https://bugzilla.kernel.org/show_bug.cgi?id=214661
Bug ID: 214661
Summary: THREAD_SIZE on x86_64 is 4*PAGE_SIZE, not 2*PAGE_SIZE
Product: Documentation
Version: unspecified
Hardware: All
OS: Linux
Status: NEW
Severity: normal
Priority: P1
Component: man-pages
Assignee: documentation_man-pages@xxxxxxxxxxxxxxxxxxxx
Reporter: me@xxxxxxxxxx
Regression: No
According to '/root/linux/arch/x86/include/asm/page_64_types.h', THREAD_SIZE on
x86_64 now is 4*PAGE_SIZE:
#ifdef CONFIG_KASAN
#define KASAN_STACK_ORDER 1
#else
#define KASAN_STACK_ORDER 0
#endif
#define THREAD_SIZE_ORDER (2 + KASAN_STACK_ORDER)
#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
However, the Documentation/x86/kernel-stacks.rst shows that THREAD_SIZE on
x86_64 is 2*PAGE_SIZE:
Like all other architectures, x86_64 has a kernel stack for every
active thread. These thread stacks are THREAD_SIZE (2*PAGE_SIZE) big.
I am not quite sure which is correct, Maybe the document needs an upgrade?
Thanks a lot for any reply.