| Message ID | 20240612195921.2685842-1-kees@kernel.org (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | 51104c19d8570eb23208e08eac0e9ae09ced1c15 |
| Headers | show |
| Series | usercopy: Convert test_user_copy to KUnit test | expand |
Hi, On Wed, Jun 12, 2024 at 12:59:18PM -0700, Kees Cook wrote: > For tests that need to allocate using vm_mmap() (e.g. usercopy and > execve), provide the interface to have the allocation tracked by KUnit > itself. This requires bringing up a placeholder userspace mm. > > This combines my earlier attempt at this with Mark Rutland's version[1]. > > Normally alloc_mm() and arch_pick_mmap_layout() aren't exported for > modules, so export these only for KUnit testing. > > Link: https://lore.kernel.org/lkml/20230321122514.1743889-2-mark.rutland@arm.com/ [1] FWIW, not sure I understand what the above link has to do with this patch. > Co-developed-by: Mark Rutland <mark.rutland@arm.com> > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Reviewed-by: David Gow <davidgow@google.com> > Signed-off-by: Kees Cook <kees@kernel.org> This patch results in a build failure for nommu_kc705_defconfig if kunit tests are also enabled. ERROR: modpost: vmlinux: local symbol 'arch_pick_mmap_layout' was exported If CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT=n, CONFIG_MMU=n, and CONFIG_KUNIT=y, arch_pick_mmap_layout is exported. However, if CONFIG_MMU=n, it is declared as static inline function. Guenter --- bisect log: # bad: [b992b79ca8bc336fa8e2c80990b5af80ed8f36fd] Add linux-next specific files for 20240620 # good: [6ba59ff4227927d3a8530fc2973b80e94b54d58f] Linux 6.10-rc4 git bisect start 'HEAD' 'v6.10-rc4' # good: [c02e717c5a89654b244fec58bb5cda32770966b5] Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/cryptodev-2.6.git git bisect good c02e717c5a89654b244fec58bb5cda32770966b5 # good: [29e7d78253b7ebf4b76fcf6d95e227d0b0c57dc0] Merge branch 'msm-next' of https://gitlab.freedesktop.org/drm/msm.git git bisect good 29e7d78253b7ebf4b76fcf6d95e227d0b0c57dc0 # good: [bf8fd0d956bfcbf4fd6ff063366374c4bf87d806] Merge branch 'non-rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git git bisect good bf8fd0d956bfcbf4fd6ff063366374c4bf87d806 # good: [1110f16317b1e0742521eaef5613eb1eb17f55ca] Merge branch 'icc-next' of git://git.kernel.org/pub/scm/linux/kernel/git/djakov/icc.git git bisect good 1110f16317b1e0742521eaef5613eb1eb17f55ca # good: [63f3716198e5644713748d83e6a6df3b4a6a3b10] Merge branch 'gpio/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux.git git bisect good 63f3716198e5644713748d83e6a6df3b4a6a3b10 # bad: [91b48d9adafddb242264ba19c0bae6e23f71b18a] Merge branch 'kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git git bisect bad 91b48d9adafddb242264ba19c0bae6e23f71b18a # good: [9b401f4a7170125365160c9af267a41ff6b39001] pinctrl: ti: ti-iodelay: fix possible memory leak when pinctrl_enable() fails git bisect good 9b401f4a7170125365160c9af267a41ff6b39001 # good: [1963f932d368f18185466979cc0bc89414d798e7] Merge branch 'pwm/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux.git git bisect good 1963f932d368f18185466979cc0bc89414d798e7 # good: [f91869accbe23a2bb08712b7262fa61eab716d42] selftests/resctrl: Simplify bandwidth report type handling git bisect good f91869accbe23a2bb08712b7262fa61eab716d42 # good: [cbf284291604e818424f45dbdf6a8a705b5480ad] Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git git bisect good cbf284291604e818424f45dbdf6a8a705b5480ad # good: [a5217468214c228b89da37291de604cd756914ab] kunit: add missing MODULE_DESCRIPTION() macros to core modules git bisect good a5217468214c228b89da37291de604cd756914ab # bad: [51104c19d8570eb23208e08eac0e9ae09ced1c15] kunit: test: Add vm_mmap() allocation resource manager git bisect bad 51104c19d8570eb23208e08eac0e9ae09ced1c15 # good: [425ae3ab5a1fa744a00680f059cf1accaaaecb28] list: test: add the missing MODULE_DESCRIPTION() macro git bisect good 425ae3ab5a1fa744a00680f059cf1accaaaecb28 # first bad commit: [51104c19d8570eb23208e08eac0e9ae09ced1c15] kunit: test: Add vm_mmap() allocation resource manager
On Sat, Jun 22, 2024 at 06:47:39AM -0700, Guenter Roeck wrote: > Hi, > > On Wed, Jun 12, 2024 at 12:59:18PM -0700, Kees Cook wrote: > > For tests that need to allocate using vm_mmap() (e.g. usercopy and > > execve), provide the interface to have the allocation tracked by KUnit > > itself. This requires bringing up a placeholder userspace mm. > > > > This combines my earlier attempt at this with Mark Rutland's version[1]. > > > > Normally alloc_mm() and arch_pick_mmap_layout() aren't exported for > > modules, so export these only for KUnit testing. > > > > Link: https://lore.kernel.org/lkml/20230321122514.1743889-2-mark.rutland@arm.com/ [1] > > FWIW, not sure I understand what the above link has to do with this patch. Both the above Link and this patch were implementing KUnit usercopy tests (and the required infrastructure). > > > Co-developed-by: Mark Rutland <mark.rutland@arm.com> > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > > Reviewed-by: David Gow <davidgow@google.com> > > Signed-off-by: Kees Cook <kees@kernel.org> > > This patch results in a build failure for nommu_kc705_defconfig if kunit tests > are also enabled. > > ERROR: modpost: vmlinux: local symbol 'arch_pick_mmap_layout' was exported > > If CONFIG_ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT=n, CONFIG_MMU=n, and > CONFIG_KUNIT=y, arch_pick_mmap_layout is exported. However, if > CONFIG_MMU=n, it is declared as static inline function. I replied in the other thread too, but this has had a fix pending: https://lore.kernel.org/lkml/202406271005.4E767DAE@keescook/ I pinged the patch again today. -Kees
diff --git a/include/kunit/test.h b/include/kunit/test.h index e32b4cb7afa2..ec61cad6b71d 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -480,6 +480,23 @@ static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp return kunit_kmalloc_array(test, n, size, gfp | __GFP_ZERO); } +/** + * kunit_vm_mmap() - Allocate KUnit-tracked vm_mmap() area + * @test: The test context object. + * @file: struct file pointer to map from, if any + * @addr: desired address, if any + * @len: how many bytes to allocate + * @prot: mmap PROT_* bits + * @flag: mmap flags + * @offset: offset into @file to start mapping from. + * + * See vm_mmap() for more information. + */ +unsigned long kunit_vm_mmap(struct kunit *test, struct file *file, + unsigned long addr, unsigned long len, + unsigned long prot, unsigned long flag, + unsigned long offset); + void kunit_cleanup(struct kunit *test); void __printf(2, 3) kunit_log_append(struct string_stream *log, const char *fmt, ...); diff --git a/kernel/fork.c b/kernel/fork.c index 99076dbe27d8..cea203197136 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -115,6 +115,8 @@ #define CREATE_TRACE_POINTS #include <trace/events/task.h> +#include <kunit/visibility.h> + /* * Minimum number of threads to boot the kernel */ @@ -1334,6 +1336,7 @@ struct mm_struct *mm_alloc(void) memset(mm, 0, sizeof(*mm)); return mm_init(mm, current, current_user_ns()); } +EXPORT_SYMBOL_IF_KUNIT(mm_alloc); static inline void __mmput(struct mm_struct *mm) { diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 309659a32a78..56dd67dc6e57 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_KUNIT) += kunit.o kunit-objs += test.o \ resource.o \ + user_alloc.o \ static_stub.o \ string-stream.o \ assert.o \ diff --git a/lib/kunit/user_alloc.c b/lib/kunit/user_alloc.c new file mode 100644 index 000000000000..76d3d1345ed7 --- /dev/null +++ b/lib/kunit/user_alloc.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit userspace memory allocation resource management. + */ +#include <kunit/resource.h> +#include <kunit/test.h> +#include <linux/kthread.h> +#include <linux/mm.h> + +struct kunit_vm_mmap_resource { + unsigned long addr; + size_t size; +}; + +/* vm_mmap() arguments */ +struct kunit_vm_mmap_params { + struct file *file; + unsigned long addr; + unsigned long len; + unsigned long prot; + unsigned long flag; + unsigned long offset; +}; + +/* Create and attach a new mm if it doesn't already exist. */ +static int kunit_attach_mm(void) +{ + struct mm_struct *mm; + + if (current->mm) + return 0; + + mm = mm_alloc(); + if (!mm) + return -ENOMEM; + + /* Define the task size. */ + mm->task_size = TASK_SIZE; + + /* Make sure we can allocate new VMAs. */ + arch_pick_mmap_layout(mm, ¤t->signal->rlim[RLIMIT_STACK]); + + /* Attach the mm. It will be cleaned up when the process dies. */ + kthread_use_mm(mm); + + return 0; +} + +static int kunit_vm_mmap_init(struct kunit_resource *res, void *context) +{ + struct kunit_vm_mmap_params *p = context; + struct kunit_vm_mmap_resource vres; + int ret; + + ret = kunit_attach_mm(); + if (ret) + return ret; + + vres.size = p->len; + vres.addr = vm_mmap(p->file, p->addr, p->len, p->prot, p->flag, p->offset); + if (!vres.addr) + return -ENOMEM; + res->data = kmemdup(&vres, sizeof(vres), GFP_KERNEL); + if (!res->data) { + vm_munmap(vres.addr, vres.size); + return -ENOMEM; + } + + return 0; +} + +static void kunit_vm_mmap_free(struct kunit_resource *res) +{ + struct kunit_vm_mmap_resource *vres = res->data; + + /* + * Since this is executed from the test monitoring process, + * the test's mm has already been torn down. We don't need + * to run vm_munmap(vres->addr, vres->size), only clean up + * the vres. + */ + + kfree(vres); + res->data = NULL; +} + +unsigned long kunit_vm_mmap(struct kunit *test, struct file *file, + unsigned long addr, unsigned long len, + unsigned long prot, unsigned long flag, + unsigned long offset) +{ + struct kunit_vm_mmap_params params = { + .file = file, + .addr = addr, + .len = len, + .prot = prot, + .flag = flag, + .offset = offset, + }; + struct kunit_vm_mmap_resource *vres; + + vres = kunit_alloc_resource(test, + kunit_vm_mmap_init, + kunit_vm_mmap_free, + GFP_KERNEL, + ¶ms); + if (vres) + return vres->addr; + return 0; +} +EXPORT_SYMBOL_GPL(kunit_vm_mmap); + +MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING); diff --git a/mm/util.c b/mm/util.c index c9e519e6811f..df37c47d9374 100644 --- a/mm/util.c +++ b/mm/util.c @@ -26,6 +26,8 @@ #include <linux/uaccess.h> +#include <kunit/visibility.h> + #include "internal.h" #include "swap.h" @@ -482,6 +484,7 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) clear_bit(MMF_TOPDOWN, &mm->flags); } #endif +EXPORT_SYMBOL_IF_KUNIT(arch_pick_mmap_layout); /** * __account_locked_vm - account locked pages to an mm's locked_vm