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| author |   Kees Cook <keescook@chromium.org> | 2016-06-26 08:51:14 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2016-07-07 11:09:20 -0700 |
| commit | 0edca7b5afb4b0909eecd2ede9a6736ef7cafc42 (patch) | |
| tree | 4646c4bc53eddb1ce8be1c72ef88ba9b166e3a17 /drivers/misc | |
| parent | lkdtm: add usercopy test for blocking kernel text (diff) | |
| download | linux-dev-0edca7b5afb4b0909eecd2ede9a6736ef7cafc42.tar.xz linux-dev-0edca7b5afb4b0909eecd2ede9a6736ef7cafc42.zip | |
lkdtm: drop "alloc_size" parameter
There is no good reason to have the alloc_size parameter currently. The
compiler-tricking value used to exercise the stack can just use a stack
address instead. Similarly hard-code cache_size.
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/lkdtm_core.c | 15 |
1 files changed, 5 insertions, 10 deletions
diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c index c915961c4df2..1454d58aa278 100644 --- a/drivers/misc/lkdtm_core.c +++ b/drivers/misc/lkdtm_core.c @@ -184,8 +184,6 @@ static char* cpoint_name; static char* cpoint_type; static int cpoint_count = DEFAULT_COUNT; static int recur_count = REC_NUM_DEFAULT; -static int alloc_size = 1024; -static size_t cache_size; static enum cname cpoint = CN_INVALID; static enum ctype cptype = CT_NONE; @@ -194,6 +192,8 @@ static DEFINE_SPINLOCK(count_lock); static DEFINE_SPINLOCK(lock_me_up); static u8 data_area[EXEC_SIZE]; + +static size_t cache_size = 1024; static struct kmem_cache *bad_cache; static const unsigned char test_text[] = "This is a test.\n"; @@ -210,9 +210,6 @@ MODULE_PARM_DESC(cpoint_type, " Crash Point Type, action to be taken on "\ module_param(cpoint_count, int, 0644); MODULE_PARM_DESC(cpoint_count, " Crash Point Count, number of times the "\ "crash point is to be hit to trigger action"); -module_param(alloc_size, int, 0644); -MODULE_PARM_DESC(alloc_size, " Size of allocation for user copy tests "\ - "(from 1 to PAGE_SIZE)"); static unsigned int jp_do_irq(unsigned int irq) { @@ -441,7 +438,7 @@ static noinline void do_usercopy_stack(bool to_user, bool bad_frame) /* This is a pointer to outside our current stack frame. */ if (bad_frame) { - bad_stack = do_usercopy_stack_callee(alloc_size); + bad_stack = do_usercopy_stack_callee((uintptr_t)bad_stack); } else { /* Put start address just inside stack. */ bad_stack = task_stack_page(current) + THREAD_SIZE; @@ -530,7 +527,7 @@ static void do_usercopy_heap_size(bool to_user) { unsigned long user_addr; unsigned char *one, *two; - size_t size = clamp_t(int, alloc_size, 1, PAGE_SIZE); + size_t size = 1024; one = kmalloc(size, GFP_KERNEL); two = kmalloc(size, GFP_KERNEL); @@ -564,8 +561,7 @@ static void do_usercopy_heap_size(bool to_user) } } else { pr_info("attempting good copy_from_user of correct size\n"); - if (copy_from_user(one, (void __user *)user_addr, - size)) { + if (copy_from_user(one, (void __user *)user_addr, size)) { pr_warn("copy_from_user failed unexpectedly?!\n"); goto free_user; } @@ -1284,7 +1280,6 @@ static int __init lkdtm_module_init(void) ro_after_init |= 0xAA; /* Prepare cache that lacks SLAB_USERCOPY flag. */ - cache_size = clamp_t(int, alloc_size, 1, PAGE_SIZE); bad_cache = kmem_cache_create("lkdtm-no-usercopy", cache_size, 0, 0, NULL); |