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@linaro.org
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Cc: Rob Herring <rob.herring@linaro.org>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both of these options are poorly named. The features they provide are
necessary for system security and should not be considered debug only.
Change the names to CONFIG_STRICT_KERNEL_RWX and
CONFIG_STRICT_MODULE_RWX to better describe what these options do.
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
CONFIG_MD is in recommended, but other dependent options like DM_CRYPT and
DM_VERITY options are in base. The result is the options in base don't
get enabled when applying both base and recommended fragments. Move all
the options to recommended.
Link: http://lkml.kernel.org/r/20160908185934.18098-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: John Stultz <john.stultz@linaro.org>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Copy the config fragments from the AOSP common kernel android-4.4
branch. It is becoming possible to run mainline kernels with Android,
but the kernel defconfigs don't work as-is and debugging missing config
options is a pain. Adding the config fragments into the kernel tree,
makes configuring a mainline kernel as simple as:
make ARCH=arm multi_v7_defconfig android-base.config android-recommended.config
The following non-upstream config options were removed:
CONFIG_NETFILTER_XT_MATCH_QTAGUID
CONFIG_NETFILTER_XT_MATCH_QUOTA2
CONFIG_NETFILTER_XT_MATCH_QUOTA2_LOG
CONFIG_PPPOLAC
CONFIG_PPPOPNS
CONFIG_SECURITY_PERF_EVENTS_RESTRICT
CONFIG_USB_CONFIGFS_F_MTP
CONFIG_USB_CONFIGFS_F_PTP
CONFIG_USB_CONFIGFS_F_ACC
CONFIG_USB_CONFIGFS_F_AUDIO_SRC
CONFIG_USB_CONFIGFS_UEVENT
CONFIG_INPUT_KEYCHORD
CONFIG_INPUT_KEYRESET
Link: http://lkml.kernel.org/r/1466708235-28593-1-git-send-email-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Rom Lemarchand <romlem@android.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
