f06bfe3dc3
zicfiss has following instructions - sspopchk: pops a value from shadow stack and compares with x1/x5. If they dont match, reports a sw check exception with tval = 3. - sspush: pushes value in x1/x5 on shadow stack - ssrdp: reads current shadow stack - ssamoswap: swaps contents of shadow stack atomically sspopchk/sspush/ssrdp default to zimop if zimop implemented and SSE=0 If SSE=0, ssamoswap is illegal instruction exception. This patch implements shadow stack operations for qemu-user and shadow stack is not protected. Signed-off-by: Deepak Gupta <debug@rivosinc.com> Co-developed-by: Jim Shu <jim.shu@sifive.com> Co-developed-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Alistair Francis <alistair.francis@wdc.com> Message-ID: <20241008225010.1861630-17-debug@rivosinc.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
115 lines
3.6 KiB
C++
115 lines
3.6 KiB
C++
/*
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* RISC-V translation routines for the Control-Flow Integrity Extension
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*
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* Copyright (c) 2024 Rivos Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2 or later, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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static bool trans_sspopchk(DisasContext *ctx, arg_sspopchk *a)
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{
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if (!ctx->bcfi_enabled) {
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return false;
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}
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TCGv addr = tcg_temp_new();
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TCGLabel *skip = gen_new_label();
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uint32_t tmp = (get_xl(ctx) == MXL_RV64) ? 8 : 4;
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TCGv data = tcg_temp_new();
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tcg_gen_ld_tl(addr, tcg_env, offsetof(CPURISCVState, ssp));
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decode_save_opc(ctx, RISCV_UW2_ALWAYS_STORE_AMO);
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tcg_gen_qemu_ld_tl(data, addr, SS_MMU_INDEX(ctx),
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mxl_memop(ctx) | MO_ALIGN);
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TCGv rs1 = get_gpr(ctx, a->rs1, EXT_NONE);
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tcg_gen_brcond_tl(TCG_COND_EQ, data, rs1, skip);
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tcg_gen_st_tl(tcg_constant_tl(RISCV_EXCP_SW_CHECK_BCFI_TVAL),
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tcg_env, offsetof(CPURISCVState, sw_check_code));
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gen_helper_raise_exception(tcg_env,
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tcg_constant_i32(RISCV_EXCP_SW_CHECK));
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gen_set_label(skip);
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tcg_gen_addi_tl(addr, addr, tmp);
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tcg_gen_st_tl(addr, tcg_env, offsetof(CPURISCVState, ssp));
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return true;
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}
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static bool trans_sspush(DisasContext *ctx, arg_sspush *a)
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{
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if (!ctx->bcfi_enabled) {
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return false;
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}
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TCGv addr = tcg_temp_new();
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int tmp = (get_xl(ctx) == MXL_RV64) ? -8 : -4;
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TCGv data = get_gpr(ctx, a->rs2, EXT_NONE);
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decode_save_opc(ctx, RISCV_UW2_ALWAYS_STORE_AMO);
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tcg_gen_ld_tl(addr, tcg_env, offsetof(CPURISCVState, ssp));
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tcg_gen_addi_tl(addr, addr, tmp);
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tcg_gen_qemu_st_tl(data, addr, SS_MMU_INDEX(ctx),
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mxl_memop(ctx) | MO_ALIGN);
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tcg_gen_st_tl(addr, tcg_env, offsetof(CPURISCVState, ssp));
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return true;
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}
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static bool trans_ssrdp(DisasContext *ctx, arg_ssrdp *a)
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{
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if (!ctx->bcfi_enabled || a->rd == 0) {
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return false;
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}
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TCGv dest = dest_gpr(ctx, a->rd);
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tcg_gen_ld_tl(dest, tcg_env, offsetof(CPURISCVState, ssp));
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gen_set_gpr(ctx, a->rd, dest);
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return true;
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}
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static bool trans_ssamoswap_w(DisasContext *ctx, arg_amoswap_w *a)
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{
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REQUIRE_A_OR_ZAAMO(ctx);
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if (!ctx->bcfi_enabled) {
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return false;
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}
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TCGv dest = dest_gpr(ctx, a->rd);
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TCGv src1, src2 = get_gpr(ctx, a->rs2, EXT_NONE);
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decode_save_opc(ctx, RISCV_UW2_ALWAYS_STORE_AMO);
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src1 = get_address(ctx, a->rs1, 0);
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tcg_gen_atomic_xchg_tl(dest, src1, src2, SS_MMU_INDEX(ctx),
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(MO_ALIGN | MO_TESL));
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gen_set_gpr(ctx, a->rd, dest);
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return true;
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}
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static bool trans_ssamoswap_d(DisasContext *ctx, arg_amoswap_w *a)
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{
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REQUIRE_64BIT(ctx);
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REQUIRE_A_OR_ZAAMO(ctx);
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if (!ctx->bcfi_enabled) {
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return false;
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}
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TCGv dest = dest_gpr(ctx, a->rd);
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TCGv src1, src2 = get_gpr(ctx, a->rs2, EXT_NONE);
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decode_save_opc(ctx, RISCV_UW2_ALWAYS_STORE_AMO);
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src1 = get_address(ctx, a->rs1, 0);
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tcg_gen_atomic_xchg_tl(dest, src1, src2, SS_MMU_INDEX(ctx),
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(MO_ALIGN | MO_TESQ));
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gen_set_gpr(ctx, a->rd, dest);
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return true;
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}
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