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target/arm: Don't skip MTE checks for LDRT/STRT at EL0

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The LDRT/STRT "unprivileged load/store" instructions behave like
normal ones if executed at EL0. We handle this correctly for
the load/store semantics, but get the MTE checking wrong.

We always look at s->mte_active[is_unpriv] to see whether we should
be doing MTE checks, but in hflags.c when we set the TB flags that
will be used to fill the mte_active[] array we only set the
MTE0_ACTIVE bit if UNPRIV is true (i.e.  we are not at EL0).

This means that a LDRT at EL0 will see s->mte_active[1] as 0,
and will not do MTE checks even when MTE is enabled.

To avoid the translate-time code having to do an explicit check on
s->unpriv to see if it is OK to index into the mte_active[] array,
duplicate MTE_ACTIVE into MTE0_ACTIVE when UNPRIV is false.

(This isn't a very serious bug because generally nobody executes
LDRT/STRT at EL0, because they have no use there.)

Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230912140434.1333369-2-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2023-09-12 15:04:23 +01:00
parent 0b5ad31d2a
commit 903dbefc2b
1 changed files with 9 additions and 0 deletions
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9
target/arm/tcg/hflags.c
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@ -306,6 +306,15 @@ static CPUARMTBFlags rebuild_hflags_a64(CPUARMState *env, int el, int fp_el,
&& !(env->pstate & PSTATE_TCO)
&& (sctlr & (el == 0 ? SCTLR_TCF0 : SCTLR_TCF))) {
DP_TBFLAG_A64(flags, MTE_ACTIVE, 1);
if (!EX_TBFLAG_A64(flags, UNPRIV)) {
/*
* In non-unpriv contexts (eg EL0), unpriv load/stores
* act like normal ones; duplicate the MTE info to
* avoid translate-a64.c having to check UNPRIV to see
* whether it is OK to index into MTE_ACTIVE[].
*/
DP_TBFLAG_A64(flags, MTE0_ACTIVE, 1);
}
}
}
/* And again for unprivileged accesses, if required. */