x86/entry: Add task_top_of_stack() to find the top of a task's stack

This will let us get rid of a few places that hardcode accesses to
thread.sp0.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/b49b3f95a8ff858c40c9b0f5b32be0355324327d.1509609304.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2017-11-02 00:59:11 -07:00 committed by Ingo Molnar
parent da51da189a
commit 3500130b84

View File

@ -795,6 +795,8 @@ static inline void spin_lock_prefetch(const void *x)
#define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
TOP_OF_KERNEL_STACK_PADDING)
#define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1))
#ifdef CONFIG_X86_32
/*
* User space process size: 3GB (default).