diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index e2a236a7341f..ee1ac1cc082c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1886,3 +1886,42 @@ 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, and IO_STRICT_DEVMEM=n, 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 IO_STRICT_DEVMEM + bool "Filter I/O access to /dev/mem" + depends on STRICT_DEVMEM + default STRICT_DEVMEM + ---help--- + If this option is disabled, you allow userspace (root) access to all + io-memory regardless of whether a driver is actively using that + range. Accidental access to this is obviously disastrous, but + specific access can be used by people debugging kernel drivers. + + If this option is switched on, the /dev/mem file only allows + userspace access to *idle* io-memory ranges (see /proc/iomem) This + may break traditional users of /dev/mem (dosemu, legacy X, etc...) + if the driver using a given range cannot be disabled. + + If in doubt, say Y. |