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authorSergey Fedorov <serge.fdrv@gmail.com>2015-11-10 13:37:33 +0000
committerPeter Maydell <peter.maydell@linaro.org>2015-11-10 13:37:33 +0000
commit577bf808958d06497928c639efaa473bf8c5e099 (patch)
tree335e0541624e71835ff22cd468b1326c9759170c /target-arm
parentfaa811f6de44d58180f5d235787678dcdd4b2e9d (diff)
downloadqemu-arm-577bf808958d06497928c639efaa473bf8c5e099.tar.gz
target-arm: Clean up DISAS_UPDATE usage in AArch32 translation codepull-target-arm-20151110
AArch32 translation code does not distinguish between DISAS_UPDATE and DISAS_JUMP. Thus, we cannot use any of them without first updating PC in CPU state. Furthermore, it is too complicated to update PC in CPU state before PC gets updated in disas context. So it is hardly possible to correctly end TB early if is is not likely to be executed before calling disas_*_insn(), e.g. just after calling breakpoint check helper. Modify DISAS_UPDATE and DISAS_JUMP usage in AArch32 translation and apply to them the same semantic as AArch64 translation does: - DISAS_UPDATE: update PC in CPU state when finishing translation - DISAS_JUMP: preserve current PC value in CPU state when finishing translation This patch fixes a bug in AArch32 breakpoint handling: when check_breakpoints helper does not generate an exception, ending the TB early with DISAS_UPDATE couldn't update PC in CPU state and execution hangs. Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com> Message-id: 1447097859-586-1-git-send-email-serge.fdrv@gmail.com Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target-arm')
-rw-r--r--target-arm/translate.c25
1 files changed, 14 insertions, 11 deletions
diff --git a/target-arm/translate.c b/target-arm/translate.c
index ff262a2572..a56f7fe532 100644
--- a/target-arm/translate.c
+++ b/target-arm/translate.c
@@ -870,7 +870,7 @@ static inline void gen_bx_im(DisasContext *s, uint32_t addr)
{
TCGv_i32 tmp;
- s->is_jmp = DISAS_UPDATE;
+ s->is_jmp = DISAS_JUMP;
if (s->thumb != (addr & 1)) {
tmp = tcg_temp_new_i32();
tcg_gen_movi_i32(tmp, addr & 1);
@@ -883,7 +883,7 @@ static inline void gen_bx_im(DisasContext *s, uint32_t addr)
/* Set PC and Thumb state from var. var is marked as dead. */
static inline void gen_bx(DisasContext *s, TCGv_i32 var)
{
- s->is_jmp = DISAS_UPDATE;
+ s->is_jmp = DISAS_JUMP;
tcg_gen_andi_i32(cpu_R[15], var, ~1);
tcg_gen_andi_i32(var, var, 1);
store_cpu_field(var, thumb);
@@ -1062,7 +1062,7 @@ static void gen_exception_insn(DisasContext *s, int offset, int excp,
static inline void gen_lookup_tb(DisasContext *s)
{
tcg_gen_movi_i32(cpu_R[15], s->pc & ~1);
- s->is_jmp = DISAS_UPDATE;
+ s->is_jmp = DISAS_JUMP;
}
static inline void gen_add_data_offset(DisasContext *s, unsigned int insn,
@@ -4096,7 +4096,7 @@ static void gen_exception_return(DisasContext *s, TCGv_i32 pc)
tmp = load_cpu_field(spsr);
gen_set_cpsr(tmp, CPSR_ERET_MASK);
tcg_temp_free_i32(tmp);
- s->is_jmp = DISAS_UPDATE;
+ s->is_jmp = DISAS_JUMP;
}
/* Generate a v6 exception return. Marks both values as dead. */
@@ -4105,7 +4105,7 @@ static void gen_rfe(DisasContext *s, TCGv_i32 pc, TCGv_i32 cpsr)
gen_set_cpsr(cpsr, CPSR_ERET_MASK);
tcg_temp_free_i32(cpsr);
store_reg(s, 15, pc);
- s->is_jmp = DISAS_UPDATE;
+ s->is_jmp = DISAS_JUMP;
}
static void gen_nop_hint(DisasContext *s, int val)
@@ -9035,7 +9035,7 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn)
tmp = load_cpu_field(spsr);
gen_set_cpsr(tmp, CPSR_ERET_MASK);
tcg_temp_free_i32(tmp);
- s->is_jmp = DISAS_UPDATE;
+ s->is_jmp = DISAS_JUMP;
}
}
break;
@@ -11355,7 +11355,7 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
/* We always get here via a jump, so know we are not in a
conditional execution block. */
gen_exception_internal(EXCP_KERNEL_TRAP);
- dc->is_jmp = DISAS_UPDATE;
+ dc->is_jmp = DISAS_EXC;
break;
}
#else
@@ -11363,7 +11363,7 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
/* We always get here via a jump, so know we are not in a
conditional execution block. */
gen_exception_internal(EXCP_EXCEPTION_EXIT);
- dc->is_jmp = DISAS_UPDATE;
+ dc->is_jmp = DISAS_EXC;
break;
}
#endif
@@ -11497,7 +11497,8 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
}
gen_set_label(dc->condlabel);
}
- if (dc->condjmp || !dc->is_jmp) {
+ if (dc->condjmp || dc->is_jmp == DISAS_NEXT ||
+ dc->is_jmp == DISAS_UPDATE) {
gen_set_pc_im(dc, dc->pc);
dc->condjmp = 0;
}
@@ -11533,9 +11534,11 @@ void gen_intermediate_code(CPUARMState *env, TranslationBlock *tb)
case DISAS_NEXT:
gen_goto_tb(dc, 1, dc->pc);
break;
- default:
- case DISAS_JUMP:
case DISAS_UPDATE:
+ gen_set_pc_im(dc, dc->pc);
+ /* fall through */
+ case DISAS_JUMP:
+ default:
/* indicate that the hash table must be used to find the next TB */
tcg_gen_exit_tb(0);
break;