On Fri, 2 Jul 2021 at 09:45, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > tree: git://anongit.freedesktop.org/drm-intel drm-intel-gt-next > head: 5cd57f676bb946a00275408f0dd0d75dbc466d25 > commit: cf586021642d8017cde111b7dd1ba86224e9da51 [8/14] drm/i915/gt: Pipelined page migration > config: x86_64-randconfig-m001-20210630 (attached as .config) > compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@xxxxxxxxx> > Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > New smatch warnings: > drivers/gpu/drm/i915/gt/selftest_migrate.c:102 copy() error: uninitialized symbol 'rq'. > drivers/gpu/drm/i915/gt/selftest_migrate.c:113 copy() error: uninitialized symbol 'vaddr'. > > Old smatch warnings: > drivers/gpu/drm/i915/gem/i915_gem_object.h:182 __i915_gem_object_lock() error: we previously assumed 'ww' could be null (see line 171) > > vim +/rq +102 drivers/gpu/drm/i915/gt/selftest_migrate.c > > cf586021642d80 Chris Wilson 2021-06-17 32 static int copy(struct intel_migrate *migrate, > cf586021642d80 Chris Wilson 2021-06-17 33 int (*fn)(struct intel_migrate *migrate, > cf586021642d80 Chris Wilson 2021-06-17 34 struct i915_gem_ww_ctx *ww, > cf586021642d80 Chris Wilson 2021-06-17 35 struct drm_i915_gem_object *src, > cf586021642d80 Chris Wilson 2021-06-17 36 struct drm_i915_gem_object *dst, > cf586021642d80 Chris Wilson 2021-06-17 37 struct i915_request **out), > cf586021642d80 Chris Wilson 2021-06-17 38 u32 sz, struct rnd_state *prng) > cf586021642d80 Chris Wilson 2021-06-17 39 { > cf586021642d80 Chris Wilson 2021-06-17 40 struct drm_i915_private *i915 = migrate->context->engine->i915; > cf586021642d80 Chris Wilson 2021-06-17 41 struct drm_i915_gem_object *src, *dst; > cf586021642d80 Chris Wilson 2021-06-17 42 struct i915_request *rq; > cf586021642d80 Chris Wilson 2021-06-17 43 struct i915_gem_ww_ctx ww; > cf586021642d80 Chris Wilson 2021-06-17 44 u32 *vaddr; > cf586021642d80 Chris Wilson 2021-06-17 45 int err = 0; > > One way to silence these warnings would be to initialize err = -EINVAL. > Then Smatch would know that we goto err_out for an empty list. > > cf586021642d80 Chris Wilson 2021-06-17 46 int i; > cf586021642d80 Chris Wilson 2021-06-17 47 > cf586021642d80 Chris Wilson 2021-06-17 48 src = create_lmem_or_internal(i915, sz); > cf586021642d80 Chris Wilson 2021-06-17 49 if (IS_ERR(src)) > cf586021642d80 Chris Wilson 2021-06-17 50 return 0; > cf586021642d80 Chris Wilson 2021-06-17 51 > cf586021642d80 Chris Wilson 2021-06-17 52 dst = i915_gem_object_create_internal(i915, sz); > cf586021642d80 Chris Wilson 2021-06-17 53 if (IS_ERR(dst)) > cf586021642d80 Chris Wilson 2021-06-17 54 goto err_free_src; > cf586021642d80 Chris Wilson 2021-06-17 55 > cf586021642d80 Chris Wilson 2021-06-17 56 for_i915_gem_ww(&ww, err, true) { > cf586021642d80 Chris Wilson 2021-06-17 57 err = i915_gem_object_lock(src, &ww); > cf586021642d80 Chris Wilson 2021-06-17 58 if (err) > cf586021642d80 Chris Wilson 2021-06-17 59 continue; > cf586021642d80 Chris Wilson 2021-06-17 60 > cf586021642d80 Chris Wilson 2021-06-17 61 err = i915_gem_object_lock(dst, &ww); > cf586021642d80 Chris Wilson 2021-06-17 62 if (err) > cf586021642d80 Chris Wilson 2021-06-17 63 continue; > cf586021642d80 Chris Wilson 2021-06-17 64 > cf586021642d80 Chris Wilson 2021-06-17 65 vaddr = i915_gem_object_pin_map(src, I915_MAP_WC); > cf586021642d80 Chris Wilson 2021-06-17 66 if (IS_ERR(vaddr)) { > cf586021642d80 Chris Wilson 2021-06-17 67 err = PTR_ERR(vaddr); > cf586021642d80 Chris Wilson 2021-06-17 68 continue; > cf586021642d80 Chris Wilson 2021-06-17 69 } > cf586021642d80 Chris Wilson 2021-06-17 70 > cf586021642d80 Chris Wilson 2021-06-17 71 for (i = 0; i < sz / sizeof(u32); i++) > cf586021642d80 Chris Wilson 2021-06-17 72 vaddr[i] = i; > cf586021642d80 Chris Wilson 2021-06-17 73 i915_gem_object_flush_map(src); > cf586021642d80 Chris Wilson 2021-06-17 74 > cf586021642d80 Chris Wilson 2021-06-17 75 vaddr = i915_gem_object_pin_map(dst, I915_MAP_WC); > cf586021642d80 Chris Wilson 2021-06-17 