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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /lib/livepatch/test_klp_shadow_vars.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/livepatch/test_klp_shadow_vars.c')
-rw-r--r-- | lib/livepatch/test_klp_shadow_vars.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/lib/livepatch/test_klp_shadow_vars.c b/lib/livepatch/test_klp_shadow_vars.c new file mode 100644 index 000000000..b99116490 --- /dev/null +++ b/lib/livepatch/test_klp_shadow_vars.c @@ -0,0 +1,301 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2018 Joe Lawrence <joe.lawrence@redhat.com> + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/livepatch.h> +#include <linux/slab.h> + +/* + * Keep a small list of pointers so that we can print address-agnostic + * pointer values. Use a rolling integer count to differentiate the values. + * Ironically we could have used the shadow variable API to do this, but + * let's not lean too heavily on the very code we're testing. + */ +static LIST_HEAD(ptr_list); +struct shadow_ptr { + void *ptr; + int id; + struct list_head list; +}; + +static void free_ptr_list(void) +{ + struct shadow_ptr *sp, *tmp_sp; + + list_for_each_entry_safe(sp, tmp_sp, &ptr_list, list) { + list_del(&sp->list); + kfree(sp); + } +} + +static int ptr_id(void *ptr) +{ + struct shadow_ptr *sp; + static int count; + + list_for_each_entry(sp, &ptr_list, list) { + if (sp->ptr == ptr) + return sp->id; + } + + sp = kmalloc(sizeof(*sp), GFP_ATOMIC); + if (!sp) + return -ENOMEM; + sp->ptr = ptr; + sp->id = count++; + + list_add(&sp->list, &ptr_list); + + return sp->id; +} + +/* + * Shadow variable wrapper functions that echo the function and arguments + * to the kernel log for testing verification. Don't display raw pointers, + * but use the ptr_id() value instead. + */ +static void *shadow_get(void *obj, unsigned long id) +{ + int **sv; + + sv = klp_shadow_get(obj, id); + pr_info("klp_%s(obj=PTR%d, id=0x%lx) = PTR%d\n", + __func__, ptr_id(obj), id, ptr_id(sv)); + + return sv; +} + +static void *shadow_alloc(void *obj, unsigned long id, size_t size, + gfp_t gfp_flags, klp_shadow_ctor_t ctor, + void *ctor_data) +{ + int **var = ctor_data; + int **sv; + + sv = klp_shadow_alloc(obj, id, size, gfp_flags, ctor, var); + pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n", + __func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor), + ptr_id(*var), ptr_id(sv)); + + return sv; +} + +static void *shadow_get_or_alloc(void *obj, unsigned long id, size_t size, + gfp_t gfp_flags, klp_shadow_ctor_t ctor, + void *ctor_data) +{ + int **var = ctor_data; + int **sv; + + sv = klp_shadow_get_or_alloc(obj, id, size, gfp_flags, ctor, var); + pr_info("klp_%s(obj=PTR%d, id=0x%lx, size=%zx, gfp_flags=%pGg), ctor=PTR%d, ctor_data=PTR%d = PTR%d\n", + __func__, ptr_id(obj), id, size, &gfp_flags, ptr_id(ctor), + ptr_id(*var), ptr_id(sv)); + + return sv; +} + +static void shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor) +{ + klp_shadow_free(obj, id, dtor); + pr_info("klp_%s(obj=PTR%d, id=0x%lx, dtor=PTR%d)\n", + __func__, ptr_id(obj), id, ptr_id(dtor)); +} + +static void shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor) +{ + klp_shadow_free_all(id, dtor); + pr_info("klp_%s(id=0x%lx, dtor=PTR%d)\n", __func__, id, ptr_id(dtor)); +} + + +/* Shadow variable constructor - remember simple pointer data */ +static int shadow_ctor(void *obj, void *shadow_data, void *ctor_data) +{ + int **sv = shadow_data; + int **var = ctor_data; + + if (!var) + return -EINVAL; + + *sv = *var; + pr_info("%s: PTR%d -> PTR%d\n", __func__, ptr_id(sv), ptr_id(*var)); + + return 0; +} + +/* + * With more than one item to free in the list, order is not determined and + * shadow_dtor will not be passed to shadow_free_all() which would make the + * test fail. (see pass 6) + */ +static void shadow_dtor(void *obj, void *shadow_data) +{ + int **sv = shadow_data; + + pr_info("%s(obj=PTR%d, shadow_data=PTR%d)\n", + __func__, ptr_id(obj), ptr_id(sv)); +} + +/* number of objects we simulate that need shadow vars */ +#define NUM_OBJS 3 + +/* dynamically created obj fields have the following shadow var id