arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug

Let all the archs that implement devmem_is_allowed() opt-in to a common
definition of CONFIG_STRICT_DEVM in lib/Kconfig.debug.

Cc: Kees Cook <keescook@chromium.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
[heiko: drop 'default y' for s390]
Acked-by: Ingo Molnar <mingo@redhat.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 34e1569a11ee322a0a020bdfe0c9b801b6b58c12..b8a47974c2d7e9a2708435e9a9d665efcde337ca 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2,6 +2,7 @@ config ARM
        bool
        default y
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_HAS_ELF_RANDOMIZE
        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
        select ARCH_HAVE_CUSTOM_GPIO_H

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 259c0ca9c99a8f510410d3b1e9f2dd40707555ca..e356357d86bb94c3bc0be665c0b8cbd25be5fd1f 100644 (file)
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -15,20 +15,6 @@ config ARM_PTDUMP
          kernel.
          If in doubt, say "N"
 
-config STRICT_DEVMEM
-       bool "Filter access to /dev/mem"
-       depends on MMU
-       ---help---
-         If this option is disabled, you allow userspace (root) access to all
-         of memory, including kernel and userspace memory. Accidental
-         access to this is obviously disastrous, but specific access can
-         be used by people debugging the kernel.
-
-         If this option is switched on, the /dev/mem file only allows
-         userspace access to memory mapped peripherals.
-
-          If in doubt, say Y.
-
 # RMK wants arm kernels compiled with frame pointers or stack unwinding.
 # If you know what you are doing and are willing to live without stack
 # traces, you can get a slightly smaller kernel by setting this option to

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 871f21783866d5fdb1557ec56e5f13b602ba331a..08f64b455aa8bf87f01b60233b4d89b38a8b6cb5 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -3,6 +3,7 @@ config ARM64
        select ACPI_CCA_REQUIRED if ACPI
        select ACPI_GENERIC_GSI if ACPI
        select ACPI_REDUCED_HARDWARE_ONLY if ACPI
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_HAS_ELF_RANDOMIZE
        select ARCH_HAS_GCOV_PROFILE_ALL

diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug
index 04fb73b973f155b477425ff1841e370f0ba87d41..e13c4bf84d9e13b0047175600210d11c844afcec 100644 (file)
--- a/arch/arm64/Kconfig.debug
+++ b/arch/arm64/Kconfig.debug
@@ -14,20 +14,6 @@ config ARM64_PTDUMP
          kernel.
          If in doubt, say "N"
 
-config STRICT_DEVMEM
-       bool "Filter access to /dev/mem"
-       depends on MMU
-       help
-         If this option is disabled, you allow userspace (root) access to all
-         of memory, including kernel and userspace memory. Accidental
-         access to this is obviously disastrous, but specific access can
-         be used by people debugging the kernel.
-
-         If this option is switched on, the /dev/mem file only allows
-         userspace access to memory mapped peripherals.
-
-         If in doubt, say Y.
-
 config PID_IN_CONTEXTIDR
        bool "Write the current PID to the CONTEXTIDR register"
        help

diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index 34aa19352dc1ab87cc2cf11f38e1161dc547a518..03bfd6bf03e7a28c5b31a1b6f51b47e5471596a9 100644 (file)
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -10,6 +10,7 @@ config FRV
        select HAVE_DEBUG_BUGVERBOSE
        select ARCH_HAVE_NMI_SAFE_CMPXCHG
        select GENERIC_CPU_DEVICES
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_WANT_IPC_PARSE_VERSION
        select OLD_SIGSUSPEND3
        select OLD_SIGACTION

diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 9e44bbd8051ed1387a45eb4fca0b3f4aa49a3bf0..836ac5a963c83140d18dcd762459d19e1fd0c101 100644 (file)
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -13,6 +13,7 @@ config M32R
        select GENERIC_IRQ_PROBE
        select GENERIC_IRQ_SHOW
        select GENERIC_ATOMIC64
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_USES_GETTIMEOFFSET
        select MODULES_USE_ELF_RELA
        select HAVE_DEBUG_STACKOVERFLOW

