| Message ID | 1415121836-16241-1-git-send-email-leif.lindholm@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Nov 4, 2014 at 9:23 AM, Leif Lindholm <leif.lindholm@linaro.org> wrote: > Most, but not all, architectures supporting CONFIG_STRICT_DEVMEM treat > it as a debug feature - although its function is pretty much the > opposite of debug. > > This patch deletes all architecture-specific config options and moves > the option to core code, as a non-debug option. > > Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> > --- > Apologies for wide distribution, but this is a bit invasive, > if trivial. > > arch/Kconfig | 3 +++ > arch/arm/Kconfig | 1 + > arch/arm/Kconfig.debug | 14 -------------- > arch/arm64/Kconfig | 1 + > arch/arm64/Kconfig.debug | 14 -------------- > 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 ----------------- > drivers/char/Kconfig | 16 ++++++++++++++++ > 15 files changed, 26 insertions(+), 86 deletions(-) > > diff --git a/arch/Kconfig b/arch/Kconfig > index 05d7a8a..e5f4f03 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -484,6 +484,9 @@ config HAVE_IRQ_EXIT_ON_IRQ_STACK > This spares a stack switch and improves cache usage on softirq > processing. > > +config HAVE_ARCH_RESTRICTED_DEVMEM > + bool > + > # > # ABI hall of shame > # > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index 89c4b5c..e04910f 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -30,6 +30,7 @@ config ARM > select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT) > select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL > select HAVE_ARCH_KGDB > + select HAVE_ARCH_RESTRICTED_DEVMEM if MMU > select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) > select HAVE_ARCH_TRACEHOOK > select HAVE_BPF_JIT > diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug > index d8f6a2e..2a02a7d 100644 > --- a/arch/arm/Kconfig.debug > +++ b/arch/arm/Kconfig.debug > @@ -14,20 +14,6 @@ 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 9532f8d..90abbb2 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -37,6 +37,7 @@ config ARM64 > select HAVE_ARCH_AUDITSYSCALL > select HAVE_ARCH_JUMP_LABEL > select HAVE_ARCH_KGDB > + select HAVE_ARCH_RESTRICTED_DEVMEM if MMU > select HAVE_ARCH_TRACEHOOK > select HAVE_BPF_JIT > select HAVE_C_RECORDMCOUNT > diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug > index 0a12933..d0036dd 100644 > --- a/arch/arm64/Kconfig.debug > +++ b/arch/arm64/Kconfig.debug > @@ -6,20 +6,6 @@ config FRAME_POINTER > bool > default y > > -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/powerpc/Kconfig b/arch/powerpc/Kconfig > index 88eace4..cd35068 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -148,6 +148,7 @@ config PPC > select HAVE_ARCH_AUDITSYSCALL > select ARCH_SUPPORTS_ATOMIC_RMW > select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN > + select HAVE_ARCH_RESTRICTED_DEVMEM > > config GENERIC_CSUM > def_bool CPU_LITTLE_ENDIAN > diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug > index ec2e40f..6f11382 100644 > --- a/arch/powerpc/Kconfig.debug > +++ b/arch/powerpc/Kconfig.debug > @@ -334,18 +334,6 @@ 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 f2cf1f9..fe92272 100644 > --- a/arch/s390/Kconfig > +++ b/arch/s390/Kconfig > @@ -109,6 +109,7 @@ config S390 > select HAVE_ALIGNED_STRUCT_PAGE if SLUB > select HAVE_ARCH_AUDITSYSCALL > select HAVE_ARCH_JUMP_LABEL if !MARCH_G5 > + select HAVE_ARCH_RESTRICTED_DEVMEM > select HAVE_ARCH_SECCOMP_FILTER > select HAVE_ARCH_TRACEHOOK > select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT > diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug > index c56878e..26c5d5be 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 7cca418..f881168 100644 > --- a/arch/tile/Kconfig > +++ b/arch/tile/Kconfig > @@ -27,6 +27,7 @@ config TILE > select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE > select HAVE_DEBUG_STACKOVERFLOW > select ARCH_WANT_FRAME_POINTERS > + select HAVE_ARCH_RESTRICTED_DEVMEM > > # FIXME: investigate whether we need/want these options. > # select HAVE_IOREMAP_PROT > @@ -110,9 +111,6 @@ 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 928237a..574b07f 100644 > --- a/arch/unicore32/Kconfig > +++ b/arch/unicore32/Kconfig > @@ -18,6 +18,7 @@ config UNICORE32 > select ARCH_WANT_FRAME_POINTERS > select GENERIC_IOMAP > select MODULES_USE_ELF_REL > + select HAVE_ARCH_RESTRICTED_DEVMEM if MMU > help > UniCore-32 is 32-bit Instruction Set Architecture, > including a series of low-power-consumption RISC chip > diff --git a/arch/unicore32/Kconfig.debug b/arch/unicore32/Kconfig.debug > index 1a36262..f075bbe 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 ded8a67..91392bf 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -137,6 +137,7 @@ config X86 > select HAVE_ACPI_APEI_NMI if ACPI > select ACPI_LEGACY_TABLES_LOOKUP if ACPI > select X86_FEATURE_NAMES if PROC_FS > + select HAVE_ARCH_RESTRICTED_DEVMEM > > config INSTRUCTION_DECODER > def_bool y > diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug > index 61bd2ad..e35d4a1 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/drivers/char/Kconfig b/drivers/char/Kconfig > index efefd12..39f7817 100644 > --- a/drivers/char/Kconfig > +++ b/drivers/char/Kconfig > @@ -6,6 +6,22 @@ menu "Character devices" > > source "drivers/tty/Kconfig" > > +config STRICT_DEVMEM > + bool "Reduced access to /dev/mem" > + depends on HAVE_ARCH_RESTRICTED_DEVMEM > + default y > + 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 restricts userspace > + access to an architecture-specific subset of the physical address > + space. Great consolidation, thanks! I would probably expand this help text a bit to include some of details mentioned in the x86 portion of the option. For example: If this option is switched on, the /dev/mem file restricts userspace access to an architecture-specific subset of the physical address space. For example on x86, PCI space and BIOS code and data regions. This is sufficient for things like dosemu and non-KMS Xorg and all common users of /dev/mem. Thanks! -Kees > + > + If in doubt, say Y. > + > config DEVKMEM > bool "/dev/kmem virtual device support" > default y > -- > 1.7.10.4 >
On Tue, Nov 04, 2014 at 10:43:00AM -0800, Kees Cook wrote: > > diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig > > index efefd12..39f7817 100644 > > --- a/drivers/char/Kconfig > > +++ b/drivers/char/Kconfig > > @@ -6,6 +6,22 @@ menu "Character devices" > > > > source "drivers/tty/Kconfig" > > > > +config STRICT_DEVMEM > > + bool "Reduced access to /dev/mem" > > + depends on HAVE_ARCH_RESTRICTED_DEVMEM > > + default y > > + 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 restricts userspace > > + access to an architecture-specific subset of the physical address > > + space. > > Great consolidation, thanks! I would probably expand this help text a > bit to include some of details mentioned in the x86 portion of the > option. For example: > > > If this option is switched on, the /dev/mem file restricts userspace > access to an architecture-specific subset of the physical address > space. For example on x86, PCI space and BIOS code and data > regions. This is sufficient for things like dosemu and non-KMS > Xorg and all common users of /dev/mem. I considered doing that, but didn't want to risk listing too many details of one architecture, and too few of others. One alternative would be to add a devmem.txt somewhere in Documentation, listing the behaviours on different architectures (this would also be a good place to describe restrictions on types of mappings and suchlike). The help message could then contain a mention of that file. Would that work for you? I really don't have a strong opinion however, and would be happy to go along with whatever the most people would like to see. / Leif
