[PATCH u-boot v3 02/39] api: fix a potential serious bug caused by undef CONFIG_SYS_64BIT_LBA

Marek Behún
2021-03-16T12:25:32Z

The api_public.h header file undefined macro CONFIG_SYS_64BIT_LBA.

But api/api_storage.c includes this header before including part.h,
causing the type of lbaint_t and subsequently the type signature of
blk_dread() and blk_dwrite() functions to change from the rest of U-Boot
(if CONFIG_SYS_64BIT_LBA is defined for the board).

This is of course wrong, because the call to blk_dread() / blk_dwrite()
will receive mangled arguments.

Fix this by removing the undef of macro CONFIG_SYS_64BIT_LBA and instead
make the immediate code do what it would do as if the macro was not
defined.

Add a FIXME to whoever is maintaining this code.

CI managed to trigger this bug when compiling for lsxhl_defconfig, which
has CONFIG_API selected. The compiler complained about blk_dwrite() and
blk_dread() not matching original declarations:

include/blk.h:280:15: warning: type of ?blk_dwrite? does not match
original declaration
[-Wlto-type-mismatch]
280 | unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t st
| ^
drivers/block/blk-uclass.c:456:15: note: type mismatch in parameter 2
456 | unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t st
| ^

Signed-off-by: Marek Beh?n <marek.behun@nic.cz>
Reviewed-by: Simon Glass <sjg@chromium.org>
---
include/api_public.h | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/include/api_public.h b/include/api_public.h
index def103ce22..5a4465ea89 100644
--- a/include/api_public.h
+++ b/include/api_public.h
@@ -70,12 +70,25 @@ struct sys_info {
int mr_no; /* number of memory regions */
};

-#undef CONFIG_SYS_64BIT_LBA
-#ifdef CONFIG_SYS_64BIT_LBA
-typedef u_int64_t lbasize_t;
-#else
+/*
+ * FIXME: Previously this code was:
+ *
+ * #undef CONFIG_SYS_64BIT_LBA
+ * #ifdef CONFIG_SYS_64BIT_LBA
+ * typedef u_int64_t lbasize_t;
+ * #else
+ * typedef unsigned long lbasize_t;
+ * #endif
+ *
+ * But we cannot just undefine CONFIG_SYS_64BIT_LBA, because then in
+ * api/api_storage.c the type signature of lbaint_t will be different if
+ * CONFIG_SYS_64BIT_LBA is enabled for the board, which can result in various
+ * bugs.
+ * So simply define lbasize_t as an unsigned long, since this was what was done
+ * anyway for at least 13 years, but don't undefine CONFIG_SYS_64BIT_LBA.
+ */
typedef unsigned long lbasize_t;
-#endif
+
typedef unsigned long lbastart_t;

#define DEV_TYP_NONE 0x0000
--
2.26.2