* [Qemu-devel] [PATCH] hw/misc/tz-mpc: Fix value of BLK_MAX register
@ 2018-12-13 18:32 Peter Maydell
2018-12-13 22:02 ` Richard Henderson
0 siblings, 1 reply; 2+ messages in thread
From: Peter Maydell @ 2018-12-13 18:32 UTC (permalink / raw)
To: qemu-arm, qemu-devel; +Cc: patches
In the TZ Memory Protection Controller, the BLK_MAX register is supposed
to return the maximum permitted value of the BLK_IDX register. Our
implementation incorrectly returned max+1 (ie the total number of
valid index values, since BLK_IDX is zero-based).
Correct this off-by-one error. Since we consistently initialize
and use s->blk_max throughout the implementation as the 'size'
of the LUT, just adjust the value we return when the guest reads
the BLK_MAX register, rather than trying to change the semantics
of the s->blk_max internal struct field.
Fixes: https://bugs.launchpad.net/qemu/+bug/1806824
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
hw/misc/tz-mpc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/hw/misc/tz-mpc.c b/hw/misc/tz-mpc.c
index e0c58ba37ec..946147b1c02 100644
--- a/hw/misc/tz-mpc.c
+++ b/hw/misc/tz-mpc.c
@@ -150,7 +150,7 @@ static MemTxResult tz_mpc_reg_read(void *opaque, hwaddr addr,
r = s->ctrl;
break;
case A_BLK_MAX:
- r = s->blk_max;
+ r = s->blk_max - 1;
break;
case A_BLK_CFG:
/* We are never in "init in progress state", so this just indicates
--
2.19.2
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [Qemu-devel] [PATCH] hw/misc/tz-mpc: Fix value of BLK_MAX register
2018-12-13 18:32 [Qemu-devel] [PATCH] hw/misc/tz-mpc: Fix value of BLK_MAX register Peter Maydell
@ 2018-12-13 22:02 ` Richard Henderson
0 siblings, 0 replies; 2+ messages in thread
From: Richard Henderson @ 2018-12-13 22:02 UTC (permalink / raw)
To: Peter Maydell, qemu-arm, qemu-devel; +Cc: patches
On 12/13/18 12:32 PM, Peter Maydell wrote:
> In the TZ Memory Protection Controller, the BLK_MAX register is supposed
> to return the maximum permitted value of the BLK_IDX register. Our
> implementation incorrectly returned max+1 (ie the total number of
> valid index values, since BLK_IDX is zero-based).
>
> Correct this off-by-one error. Since we consistently initialize
> and use s->blk_max throughout the implementation as the 'size'
> of the LUT, just adjust the value we return when the guest reads
> the BLK_MAX register, rather than trying to change the semantics
> of the s->blk_max internal struct field.
>
> Fixes: https://bugs.launchpad.net/qemu/+bug/1806824
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> hw/misc/tz-mpc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
^ permalink raw reply [flat|nested] 2+ messages in thread
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2018-12-13 18:32 [Qemu-devel] [PATCH] hw/misc/tz-mpc: Fix value of BLK_MAX register Peter Maydell
2018-12-13 22:02 ` Richard Henderson
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