On Tue, Nov 4, 2014 at 11:59 AM, Leif Lindholm <leif.lindholm@linaro.org> wrote: > On Tue, Nov 04, 2014 at 10:43:00AM -0800, Kees Cook wrote: >> > diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig >> > index efefd12..39f7817 100644 >> > --- a/drivers/char/Kconfig >> > +++ b/drivers/char/Kconfig >> > @@ -6,6 +6,22 @@ menu "Character devices" >> > >> > source "drivers/tty/Kconfig" >> > >> > +config STRICT_DEVMEM >> > + bool "Reduced access to /dev/mem" >> > + depends on HAVE_ARCH_RESTRICTED_DEVMEM >> > + default y >> > + 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 restricts userspace >> > + access to an architecture-specific subset of the physical address >> > + space. >> >> Great consolidation, thanks! I would probably expand this help text a >> bit to include some of details mentioned in the x86 portion of the >> option. For example: >> >> >> If this option is switched on, the /dev/mem file restricts userspace >> access to an architecture-specific subset of the physical address >> space. For example on x86, PCI space and BIOS code and data >> regions. This is sufficient for things like dosemu and non-KMS >> Xorg and all common users of /dev/mem. > > I considered doing that, but didn't want to risk listing too many > details of one architecture, and too few of others. Well, the others only say "memory mapped peripherals", so that's what I was suggesting adding the x86 language: it was the most detailed about what that would really mean to the end-user. > One alternative would be to add a devmem.txt somewhere in > Documentation, listing the behaviours on different architectures (this > would also be a good place to describe restrictions on types of > mappings and suchlike). The help message could then contain a mention > of that file. Would that work for you? That's fine too, but feels like overkill to me. Just adding the x86 example to the common help text seemed like a reasonable consolidation of the existing help texts. I just didn't want to lose detail when dropping the x86 text. > I really don't have a strong opinion however, and would be happy to go > along with whatever the most people would like to see. Either way, I'm all for the consolidation. :) -Kees
On Tue, Nov 04, 2014 at 12:02:32PM -0800, Kees Cook wrote: > > I considered doing that, but didn't want to risk listing too many > > details of one architecture, and too few of others. > > Well, the others only say "memory mapped peripherals", so that's what > I was suggesting adding the x86 language: it was the most detailed > about what that would really mean to the end-user. The problem is that this currently isn't strictly speaking true for some architectures (at least not arm*). Without a standardised memory map, we are exposing mapping anything not system RAM. (Patches related to that will follow later this month.) / Leif
diff --git a/arch/Kconfig b/arch/Kconfig index 05d7a8a..e5f4f03 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -484,6 +484,9 @@ config HAVE_IRQ_EXIT_ON_IRQ_STACK This spares a stack switch and improves cache usage on softirq processing. +config HAVE_ARCH_RESTRICTED_DEVMEM + bool + # # ABI hall of shame # diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 89c4b5c..e04910f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -30,6 +30,7 @@ config ARM select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT) select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL select HAVE_ARCH_KGDB + select HAVE_ARCH_RESTRICTED_DEVMEM if MMU select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT) select HAVE_ARCH_TRACEHOOK select HAVE_BPF_JIT diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index d8f6a2e..2a02a7d 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -14,20 +14,6 @@ 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 9532f8d..90abbb2 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -37,6 +37,7 @@ config ARM64 select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_JUMP_LABEL select HAVE_ARCH_KGDB + select HAVE_ARCH_RESTRICTED_DEVMEM