kasan: remove mentions of unsupported Clang versions

Since the kernel now requires at least Clang 10.0.1, remove any mention of
old Clang versions and simplify the documentation.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Cc: Fangrui Song <maskray@google.com>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20200902225911.209899-7-ndesaulniers@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Marco Elver 2020-10-13 16:47:51 -07:00 committed by Linus Torvalds
parent 3511af0a72
commit 527f6750d9
2 changed files with 6 additions and 7 deletions

View File

@ -13,10 +13,10 @@ KASAN uses compile-time instrumentation to insert validity checks before every
memory access, and therefore requires a compiler version that supports that.
Generic KASAN is supported in both GCC and Clang. With GCC it requires version
8.3.0 or later. With Clang it requires version 7.0.0 or later, but detection of
8.3.0 or later. Any supported Clang version is compatible, but detection of
out-of-bounds accesses for global variables is only supported since Clang 11.
Tag-based KASAN is only supported in Clang and requires version 7.0.0 or later.
Tag-based KASAN is only supported in Clang.
Currently generic KASAN is supported for the x86_64, arm64, xtensa, s390 and
riscv architectures, and tag-based KASAN is supported only for arm64.

View File

@ -54,9 +54,9 @@ config KASAN_GENERIC
Enables generic KASAN mode.
This mode is supported in both GCC and Clang. With GCC it requires
version 8.3.0 or later. With Clang it requires version 7.0.0 or
later, but detection of out-of-bounds accesses for global variables
is supported only since Clang 11.
version 8.3.0 or later. Any supported Clang version is compatible,
but detection of out-of-bounds accesses for global variables is
supported only since Clang 11.
This mode consumes about 1/8th of available memory at kernel start
and introduces an overhead of ~x1.5 for the rest of the allocations.
@ -78,8 +78,7 @@ config KASAN_SW_TAGS
Enables software tag-based KASAN mode.
This mode requires Top Byte Ignore support by the CPU and therefore
is only supported for arm64. This mode requires Clang version 7.0.0
or later.
is only supported for arm64. This mode requires Clang.
This mode consumes about 1/16th of available memory at kernel start
and introduces an overhead of ~20% for the rest of the allocations.