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    Subject[PATCH 3.18 26/38] MIPS: End asm function prologue macros with .insn
    Date
    3.18-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Paul Burton <paul.burton@imgtec.com>


    [ Upstream commit 08889582b8aa0bbc01a1e5a0033b9f98d2e11caa ]

    When building a kernel targeting a microMIPS ISA, recent GNU linkers
    will fail the link if they cannot determine that the target of a branch
    or jump is microMIPS code, with errors such as the following:

    mips-img-linux-gnu-ld: arch/mips/built-in.o: .text+0x542c:
    Unsupported jump between ISA modes; consider recompiling with
    interlinking enabled.
    mips-img-linux-gnu-ld: final link failed: Bad value

    or:

    ./arch/mips/include/asm/uaccess.h:1017: warning: JALX to a
    non-word-aligned address

    Placing anything other than an instruction at the start of a function
    written in assembly appears to trigger such errors. In order to prepare
    for allowing us to follow function prologue macros with an EXPORT_SYMBOL
    invocation, end the prologue macros (LEAD, NESTED & FEXPORT) with a
    .insn directive. This ensures that the start of the function is marked
    as code, which always makes sense for functions & safely prevents us
    from hitting the link errors described above.

    Signed-off-by: Paul Burton <paul.burton@imgtec.com>
    Reviewed-by: Maciej W. Rozycki <macro@imgtec.com>
    Cc: linux-mips@linux-mips.org
    Patchwork: https://patchwork.linux-mips.org/patch/14508/
    Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
    Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    arch/mips/include/asm/asm.h | 10 ++++++----
    1 file changed, 6 insertions(+), 4 deletions(-)

    --- a/arch/mips/include/asm/asm.h
    +++ b/arch/mips/include/asm/asm.h
    @@ -54,7 +54,8 @@
    .align 2; \
    .type symbol, @function; \
    .ent symbol, 0; \
    -symbol: .frame sp, 0, ra
    +symbol: .frame sp, 0, ra; \
    + .insn

    /*
    * NESTED - declare nested routine entry point
    @@ -63,8 +64,9 @@ symbol: .frame sp, 0, ra
    .globl symbol; \
    .align 2; \
    .type symbol, @function; \
    - .ent symbol, 0; \
    -symbol: .frame sp, framesize, rpc
    + .ent symbol, 0; \
    +symbol: .frame sp, framesize, rpc; \
    + .insn

    /*
    * END - mark end of function
    @@ -86,7 +88,7 @@ symbol:
    #define FEXPORT(symbol) \
    .globl symbol; \
    .type symbol, @function; \
    -symbol:
    +symbol: .insn

    /*
    * ABS - export absolute symbol

    \
     
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