lkml.org 
[lkml]   [2017]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.4 21/28] powerpc/64: Fix flush_(d|i)cache_range() called from modules
    Date
    4.4-stable review patch.  If anyone has any objections, please let me know.

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

    From: Oliver O'Halloran <oohall@gmail.com>

    commit 8f5f525d5b83f7d76a6baf9c4e94d4bf312ea7f6 upstream.

    When the kernel is compiled to use 64bit ABIv2 the _GLOBAL() macro does
    not include a global entry point. A function's global entry point is
    used when the function is called from a different TOC context and in the
    kernel this typically means a call from a module into the vmlinux (or
    vice-versa).

    There are a few exported asm functions declared with _GLOBAL() and
    calling them from a module will likely crash the kernel since any TOC
    relative load will yield garbage.

    flush_icache_range() and flush_dcache_range() are both exported to
    modules, and use the TOC, so must use _GLOBAL_TOC().

    Fixes: 721aeaa9fdf3 ("powerpc: Build little endian ppc64 kernel with ABIv2")
    Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>


    ---
    arch/powerpc/kernel/misc_64.S | 5 ++++-
    1 file changed, 4 insertions(+), 1 deletion(-)

    --- a/arch/powerpc/kernel/misc_64.S
    +++ b/arch/powerpc/kernel/misc_64.S
    @@ -67,6 +67,9 @@ PPC64_CACHES:
    */

    _KPROBE(flush_icache_range)
    +0: addis r2,r12,(.TOC. - 0b)@ha
    + addi r2, r2,(.TOC. - 0b)@l
    + .localentry flush_icache_range, . - flush_icache_range
    BEGIN_FTR_SECTION
    PURGE_PREFETCHED_INS
    blr
    @@ -117,7 +120,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_I
    *
    * flush all bytes from start to stop-1 inclusive
    */
    -_GLOBAL(flush_dcache_range)
    +_GLOBAL_TOC(flush_dcache_range)

    /*
    * Flush the data cache to memory

    \
     
     \ /
      Last update: 2017-04-25 17:11    [W:4.277 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site