lkml.org 
[lkml]   [2018]   [Jun]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v5 7/9] x86: extable: use macros instead of inline assembly
    Date
    Use assembly macros for exception-tables and call them from inline
    assembly. This not only makes the code more readable and allows to
    avoid the duplicate implementation, but also improves compilation
    decision, specifically inline decisions which GCC base on the number of
    new lines in inline assembly.

    text data bss dec hex filename
    18162555 10226288 2957312 31346155 1de4deb ./vmlinux before
    18162879 10226256 2957312 31346447 1de4f0f ./vmlinux after (+292)

    This allows to inline functions such as nested_vmx_exit_reflected(),
    set_segment_reg(), __copy_xstate_to_user().

    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Ingo Molnar <mingo@redhat.com>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: x86@kernel.org
    Cc: Josh Poimboeuf <jpoimboe@redhat.com>

    Signed-off-by: Nadav Amit <namit@vmware.com>
    ---
    arch/x86/include/asm/asm.h | 61 +++++++++++++++++---------------------
    arch/x86/kernel/macros.S | 1 +
    2 files changed, 28 insertions(+), 34 deletions(-)

    diff --git a/arch/x86/include/asm/asm.h b/arch/x86/include/asm/asm.h
    index 219faaec51df..30bc1b0058ef 100644
    --- a/arch/x86/include/asm/asm.h
    +++ b/arch/x86/include/asm/asm.h
    @@ -58,28 +58,44 @@
    # define CC_OUT(c) [_cc_ ## c] "=qm"
    #endif

    -/* Exception table entry */
    #ifdef __ASSEMBLY__
    # define _ASM_EXTABLE_HANDLE(from, to, handler) \
    - .pushsection "__ex_table","a" ; \
    - .balign 4 ; \
    - .long (from) - . ; \
    - .long (to) - . ; \
    - .long (handler) - . ; \
    - .popsection
    + ASM_EXTABLE_HANDLE from to handler
    +
    +#else /* __ASSEMBLY__ */
    +
    +# define _ASM_EXTABLE_HANDLE(from, to, handler) \
    + "ASM_EXTABLE_HANDLE from=" #from " to=" #to \
    + " handler=\"" #handler "\"\n\t"
    +
    +/* For C file, we already have NOKPROBE_SYMBOL macro */
    +
    +#endif /* __ASSEMBLY__ */

    -# define _ASM_EXTABLE(from, to) \
    +#define _ASM_EXTABLE(from, to) \
    _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)

    -# define _ASM_EXTABLE_FAULT(from, to) \
    +#define _ASM_EXTABLE_FAULT(from, to) \
    _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)

    -# define _ASM_EXTABLE_EX(from, to) \
    +#define _ASM_EXTABLE_EX(from, to) \
    _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)

    -# define _ASM_EXTABLE_REFCOUNT(from, to) \
    +#define _ASM_EXTABLE_REFCOUNT(from, to) \
    _ASM_EXTABLE_HANDLE(from, to, ex_handler_refcount)

    +/* Exception table entry */
    +#ifdef __ASSEMBLY__
    +
    +.macro ASM_EXTABLE_HANDLE from:req to:req handler:req
    + .pushsection "__ex_table","a"
    + .balign 4
    + .long (\from) - .
    + .long (\to) - .
    + .long (\handler) - .
    + .popsection
    +.endm
    +
    # define _ASM_NOKPROBE(entry) \
    .pushsection "_kprobe_blacklist","aw" ; \
    _ASM_ALIGN ; \
    @@ -110,29 +126,6 @@
    _ASM_EXTABLE(101b,103b)
    .endm

    -#else
    -# define _EXPAND_EXTABLE_HANDLE(x) #x
    -# define _ASM_EXTABLE_HANDLE(from, to, handler) \
    - " .pushsection \"__ex_table\",\"a\"\n" \
    - " .balign 4\n" \
    - " .long (" #from ") - .\n" \
    - " .long (" #to ") - .\n" \
    - " .long (" _EXPAND_EXTABLE_HANDLE(handler) ") - .\n" \
    - " .popsection\n"
    -
    -# define _ASM_EXTABLE(from, to) \
    - _ASM_EXTABLE_HANDLE(from, to, ex_handler_default)
    -
    -# define _ASM_EXTABLE_FAULT(from, to) \
    - _ASM_EXTABLE_HANDLE(from, to, ex_handler_fault)
    -
    -# define _ASM_EXTABLE_EX(from, to) \
    - _ASM_EXTABLE_HANDLE(from, to, ex_handler_ext)
    -
    -# define _ASM_EXTABLE_REFCOUNT(from, to) \
    - _ASM_EXTABLE_HANDLE(from, to, ex_handler_refcount)
    -
    -/* For C file, we already have NOKPROBE_SYMBOL macro */
    #endif

    #ifndef __ASSEMBLY__
    diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S
    index 71d8b716b111..7baa40d5bf16 100644
    --- a/arch/x86/kernel/macros.S
    +++ b/arch/x86/kernel/macros.S
    @@ -11,3 +11,4 @@
    #include <asm/alternative-asm.h>
    #include <asm/bug.h>
    #include <asm/paravirt.h>
    +#include <asm/asm.h>
    --
    2.17.0
    \
     
     \ /
      Last update: 2018-06-20 05:04    [W:3.284 / U:0.908 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site