_size;
amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, reg_area_size);
/* Allocate stack area used to pass arguments to the method */
amd64_mov_reg_membase (code, AMD64_R11, AMD64_RAX, MONO_STRUCT_OFFSET (GSharedVtCallInfo, stack_usage), 4);
amd64_alu_reg_reg (code, X86_SUB, AMD64_RSP, AMD64_R11);
/* The stack now looks like this:
<caller stack params area>
<return address>
<old frame pointer>
<caller registers area>
<rgctx>
<gsharedvt info>
<callee stack area>
<callee reg area>
*/
/* Call start_gsharedvt_call () */
/* arg1 == info */
amd64_mov_reg_reg (code, MONO_AMD64_ARG_REG1, AMD64_RAX, sizeof(mgreg_t));
/* arg2 = caller stack area */
amd64_lea_membase (code, MONO_AMD64_ARG_REG2, AMD64_RBP, -(framesize - caller_reg_area_offset));
/* arg3 == callee stack area */
amd64_lea_membase (code, MONO_AMD64_ARG_REG3, AMD64_RSP, callee_reg_area_offset);
/* arg4 = mrgctx reg */
amd64_mov_reg_reg (code, MONO_AMD64_ARG_REG4, MONO_ARCH_RGCTX_REG, sizeof(mgreg_t));
if (aot) {
code = mono_arch_emit_load_aotconst (buf, code, &ji, MONO_PATCH_INFO_JIT_ICALL_ADDR, "mono_amd64_start_gsharedvt_call");
#ifdef TARGET_WIN32
/* Since we are doing a call as part of setting up stackframe, the reserved shadow stack used by Windows platform is allocated up in
the callee stack area but currently the callee reg area is in between. Windows calling convention dictates that room is made on stack where
callee can save any parameters passed in registers. Since Windows x64 calling convention
uses 4 registers for the first 4 parameters, stack needs to be adjusted before making the call.
NOTE, Windows calling convention assumes that space for all registers have been reserved, regardless
of the number of function parameters actually used.
*/
int shadow_reg_size = 0;
shadow_reg_size = ALIGN_TO (PARAM_REGS * sizeof(gpointer), MONO_ARCH_FRAME_ALIGNMENT);
amd64_alu_reg_imm (code, X86_SUB, AMD64_RSP, shadow_reg_size);
amd64_call_reg (code, AMD64_R11);
amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, shadow_reg_size);
#else
amd64_call_reg (code, AMD64_R11);
#endif
} else {
amd64_call_code (code, mono_amd64_start_gsharedvt_call);
}
/* Method to call is now on RAX. Restore regs and jump */
amd64_mov_reg_reg (code, AMD64_R11, AMD64_RAX, sizeof(mgreg_t));
for (i = 0; i < n_arg_regs; ++i)
amd64_mov_reg_membase (code, param_regs [i], AMD64_RSP, callee_reg_area_offset + i * 8, sizeof (mgreg_t));
for (i = 0; i < n_arg_fregs; ++i)
amd64_sse_movsd_reg_membase (code, i, AMD64_RSP, callee_reg_area_offset + (i + n_arg_regs) * 8);
//load rgctx
amd64_mov_reg_membase (code, MONO_ARCH_RGCTX_REG, AMD64_RBP, -(framesize - rgctx_arg_reg_offset), sizeof (mgreg_t));
/* Clear callee reg area */
amd64_alu_reg_imm (code, X86_ADD, AMD64_RSP, reg_area_size);
/* Call the thing */
amd64_call_reg (code, AMD64_R11);
/* Marshal return value. Available registers: R10 and R11 */
/* Load info struct */
amd64_mov_reg_membase (code, AMD64_R10, AMD64_RBP, -(framesize - info_offset), sizeof (mgreg_t));
/* Branch to the in/out handling code */
amd64_alu_membase_imm_size (code, X86_CMP, AMD64_R10, MONO_STRUCT_OFFSET (GSharedVtCallInfo, gsharedvt_in), 1, 4);
b_ret_index = 0;
br_out = code;
x86_branch32 (code, X86_CC_NE, 0, TRUE);
/*
* IN CASE
*/
/* Load vret_slot */
/* Use first input parameter register as scratch since it is volatile on all platforms */
amd64_mov_reg_membase (code, MONO_AMD64_ARG_REG1, AMD64_R10, MONO_STRUCT_OFFSET (GSharedVtCallInfo, vret_slot), 4);
amd64_alu_reg_imm (code, X86_SUB, MONO_AMD64_ARG_REG1, n_arg_regs + n_arg_fregs);
amd64_shift_reg_imm (code, X86_SHL, MONO_AMD64_ARG_REG1, 3);
/* vret address is RBP - (framesize - caller_reg_area_offset) */
amd64_mov_reg_reg (code, AMD64_R11, AMD64_RSP, sizeof(mgreg_t));
amd64_alu_reg_reg (code, X86_ADD, AMD64_R11, MONO_AMD64_ARG_REG1);
/* Load ret marshal type */
/* Load vret address in R11 */
amd64_mov_reg_membase (code, AMD64_R10, AMD64_R10, MONO_STRUCT_OFFSET (GSharedVtCallInfo, ret_marshal), 4);
for (i = GSHAREDVT_RET_NONE; i < GSHAREDVT_RET_NUM; ++i) {
amd64_alu_reg_imm (code, X86_CMP, AMD64_R10, i);
br [i] = code;
amd64_branch8 (code, X86_CC_EQ, 0, TRUE);
}
x86_breakpoint (code); /* unhandled case */
for (i = GSHAREDVT_RET_NONE; i < GSHAREDVT_RET_NUM; ++i) {
mono_amd64_patch (br [i], code);
switch (i) {
case GSHAREDVT_RET_NONE:
break;
case GSHAREDVT_RET_I1:
amd64_widen_membase (code, AMD64_RAX, AMD64_R11, 0, TRUE, FALSE);
break;
case GSHAREDVT_RET_U1:
amd64_widen_membase (code, AMD64_RAX, AMD64_R11, 0, FALSE, FALSE);
break;
case GSHAREDVT_RET_I2:
amd64_widen_membase (code, AMD64_RAX, AMD64_R11, 0, TRUE, TRUE);
break;
case GSHAREDVT_RET_U2:
amd64_widen_membase (code, AMD64_RAX, AMD64_R11, 0, FALSE, TRUE);
break;
case GSHAREDVT_RET_I4: // CORRECT
case GSHAREDVT_RET_U4: // THIS IS INCORRECT. WHY IS IT NOT FAILING?
