Introduce the infrastructure for the ASI driver. This driver is meant for testing ASI. It creates a test ASI, and will allow to run some test sequences on this ASI.
Signed-off-by: Alexandre Chartre <[email protected]> --- drivers/staging/asi/Makefile | 7 ++ drivers/staging/asi/asidrv.c | 129 +++++++++++++++++++++++++++++++++++ 2 files changed, 136 insertions(+) create mode 100644 drivers/staging/asi/Makefile create mode 100644 drivers/staging/asi/asidrv.c diff --git a/drivers/staging/asi/Makefile b/drivers/staging/asi/Makefile new file mode 100644 index 000000000000..a48487e48d7c --- /dev/null +++ b/drivers/staging/asi/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 + +# +# Address Space Isolation (ASI) driver +# +obj-m += asi.o +asi-y := asidrv.o diff --git a/drivers/staging/asi/asidrv.c b/drivers/staging/asi/asidrv.c new file mode 100644 index 000000000000..c06e4734e0e5 --- /dev/null +++ b/drivers/staging/asi/asidrv.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020, Oracle and/or its affiliates. + */ + +#include <linux/fs.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include <asm/asi.h> +#include <asm/dpt.h> + +struct asidrv_test { + struct asi *asi; /* ASI for testing */ + struct dpt *dpt; /* ASI decorated page-table */ +}; + +static struct asidrv_test *asidrv_test; + +static void asidrv_test_destroy(struct asidrv_test *test); + +static struct asidrv_test *asidrv_test_create(void) +{ + struct asidrv_test *test; + int err; + + test = kzalloc(sizeof(*test), GFP_KERNEL); + if (!test) + return NULL; + + /* + * Create and fill a decorator page-table to be used with the ASI. + */ + test->dpt = dpt_create(ASI_PGTABLE_MASK); + if (!test->dpt) + goto error; + + err = asi_init_dpt(test->dpt); + if (err) + goto error; + + err = DPT_MAP_THIS_MODULE(test->dpt); + if (err) + goto error; + + /* map the asidrv_test as we will access it during the test */ + err = dpt_map(test->dpt, test, sizeof(*test)); + if (err) + goto error; + + test->asi = asi_create_test(); + if (!test->asi) + goto error; + + /* + * By default, the ASI structure is not mapped into the ASI. We + * map it so that we can access it and verify the consistency + * of some values (for example the CR3 value). + */ + err = dpt_map(test->dpt, test->asi, sizeof(*test->asi)); + if (err) + goto error; + + asi_set_pagetable(test->asi, test->dpt->pagetable); + + return test; + +error: + pr_debug("Failed to create ASI Test\n"); + asidrv_test_destroy(test); + return NULL; +} + +static void asidrv_test_destroy(struct asidrv_test *test) +{ + if (!test) + return; + + if (test->dpt) + dpt_destroy(test->dpt); + + if (test->asi) + asi_destroy(test->asi); + + kfree(test); +} + +static const struct file_operations asidrv_fops = { + .owner = THIS_MODULE, +}; + +static struct miscdevice asidrv_miscdev = { + .minor = MISC_DYNAMIC_MINOR, + .name = KBUILD_MODNAME, + .fops = &asidrv_fops, +}; + +static int __init asidrv_init(void) +{ + int err; + + asidrv_test = asidrv_test_create(); + if (!asidrv_test) + return -ENOMEM; + + err = misc_register(&asidrv_miscdev); + if (err) { + asidrv_test_destroy(asidrv_test); + asidrv_test = NULL; + } + + return err; +} + +static void __exit asidrv_exit(void) +{ + asidrv_test_destroy(asidrv_test); + asidrv_test = NULL; + misc_deregister(&asidrv_miscdev); +} + +module_init(asidrv_init); +module_exit(asidrv_exit); + +MODULE_AUTHOR("Alexandre Chartre <[email protected]>"); +MODULE_DESCRIPTION("Privileged interface to ASI"); +MODULE_VERSION("1.0"); +MODULE_LICENSE("GPL v2"); -- 2.18.2
