Commit Graph

4 Commits

Author SHA1 Message Date
Jacob Garber
5e4021a2f5 lib: Prevent unintended sign extensions
In the last argument to sbi_memset() we essentially have the following
multiplication:

    size_t = u16 * u16

Due to C's integer semantics, both u16's are implicitly converted to int
before the multiplication, which cannot hold all possible values of a
u16 * u16. If the multiplication overflows, the intermediate result will
be a negative number. On 64-bit platforms, this will be sign-extended to
a huge integer in the conversion to a u64 (aka size_t). Being the size
argument to sbi_memset(), this could potentially cause a large
out-of-bounds write. The solution is to manually cast one of the u16 to
a size_t, which will make it large enough to avoid the implicit
conversion and any overflow.

Signed-off-by: Jacob Garber <jgarber1@ualberta.ca>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
2019-08-12 09:26:38 +05:30
Atish Patra
200ed7c1bd lib: Rename string.x to sbi_string.x
All string functions are part of libsbi. It makes more sense
to rename them to sbi_string.x as the libsbi can be linked
with external libraries that can have similar implementation.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:59 +05:30
Atish Patra
98aaf8317b lib: Include helper libc functions directly in libsbi.
libsbi needs some of the custom libc functions. It should be directly
included in libsbi instead of platform specific libraries.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:54 +05:30
Atish Patra
749b0b0932 lib: Move sbi core library to lib/sbi
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
2019-06-19 09:48:51 +05:30