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@xxxxxxxxxxxx> Cc: Russell King <linux@xxxxxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> Acked-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> [heiko: drop 'default y' for s390] Acked-by: Ingo Molnar <mingo@xxxxxxxxxx> Suggested-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- arch/arm/Kconfig | 1 + arch/arm/Kconfig.debug | 14 -------------- arch/arm64/Kconfig | 1 + arch/arm64/Kconfig.debug | 14 -------------- arch/frv/Kconfig | 1 + arch/m32r/Kconfig | 1 + arch/powerpc/Kconfig | 1 + arch/powerpc/Kconfig.debug | 12 ------------ arch/s390/Kconfig | 1 + arch/s390/Kconfig.debug | 12 ------------ arch/tile/Kconfig | 4 +--- arch/unicore32/Kconfig | 1 + arch/unicore32/Kconfig.debug | 14 -------------- arch/x86/Kconfig | 1 + arch/x86/Kconfig.debug | 17 ----------------- lib/Kconfig.debug | 22 ++++++++++++++++++++++ 16 files changed, 31 insertions(+), 86 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 0365cbbc9179..c7d92948bb49 100644 --- 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 259c0ca9c99a..e356357d86bb 100644 --- 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 9ac16a482ff1..4e7bf1d73038 100644 --- 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 04fb73b973f1..e13c4bf84d9e 100644 --- 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 34aa19352dc1..03bfd6bf03e7 100644 --- 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 9e44bbd8051e..836ac5a963c8 100644 --- 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 db49e0d796b1..85eabc49de61 100644 --- 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 3a510f4a6b68..a0e44a9c456f 100644 --- 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 3a55f493c7da..779becb895be 100644 --- 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 c56878e1245f..26c5d5beb4be 100644 --- 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 106c21bd7f44..cf3116887509 100644 --- 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 c9faddc61100..5dc4c0a43ccd 100644 --- 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 1a3626239843..f075bbe1d46f 100644 --- 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 db3622f22b61..75fba1fc205d 100644 --- 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 137dfa96aa14..1116452fcfc2 100644 --- 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 8c15b29d5adc..289dfcbc14eb 100644 --- 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. -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
