lkml.org 
[lkml]   [2017]   [Jun]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 4.9 016/119] sparc64: reset mm cpumask after wrap
    Date
    4.9-stable review patch.  If anyone has any objections, please let me know.

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

    From: Pavel Tatashin <pasha.tatashin@oracle.com>


    [ Upstream commit 588974857359861891f478a070b1dc7ae04a3880 ]

    After a wrap (getting a new context version) a process must get a new
    context id, which means that we would need to flush the context id from
    the TLB before running for the first time with this ID on every CPU. But,
    we use mm_cpumask to determine if this process has been running on this CPU
    before, and this mask is not reset after a wrap. So, there are two possible
    fixes for this issue:

    1. Clear mm cpumask whenever mm gets a new context id
    2. Unconditionally flush context every time process is running on a CPU

    This patch implements the first solution

    Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
    Reviewed-by: Bob Picco <bob.picco@oracle.com>
    Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    arch/sparc/mm/init_64.c | 2 ++
    1 file changed, 2 insertions(+)

    --- a/arch/sparc/mm/init_64.c
    +++ b/arch/sparc/mm/init_64.c
    @@ -710,6 +710,8 @@ void get_new_mmu_context(struct mm_struc
    goto out;
    }
    }
    + if (mm->context.sparc64_ctx_val)
    + cpumask_clear(mm_cpumask(mm));
    mmu_context_bmap[new_ctx>>6] |= (1UL << (new_ctx & 63));
    new_ctx |= (tlb_context_cache & CTX_VERSION_MASK);
    out:

    \
     
     \ /
      Last update: 2017-06-12 20:55    [W:4.144 / U:0.116 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site