From 9d0c914c60f4d3123debb653340dc1f7cf44939d Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Thu, 5 Mar 2015 19:19:04 -0800 Subject: x86/asm/entry/64/compat: Change the 32-bit sysenter code to use sp0 The ia32 sysenter code loaded the top of the kernel stack into rsp by loading kernel_stack and then adjusting it. It can be simplified to just read sp0 directly. This requires the addition of a new asm-offsets entry for sp0. Signed-off-by: Andy Lutomirski Cc: Borislav Petkov Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/88ff9006163d296a0665338585c36d9bfb85235d.1425611534.git.luto@amacapital.net Signed-off-by: Ingo Molnar --- arch/x86/ia32/ia32entry.S | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'arch/x86/ia32') diff --git a/arch/x86/ia32/ia32entry.S b/arch/x86/ia32/ia32entry.S index ed9746340363..719db63b35c4 100644 --- a/arch/x86/ia32/ia32entry.S +++ b/arch/x86/ia32/ia32entry.S @@ -113,8 +113,7 @@ ENTRY(ia32_sysenter_target) CFI_DEF_CFA rsp,0 CFI_REGISTER rsp,rbp SWAPGS_UNSAFE_STACK - movq PER_CPU_VAR(kernel_stack), %rsp - addq $(KERNEL_STACK_OFFSET),%rsp + movq PER_CPU_VAR(init_tss + TSS_sp0), %rsp /* * No need to follow this irqs on/off section: the syscall * disabled irqs, here we enable it straight after entry: -- cgit v1.2.3