if MMU select HAVE_ARCH_TRACEHOOK select HAVE_BPF_JIT select HAVE_C_RECORDMCOUNT diff --git a/arch/arm64/Kconfig.debug b/arch/arm64/Kconfig.debug index 0a12933..d0036dd 100644 --- a/arch/arm64/Kconfig.debug +++ b/arch/arm64/Kconfig.debug @@ -6,20 +6,6 @@ config FRAME_POINTER bool default y -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/powerpc/Kconfig b/arch/powerpc/Kconfig index 88eace4..cd35068 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -148,6 +148,7 @@ config PPC select HAVE_ARCH_AUDITSYSCALL select ARCH_SUPPORTS_ATOMIC_RMW select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN + select HAVE_ARCH_RESTRICTED_DEVMEM config GENERIC_CSUM def_bool CPU_LITTLE_ENDIAN diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug index ec2e40f..6f11382 100644 --- a/arch/powerpc/Kconfig.debug +++ b/arch/powerpc/Kconfig.debug @@ -334,18 +334,6 @@ 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 f2cf1f9..fe92272 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -109,6 +109,7 @@ config S390 select HAVE_ALIGNED_STRUCT_PAGE if SLUB select HAVE_ARCH_AUDITSYSCALL select HAVE_ARCH_JUMP_LABEL if !MARCH_G5 + select HAVE_ARCH_RESTRICTED_DEVMEM select HAVE_ARCH_SECCOMP_FILTER select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug index c56878e..26c5d5be 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 7cca418..f881168 100644 --- a/arch/tile/Kconfig +++ b/arch/tile/Kconfig @@ -27,6 +27,7 @@ config TILE select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select HAVE_DEBUG_STACKOVERFLOW select ARCH_WANT_FRAME_POINTERS + select HAVE_ARCH_RESTRICTED_DEVMEM # FIXME: investigate whether we need/want these options. # select HAVE_IOREMAP_PROT @@ -110,9 +111,6 @@ 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 928237a..574b07f 100644 --- a/arch/unicore32/Kconfig +++ b/arch/unicore32/Kconfig @@ -18,6 +18,7 @@ config UNICORE32 select ARCH_WANT_FRAME_POINTERS select GENERIC_IOMAP select MODULES_USE_ELF_REL + select HAVE_ARCH_RESTRICTED_DEVMEM if MMU help UniCore-32 is 32-bit Instruction Set Architecture, including a series of low-power-consumption RISC chip diff --git a/arch/unicore32/Kconfig.debug b/arch/unicore32/Kconfig.debug index 1a36262..f075bbe 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 ded8a67..91392bf 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -137,6 +137,7 @@ config X86 select HAVE_ACPI_APEI_NMI if ACPI select ACPI_LEGACY_TABLES_LOOKUP if ACPI select X86_FEATURE_NAMES if PROC_FS + select HAVE_ARCH_RESTRICTED_DEVMEM config INSTRUCTION_DECODER def_bool y diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 61bd2ad..e35d4a1 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/drivers/char/Kconfig b/drivers/char/Kconfig index efefd12..39f7817 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -6,6 +6,22 @@ menu "Character devices" source "drivers/tty/Kconfig" +config STRICT_DEVMEM + bool "Reduced access to /dev/mem" + depends on HAVE_ARCH_RESTRICTED_DEVMEM + default y + 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 restricts userspace + access to an architecture-specific subset of the physical address + space. + + If in doubt, say Y. + config DEVKMEM bool "/dev/kmem virtual device support" default y
Most, but not all, architectures supporting CONFIG_STRICT_DEVMEM treat it as a debug feature - although its function is pretty much the opposite of debug. This patch deletes all architecture-specific config options and moves the option to core code, as a non-debug option. Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> --- Apologies for wide distribution, but this is a bit invasive, if trivial. arch/Kconfig | 3 +++ arch/arm/Kconfig | 1 + arch/arm/Kconfig.debug | 14 -------------- arch/arm64/Kconfig | 1 + arch/arm64/Kconfig.debug | 14 -------------- 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 ----------------- drivers/char/Kconfig | 16 ++++++++++++++++ 15 files changed, 26 insertions(+), 86 deletions(-)