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index db49e0d796b1bf50642365aa92d63c5a83a07320..85eabc49de61ad8900938def85791ef5d62c1402 100644 (file)
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -159,6 +159,7 @@ config PPC
        select EDAC_SUPPORT
        select EDAC_ATOMIC_SCRUB
        select ARCH_HAS_DMA_SET_COHERENT_MASK
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select HAVE_ARCH_SECCOMP_FILTER
 
 config GENERIC_CSUM

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 3a510f4a6b68cfe56f711ed81d46fcf1b2e0ee72..a0e44a9c456fcee2a187f3af8a911e8cf63e10d2 100644 (file)
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -335,18 +335,6 @@ config PPC_EARLY_DEBUG_CPM_ADDR
          platform probing is done, all platforms selected must
          share the same address.
 
-config STRICT_DEVMEM
-       def_bool y
-       prompt "Filter access to /dev/mem"
-       help
-         This option restricts access to /dev/mem.  If this option is
-         disabled, you allow userspace access to all memory, including
-         kernel and userspace memory. Accidental memory access is likely
-         to be disastrous.
-         Memory access is required for experts who want to debug the kernel.
-
-         If you are unsure, say Y.
-
 config FAIL_IOMMU
        bool "Fault-injection capability for IOMMU"
        depends on FAULT_INJECTION

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 3a55f493c7da72b9ee7ee7ad7c8c76d9e01bed8d..779becb895befa2e1aeca68768259e687488fb72 100644 (file)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -66,6 +66,7 @@ config S390
        def_bool y
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_HAS_ELF_RANDOMIZE
        select ARCH_HAS_GCOV_PROFILE_ALL
        select ARCH_HAS_SG_CHAIN

diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug
index c56878e1245fb4c4e75425f6e87ddd86457d5da1..26c5d5beb4bebd2e060654d2d9d6e480f7f5da34 100644 (file)
--- a/arch/s390/Kconfig.debug
+++ b/arch/s390/Kconfig.debug
@@ -5,18 +5,6 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
-config STRICT_DEVMEM
-       def_bool y
-       prompt "Filter access to /dev/mem"
-       ---help---
-         This option restricts access to /dev/mem.  If this option is
-         disabled, you allow userspace access to all memory, including
-         kernel and userspace memory. Accidental memory access is likely
-         to be disastrous.
-         Memory access is required for experts who want to debug the kernel.
-
-         If you are unsure, say Y.
-
 config S390_PTDUMP
        bool "Export kernel pagetable layout to userspace via debugfs"
        depends on DEBUG_KERNEL

diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 106c21bd7f449d947094db5fdefce8a9a6e1b142..cf3116887509374903deb5f5a63b4c9a8eefbc69 100644 (file)
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -19,6 +19,7 @@ config TILE
        select VIRT_TO_BUS
        select SYS_HYPERVISOR
        select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_HAVE_NMI_SAFE_CMPXCHG
        select GENERIC_CLOCKEVENTS
        select MODULES_USE_ELF_RELA
@@ -116,9 +117,6 @@ config ARCH_DISCONTIGMEM_DEFAULT
 config TRACE_IRQFLAGS_SUPPORT
        def_bool y
 
-config STRICT_DEVMEM
-       def_bool y
-
 # SMP is required for Tilera Linux.
 config SMP
        def_bool y

diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index c9faddc61100f1bc44dd68f1b42e6b596ecc8bc4..5dc4c0a43ccdea7b8f1317a2a6a87d06c2fa9648 100644 (file)
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig
@@ -1,5 +1,6 @@
 config UNICORE32
        def_bool y
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_MIGHT_HAVE_PC_PARPORT
        select ARCH_MIGHT_HAVE_PC_SERIO
        select HAVE_MEMBLOCK

diff --git a/arch/unicore32/Kconfig.debug b/arch/unicore32/Kconfig.debug
index 1a36262398435ff9f9f224cab74da1a3d2bb0233..f075bbe1d46f4ec1084f40ddd68396c39515e5ff 100644 (file)
--- a/arch/unicore32/Kconfig.debug
+++ b/arch/unicore32/Kconfig.debug
@@ -2,20 +2,6 @@ menu "Kernel hacking"
 
 source "lib/Kconfig.debug"
 
