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x86: set %fs to __KERNEL_PERCPU unconditionally for x86_32

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Impact: cleanup

%fs is currently set to __KERNEL_DS at boot, and conditionally
switched to __KERNEL_PERCPU for secondary cpus.  Instead, initialize
GDT_ENTRY_PERCPU to the same attributes as GDT_ENTRY_KERNEL_DS and
set %fs to __KERNEL_PERCPU unconditionally.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Brian Gerst
2009-01-21 17:26:05 +09:00
committed by Tejun Heo
parent 299e26992a
commit 0dd76d736e
2 changed files with 4 additions and 4 deletions
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6
arch/x86/kernel/head_32.S
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@@ -429,12 +429,14 @@ is386: movl $2,%ecx # set MP
ljmp $(__KERNEL_CS),$1f
1: movl $(__KERNEL_DS),%eax # reload all the segment registers
movl %eax,%ss # after changing gdt.
movl %eax,%fs # gets reset once there's real percpu
movl $(__USER_DS),%eax # DS/ES contains default USER segment
movl %eax,%ds
movl %eax,%es
movl $(__KERNEL_PERCPU), %eax
movl %eax,%fs # set this cpu's percpu
xorl %eax,%eax # Clear GS and LDT
movl %eax,%gs
lldt %ax
@@ -446,8 +448,6 @@ is386: movl $2,%ecx # set MP
movb $1, ready
cmpb $0,%cl # the first CPU calls start_kernel
je 1f
movl $(__KERNEL_PERCPU), %eax
movl %eax,%fs # set this cpu's percpu
movl (stack_start), %esp
1:
#endif /* CONFIG_SMP */