diff options
author | Peter Maydell <peter.maydell@linaro.org> | 2018-04-06 17:52:34 +0100 |
---|---|---|
committer | Peter Maydell <peter.maydell@linaro.org> | 2018-04-06 17:52:34 +0100 |
commit | 5a7d211bbd9fb2766ab91eb56d4e5e078be62365 (patch) | |
tree | 308574bf56841cc84c42031f3b3929f685bd58dd | |
parent | 31d4f5487313eb5c073eb8e3fa1b03828a73b253 (diff) |
target/arm: Don't corrupt insn_start arguments on 32-bit hostsicount-debug
For the Arm target, we have a 3-operand tcg_insn_start,
where the 3 arguments are the PC, condexec bits, and
a syndrome value. We set it up like this:
tcg_gen_insn_start(dc->pc,
(dc->condexec_cond << 4) | (dc->condexec_mask >> 1),
0);
dc->insn_start = tcg_last_op();
and then we patch in the 3rd operand later in disas_set_insn_syndrome():
tcg_set_insn_param(s->insn_start, 2, syn);
Unfortunately, if we're running on a setup where
TARGET_LONG_BITS > TCG_TARGET_REG_BITS (ie 64 bit guest
on 32 bit host), tcg_gen_insn_start() has under the hood
split the 3 operands we gave it into 6, and so we end
up patching a syndrome value into the condexec bits.
This means we'll end up with corrupted guest condexec
state if we have to do a cpu_restore_state(), which happens
often when using icount and occasionally for load/store
instructions that fault.
Fix the bug by using the correct operand offset for the
64-on-32 case.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r-- | target/arm/translate.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/target/arm/translate.h b/target/arm/translate.h index c47febf99d..f04ece9cfd 100644 --- a/target/arm/translate.h +++ b/target/arm/translate.h @@ -120,7 +120,15 @@ static inline void disas_set_insn_syndrome(DisasContext *s, uint32_t syn) /* We check and clear insn_start_idx to catch multiple updates. */ assert(s->insn_start != NULL); +#if TARGET_LONG_BITS <= TCG_TARGET_REG_BITS tcg_set_insn_param(s->insn_start, 2, syn); +#else + /* tcg_gen_insn_start has split every target_ulong argument to + * op_insn_start into two 32-bit arguments, so we want the low + * half of the 3rd argument, which is at index 4. + */ + tcg_set_insn_param(s->insn_start, 4, syn); +#endif s->insn_start = NULL; } |