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cxl/acpi: Cleanup __cxl_parse_cfmws()

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As a follow on to the recent rework of __cxl_parse_cfmws() to always
return errors [1], use cleanup.h helpers to remove goto and other cleanups
now that logging is moved to the cxl_parse_cfmws() wrapper.

This ends up adding more code than it deletes, but __cxl_parse_cfmws()
itself does get smaller. The takeaway from the cond_no_free_ptr()
discussion [2] was to not add new macros to handle the cases where
no_free_ptr() is awkward, instead rework the code to have helpers and
clearer delineation of responsibility.

Now one might say that  __free(del_cxl_resource) is excessive given it
is immediately registered with add_or_reset_cxl_resource(). The
rationale for keeping it is that it forces use of "no_free_ptr()" on the
argument passed to add_or_reset_cxl_resource(). That in turn makes it
clear that @res is NULL for the rest of the function which is part of
the point of the cleanup helpers, to turn subtle use after free errors
[3] into loud NULL pointer de-references.

Link: http://lore.kernel.org/r/170820177238.631006.1012639681618409284.stgit@dwillia2-xfh.jf.intel.com [1]
Link: http://lore.kernel.org/r/CAHk-=whBVhnh=KSeBBRet=E7qJAwnPR_aj5em187Q3FiD+LXnA@mail.gmail.com [2]
Link: http://lore.kernel.org/r/20230714093146.2253438-1-leitao@debian.org [3]
Reported-by: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Closes: http://lore.kernel.org/r/20240219124041.00002bda@Huawei.com
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/171235474028.2718248.14109646123143505522.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
This commit is contained in:
Dan Williams 2024-04-05 15:05:50 -07:00 committed by Dave Jiang
parent 1c987cf22d
commit e4ff70a8e3
2 changed files with 56 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

93
drivers/cxl/acpi.c
View File

@ -316,28 +316,59 @@ static const struct cxl_root_ops acpi_root_ops = {
.qos_class = cxl_acpi_qos_class,
};
static void del_cxl_resource(struct resource *res)
{
if (!res)
return;
kfree(res->name);
kfree(res);
}
static struct resource *alloc_cxl_resource(resource_size_t base,
resource_size_t n, int id)
{
struct resource *res __free(kfree) = kzalloc(sizeof(*res), GFP_KERNEL);
if (!res)
return NULL;
res->start = base;
res->end = base + n - 1;
res->flags = IORESOURCE_MEM;
res->name = kasprintf(GFP_KERNEL, "CXL Window %d", id);
if (!res->name)
return NULL;
return no_free_ptr(res);
}
static int add_or_reset_cxl_resource(struct resource *parent, struct resource *res)
{
int rc = insert_resource(parent, res);
if (rc)
del_cxl_resource(res);
return rc;
}
DEFINE_FREE(put_cxlrd, struct cxl_root_decoder *,
if (!IS_ERR_OR_NULL(_T)) put_device(&_T->cxlsd.cxld.dev))
DEFINE_FREE(del_cxl_resource, struct resource *, if (_T) del_cxl_resource(_T))
static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
struct cxl_cfmws_context *ctx)
{
int target_map[CXL_DECODER_MAX_INTERLEAVE];
struct cxl_port *root_port = ctx->root_port;
struct resource *cxl_res = ctx->cxl_res;
struct cxl_cxims_context cxims_ctx;
struct cxl_root_decoder *cxlrd;
struct device *dev = ctx->dev;
cxl_calc_hb_fn cxl_calc_hb;
struct cxl_decoder *cxld;
unsigned int ways, i, ig;
struct resource *res;
int rc;
rc = cxl_acpi_cfmws_verify(dev, cfmws);
if (rc) {
dev_err(dev, "CFMWS range %#llx-%#llx not registered\n",
cfmws->base_hpa,
cfmws->base_hpa + cfmws->window_size - 1);
if (rc)
return rc;
}
rc = eiw_to_ways(cfmws->interleave_ways, &ways);
if (rc)
@ -348,29 +379,23 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
for (i = 0; i < ways; i++)
target_map[i] = cfmws->interleave_targets[i];
res = kzalloc(sizeof(*res), GFP_KERNEL);
struct resource *res __free(del_cxl_resource) = alloc_cxl_resource(
cfmws->base_hpa, cfmws->window_size, ctx->id++);
if (!res)
return -ENOMEM;
res->name = kasprintf(GFP_KERNEL, "CXL Window %d", ctx->id++);
if (!res->name)
goto err_name;
res->start = cfmws->base_hpa;
res->end = cfmws->base_hpa + cfmws->window_size - 1;
res->flags = IORESOURCE_MEM;
/* add to the local resource tracking to establish a sort order */
rc = insert_resource(cxl_res, res);
rc = add_or_reset_cxl_resource(ctx->cxl_res, no_free_ptr(res));
if (rc)
goto err_insert;
return rc;
if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_MODULO)
cxl_calc_hb = cxl_hb_modulo;
else
cxl_calc_hb = cxl_hb_xor;
cxlrd = cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb);
struct cxl_root_decoder *cxlrd __free(put_cxlrd) =
cxl_root_decoder_alloc(root_port, ways, cxl_calc_hb);
if (IS_ERR(cxlrd))
return PTR_ERR(cxlrd);
@ -378,8 +403,8 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
cxld->flags = cfmws_to_decoder_flags(cfmws->restrictions);
cxld->target_type = CXL_DECODER_HOSTONLYMEM;
cxld->hpa_range = (struct range) {
.start = res->start,
.end = res->end,
.start = cfmws->base_hpa,
.end = cfmws->base_hpa + cfmws->window_size - 1,
};
cxld->interleave_ways = ways;
/*
@ -399,11 +424,10 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
rc = acpi_table_parse_cedt(ACPI_CEDT_TYPE_CXIMS,
cxl_parse_cxims, &cxims_ctx);
if (rc < 0)
goto err_xormap;
return rc;
if (!cxlrd->platform_data) {
dev_err(dev, "No CXIMS for HBIG %u\n", ig);
rc = -EINVAL;
goto err_xormap;
return -EINVAL;
}
}
}
@ -411,18 +435,9 @@ static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
cxlrd->qos_class = cfmws->qtg_id;
rc = cxl_decoder_add(cxld, target_map);
err_xormap:
if (rc)
put_device(&cxld->dev);
else
rc = cxl_decoder_autoremove(dev, cxld);
return rc;
err_insert:
kfree(res->name);
err_name:
kfree(res);
return -ENOMEM;
return rc;
return cxl_root_decoder_autoremove(dev, no_free_ptr(cxlrd));
}
static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
@ -683,12 +698,6 @@ static void cxl_acpi_lock_reset_class(void *dev)
device_lock_reset_class(dev);
}
static void del_cxl_resource(struct resource *res)
{
kfree(res->name);
kfree(res);
}
static void cxl_set_public_resource(struct resource *priv, struct resource *pub)
{
priv->desc = (unsigned long) pub;

5
drivers/cxl/cxl.h
View File

@ -781,6 +781,11 @@ int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port);
int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map);
int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld);
static inline int cxl_root_decoder_autoremove(struct device *host,
struct cxl_root_decoder *cxlrd)
{
return cxl_decoder_autoremove(host, &cxlrd->cxlsd.cxld);
}
int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint);
/**