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authorAndy Lutomirski <luto@kernel.org>2017-11-02 00:59:11 -0700
committerIngo Molnar <mingo@kernel.org>2017-11-02 11:04:44 +0100
commit3500130b84a3cdc5b6796eba1daf178944935efe (patch)
treefb207c28ace59732ef5e4b16807b5db3d83c69bb
parentda51da189a24bb9b7e2d5a123be096e51a4695a5 (diff)
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>
-rw-r--r--arch/x86/include/asm/processor.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 064b84722166..ad59cec14239 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -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).