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authorAndy Lutomirski <luto@amacapital.net>2015-03-05 19:19:04 -0800
committerIngo Molnar <mingo@kernel.org>2015-03-06 08:32:58 +0100
commit9d0c914c60f4d3123debb653340dc1f7cf44939d (patch)
tree41cd00a5332551608057bd6a08d1724a081971f5 /arch/x86/ia32
parent75182b1632a89f12540baa1806a7c5c180db620c (diff)
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 <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/88ff9006163d296a0665338585c36d9bfb85235d.1425611534.git.luto@amacapital.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/ia32')
-rw-r--r--arch/x86/ia32/ia32entry.S3
1 files changed, 1 insertions, 2 deletions
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: