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    Subject[patch V4 part 3 14/29] x86/entry: Convert Divide Error to IDTENTRY
    From: Thomas Gleixner <tglx@linutronix.de>

    Convert #DE to IDTENTRY:
    - Implement the C entry point with DEFINE_IDTENTRY
    - Emit the ASM stub with DECLARE_IDTENTRY
    - Remove the ASM idtentry in 64bit
    - Remove the open coded ASM entry code in 32bit
    - Fixup the XEN/PV code

    No functional change.

    Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
    Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
    ---
    V2: Add comment to explain the DECLARE_IDTENTRY macro magic at the
    actual usage site.
    ---
    arch/x86/entry/entry_32.S | 7 -------
    arch/x86/entry/entry_64.S | 1 -
    arch/x86/include/asm/idtentry.h | 12 ++++++++++++
    arch/x86/include/asm/traps.h | 3 ---
    arch/x86/kernel/idt.c | 2 +-
    arch/x86/kernel/traps.c | 7 ++++++-
    arch/x86/xen/enlighten_pv.c | 7 ++++++-
    arch/x86/xen/xen-asm_64.S | 2 +-
    8 files changed, 26 insertions(+), 15 deletions(-)

    --- a/arch/x86/entry/entry_32.S
    +++ b/arch/x86/entry/entry_32.S
    @@ -1377,13 +1377,6 @@ SYM_CODE_START(alignment_check)
    jmp common_exception
    SYM_CODE_END(alignment_check)

    -SYM_CODE_START(divide_error)
    - ASM_CLAC
    - pushl $0 # no error code
    - pushl $do_divide_error
    - jmp common_exception
    -SYM_CODE_END(divide_error)
    -
    #ifdef CONFIG_X86_MCE
    SYM_CODE_START(machine_check)
    ASM_CLAC
    --- a/arch/x86/entry/entry_64.S
    +++ b/arch/x86/entry/entry_64.S
    @@ -1073,7 +1073,6 @@ apicinterrupt IRQ_WORK_VECTOR irq_work
    * Exception entry points.
    */

    -idtentry X86_TRAP_DE divide_error do_divide_error has_error_code=0
    idtentry X86_TRAP_OF overflow do_overflow has_error_code=0
    idtentry X86_TRAP_BP int3 do_int3 has_error_code=0
    idtentry X86_TRAP_BR bounds do_bounds has_error_code=0
    --- a/arch/x86/include/asm/idtentry.h
    +++ b/arch/x86/include/asm/idtentry.h
    @@ -67,4 +67,16 @@ static __always_inline void __##func(str

    #endif /* __ASSEMBLY__ */

    +/*
    + * The actual entry points. Note that DECLARE_IDTENTRY*() serves two
    + * purposes:
    + * - provide the function declarations when included from C-Code
    + * - emit the ASM stubs when included from entry_32/64.S
    + *
    + * This avoids duplicate defines and ensures that everything is consistent.
    + */
    +
    +/* Simple exception entry points. No hardware error code */
    +DECLARE_IDTENTRY(X86_TRAP_DE, exc_divide_error);
    +
    #endif
    --- a/arch/x86/include/asm/traps.h
    +++ b/arch/x86/include/asm/traps.h
    @@ -11,7 +11,6 @@

    #define dotraplinkage __visible

    -asmlinkage void divide_error(void);
    asmlinkage void debug(void);
    asmlinkage void nmi(void);
    asmlinkage void int3(void);
    @@ -38,7 +37,6 @@ asmlinkage void machine_check(void);
    asmlinkage void simd_coprocessor_error(void);

    #if defined(CONFIG_X86_64) && defined(CONFIG_XEN_PV)
    -asmlinkage void xen_divide_error(void);
    asmlinkage void xen_xennmi(void);
    asmlinkage void xen_xendebug(void);
    asmlinkage void xen_int3(void);
    @@ -62,7 +60,6 @@ asmlinkage void xen_machine_check(void);
    asmlinkage void xen_simd_coprocessor_error(void);
    #endif

    -dotraplinkage void do_divide_error(struct pt_regs *regs, long error_code);
    dotraplinkage void do_debug(struct pt_regs *regs, long error_code);
    dotraplinkage void do_nmi(struct pt_regs *regs, long error_code);
    dotraplinkage void do_int3(struct pt_regs *regs, long error_code);
    --- a/arch/x86/kernel/idt.c
    +++ b/arch/x86/kernel/idt.c
    @@ -70,7 +70,7 @@ static const __initconst struct idt_data
    * set up TSS.
    */
    static const __initconst struct idt_data def_idts[] = {
    - INTG(X86_TRAP_DE, divide_error),
    + INTG(X86_TRAP_DE, asm_exc_divide_error),
    INTG(X86_TRAP_NMI, nmi),
    INTG(X86_TRAP_BR, bounds),
    INTG(X86_TRAP_UD, invalid_op),
    --- a/arch/x86/kernel/traps.c
    +++ b/arch/x86/kernel/traps.c
    @@ -210,6 +210,12 @@ static __always_inline void __user *erro
    return (void __user *)uprobe_get_trap_addr(regs);
    }

    +DEFINE_IDTENTRY(exc_divide_error)
    +{
    + do_error_trap(regs, 0, "divide_error", X86_TRAP_DE, SIGFPE,
    + FPE_INTDIV, error_get_trap_addr(regs));
    +}
    +
    #define IP ((void __user *)uprobe_get_trap_addr(regs))
    #define DO_ERROR(trapnr, signr, sicode, addr, str, name) \
    dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
    @@ -217,7 +223,6 @@ dotraplinkage void do_##name(struct pt_r
    do_error_trap(regs, error_code, str, trapnr, signr, sicode, addr); \
    }

    -DO_ERROR(X86_TRAP_DE, SIGFPE, FPE_INTDIV, IP, "divide error", divide_error)
    DO_ERROR(X86_TRAP_OF, SIGSEGV, 0, NULL, "overflow", overflow)
    DO_ERROR(X86_TRAP_UD, SIGILL, ILL_ILLOPN, IP, "invalid opcode", invalid_op)
    DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, 0, NULL, "coprocessor segment overrun", coprocessor_segment_overrun)
    --- a/arch/x86/xen/enlighten_pv.c
    +++ b/arch/x86/xen/enlighten_pv.c
    @@ -605,6 +605,11 @@ struct trap_array_entry {
    bool ist_okay;
    };

    +#define TRAP_ENTRY(func, ist_ok) { \
    + .orig = asm_##func, \
    + .xen = xen_asm_##func, \
    + .ist_okay = ist_ok }
    +
    static struct trap_array_entry trap_array[] = {
    { debug, xen_xendebug, true },
    { double_fault, xen_double_fault, true },
    @@ -618,7 +623,7 @@ static struct trap_array_entry trap_arra
    { entry_INT80_compat, xen_entry_INT80_compat, false },
    #endif
    { page_fault, xen_page_fault, false },
    - { divide_error, xen_divide_error, false },
    + TRAP_ENTRY(exc_divide_error, false ),
    { bounds, xen_bounds, false },
    { invalid_op, xen_invalid_op, false },
    { device_not_available, xen_device_not_available, false },
    --- a/arch/x86/xen/xen-asm_64.S
    +++ b/arch/x86/xen/xen-asm_64.S
    @@ -28,7 +28,7 @@ SYM_CODE_END(xen_\name)
    _ASM_NOKPROBE(xen_\name)
    .endm

    -xen_pv_trap divide_error
    +xen_pv_trap asm_exc_divide_error
    xen_pv_trap debug
    xen_pv_trap xendebug
    xen_pv_trap int3
    \
     
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