From: Daniel Micay <danielmicay@xxxxxxxxx> Subject: config: android-recommended: disable aio support The aio interface adds substantial attack surface for a feature that's not being exposed by Android at all. It's unlikely that anyone is using the kernel feature directly either. This feature is rarely used even on servers. The glibc POSIX aio calls really use thread pools. The lack of widespread usage also means this is relatively poorly audited/tested. The kernel's aio rarely provides performance benefits over using a thread pool and is quite incomplete in terms of system call coverage along with having edge cases where blocking can occur. Part of the performance issue is the fact that it only supports direct io, not buffered io. The existing API is considered fundamentally flawed and it's unlikely it will be expanded, but rather replaced: https://marc.info/?l=linux-aio&m=145255815216051&w=2 Since ext4 encryption means no direct io support, kernel aio isn't even going to work properly on Android devices using file-based encryption. Reviewed-at: https://android-review.googlesource.com/#/c/292158/ Link: http://lkml.kernel.org/r/1481113148-29204-1-git-send-email-amit.pundir@xxxxxxxxxx Signed-off-by: Daniel Micay <danielmicay@xxxxxxxxx> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Cc: Rob Herring <rob.herring@xxxxxxxxxx> Cc: John Stultz <john.stultz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/configs/android-recommended.config | 1 + 1 file changed, 1 insertion(+) diff -puN kernel/configs/android-recommended.config~config-android-recommended-disable-aio-support kernel/configs/android-recommended.config --- a/kernel/configs/android-recommended.config~config-android-recommended-disable-aio-support +++ a/kernel/configs/android-recommended.config @@ -1,4 +1,5 @@ # KEEP ALPHABETICALLY SORTED +# CONFIG_AIO is not set # CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS is not set # CONFIG_INPUT_MOUSE is not set # CONFIG_LEGACY_PTYS is not set _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