-config STRICT_DEVMEM
-       bool "Filter access to /dev/mem"
-       depends on MMU
-       ---help---
-         If this option is disabled, you allow userspace (root) access to all
-         of memory, including kernel and userspace memory. Accidental
-         access to this is obviously disastrous, but specific access can
-         be used by people debugging the kernel.
-
-         If this option is switched on, the /dev/mem file only allows
-         userspace access to memory mapped peripherals.
-
-          If in doubt, say Y.
-
 config EARLY_PRINTK
        def_bool DEBUG_OCD
        help

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index db3622f22b618303a8bc9c3c2f34762f400dbafb..75fba1fc205d015d1d0f80c0980d1c8aba10da6f 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -24,6 +24,7 @@ config X86
        select ARCH_DISCARD_MEMBLOCK
        select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
        select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
+       select ARCH_HAS_DEVMEM_IS_ALLOWED
        select ARCH_HAS_ELF_RANDOMIZE
        select ARCH_HAS_FAST_MULTIPLIER
        select ARCH_HAS_GCOV_PROFILE_ALL

diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug
index 137dfa96aa14e1c8c3a9c1d7b50b21d910cabae4..1116452fcfc2306c159f3985e53b06712f9da2e2 100644 (file)
--- a/arch/x86/Kconfig.debug
+++ b/arch/x86/Kconfig.debug
@@ -5,23 +5,6 @@ config TRACE_IRQFLAGS_SUPPORT
 
 source "lib/Kconfig.debug"
 
-config STRICT_DEVMEM
-       bool "Filter access to /dev/mem"
-       ---help---
-         If this option is disabled, you allow userspace (root) access to all
-         of memory, including kernel and userspace memory. Accidental
-         access to this is obviously disastrous, but specific access can
-         be used by people debugging the kernel. Note that with PAT support
-         enabled, even in this case there are restrictions on /dev/mem
-         use due to the cache aliasing requirements.
-
-         If this option is switched on, the /dev/mem file only allows
-         userspace access to PCI space and the BIOS code and data regions.
-         This is sufficient for dosemu and X and all common users of
-         /dev/mem.
-
-         If in doubt, say Y.
-
 config X86_VERBOSE_BOOTUP
        bool "Enable verbose x86 bootup info messages"
        default y

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 8c15b29d5adc64214880cf7c066fb83349f612aa..289dfcbc14eb6a96607b33e7baa9c39fe27cfd27 100644 (file)
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1853,3 +1853,25 @@ source "samples/Kconfig"
 
 source "lib/Kconfig.kgdb"
 
+config ARCH_HAS_DEVMEM_IS_ALLOWED
+       bool
+
+config STRICT_DEVMEM
+       bool "Filter access to /dev/mem"
+       depends on MMU
+       depends on ARCH_HAS_DEVMEM_IS_ALLOWED
+       default y if TILE || PPC
+       ---help---
+         If this option is disabled, you allow userspace (root) access to all
+         of memory, including kernel and userspace memory. Accidental
+         access to this is obviously disastrous, but specific access can
+         be used by people debugging the kernel. Note that with PAT support
+         enabled, even in this case there are restrictions on /dev/mem
+         use due to the cache aliasing requirements.
+
+         If this option is switched on, the /dev/mem file only allows
+         userspace access to PCI space and the BIOS code and data regions.
+         This is sufficient for dosemu and X and all common users of
+         /dev/mem.
+
+         If in doubt, say Y.