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* [PATCH] mci: fix wrong sd/mmc/emmc card size computation for arch where char is signed
@ 2020-09-14 15:27 Yann Sionneau
  2020-09-14 15:51 ` Ahmad Fatoum
  0 siblings, 1 reply; 5+ messages in thread
From: Yann Sionneau @ 2020-09-14 15:27 UTC (permalink / raw)
  To: barebox; +Cc: Yann Sionneau

char type can be either signed or unsigned according to C standard.
If your arch has signed char, this kind of computation will end up wrong
because of sign extension:

https://git.pengutronix.de/cgit/barebox/tree/drivers/mci/mci-core.c#n869

mci->capacity = mci->ext_csd[EXT_CSD_SEC_COUNT] << 0 |
		mci->ext_csd[EXT_CSD_SEC_COUNT + 1] << 8 |
		mci->ext_csd[EXT_CSD_SEC_COUNT + 2] << 16 |
		mci->ext_csd[EXT_CSD_SEC_COUNT + 3] << 24;

Turning the ext_csd field into u8 * fixes the issue.
---
 include/mci.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/mci.h b/include/mci.h
index 96547fb39..f6d845440 100644
--- a/include/mci.h
+++ b/include/mci.h
@@ -456,7 +456,7 @@ struct mci {
 	uint64_t capacity;	/**< Card's data capacity in bytes */
 	int ready_for_use;	/** true if already probed */
 	int dsr_imp;		/**< DSR implementation state from CSD */
-	char *ext_csd;
+	u8 *ext_csd;
 	int probe;
 	struct param_d *param_boot;
 	int bootpart;
-- 
2.17.1



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^ permalink raw reply	[flat|nested] 5+ messages in thread
* [PATCH] mci: fix wrong sd/mmc/emmc card size computation for arch where char is signed
@ 2020-09-14 16:02 Yann Sionneau
  2020-09-15  7:33 ` Sascha Hauer
  0 siblings, 1 reply; 5+ messages in thread
From: Yann Sionneau @ 2020-09-14 16:02 UTC (permalink / raw)
  To: barebox; +Cc: Yann Sionneau

char type can be either signed or unsigned according to C standard.
If your arch has signed char, this kind of computation will end up wrong
because of sign extension:

https://git.pengutronix.de/cgit/barebox/tree/drivers/mci/mci-core.c#n869

mci->capacity = mci->ext_csd[EXT_CSD_SEC_COUNT] << 0 |
		mci->ext_csd[EXT_CSD_SEC_COUNT + 1] << 8 |
		mci->ext_csd[EXT_CSD_SEC_COUNT + 2] << 16 |
		mci->ext_csd[EXT_CSD_SEC_COUNT + 3] << 24;

Turning the ext_csd field into u8 * fixes the issue.

Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
---
 include/mci.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/mci.h b/include/mci.h
index 96547fb39..f6d845440 100644
--- a/include/mci.h
+++ b/include/mci.h
@@ -456,7 +456,7 @@ struct mci {
 	uint64_t capacity;	/**< Card's data capacity in bytes */
 	int ready_for_use;	/** true if already probed */
 	int dsr_imp;		/**< DSR implementation state from CSD */
-	char *ext_csd;
+	u8 *ext_csd;
 	int probe;
 	struct param_d *param_boot;
 	int bootpart;
-- 
2.17.1



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barebox mailing list
barebox@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/barebox

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2020-09-15  7:33 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-14 15:27 [PATCH] mci: fix wrong sd/mmc/emmc card size computation for arch where char is signed Yann Sionneau
2020-09-14 15:51 ` Ahmad Fatoum
2020-09-14 16:03   ` Yann Sionneau
2020-09-14 16:02 Yann Sionneau
2020-09-15  7:33 ` Sascha Hauer

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