amd64_movsxd_reg_membase (code, AMD64_RAX, AMD64_R11, 0);
break;
case GSHAREDVT_RET_I8:
amd64_mov_reg_membase (code, AMD64_RAX, AMD64_R11, 0, 8);
break;
case GSHAREDVT_RET_IREGS_1:
amd64_mov_reg_membase (code, return_regs [i - GSHAREDVT_RET_IREGS_1], AMD64_R11, 0, 8);
break;
case GSHAREDVT_RET_R8:
amd64_sse_movsd_reg_membase (code, AMD64_XMM0, AMD64_R11, 0);
break;
default:
x86_breakpoint (code); /* can't handle specific case */
}
br_ret [b_ret_index ++] = code;
x86_jump32 (code, 0);
}
/*
* OUT CASE
*/
mono_amd64_patch (br_out, code);
/*
Address to write return to is in the original value of the register specified by vret_arg_reg.
This will be either RSI, RDI (System V) or RCX, RDX (Windows) depending on whether this is a static call.
Its location:
We alloc 'framesize' bytes below RBP to save regs, info and rgctx. RSP = RBP - framesize
We store RDI (System V), RCX (Windows) at RSP + caller_reg_area_offset + slot_index_of (register) * 8.
address: RBP - framesize + caller_reg_area_offset + 8*slot
*/
int caller_vret_offset = caller_reg_area_offset - framesize;
/* Load vret address in R11 */
/* Position to return to is passed as a hidden argument. Load 'vret_arg_slot' to find it */
amd64_movsxd_reg_membase (code, AMD64_R11, AMD64_R10, MONO_STRUCT_OFFSET (GSharedVtCallInfo, vret_arg_reg));
// In the GSHAREDVT_RET_NONE case, vret_arg_slot is -1. In this case, skip marshalling.
amd64_alu_reg_imm (code, X86_CMP, AMD64_R11, 0);
br_ret [b_ret_index ++] = code;
amd64_branch32 (code, X86_CC_LT, 0, TRUE);
/* Compute ret area address in the caller frame, *( ((gpointer *)RBP) [R11+2] ) */
amd64_shift_reg_imm (code, X86_SHL, AMD64_R11, 3);
amd64_alu_reg_imm (code, X86_ADD, AMD64_R11, caller_vret_offset);
amd64_alu_reg_reg (code, X86_ADD, AMD64_R11, AMD64_RBP);
amd64_mov_reg_membase (code, AMD64_R11, AMD64_R11, 0, sizeof (gpointer));
/* Load ret marshal type in R10 */
amd64_mov_reg_membase (code, AMD64_R10, AMD64_R10, MONO_STRUCT_OFFSET (GSharedVtCallInfo, ret_marshal), 4);
// Switch table for ret_marshal value
for (i = GSHAREDVT_RET_NONE; i < GSHAREDVT_RET_NUM; ++i) {
amd64_alu_reg_imm (code, X86_CMP, AMD64_R10, i);
br [i] = code;
amd64_branch8 (code, X86_CC_EQ, 0, TRUE);
}
x86_breakpoint (code); /* unhandled case */
for (i = GSHAREDVT_RET_NONE; i < GSHAREDVT_RET_NUM; ++i) {
mono_amd64_patch (br [i], code);
switch (i) {
case GSHAREDVT_RET_NONE:
break;
case GSHAREDVT_RET_IREGS_1:
amd64_mov_membase_reg (code, AMD64_R11, 0, return_regs [i - GSHAREDVT_RET_IREGS_1], 8);
break;
case GSHAREDVT_RET_R8:
amd64_sse_movsd_membase_reg (code, AMD64_R11, 0, AMD64_XMM0);
break;
default:
x86_breakpoint (code); /* can't handle specific case */
}
br_ret [b_ret_index ++] = code;
x86_jump32 (code, 0);
}
/* exit path */
for (i = 0; i < b_ret_index; ++i)
mono_amd64_patch (br_ret [i], code);
/* Exit code path */
#if TARGET_WIN32
amd64_lea_membase (code, AMD64_RSP, AMD64_RBP, 0);
amd64_pop_reg (code, AMD64_RBP);
mono_add_unwind_op_same_value (unwind_ops, code, buf, AMD64_RBP);
#else
amd64_leave (code);
#endif
amd64_ret (code);
g_assert ((code - buf) < buf_len);
g_assert_checked (mono_arch_unwindinfo_validate_size (unwind_ops, MONO_MAX_TRAMPOLINE_UNWINDINFO_SIZE));
if (info)
*info = mono_tramp_info_create ("gsharedvt_trampoline", buf, code - buf, ji, unwind_ops);
mono_arch_flush_icache (buf, code - buf);
return buf;
}