From e4ff70a8e3352f71b5db52c752a9417402a098c8 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 5 Apr 2024 15:05:50 -0700 Subject: cxl/acpi: Cleanup __cxl_parse_cfmws() 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 Closes: http://lore.kernel.org/r/20240219124041.00002bda@Huawei.com Reviewed-by: Alison Schofield Reviewed-by: Vishal Verma Signed-off-by: Dan Williams Reviewed-by: Jonathan Cameron Link: https://lore.kernel.org/r/171235474028.2718248.14109646123143505522.stgit@dwillia2-xfh.jf.intel.com Signed-off-by: Dave Jiang --- drivers/cxl/acpi.c | 93 ++++++++++++++++++++++++++++++------------------------ drivers/cxl/cxl.h | 5 +++ 2 files changed, 56 insertions(+), 42 deletions(-) (limited to 'drivers/cxl') diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c index cb8c155a2c9b..571069863c62 100644 --- a/drivers/cxl/acpi.c +++ b/drivers/cxl/acpi.c @@ -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; diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h index 2a09db5f72ee..80f58b96dc1c 100644 --- a/drivers/cxl/cxl.h +++ b/drivers/cxl/cxl.h @@ -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); /** -- cgit v1.2.3