From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id A88621A0612 for ; Tue, 19 May 2015 21:23:20 +1000 (AEST) From: Michael Neuling To: mpe@ellerman.id.au, benh@kernel.crashing.org Subject: [PATCH 13/19] cxl: Only check pid for userspace contexts Date: Tue, 19 May 2015 21:22:30 +1000 Message-Id: <1432034556-32400-14-git-send-email-mikey@neuling.org> In-Reply-To: <1432034556-32400-1-git-send-email-mikey@neuling.org> References: <1432034556-32400-1-git-send-email-mikey@neuling.org> Cc: mikey@neuling.org, "Matthew R. Ochs" , imunsie@au.ibm.com, linuxppc-dev@ozlabs.org, "Manoj N. Kumar" , brking@linux.vnet.ibm.com, Daniel Axtens List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- 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 5286b8b..25a5418 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) -- 2.1.0