values */ +#define SV_ID1 0x1234 +#define SV_ID2 0x1235 + +/* + * The main test case adds/removes new fields (shadow var) to each of these + * test structure instances. The last group of fields in the struct represent + * the idea that shadow variables may be added and removed to and from the + * struct during execution. + */ +struct test_object { + /* add anything here below and avoid to define an empty struct */ + struct shadow_ptr sp; + + /* these represent shadow vars added and removed with SV_ID{1,2} */ + /* char nfield1; */ + /* int nfield2; */ +}; + +static int test_klp_shadow_vars_init(void) +{ + struct test_object objs[NUM_OBJS]; + char nfields1[NUM_OBJS], *pnfields1[NUM_OBJS], **sv1[NUM_OBJS]; + char *pndup[NUM_OBJS]; + int nfields2[NUM_OBJS], *pnfields2[NUM_OBJS], **sv2[NUM_OBJS]; + void **sv; + int ret; + int i; + + ptr_id(NULL); + + /* + * With an empty shadow variable hash table, expect not to find + * any matches. + */ + sv = shadow_get(&objs[0], SV_ID1); + if (!sv) + pr_info(" got expected NULL result\n"); + + /* pass 1: init & alloc a char+int pair of svars for each objs */ + for (i = 0; i < NUM_OBJS; i++) { + pnfields1[i] = &nfields1[i]; + ptr_id(pnfields1[i]); + + if (i % 2) { + sv1[i] = shadow_alloc(&objs[i], SV_ID1, + sizeof(pnfields1[i]), GFP_KERNEL, + shadow_ctor, &pnfields1[i]); + } else { + sv1[i] = shadow_get_or_alloc(&objs[i], SV_ID1, + sizeof(pnfields1[i]), GFP_KERNEL, + shadow_ctor, &pnfields1[i]); + } + if (!sv1[i]) { + ret = -ENOMEM; + goto out; + } + + pnfields2[i] = &nfields2[i]; + ptr_id(pnfields2[i]); + sv2[i] = shadow_alloc(&objs[i], SV_ID2, sizeof(pnfields2[i]), + GFP_KERNEL, shadow_ctor, &pnfields2[i]); + if (!sv2[i]) { + ret = -ENOMEM; + goto out; + } + } + + /* pass 2: verify we find allocated svars and where they point to */ + for (i = 0; i < NUM_OBJS; i++) { + /* check the "char" svar for all objects */ + sv = shadow_get(&objs[i], SV_ID1); + if (!sv) { + ret = -EINVAL; + goto out; + } + if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i]) + pr_info(" got expected PTR%d -> PTR%d result\n", + ptr_id(sv1[i]), ptr_id(*sv1[i])); + + /* check the "int" svar for all objects */ + sv = shadow_get(&objs[i], SV_ID2); + if (!sv) { + ret = -EINVAL; + goto out; + } + if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i]) + pr_info(" got expected PTR%d -> PTR%d result\n", + ptr_id(sv2[i]), ptr_id(*sv2[i])); + } + + /* pass 3: verify that 'get_or_alloc' returns already allocated svars */ + for (i = 0; i < NUM_OBJS; i++) { + pndup[i] = &nfields1[i]; + ptr_id(pndup[i]); + + sv = shadow_get_or_alloc(&objs[i], SV_ID1, sizeof(pndup[i]), + GFP_KERNEL, shadow_ctor, &pndup[i]); + if (!sv) { + ret = -EINVAL; + goto out; + } + if ((char **)sv == sv1[i] && *sv1[i] == pnfields1[i]) + pr_info(" got expected PTR%d -> PTR%d result\n", + ptr_id(sv1[i]), ptr_id(*sv1[i])); + } + + /* pass 4: free <objs[*], SV_ID1> pairs of svars, verify removal */ + for (i = 0; i < NUM_OBJS; i++) { + shadow_free(&objs[i], SV_ID1, shadow_dtor); /* 'char' pairs */ + sv = shadow_get(&objs[i], SV_ID1); + if (!sv) + pr_info(" got expected NULL result\n"); + } + + /* pass 5: check we still find <objs[*], SV_ID2> svar pairs */ + for (i = 0; i < NUM_OBJS; i++) { + sv = shadow_get(&objs[i], SV_ID2); /* 'int' pairs */ + if (!sv) { + ret = -EINVAL; + goto out; + } + if ((int **)sv == sv2[i] && *sv2[i] == pnfields2[i]) + pr_info(" got expected PTR%d -> PTR%d result\n", + ptr_id(sv2[i]), ptr_id(*sv2[i])); + } + + /* pass 6: free all the <objs[*], SV_ID2> svar pairs too. */ + shadow_free_all(SV_ID2, NULL); /* 'int' pairs */ + for (i = 0; i < NUM_OBJS; i++) { + sv = shadow_get(&objs[i], SV_ID2); + if (!sv) + pr_info(" got expected NULL result\n"); + } + + free_ptr_list(); + + return 0; +out: + shadow_free_all(SV_ID1, NULL); /* 'char' pairs */ + shadow_free_all(SV_ID2, NULL); /* 'int' pairs */ + free_ptr_list(); + + return ret; +} + +static void test_klp_shadow_vars_exit(void) +{ +} + +module_init(test_klp_shadow_vars_init); +module_exit(test_klp_shadow_vars_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Joe Lawrence <joe.lawrence@redhat.com>"); +MODULE_DESCRIPTION("Livepatch test: shadow variables"); |