From: Arnd Bergmann Date: Wed, 23 Apr 2025 16:48:16 +0000 (+0200) Subject: iommu/io-pgtable-arm: dynamically allocate selftest device struct X-Git-Tag: v6.16-rc1~110^2^12~10 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fa26198d30f3cdd7627ce47362057848219de765;p=thirdparty%2Fkernel%2Flinux.git iommu/io-pgtable-arm: dynamically allocate selftest device struct In general a 'struct device' is way too large to be put on the kernel stack. Apparently something just caused it to grow a slightly larger, which pushed the arm_lpae_do_selftests() function over the warning limit in some configurations: drivers/iommu/io-pgtable-arm.c:1423:19: error: stack frame size (1032) exceeds limit (1024) in 'arm_lpae_do_selftests' [-Werror,-Wframe-larger-than] 1423 | static int __init arm_lpae_do_selftests(void) | ^ Change the function to use a dynamically allocated faux_device instead of the on-stack device structure. Fixes: ca25ec247aad ("iommu/io-pgtable-arm: Remove iommu_dev==NULL special case") Link: https://lore.kernel.org/all/ab75a444-22a1-47f5-b3c0-253660395b5a@arm.com/ Signed-off-by: Arnd Bergmann Reviewed-by: Robin Murphy Link: https://lore.kernel.org/r/20250423164826.2931382-1-arnd@kernel.org Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index 545229cf62d2d..bbd42323c0290 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -1437,15 +1438,17 @@ static int __init arm_lpae_do_selftests(void) }; int i, j, k, pass = 0, fail = 0; - struct device dev; + struct faux_device *dev; struct io_pgtable_cfg cfg = { .tlb = &dummy_tlb_ops, .coherent_walk = true, - .iommu_dev = &dev, }; - /* __arm_lpae_alloc_pages() merely needs dev_to_node() to work */ - set_dev_node(&dev, NUMA_NO_NODE); + dev = faux_device_create("io-pgtable-test", NULL, 0); + if (!dev) + return -ENOMEM; + + cfg.iommu_dev = &dev->dev; for (i = 0; i < ARRAY_SIZE(pgsize); ++i) { for (j = 0; j < ARRAY_SIZE(address_size); ++j) { @@ -1465,6 +1468,8 @@ static int __init arm_lpae_do_selftests(void) } pr_info("selftest: completed with %d PASS %d FAIL\n", pass, fail); + faux_device_destroy(dev); + return fail ? -EFAULT : 0; } subsys_initcall(arm_lpae_do_selftests);