x86/asm/entry: Unify and fix initial thread_struct::sp0 values
x86_32 and x86_64 need slightly different thread_struct::sp0 values, and
x86_32's was incorrect for init.
This never mattered -- the init thread never runs user code, so we never
used thread_struct::sp0 for anything.
Fix it and mostly unify them.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1b810c1d2e797e27bb4a7708c426101161edd1f6.1426009661.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 88d9aa7..fc6d8d0 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -811,6 +811,9 @@
prefetchw(x);
}
+#define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \
+ TOP_OF_KERNEL_STACK_PADDING)
+
#ifdef CONFIG_X86_32
/*
* User space process size: 3GB (default).
@@ -821,7 +824,7 @@
#define STACK_TOP_MAX STACK_TOP
#define INIT_THREAD { \
- .sp0 = sizeof(init_stack) + (long)&init_stack, \
+ .sp0 = TOP_OF_INIT_STACK, \
.vm86_info = NULL, \
.sysenter_cs = __KERNEL_CS, \
.io_bitmap_ptr = NULL, \
@@ -883,7 +886,7 @@
#define STACK_TOP_MAX TASK_SIZE_MAX
#define INIT_THREAD { \
- .sp0 = (unsigned long)&init_stack + sizeof(init_stack) \
+ .sp0 = TOP_OF_INIT_STACK \
}
/*