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[PATCH v7 52/64] target/nios2: Implement Misaligned destination exceptio
From: |
Richard Henderson |
Subject: |
[PATCH v7 52/64] target/nios2: Implement Misaligned destination exception |
Date: |
Thu, 21 Apr 2022 08:17:23 -0700 |
Indirect branches, plus eret and bret optionally raise
an exception when branching to a misaligned address.
The exception is required when an mmu is enabled, but
enable it always because the fallback behaviour is not
documented (though presumably it discards low bits).
For the purposes of the linux-user cpu loop, if EXCP_UNALIGN
(misaligned data) were to arrive, it would be treated the
same as EXCP_UNALIGND (misaligned destination). See the
!defined(CONFIG_NIOS2_ALIGNMENT_TRAP) block in kernel/traps.c.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/nios2/cpu_loop.c | 6 ++++++
target/nios2/op_helper.c | 9 ++++++++-
target/nios2/translate.c | 15 ++++++++++++++-
3 files changed, 28 insertions(+), 2 deletions(-)
diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c
index 11ecb71843..30a27f252b 100644
--- a/linux-user/nios2/cpu_loop.c
+++ b/linux-user/nios2/cpu_loop.c
@@ -42,6 +42,12 @@ void cpu_loop(CPUNios2State *env)
force_sig_fault(TARGET_SIGFPE, TARGET_FPE_INTDIV, env->pc);
break;
+ case EXCP_UNALIGN:
+ case EXCP_UNALIGND:
+ force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN,
+ env->ctrl[CR_BADADDR]);
+ break;
+
case EXCP_TRAP:
/*
* TODO: This advance should be done in the translator, as
diff --git a/target/nios2/op_helper.c b/target/nios2/op_helper.c
index a19b504b0e..38a71a1f2d 100644
--- a/target/nios2/op_helper.c
+++ b/target/nios2/op_helper.c
@@ -64,6 +64,13 @@ uint32_t helper_divu(CPUNios2State *env, uint32_t num,
uint32_t den)
void helper_eret(CPUNios2State *env, uint32_t new_status, uint32_t new_pc)
{
Nios2CPU *cpu = env_archcpu(env);
+ CPUState *cs = env_cpu(env);
+
+ if (unlikely(new_pc & 3)) {
+ env->ctrl[CR_BADADDR] = new_pc;
+ cs->exception_index = EXCP_UNALIGND;
+ cpu_loop_exit_restore(cs, GETPC());
+ }
/*
* Both estatus and bstatus have no constraints on write;
@@ -74,6 +81,6 @@ void helper_eret(CPUNios2State *env, uint32_t new_status,
uint32_t new_pc)
env->ctrl[CR_STATUS] = new_status;
env->pc = new_pc;
- cpu_loop_exit(env_cpu(env));
+ cpu_loop_exit(cs);
}
#endif /* !CONFIG_USER_ONLY */
diff --git a/target/nios2/translate.c b/target/nios2/translate.c
index f0f5c6843a..827d957719 100644
--- a/target/nios2/translate.c
+++ b/target/nios2/translate.c
@@ -191,11 +191,24 @@ static void gen_goto_tb(DisasContext *dc, int n, uint32_t
dest)
static void gen_jumpr(DisasContext *dc, int regno, bool is_call)
{
- tcg_gen_mov_tl(cpu_pc, load_gpr(dc, regno));
+ TCGLabel *l = gen_new_label();
+ TCGv test = tcg_temp_new();
+ TCGv dest = load_gpr(dc, regno);
+
+ tcg_gen_andi_tl(test, dest, 3);
+ tcg_gen_brcondi_tl(TCG_COND_NE, test, 0, l);
+ tcg_temp_free(test);
+
+ tcg_gen_mov_tl(cpu_pc, dest);
if (is_call) {
tcg_gen_movi_tl(dest_gpr(dc, R_RA), dc->base.pc_next);
}
tcg_gen_lookup_and_goto_ptr();
+
+ gen_set_label(l);
+ tcg_gen_st_tl(dest, cpu_env, offsetof(CPUNios2State, ctrl[CR_BADADDR]));
+ t_gen_helper_raise_exception(dc, EXCP_UNALIGND);
+
dc->base.is_jmp = DISAS_NORETURN;
}
--
2.34.1
- [PATCH v7 43/64] target/nios2: Split out named structs for [IRJ]_TYPE, (continued)
- [PATCH v7 43/64] target/nios2: Split out named structs for [IRJ]_TYPE, Richard Henderson, 2022/04/21
- [PATCH v7 48/64] target/nios2: Create gen_jumpr, Richard Henderson, 2022/04/21
- [PATCH v7 40/64] target/nios2: Remove CPU_INTERRUPT_NMI, Richard Henderson, 2022/04/21
- [PATCH v7 51/64] target/nios2: Use tcg_gen_lookup_and_goto_ptr, Richard Henderson, 2022/04/21
- [PATCH v7 45/64] target/nios2: Introduce dest_gpr, Richard Henderson, 2022/04/21
- [PATCH v7 47/64] target/nios2: Enable unaligned traps for system mode, Richard Henderson, 2022/04/21
- [PATCH v7 46/64] target/nios2: Drop CR_STATUS_EH from tb->flags, Richard Henderson, 2022/04/21
- [PATCH v7 49/64] target/nios2: Hoist set of is_jmp into gen_goto_tb, Richard Henderson, 2022/04/21
- [PATCH v7 50/64] target/nios2: Use gen_goto_tb for DISAS_TOO_MANY, Richard Henderson, 2022/04/21
- [PATCH v7 52/64] target/nios2: Implement Misaligned destination exception,
Richard Henderson <=
- [PATCH v7 58/64] linux-user/nios2: Handle various SIGILL exceptions, Richard Henderson, 2022/04/21
- [PATCH v7 61/64] hw/nios2: Move memory regions into Nios2Machine, Richard Henderson, 2022/04/21
- [PATCH v7 56/64] target/nios2: Implement EIC interrupt processing, Richard Henderson, 2022/04/21
- [PATCH v7 55/64] target/nios2: Update helper_eret for shadow registers, Richard Henderson, 2022/04/21
- [PATCH v7 59/64] hw/intc: Vectored Interrupt Controller (VIC), Richard Henderson, 2022/04/21
- [PATCH v7 64/64] tests/tcg/nios2: Add test-shadow-1, Richard Henderson, 2022/04/21
- [PATCH v7 53/64] target/nios2: Introduce shadow register sets, Richard Henderson, 2022/04/21