From a6b07d825750f76eeb2972c70a8f0e6e62566954 Mon Sep 17 00:00:00 2001 From: Michael Neuling Date: Wed, 27 May 2015 16:07:11 +1000 Subject: [PATCH] cxl: Only check pid for userspace contexts We only need to check the pid attached to this context for userspace contexts. Kernel contexts can skip this check. Signed-off-by: Michael Neuling Acked-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/fault.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-) diff --git a/drivers/misc/cxl/fault.c b/drivers/misc/cxl/fault.c index 5286b8b704f5..25a5418c55cb 100644 --- a/drivers/misc/cxl/fault.c +++ b/drivers/misc/cxl/fault.c @@ -172,8 +172,8 @@ void cxl_handle_fault(struct work_struct *fault_work) container_of(fault_work, struct cxl_context, fault_work); u64 dsisr = ctx->dsisr; u64 dar = ctx->dar; - struct task_struct *task; - struct mm_struct *mm; + struct task_struct *task = NULL; + struct mm_struct *mm = NULL; if (cxl_p2n_read(ctx->afu, CXL_PSL_DSISR_An) != dsisr || cxl_p2n_read(ctx->afu, CXL_PSL_DAR_An) != dar || @@ -194,17 +194,19 @@ void cxl_handle_fault(struct work_struct *fault_work) pr_devel("CXL BOTTOM HALF handling fault for afu pe: %i. " "DSISR: %#llx DAR: %#llx\n", ctx->pe, dsisr, dar); - if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) { - pr_devel("cxl_handle_fault unable to get task %i\n", - pid_nr(ctx->pid)); - cxl_ack_ae(ctx); - return; - } - if (!(mm = get_task_mm(task))) { - pr_devel("cxl_handle_fault unable to get mm %i\n", - pid_nr(ctx->pid)); - cxl_ack_ae(ctx); - goto out; + if (!ctx->kernel) { + if (!(task = get_pid_task(ctx->pid, PIDTYPE_PID))) { + pr_devel("cxl_handle_fault unable to get task %i\n", + pid_nr(ctx->pid)); + cxl_ack_ae(ctx); + return; + } + if (!(mm = get_task_mm(task))) { + pr_devel("cxl_handle_fault unable to get mm %i\n", + pid_nr(ctx->pid)); + cxl_ack_ae(ctx); + goto out; + } } if (dsisr & CXL_PSL_DSISR_An_DS) @@ -214,9 +216,11 @@ void cxl_handle_fault(struct work_struct *fault_work) else WARN(1, "cxl_handle_fault has nothing to handle\n"); - mmput(mm); + if (mm) + mmput(mm); out: - put_task_struct(task); + if (task) + put_task_struct(task); } static void cxl_prefault_one(struct cxl_context *ctx, u64 ea) -- 2.20.1