From: Lai Jiangshan <la...@linux.alibaba.com>
In x86_64, tss.sp1 is reused as cpu_current_top_of_stack. But we can
directly use percpu since CR3 and gs_base is correct when it is used.
In x86_32, tss.sp1 is resued as thread.sp0 in three places in entry
code. We have the correct CR3 and %fs at two of the places. The last
one is sysenter. This patchset makes %fs available earlier so that
we can also use percpu in sysenter. And add a percpu cpu_current_thread_sp0
for thread.sp0 instead of tss.sp1
Changed from V1
Requested from Andy to also fix sp1 for x86_32.
Update comments in the x86_64 patch as Andy sugguested.
Lai Jiangshan (6):
x86_64: move cpu_current_top_of_stack out of TSS
x86_32: use percpu instead of offset-calculation to get thread.sp0
when SWITCH_TO_KERNEL_STACK
x86_32/sysenter: switch to the task stack without emptying the entry
stack
x86_32/sysenter: restore %fs before switching stack
x86_32/sysenter: use percpu to get thread.sp0 when sysenter
x86_32: use cpu_current_thread_sp0 instead of cpu_tss_rw.x86_tss.sp1
arch/x86/entry/entry_32.S | 38 +++++++++++++++++-------------
arch/x86/include/asm/processor.h | 12 ++--------
arch/x86/include/asm/switch_to.h | 9 ++-----
arch/x86/include/asm/thread_info.h | 6 -----
arch/x86/kernel/asm-offsets.c | 1 -
arch/x86/kernel/asm-offsets_32.c | 10 --------
arch/x86/kernel/cpu/common.c | 12 +++++++++-
arch/x86/kernel/process.c | 7 ------
arch/x86/mm/pti.c | 7 +++---
9 files changed, 40 insertions(+), 62 deletions(-)
--
2.19.1.6.gb485710b
