Dong Bo 48f99c8ec0 arm64: Preventing READ_IMPLIES_EXEC propagation ... Like arch/arm/, we inherit the READ_IMPLIES_EXEC personality flag across fork(). This is undesirable for a number of reasons: * ELF files that don't require executable stack can end up with it anyway * We end up performing un-necessary I-cache maintenance when mapping what should be non-executable pages * Restricting what is executable is generally desirable when defending against overflow attacks This patch clears the personality flag when setting up the personality for newly spwaned native tasks. Given that semi-recent AArch64 toolchains emit a non-executable PT_GNU_STACK header, userspace applications can already not rely on READ_IMPLIES_EXEC so shouldn't be adversely affected by this change. Cc: <stable@vger.kernel.org> Reported-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Dong Bo <dongbo4@huawei.com> [will: added comment to compat code, rewrote commit message] Signed-off-by: Will Deacon <will.deacon@arm.com>		2017-05-30 11:07:41 +01:00
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asm	arm64: Preventing READ_IMPLIES_EXEC propagation	2017-05-30 11:07:41 +01:00
uapi/asm	Kbuild UAPI header export updates for v4.12	2017-05-10 20:45:36 -07:00