diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig.debug | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 289dfcbc14eb..073496dea848 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1869,9 +1869,26 @@ config STRICT_DEVMEM 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 PCI space and the BIOS code and data regions. - This is sufficient for dosemu and X and all common users of - /dev/mem. + 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. |