76 if (IS_ERR(vaddr)) { > cf586021642d80 Chris Wilson 2021-06-17 77 err = PTR_ERR(vaddr); > cf586021642d80 Chris Wilson 2021-06-17 78 goto unpin_src; > cf586021642d80 Chris Wilson 2021-06-17 79 } > cf586021642d80 Chris Wilson 2021-06-17 80 > cf586021642d80 Chris Wilson 2021-06-17 81 for (i = 0; i < sz / sizeof(u32); i++) > cf586021642d80 Chris Wilson 2021-06-17 82 vaddr[i] = ~i; > cf586021642d80 Chris Wilson 2021-06-17 83 i915_gem_object_flush_map(dst); > cf586021642d80 Chris Wilson 2021-06-17 84 > cf586021642d80 Chris Wilson 2021-06-17 85 err = fn(migrate, &ww, src, dst, &rq); > cf586021642d80 Chris Wilson 2021-06-17 86 if (!err) > cf586021642d80 Chris Wilson 2021-06-17 87 continue; > > Does fn() initialize "rq" on the success path? Anyway Smatch would > complain anyway because it thinks the list could be empty or that we > might hit and early continue for everything. The fn() will always first initialize the rq to NULL. If it returns success then rq will always be a valid rq. If it returns an err then the rq might be NULL, or a valid rq depending on how far the copy/fn got. And for_i915_gem_ww() will always run at least once, since ww->loop = true, so this looks like a false positive? > > cf586021642d80 Chris Wilson 2021-06-17 88 > cf586021642d80 Chris Wilson 2021-06-17 89 if (err != -EDEADLK && err != -EINTR && err != -ERESTARTSYS) > cf586021642d80 Chris Wilson 2021-06-17 90 pr_err("%ps failed, size: %u\n", fn, sz); > cf586021642d80 Chris Wilson 2021-06-17 91 if (rq) { > cf586021642d80 Chris Wilson 2021-06-17 92 i915_request_wait(rq, 0, HZ); > cf586021642d80 Chris Wilson 2021-06-17 93 i915_request_put(rq); > cf586021642d80 Chris Wilson 2021-06-17 94 } > cf586021642d80 Chris Wilson 2021-06-17 95 i915_gem_object_unpin_map(dst); > cf586021642d80 Chris Wilson 2021-06-17 96 unpin_src: > cf586021642d80 Chris Wilson 2021-06-17 97 i915_gem_object_unpin_map(src); > cf586021642d80 Chris Wilson 2021-06-17 98 } > cf586021642d80 Chris Wilson 2021-06-17 99 if (err) > cf586021642d80 Chris Wilson 2021-06-17 100 goto err_out; > cf586021642d80 Chris Wilson 2021-06-17 101 > cf586021642d80 Chris Wilson 2021-06-17 @102 if (rq) { > cf586021642d80 Chris Wilson 2021-06-17 103 if (i915_request_wait(rq, 0, HZ) < 0) { > cf586021642d80 Chris Wilson 2021-06-17 104 pr_err("%ps timed out, size: %u\n", fn, sz); > cf586021642d80 Chris Wilson 2021-06-17 105 err = -ETIME; > cf586021642d80 Chris Wilson 2021-06-17 106 } > cf586021642d80 Chris Wilson 2021-06-17 107 i915_request_put(rq); > cf586021642d80 Chris Wilson 2021-06-17 108 } > cf586021642d80 Chris Wilson 2021-06-17 109 > cf586021642d80 Chris Wilson 2021-06-17 110 for (i = 0; !err && i < sz / PAGE_SIZE; i++) { > cf586021642d80 Chris Wilson 2021-06-17 111 int x = i * 1024 + i915_prandom_u32_max_state(1024, prng); > cf586021642d80 Chris Wilson 2021-06-17 112 > cf586021642d80 Chris Wilson 2021-06-17 @113 if (vaddr[x] != x) { > cf586021642d80 Chris Wilson 2021-06-17 114 pr_err("%ps failed, size: %u, offset: %zu\n", > cf586021642d80 Chris Wilson 2021-06-17 115 fn, sz, x * sizeof(u32)); > cf586021642d80 Chris Wilson 2021-06-17 116 igt_hexdump(vaddr + i * 1024, 4096); > cf586021642d80 Chris Wilson 2021-06-17 117 err = -EINVAL; > cf586021642d80 Chris Wilson 2021-06-17 118 } > cf586021642d80 Chris Wilson 2021-06-17 119 } > cf586021642d80 Chris Wilson 2021-06-17 120 > cf586021642d80 Chris Wilson 2021-06-17 121 i915_gem_object_unpin_map(dst); > cf586021642d80 Chris Wilson 2021-06-17 122 i915_gem_object_unpin_map(src); > cf586021642d80 Chris Wilson 2021-06-17 123 > cf586021642d80 Chris Wilson 2021-06-17 124 err_out: > cf586021642d80 Chris Wilson 2021-06-17 125 i915_gem_object_put(dst); > cf586021642d80 Chris Wilson 2021-06-17 126 err_free_src: > cf586021642d80 Chris Wilson 2021-06-17 127 i915_gem_object_put(src); > cf586021642d80 Chris Wilson 2021-06-17 128 > cf586021642d80 Chris Wilson 2021-06-17 129 return err; > cf586021642d80 Chris Wilson 2021-06-17 130 } > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/intel-gfx