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target/riscv: tb flag for shadow stack instructions

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Shadow stack instructions can be decoded as zimop / zcmop or shadow stack
instructions depending on whether shadow stack are enabled at current
privilege. This requires a TB flag so that correct TB generation and correct
TB lookup happens. `DisasContext` gets a field indicating whether bcfi is
enabled or not.

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: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241008225010.1861630-13-debug@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
This commit is contained in:
Deepak Gupta 2024-10-08 15:50:02 -07:00 committed by Alistair Francis
parent 8205bc127a
commit f9fdf9077c
3 changed files with 9 additions and 0 deletions
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2
target/riscv/cpu.h
View File

@ -628,6 +628,8 @@ FIELD(TB_FLAGS, AXL, 26, 2)
/* zicfilp needs a TB flag to track indirect branches */
FIELD(TB_FLAGS, FCFI_ENABLED, 28, 1)
FIELD(TB_FLAGS, FCFI_LP_EXPECTED, 29, 1)
/* zicfiss needs a TB flag so that correct TB is located based on tb flags */
FIELD(TB_FLAGS, BCFI_ENABLED, 30, 1)
#ifdef TARGET_RISCV32
#define riscv_cpu_mxl(env) ((void)(env), MXL_RV32)

4
target/riscv/cpu_helper.c
View File

@ -171,6 +171,10 @@ void cpu_get_tb_cpu_state(CPURISCVState *env, vaddr *pc,
flags = FIELD_DP32(flags, TB_FLAGS, FCFI_ENABLED, 1);
}
if (cpu_get_bcfien(env)) {
flags = FIELD_DP32(flags, TB_FLAGS, BCFI_ENABLED, 1);
}
#ifdef CONFIG_USER_ONLY
fs = EXT_STATUS_DIRTY;
vs = EXT_STATUS_DIRTY;

3
target/riscv/translate.c
View File

@ -119,6 +119,8 @@ typedef struct DisasContext {
/* zicfilp extension. fcfi_enabled, lp expected or not */
bool fcfi_enabled;
bool fcfi_lp_expected;
/* zicfiss extension, if shadow stack was enabled during TB gen */
bool bcfi_enabled;
} DisasContext;
static inline bool has_ext(DisasContext *ctx, uint32_t ext)
@ -1241,6 +1243,7 @@ static void riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
ctx->pm_base_enabled = FIELD_EX32(tb_flags, TB_FLAGS, PM_BASE_ENABLED);
ctx->ztso = cpu->cfg.ext_ztso;
ctx->itrigger = FIELD_EX32(tb_flags, TB_FLAGS, ITRIGGER);
ctx->bcfi_enabled = FIELD_EX32(tb_flags, TB_FLAGS, BCFI_ENABLED);
ctx->fcfi_lp_expected = FIELD_EX32(tb_flags, TB_FLAGS, FCFI_LP_EXPECTED);
ctx->fcfi_enabled = FIELD_EX32(tb_flags, TB_FLAGS, FCFI_ENABLED);
ctx->zero = tcg_constant_tl(0);