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    Subject[PATCH 4.14 249/293] powerpc/xmon: Fix disabling tracing while in xmon
    Date
    [ Upstream commit aaf06665f7ea3ee9f9754e16c1a507a89f1de5b1 ]

    Commit ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering
    xmon") added code to disable recording trace entries while in xmon. The
    commit introduced a variable 'tracing_enabled' to record if tracing was
    enabled on xmon entry, and used this to conditionally enable tracing
    during exit from xmon.

    However, we are not checking the value of 'fromipi' variable in
    xmon_core() when setting 'tracing_enabled'. Due to this, when secondary
    cpus enter xmon, they will see tracing as being disabled already and
    tracing won't be re-enabled on exit. Fix the same.

    Fixes: ed49f7fd6438d ("powerpc/xmon: Disable tracing when entering xmon")
    Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
    Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    arch/powerpc/xmon/xmon.c | 6 ++++--
    1 file changed, 4 insertions(+), 2 deletions(-)

    diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
    index f752f771f29d..6b9038a3e79f 100644
    --- a/arch/powerpc/xmon/xmon.c
    +++ b/arch/powerpc/xmon/xmon.c
    @@ -465,8 +465,10 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
    local_irq_save(flags);
    hard_irq_disable();

    - tracing_enabled = tracing_is_on();
    - tracing_off();
    + if (!fromipi) {
    + tracing_enabled = tracing_is_on();
    + tracing_off();
    + }

    bp = in_breakpoint_table(regs->nip, &offset);
    if (bp != NULL) {
    --
    2.20.1


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