Commit-ID: ff8287f36381deff729aa4e7b02296a080519fd0 Gitweb: http://git.kernel.org/tip/ff8287f36381deff729aa4e7b02296a080519fd0 Author: Andy Lutomirski <[email protected]> AuthorDate: Thu, 2 Apr 2015 12:41:44 -0700 Committer: Ingo Molnar <[email protected]> CommitDate: Fri, 3 Apr 2015 08:30:44 +0200
x86/asm/entry/32: Improve a TOP_OF_KERNEL_STACK_PADDING comment At Denys' request, clean up the comment describing stack padding in the 32-bit sysenter path. No code changes. Signed-off-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/41fee7bb8490ae840fe7ef2699f9c2feb932e729.1428002830.git.l...@kernel.org Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/kernel/entry_32.S | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 4c8cc34..effa279 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -395,10 +395,13 @@ sysenter_past_esp: /*CFI_REL_OFFSET cs, 0*/ /* * Push current_thread_info()->sysenter_return to the stack. - * A tiny bit of offset fixup is necessary - 4*4 means the 4 words - * pushed above; +8 corresponds to copy_thread's esp0 setting. + * A tiny bit of offset fixup is necessary: TI_sysenter_return + * is relative to thread_info, which is at the bottom of the + * kernel stack page. 4*4 means the 4 words pushed above; + * TOP_OF_KERNEL_STACK_PADDING takes us to the top of the stack; + * and THREAD_SIZE takes us to the bottom. */ - pushl_cfi ((TI_sysenter_return)-THREAD_SIZE+TOP_OF_KERNEL_STACK_PADDING+4*4)(%esp) + pushl_cfi ((TI_sysenter_return) - THREAD_SIZE + TOP_OF_KERNEL_STACK_PADDING + 4*4)(%esp) CFI_REL_OFFSET eip, 0 pushl_cfi %eax -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
