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    Subject[PATCH V6 13/49] x86/entry: Expose the address of .Lgs_change to entry64.c
    Date
    From: Lai Jiangshan <laijs@linux.alibaba.com>

    The address of .Lgs_change will be used in traps.c in later patch when
    some entry code is implemented in entry64.c. So the address of .Lgs_change
    is exposed to traps.c for preparation.

    Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
    ---
    arch/x86/entry/entry64.c | 2 ++
    arch/x86/entry/entry_64.S | 6 +++---
    2 files changed, 5 insertions(+), 3 deletions(-)

    diff --git a/arch/x86/entry/entry64.c b/arch/x86/entry/entry64.c
    index 762595603ce7..9813a30dbadb 100644
    --- a/arch/x86/entry/entry64.c
    +++ b/arch/x86/entry/entry64.c
    @@ -12,3 +12,5 @@
    * is PTI user CR3 or both.
    */
    #include <asm/traps.h>
    +
    +extern unsigned char asm_load_gs_index_gs_change[];
    diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
    index 44774cc5bcc9..5db0196835cd 100644
    --- a/arch/x86/entry/entry_64.S
    +++ b/arch/x86/entry/entry_64.S
    @@ -733,7 +733,7 @@ _ASM_NOKPROBE(common_interrupt_return)
    SYM_FUNC_START(asm_load_gs_index)
    FRAME_BEGIN
    swapgs
    -.Lgs_change:
    +SYM_INNER_LABEL(asm_load_gs_index_gs_change, SYM_L_GLOBAL)
    movl %edi, %gs
    2: ALTERNATIVE "", "mfence", X86_BUG_SWAPGS_FENCE
    swapgs
    @@ -742,7 +742,7 @@ SYM_FUNC_START(asm_load_gs_index)
    SYM_FUNC_END(asm_load_gs_index)
    EXPORT_SYMBOL(asm_load_gs_index)

    - _ASM_EXTABLE(.Lgs_change, .Lbad_gs)
    + _ASM_EXTABLE(asm_load_gs_index_gs_change, .Lbad_gs)
    .section .fixup, "ax"
    /* running with kernelgs */
    SYM_CODE_START_LOCAL_NOALIGN(.Lbad_gs)
    @@ -1008,7 +1008,7 @@ SYM_CODE_START_LOCAL(error_entry)
    movl %ecx, %eax /* zero extend */
    cmpq %rax, RIP+8(%rsp)
    je .Lbstep_iret
    - cmpq $.Lgs_change, RIP+8(%rsp)
    + cmpq $asm_load_gs_index_gs_change, RIP+8(%rsp)
    jne .Lerror_entry_done_lfence

    /*
    --
    2.19.1.6.gb485710b
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