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| author | Nicolas Pitre <nico@fluxnic.net> | 2010-09-22 18:34:36 -0400 |
|---|---|---|
| committer | Nicolas Pitre <nicolas.pitre@linaro.org> | 2010-10-01 22:31:34 -0400 |
| commit | 087aaffcdf9c91667c93923fbc05fa8fb6bc7d3a (patch) | |
| tree | ec94d9fd07baa4802ff0a3a2811ef3c3e1c7f3f3 /arch/arm/Kconfig.debug | |
| parent | 7c63984b86f96c71c541132c74c4b56fe2a13e1a (diff) | |
| download | lwn-087aaffcdf9c91667c93923fbc05fa8fb6bc7d3a.tar.gz lwn-087aaffcdf9c91667c93923fbc05fa8fb6bc7d3a.zip | |
ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem
There are very few legitimate use cases, if any, for directly accessing
system RAM through /dev/mem. So let's mimic what they do on x86 and
forbid it when CONFIG_STRICT_DEVMEM is turned on.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Diffstat (limited to 'arch/arm/Kconfig.debug')
| -rw-r--r-- | arch/arm/Kconfig.debug | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug index 91344af75f39..c29fb382aeee 100644 --- a/arch/arm/Kconfig.debug +++ b/arch/arm/Kconfig.debug @@ -2,6 +2,20 @@ 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. + # 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 |