It used to be mapped at the top of the UVA. If the randomization is enabled any address above .data section will be randomly chosen and a guard page will be inserted in the shared page default location. The shared page is now mapped in exec_map_stack, instead of exec_new_vmspace. The latter function is called before image activator has a chance to parse ASLR related flags. The KERN_PROC_VM_LAYOUT sysctl was extended to provide shared page address. The feature is enabled by default for 64 bit applications on all architectures. It can be toggled kern.elf64.aslr.shared_page sysctl. Approved by: mw(mentor) Sponsored by: Stormshield Obtained from: Semihalf Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D35349 |
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freebsd32 | ||
ia32 | ||
lindebugfs | ||
linprocfs | ||
linsysfs | ||
linux | ||
linuxkpi/common | ||
x86bios |