diff options
| -rw-r--r-- | src/kernel/arch/amd64/pagedir.c | 10 | ||||
| -rw-r--r-- | src/user/tests/main.c | 26 |
2 files changed, 32 insertions, 4 deletions
diff --git a/src/kernel/arch/amd64/pagedir.c b/src/kernel/arch/amd64/pagedir.c index 6f5fd4e..f043289 100644 --- a/src/kernel/arch/amd64/pagedir.c +++ b/src/kernel/arch/amd64/pagedir.c @@ -15,6 +15,12 @@ static void *addr_validate(void *addr) { return addr; } +static bool addr_canonical(const __user void *addr) { + const int addr_bits = 48; + uintptr_t n = (uintptr_t)addr >> addr_bits; + return (n == 0) || ((~n) << addr_bits == 0); +} + struct pagedir *pagedir_new(void) { struct pagedir *dir = page_alloc(1); @@ -57,7 +63,7 @@ get_entry(struct pagedir *dir, const void __user *virt) { pe_generic_t *pml4e, *pdpte, *pde, *pte; const union virt_addr v = {.full = (void __user *)virt}; - // TODO check if sign extension is valid + if (!addr_canonical(virt)) return NULL; pml4e = &dir->e[v.pml4]; if (!pml4e->present) return NULL; @@ -88,7 +94,7 @@ void pagedir_map(struct pagedir *dir, void __user *virt, void *phys, pe_generic_t *pml4e, *pdpte, *pde, *pte; const union virt_addr v = {.full = virt}; - // TODO check if sign extension is valid + if (!addr_canonical(virt)) return; pml4e = &dir->e[v.pml4]; if (!pml4e->present) { diff --git a/src/user/tests/main.c b/src/user/tests/main.c index b4587f9..ab6b4a8 100644 --- a/src/user/tests/main.c +++ b/src/user/tests/main.c @@ -189,13 +189,35 @@ static void test_malloc(void) { } static void test_efault(void) { + const char *str = "o, 16 characters"; + char str2[16]; char *invalid = (void*)0x1000; handle_t h; + memcpy(str2, str, 16); + assert((h = _syscall_open(tmpfilepath, strlen(tmpfilepath), OPEN_CREATE))); - assert(_syscall_write(h, "dzwdz sucks ass!", 16, 0) == 16); + assert(_syscall_write(h, str, 16, 0) == 16); + assert(_syscall_write(h, str2, 16, 0) == 16); + assert(_syscall_write(h, invalid, 16, 0) == -EFAULT); - assert(_syscall_write(h, "dzwdz is cool!!!", 16, 0) == 16); + + /* x64 canonical pointers */ + assert(_syscall_write(h, (void*)((uintptr_t)str ^ 0x8000000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str ^ 0x1000000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str ^ 0x0100000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str ^ 0x0010000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str ^ 0x0001000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str ^ 0x0000800000000000), 16, 0) == -EFAULT); + + assert(_syscall_write(h, (void*)((uintptr_t)str2 ^ 0x8000000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str2 ^ 0x1000000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str2 ^ 0x0100000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str2 ^ 0x0010000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str2 ^ 0x0001000000000000), 16, 0) == -EFAULT); + assert(_syscall_write(h, (void*)((uintptr_t)str2 ^ 0x0000800000000000), 16, 0) == -EFAULT); + + assert(_syscall_write(h, str, 16, 0) == 16); close(h); } |