linux-kernel - [PATCH 5.1 299/405] misc: fastrpc: make sure memory read and writes are visible

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 29 May 2019 20:04:57 -0700
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Srinivas Kandagatla <srinivas.kandagatla@...aro.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.1 299/405] misc: fastrpc: make sure memory read and writes are visible

[ Upstream commit 415a0729bd1225f0ffbc0ba82888dd65772554f7 ]

dma_alloc_coherent buffers could have writes queued in store buffers so
commit them before sending buffer to DSP using correct dma barriers.
Same with vice-versa.

Fixes: c68cfb718c8f ("misc: fastrpc: Add support for context Invoke method")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/misc/fastrpc.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 9996c83ba5cb9..a10937652ca73 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -790,6 +790,9 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
 		if (err)
 			goto bail;
 	}
+
+	/* make sure that all CPU memory writes are seen by DSP */
+	dma_wmb();
 	/* Send invoke buffer to remote dsp */
 	err = fastrpc_invoke_send(fl->sctx, ctx, kernel, handle);
 	if (err)
@@ -806,6 +809,8 @@ static int fastrpc_internal_invoke(struct fastrpc_user *fl,  u32 kernel,
 		goto bail;
 
 	if (ctx->nscalars) {
+		/* make sure that all memory writes by DSP are seen by CPU */
+		dma_rmb();
 		/* populate all the output buffers with results */
 		err = fastrpc_put_args(ctx, kernel);
 		if (err)
-- 
2.20.1