Patch series "mm: ptdump: Refactor CONFIG_DEBUG_WX and check_wx_pages
debugfs attribute", v2.
This series refactors CONFIG_DEBUG_WX for the 5 architectures implementing
CONFIG_GENERIC_PTDUMP
First rename stuff in ARM which uses similar names while not implementing
CONFIG_GENERIC_PTDUMP.
Then define a generic version of debug_checkwx() that calls
ptdump_check_wx() when CONFIG_DEBUG_WX is set. Call it immediately after
calling mark_rodata_ro() instead of calling it at the end of every
mark_rodata_ro().
Then implement a debugfs attribute that can be used to trigger a W^X test
at anytime and regardless of CONFIG_DEBUG_WX
This patch (of 5):
CONFIG_DEBUG_WX is a core option defined in mm/Kconfig.debug
To avoid any future conflict, rename ARM version into CONFIG_ARM_DEBUG_WX.
Link: https://lore.kernel.org/lkml/20200422152656.GF676@willie-the-truck/T/#m802eaf33efd6f8d575939d157301b35ac0d4a64f
Link: https://github.com/KSPP/linux/issues/35
Link: https://lkml.kernel.org/r/cover.1706610398.git.christophe.leroy@csgroup.eu
Link: https://lkml.kernel.org/r/fa297aa90caeb61eee2b70c6c5897a2ab58a9562.1706610398.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "Aneesh Kumar K.V (IBM)" <aneesh.kumar@kernel.org>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Greg KH <greg@kroah.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Phong Tran <tranmanphong@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Steven Price <steven.price@arm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
UEFI runtime page tables dump only for ARM64 at present,
but ARM support EFI and ARM_PTDUMP_DEBUGFS now. Since
ARM could potentially execute with a 1G/3G user/kernel
split, choosing 1G as the upper limit for UEFI runtime
end, with this, we could enable UEFI runtime page tables
on ARM.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Cc: Russell King <linux@armlinux.org.uk>
Cc: Jinbum Park <jinb.park7@gmail.com>
Cc: linux-arm-kernel@lists.infradead.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Page mappings with full RWX permissions are a security risk.
x86, arm64 has an option to walk the page tables
and dump any bad pages.
(1404d6f13e
("arm64: dump: Add checking for writable and exectuable pages"))
Add a similar implementation for arm.
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This patch refactors the arm page table dumping code,
so multiple tables may be registered with the framework.
This patch refers below commits of arm64.
(4674fdb9f1 ("arm64: mm: dump: make page table dumping reusable"))
(4ddb9bf833 ("arm64: dump: Make ptdump debugfs a separate option"))
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Christophe Leroy