fs/tests/exec_kunit.c

Source file repositories/reference/linux-study-clean/fs/tests/exec_kunit.c

File Facts

System
Linux kernel
Corpus path
fs/tests/exec_kunit.c
Extension
.c
Size
6182 bytes
Lines
133
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

struct bprm_stack_limits_result {
	struct linux_binprm bprm;
	int expected_rc;
	unsigned long expected_argmin;
};

static const struct bprm_stack_limits_result bprm_stack_limits_results[] = {
	/* Negative argc/envc counts produce -E2BIG */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = INT_MIN, .envc = INT_MIN }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = 5, .envc = -1 }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = -1, .envc = 10 }, .expected_rc = -E2BIG },
	/* The max value of argc or envc is MAX_ARG_STRINGS. */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = INT_MAX, .envc = INT_MAX }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = MAX_ARG_STRINGS, .envc = MAX_ARG_STRINGS }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = 0, .envc = MAX_ARG_STRINGS }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = MAX_ARG_STRINGS, .envc = 0 }, .expected_rc = -E2BIG },
	/*
	 * On 32-bit system these argc and envc counts, while likely impossible
	 * to represent within the associated TASK_SIZE, could overflow the
	 * limit calculation, and bypass the ptr_size <= limit check.
	 */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = 0x20000001, .envc = 0x20000001 }, .expected_rc = -E2BIG },
#ifdef CONFIG_MMU
	/* Make sure a pathological bprm->p doesn't cause an overflow. */
	{ { .p = sizeof(void *), .rlim_stack.rlim_cur = ULONG_MAX,
	    .argc = 10, .envc = 10 }, .expected_rc = -E2BIG },
#endif
	/*
	 * 0 rlim_stack will get raised to ARG_MAX. With 1 string pointer,
	 * we should see p - ARG_MAX + sizeof(void *).
	 */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = 1, .envc = 0 }, .expected_argmin = ULONG_MAX - ARG_MAX + sizeof(void *)},
	/* Validate that argc is always raised to a minimum of 1. */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = 0, .envc = 0 }, .expected_argmin = ULONG_MAX - ARG_MAX + sizeof(void *)},
	/*
	 * 0 rlim_stack will get raised to ARG_MAX. With pointers filling ARG_MAX,
	 * we should see -E2BIG. (Note argc is always raised to at least 1.)
	 */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = ARG_MAX / sizeof(void *), .envc = 0 }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = 0, .envc = ARG_MAX / sizeof(void *) - 1 }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = ARG_MAX / sizeof(void *) + 1, .envc = 0 }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = 0, .envc = ARG_MAX / sizeof(void *) }, .expected_rc = -E2BIG },
	/* And with one less, we see space for exactly 1 pointer. */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = (ARG_MAX / sizeof(void *)) - 1, .envc = 0 },
	  .expected_argmin = ULONG_MAX - sizeof(void *) },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 0,
	    .argc = 0, .envc = (ARG_MAX / sizeof(void *)) - 2, },
	  .expected_argmin = ULONG_MAX - sizeof(void *) },
	/* If we raise rlim_stack / 4 to exactly ARG_MAX, nothing changes. */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ARG_MAX * 4,
	    .argc = ARG_MAX / sizeof(void *), .envc = 0 }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ARG_MAX * 4,
	    .argc = 0, .envc = ARG_MAX / sizeof(void *) - 1 }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ARG_MAX * 4,
	    .argc = ARG_MAX / sizeof(void *) + 1, .envc = 0 }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ARG_MAX * 4,
	    .argc = 0, .envc = ARG_MAX / sizeof(void *) }, .expected_rc = -E2BIG },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ARG_MAX * 4,
	    .argc = (ARG_MAX / sizeof(void *)) - 1, .envc = 0 },
	  .expected_argmin = ULONG_MAX - sizeof(void *) },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = ARG_MAX * 4,
	    .argc = 0, .envc = (ARG_MAX / sizeof(void *)) - 2, },
	  .expected_argmin = ULONG_MAX - sizeof(void *) },
	/* But raising it another pointer * 4 will provide space for 1 more pointer. */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = (ARG_MAX + sizeof(void *)) * 4,
	    .argc = ARG_MAX / sizeof(void *), .envc = 0 },
	  .expected_argmin = ULONG_MAX - sizeof(void *) },
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = (ARG_MAX + sizeof(void *)) * 4,
	    .argc = 0, .envc = ARG_MAX / sizeof(void *) - 1 },
	  .expected_argmin = ULONG_MAX - sizeof(void *) },
	/* Raising rlim_stack / 4 to _STK_LIM / 4 * 3 will see more space. */
	{ { .p = ULONG_MAX, .rlim_stack.rlim_cur = 4 * (_STK_LIM / 4 * 3),
	    .argc = 0, .envc = 0 },
	  .expected_argmin = ULONG_MAX - (_STK_LIM / 4 * 3) + sizeof(void *) },
	/* But raising it any further will see no increase. */

Annotation

Implementation Notes