From: Mukesh Ojha Date: Thu, 21 Mar 2024 15:24:02 +0000 (+0530) Subject: firmware: qcom: scm: Fix __scm and waitq completion variable initialization X-Git-Tag: v6.8.12~350 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9e1d1cbc2aa809bcce75fdd21499db23fc121f93;p=thirdparty%2Fkernel%2Fstable.git firmware: qcom: scm: Fix __scm and waitq completion variable initialization [ Upstream commit 2e4955167ec5c04534cebea9e8273a907e7a75e1 ] It is possible qcom_scm_is_available() gives wrong indication that if __scm is initialized while __scm->dev is not and similar issue is also possible with __scm->waitq_comp. Fix this appropriately by the use of release barrier and read barrier that will make sure if __scm is initialized so, is all of its field variable. Fixes: d0f6fa7ba2d6 ("firmware: qcom: scm: Convert SCM to platform driver") Fixes: 6bf325992236 ("firmware: qcom: scm: Add wait-queue handling logic") Signed-off-by: Mukesh Ojha Link: https://lore.kernel.org/r/1711034642-22860-4-git-send-email-quic_mojha@quicinc.com Signed-off-by: Bjorn Andersson Signed-off-by: Sasha Levin --- diff --git a/drivers/firmware/qcom/qcom_scm.c b/drivers/firmware/qcom/qcom_scm.c index ca381cb2ee979..29c24578ad2bf 100644 --- a/drivers/firmware/qcom/qcom_scm.c +++ b/drivers/firmware/qcom/qcom_scm.c @@ -1713,7 +1713,7 @@ static int qcom_scm_qseecom_init(struct qcom_scm *scm) */ bool qcom_scm_is_available(void) { - return !!__scm; + return !!READ_ONCE(__scm); } EXPORT_SYMBOL_GPL(qcom_scm_is_available); @@ -1794,10 +1794,12 @@ static int qcom_scm_probe(struct platform_device *pdev) if (!scm) return -ENOMEM; + scm->dev = &pdev->dev; ret = qcom_scm_find_dload_address(&pdev->dev, &scm->dload_mode_addr); if (ret < 0) return ret; + init_completion(&scm->waitq_comp); mutex_init(&scm->scm_bw_lock); scm->path = devm_of_icc_get(&pdev->dev, NULL); @@ -1829,10 +1831,8 @@ static int qcom_scm_probe(struct platform_device *pdev) if (ret) return ret; - __scm = scm; - __scm->dev = &pdev->dev; - - init_completion(&__scm->waitq_comp); + /* Let all above stores be available after this */ + smp_store_release(&__scm, scm); irq = platform_get_irq_optional(pdev, 0); if (irq < 0) {