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    Subject[PATCH 1/1] arm: fault.c: correct how the tsk->[maj|min]_flt gets incremented
    Date
    commit 8878a539ff19a43cf3729e7562cd528f490246ae was done by me
    to make the page fault handler retryable as well as interruptible.

    Due to this commit, there is a mistake in the way in which
    tsk->[maj|min]_flt counter gets incremented for VM_FAULT_ERROR:
    If VM_FAULT_ERROR is returned in the fault flags by handle_mm_fault,
    then either maj_flt or min_flt will get incremented. This is wrong
    as in the case of a VM_FAULT_ERROR we need to be skip ahead to the
    error handling code in do_page_fault.

    Added a check after the call to __do_page_fault() to check for
    (fault & VM_FAULT_ERROR).

    Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
    ---
    arch/arm/mm/fault.c | 2 +-
    1 files changed, 1 insertions(+), 1 deletions(-)

    diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
    index bb7eac3..ec8c88b 100644
    --- a/arch/arm/mm/fault.c
    +++ b/arch/arm/mm/fault.c
    @@ -318,7 +318,7 @@ retry:
    */

    perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
    - if (flags & FAULT_FLAG_ALLOW_RETRY) {
    + if (!(fault & VM_FAULT_ERROR) && (flags & FAULT_FLAG_ALLOW_RETRY)) {
    if (fault & VM_FAULT_MAJOR) {
    tsk->maj_flt++;
    perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1,
    --
    1.7.5.4


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