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[PATCH-for-6.1 v2 1/2] hw/sd/sdcard: Document out-of-range addresses for
From: |
Philippe Mathieu-Daudé |
Subject: |
[PATCH-for-6.1 v2 1/2] hw/sd/sdcard: Document out-of-range addresses for SEND_WRITE_PROT |
Date: |
Tue, 3 Aug 2021 01:55:23 +0200 |
Per the 'Physical Layer Simplified Specification Version 3.01',
Table 4-22: 'Block Oriented Write Protection Commands'
SEND_WRITE_PROT (CMD30)
If the card provides write protection features, this command asks
the card to send the status of the write protection bits [1].
[1] 32 write protection bits (representing 32 write protect groups
starting at the specified address) [...]
The last (least significant) bit of the protection bits corresponds
to the first addressed group. If the addresses of the last groups
are outside the valid range, then the corresponding write protection
bits shall be set to 0.
Split the if() statement (without changing the behaviour of the code)
to better position the description comment.
Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
---
hw/sd/sd.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index 1f964e022b1..707dcc12a14 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -822,7 +822,14 @@ static uint32_t sd_wpbits(SDState *sd, uint64_t addr)
for (i = 0; i < 32; i++, wpnum++, addr += WPGROUP_SIZE) {
assert(wpnum < sd->wpgrps_size);
- if (addr < sd->size && test_bit(wpnum, sd->wp_groups)) {
+ if (addr >= sd->size) {
+ /*
+ * If the addresses of the last groups are outside the valid range,
+ * then the corresponding write protection bits shall be set to 0.
+ */
+ continue;
+ }
+ if (test_bit(wpnum, sd->wp_groups)) {
ret |= (1 << i);
}
}
--
2.31.1