Messages in this thread | | | Subject | Re: [PATCH v7 03/14] x86/cet/ibt: Add IBT legacy code bitmap setup function | From | Dave Hansen <> | Date | Mon, 10 Jun 2019 11:02:45 -0700 |
| |
On 6/10/19 8:22 AM, Yu-cheng Yu wrote: >> How does glibc know the linear address space size? We don’t want LA64 to >> break old binaries because the address calculation changed. > When an application starts, its highest stack address is determined. > It uses that as the maximum the bitmap needs to cover.
Huh, I didn't think we ran code from the stack. ;)
Especially given the way that we implemented the new 5-level-paging address space, I don't think that expecting code to be below the stack is a good universal expectation.
| |