tcg/i386: Support raising sigbus for user-only

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-07-27 19:42:35 -10:00
parent 7b17a47540
commit b1ee3c6725
2 changed files with 98 additions and 7 deletions

View File

@ -22,6 +22,7 @@
* THE SOFTWARE.
*/
#include "../tcg-ldst.c.inc"
#include "../tcg-pool.c.inc"
#ifdef CONFIG_DEBUG_TCG
@ -421,8 +422,9 @@ static bool tcg_target_const_match(int64_t val, TCGType type, int ct)
#define OPC_VZEROUPPER (0x77 | P_EXT)
#define OPC_XCHG_ax_r32 (0x90)
#define OPC_GRP3_Ev (0xf7)
#define OPC_GRP5 (0xff)
#define OPC_GRP3_Eb (0xf6)
#define OPC_GRP3_Ev (0xf7)
#define OPC_GRP5 (0xff)
#define OPC_GRP14 (0x73 | P_EXT | P_DATA16)
/* Group 1 opcode extensions for 0x80-0x83.
@ -444,6 +446,7 @@ static bool tcg_target_const_match(int64_t val, TCGType type, int ct)
#define SHIFT_SAR 7
/* Group 3 opcode extensions for 0xf6, 0xf7. To be used with OPC_GRP3. */
#define EXT3_TESTi 0
#define EXT3_NOT 2
#define EXT3_NEG 3
#define EXT3_MUL 4
@ -1606,8 +1609,6 @@ static void tcg_out_nopn(TCGContext *s, int n)
}
#if defined(CONFIG_SOFTMMU)
#include "../tcg-ldst.c.inc"
/* helper signature: helper_ret_ld_mmu(CPUState *env, target_ulong addr,
* int mmu_idx, uintptr_t ra)
*/
@ -1916,7 +1917,84 @@ static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
tcg_out_jmp(s, qemu_st_helpers[opc & (MO_BSWAP | MO_SIZE)]);
return true;
}
#elif TCG_TARGET_REG_BITS == 32
#else
static void tcg_out_test_alignment(TCGContext *s, bool is_ld, TCGReg addrlo,
TCGReg addrhi, unsigned a_bits)
{
unsigned a_mask = (1 << a_bits) - 1;
TCGLabelQemuLdst *label;
/*
* We are expecting a_bits to max out at 7, so we can usually use testb.
* For i686, we have to use testl for %esi/%edi.
*/
if (a_mask <= 0xff && (TCG_TARGET_REG_BITS == 64 || addrlo < 4)) {
tcg_out_modrm(s, OPC_GRP3_Eb | P_REXB_RM, EXT3_TESTi, addrlo);
tcg_out8(s, a_mask);
} else {
tcg_out_modrm(s, OPC_GRP3_Ev, EXT3_TESTi, addrlo);
tcg_out32(s, a_mask);
}
/* jne slow_path */
tcg_out_opc(s, OPC_JCC_long + JCC_JNE, 0, 0, 0);
label = new_ldst_label(s);
label->is_ld = is_ld;
label->addrlo_reg = addrlo;
label->addrhi_reg = addrhi;
label->raddr = tcg_splitwx_to_rx(s->code_ptr + 4);
label->label_ptr[0] = s->code_ptr;
s->code_ptr += 4;
}
static bool tcg_out_fail_alignment(TCGContext *s, TCGLabelQemuLdst *l)
{
/* resolve label address */
tcg_patch32(l->label_ptr[0], s->code_ptr - l->label_ptr[0] - 4);
if (TCG_TARGET_REG_BITS == 32) {
int ofs = 0;
tcg_out_st(s, TCG_TYPE_PTR, TCG_AREG0, TCG_REG_ESP, ofs);
ofs += 4;
tcg_out_st(s, TCG_TYPE_I32, l->addrlo_reg, TCG_REG_ESP, ofs);
ofs += 4;
if (TARGET_LONG_BITS == 64) {
tcg_out_st(s, TCG_TYPE_I32, l->addrhi_reg, TCG_REG_ESP, ofs);
ofs += 4;
}
tcg_out_pushi(s, (uintptr_t)l->raddr);
} else {
tcg_out_mov(s, TCG_TYPE_TL, tcg_target_call_iarg_regs[1],
l->addrlo_reg);
tcg_out_mov(s, TCG_TYPE_PTR, tcg_target_call_iarg_regs[0], TCG_AREG0);
tcg_out_movi(s, TCG_TYPE_PTR, TCG_REG_RAX, (uintptr_t)l->raddr);
tcg_out_push(s, TCG_REG_RAX);
}
/* "Tail call" to the helper, with the return address back inline. */
tcg_out_jmp(s, (const void *)(l->is_ld ? helper_unaligned_ld
: helper_unaligned_st));
return true;
}
static bool tcg_out_qemu_ld_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
{
return tcg_out_fail_alignment(s, l);
}
static bool tcg_out_qemu_st_slow_path(TCGContext *s, TCGLabelQemuLdst *l)
{
return tcg_out_fail_alignment(s, l);
}
#if TCG_TARGET_REG_BITS == 32
# define x86_guest_base_seg 0
# define x86_guest_base_index -1
# define x86_guest_base_offset guest_base
@ -1950,6 +2028,7 @@ static inline int setup_guest_base_seg(void)
return 0;
}
# endif
#endif
#endif /* SOFTMMU */
static void tcg_out_qemu_ld_direct(TCGContext *s, TCGReg datalo, TCGReg datahi,
@ -2059,6 +2138,8 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, bool is64)
#if defined(CONFIG_SOFTMMU)
int mem_index;
tcg_insn_unit *label_ptr[2];
#else
unsigned a_bits;
#endif
datalo = *args++;
@ -2081,6 +2162,11 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, bool is64)
add_qemu_ldst_label(s, true, is64, oi, datalo, datahi, addrlo, addrhi,
s->code_ptr, label_ptr);
#else
a_bits = get_alignment_bits(opc);
if (a_bits) {
tcg_out_test_alignment(s, true, addrlo, addrhi, a_bits);
}
tcg_out_qemu_ld_direct(s, datalo, datahi, addrlo, x86_guest_base_index,
x86_guest_base_offset, x86_guest_base_seg,
is64, opc);
@ -2148,6 +2234,8 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is64)
#if defined(CONFIG_SOFTMMU)
int mem_index;
tcg_insn_unit *label_ptr[2];
#else
unsigned a_bits;
#endif
datalo = *args++;
@ -2170,6 +2258,11 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, bool is64)
add_qemu_ldst_label(s, false, is64, oi, datalo, datahi, addrlo, addrhi,
s->code_ptr, label_ptr);
#else
a_bits = get_alignment_bits(opc);
if (a_bits) {
tcg_out_test_alignment(s, false, addrlo, addrhi, a_bits);
}
tcg_out_qemu_st_direct(s, datalo, datahi, addrlo, x86_guest_base_index,
x86_guest_base_offset, x86_guest_base_seg, opc);
#endif

View File

@ -232,9 +232,7 @@ static inline void tb_target_set_jmp_target(uintptr_t tc_ptr, uintptr_t jmp_rx,
#define TCG_TARGET_HAS_MEMORY_BSWAP have_movbe
#ifdef CONFIG_SOFTMMU
#define TCG_TARGET_NEED_LDST_LABELS
#endif
#define TCG_TARGET_NEED_POOL_LABELS
#endif