Commit-ID: 42503341cde213c5928a19f7c6e1eb8c85f2df3d Gitweb: http://git.kernel.org/tip/42503341cde213c5928a19f7c6e1eb8c85f2df3d Author: Denys Vlasenko <dvlas...@redhat.com> AuthorDate: Fri, 13 Mar 2015 15:09:03 +0100 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 16 Mar 2015 11:05:36 +0100
x86/asm/entry: Simplify task_pt_regs() macro definition Before this change, task_pt_regs() was using KSTK_TOP(), and it was the only use of that macro. In turn, KSTK_TOP used THREAD_SIZE_LONGS, and it was the only use of that macro too. Fold these macros into task_pt_regs(). Tweak comment about "- 8" - we now use a symbolic constant, not literal 8. Signed-off-by: Denys Vlasenko <dvlas...@redhat.com> Reviewed-by: Steven Rostedt <rost...@goodmis.org> Cc: Alexei Starovoitov <a...@plumgrid.com> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: H. Peter Anvin <h...@zytor.com> Cc: Kees Cook <keesc...@chromium.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Oleg Nesterov <o...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Will Drewry <w...@chromium.org> Link: http://lkml.kernel.org/r/1426255743-5394-1-git-send-email-dvlas...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/include/asm/processor.h | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index c3a037b..d157f94 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -846,15 +846,8 @@ static inline void spin_lock_prefetch(const void *x) extern unsigned long thread_saved_pc(struct task_struct *tsk); -#define THREAD_SIZE_LONGS (THREAD_SIZE/sizeof(unsigned long)) -#define KSTK_TOP(info) \ -({ \ - unsigned long *__ptr = (unsigned long *)(info); \ - (unsigned long)(&__ptr[THREAD_SIZE_LONGS]); \ -}) - /* - * The below -8 is to reserve 8 bytes on top of the ring0 stack. + * TOP_OF_KERNEL_STACK_PADDING reserves 8 bytes on top of the ring0 stack. * This is necessary to guarantee that the entire "struct pt_regs" * is accessible even if the CPU haven't stored the SS/ESP registers * on the stack (interrupt gate does not save these registers @@ -863,12 +856,11 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk); * "struct pt_regs" is possible, but they may contain the * completely wrong values. */ -#define task_pt_regs(task) \ -({ \ - struct pt_regs *__regs__; \ - __regs__ = (struct pt_regs *)(KSTK_TOP(task_stack_page(task)) - \ - TOP_OF_KERNEL_STACK_PADDING); \ - __regs__ - 1; \ +#define task_pt_regs(task) \ +({ \ + unsigned long __ptr = (unsigned long)task_stack_page(task); \ + __ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; \ + ((struct pt_regs *)__ptr) - 1; \ }) #define KSTK_ESP(task) (task_pt_regs(task)->sp) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
