This is a note to let you know that I've just added the patch titled
cxl/hdm: Remove broken error path
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cxl-hdm-remove-broken-error-path.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 959d3364a1d8450077c91d1cee9880a09505c8dc
Author: Dan Williams <dan.j.williams@xxxxxxxxx>
Date: Tue Oct 31 14:09:19 2023 -0700
cxl/hdm: Remove broken error path
[ Upstream commit 5d09c63f11f083707b60c8ea0bb420651c47740f ]
Dan reports that cxl_decoder_commit() potentially leaks a hold of
cxl_dpa_rwsem. The potential error case is a "should not" happen
scenario, turn it into a "can not" happen scenario by adding the error
check to cxl_port_setup_targets() where other setting validation occurs.
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Closes: http://lore.kernel.org/r/63295673-5d63-4919-b851-3b06d48734c0@moroto.mountain
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware")
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 3ad0d39d3d3fa..64e86b786db52 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -575,17 +575,11 @@ static void cxld_set_type(struct cxl_decoder *cxld, u32 *ctrl)
CXL_HDM_DECODER0_CTRL_HOSTONLY);
}
-static int cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
+static void cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
{
struct cxl_dport **t = &cxlsd->target[0];
int ways = cxlsd->cxld.interleave_ways;
- if (dev_WARN_ONCE(&cxlsd->cxld.dev,
- ways > 8 || ways > cxlsd->nr_targets,
- "ways: %d overflows targets: %d\n", ways,
- cxlsd->nr_targets))
- return -ENXIO;
-
*tgt = FIELD_PREP(GENMASK(7, 0), t[0]->port_id);
if (ways > 1)
*tgt |= FIELD_PREP(GENMASK(15, 8), t[1]->port_id);
@@ -601,8 +595,6 @@ static int cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
*tgt |= FIELD_PREP(GENMASK_ULL(55, 48), t[6]->port_id);
if (ways > 7)
*tgt |= FIELD_PREP(GENMASK_ULL(63, 56), t[7]->port_id);
-
- return 0;
}
/*
@@ -689,13 +681,7 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
void __iomem *tl_lo = hdm + CXL_HDM_DECODER0_TL_LOW(id);
u64 targets;
- rc = cxlsd_set_targets(cxlsd, &targets);
- if (rc) {
- dev_dbg(&port->dev, "%s: target configuration error\n",
- dev_name(&cxld->dev));
- goto err;
- }
-
+ cxlsd_set_targets(cxlsd, &targets);
writel(upper_32_bits(targets), tl_hi);
writel(lower_32_bits(targets), tl_lo);
} else {
@@ -713,7 +699,6 @@ static int cxl_decoder_commit(struct cxl_decoder *cxld)
port->commit_end++;
rc = cxld_await_commit(hdm, cxld->id);
-err:
if (rc) {
dev_dbg(&port->dev, "%s: error %d committing decoder\n",
dev_name(&cxld->dev), rc);
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 7392206eb8699..a25f5deb3de51 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -1190,6 +1190,14 @@ static int cxl_port_setup_targets(struct cxl_port *port,
return rc;
}
+ if (iw > 8 || iw > cxlsd->nr_targets) {
+ dev_dbg(&cxlr->dev,
+ "%s:%s:%s: ways: %d overflows targets: %d\n",
+ dev_name(port->uport_dev), dev_name(&port->dev),
+ dev_name(&cxld->dev), iw, cxlsd->nr_targets);
+ return -ENXIO;
+ }
+
if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
if (cxld->interleave_ways != iw ||
cxld->interleave_granularity != ig ||
