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Diffstat (limited to 'Documentation/sysctl/vm.txt')
| -rw-r--r-- | Documentation/sysctl/vm.txt | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 1d192565e182..8cfca173d4bc 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -31,6 +31,7 @@ Currently, these files are in /proc/sys/vm: - min_unmapped_ratio - min_slab_ratio - panic_on_oom +- mmap_min_address ============================================================== @@ -216,3 +217,17 @@ above-mentioned. The default value is 0. 1 and 2 are for failover of clustering. Please select either according to your policy of failover. + +============================================================== + +mmap_min_addr + +This file indicates the amount of address space which a user process will +be restricted from mmaping. Since kernel null dereference bugs could +accidentally operate based on the information in the first couple of pages +of memory userspace processes should not be allowed to write to them. By +default this value is set to 0 and no protections will be enforced by the +security module. Setting this value to something like 64k will allow the +vast majority of applications to work correctly and provide defense in depth +against future potential kernel bugs. + |