A GCC -fstack-protector vulnerability on arm64

Posted Sep 18, 2023 6:11 UTC (Mon) by Cyberax (✭ supporter ✭, #52523)
In reply to: A GCC -fstack-protector vulnerability on arm64 by ianmcc
Parent article: A GCC -fstack-protector vulnerability on arm64

A typical userspace stack is, what, 8Mb? And a kernel stack is 16kb (yes, with a "k").

And a typical system now has gigabytes of RAM.

A GCC -fstack-protector vulnerability on arm64

Posted Sep 18, 2023 8:31 UTC (Mon) by geert (subscriber, #98403) [Link]

But with "B"s, not "b"s. And actually "Ki" instead of "k" ;-)

A GCC -fstack-protector vulnerability on arm64

Posted Sep 18, 2023 9:13 UTC (Mon) by mathstuf (subscriber, #69389) [Link] (1 responses)

> And a kernel stack is 16kb (yes, with a "k").

Hmm. So 4 pages on typical builds. Is the stack still this small even with something like 64k-sized pages?

A GCC -fstack-protector vulnerability on arm64

Posted Sep 18, 2023 9:57 UTC (Mon) by geert (subscriber, #98403) [Link]

arch/powerpc/Kconfig:config THREAD_SHIFT
arch/powerpc/Kconfig- int "Thread shift" if EXPERT
arch/powerpc/Kconfig- range 13 15
arch/powerpc/Kconfig- default "15" if PPC_256K_PAGES
arch/powerpc/Kconfig- default "14" if PPC64
arch/powerpc/Kconfig- default "13"
arch/powerpc/Kconfig- help
arch/powerpc/Kconfig- Used to define the stack size. The default is almost always what you
arch/powerpc/Kconfig- want. Only change this if you know what you are doing.