From: Matthew Auld <matthew.william.auld@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
kbuild-all@lists.01.org, kbuild@lists.01.org,
"ML dri-devel" <dri-devel@lists.freedesktop.org>,
"Chris Wilson" <chris@chris-wilson.co.uk>,
"Matthew Auld" <matthew.auld@intel.com>,
"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>
Subject: Re: [Intel-gfx] [drm-intel:drm-intel-gt-next 8/14] drivers/gpu/drm/i915/gt/selftest_migrate.c:102 copy() error: uninitialized symbol 'rq'.
Date: Fri, 2 Jul 2021 11:32:45 +0100 [thread overview]
Message-ID: <CAM0jSHOb0bGWMt-tmUn62R_FpiM5TL2HFLbBqxhpqk1gH0qSUA@mail.gmail.com> (raw)
In-Reply-To: <202107020708.XXwacDfG-lkp@intel.com>
On Fri, 2 Jul 2021 at 09:45, Dan Carpenter <dan.carpenter@oracle.com> 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@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> 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@lists.01.org
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
WARNING: multiple messages have this Message-ID (diff)
From: Matthew Auld <matthew.william.auld@gmail.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>,
kbuild-all@lists.01.org, kbuild@lists.01.org,
"ML dri-devel" <dri-devel@lists.freedesktop.org>,
"Chris Wilson" <chris@chris-wilson.co.uk>,
"Matthew Auld" <matthew.auld@intel.com>,
"Intel Graphics Development" <intel-gfx@lists.freedesktop.org>
Subject: Re: [Intel-gfx] [drm-intel:drm-intel-gt-next 8/14] drivers/gpu/drm/i915/gt/selftest_migrate.c:102 copy() error: uninitialized symbol 'rq'.
Date: Fri, 2 Jul 2021 11:32:45 +0100 [thread overview]
Message-ID: <CAM0jSHOb0bGWMt-tmUn62R_FpiM5TL2HFLbBqxhpqk1gH0qSUA@mail.gmail.com> (raw)
In-Reply-To: <202107020708.XXwacDfG-lkp@intel.com>
On Fri, 2 Jul 2021 at 09:45, Dan Carpenter <dan.carpenter@oracle.com> 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@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> 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@lists.01.org
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
WARNING: multiple messages have this Message-ID (diff)
From: Matthew Auld <matthew.william.auld@gmail.com>
To: kbuild-all@lists.01.org
Subject: Re: [Intel-gfx] [drm-intel:drm-intel-gt-next 8/14] drivers/gpu/drm/i915/gt/selftest_migrate.c:102 copy() error: uninitialized symbol 'rq'.
Date: Fri, 02 Jul 2021 11:32:45 +0100 [thread overview]
Message-ID: <CAM0jSHOb0bGWMt-tmUn62R_FpiM5TL2HFLbBqxhpqk1gH0qSUA@mail.gmail.com> (raw)
In-Reply-To: <202107020708.XXwacDfG-lkp@intel.com>
[-- Attachment #1: Type: text/plain, Size: 9587 bytes --]
On Fri, 2 Jul 2021 at 09:45, Dan Carpenter <dan.carpenter@oracle.com> 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@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> 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(a)lists.01.org
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx(a)lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
next prev parent reply other threads:[~2021-07-02 10:33 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-01 23:14 [drm-intel:drm-intel-gt-next 8/14] drivers/gpu/drm/i915/gt/selftest_migrate.c:102 copy() error: uninitialized symbol 'rq' kernel test robot
2021-07-02 8:44 ` Dan Carpenter
2021-07-02 8:44 ` [Intel-gfx] " Dan Carpenter
2021-07-02 8:44 ` Dan Carpenter
2021-07-02 10:32 ` Matthew Auld [this message]
2021-07-02 10:32 ` [Intel-gfx] " Matthew Auld
2021-07-02 10:32 ` Matthew Auld
2021-07-02 11:07 ` Dan Carpenter
2021-07-02 11:07 ` Dan Carpenter
2021-07-02 11:07 ` Dan Carpenter
2021-07-02 11:07 ` Dan Carpenter
2021-07-02 11:13 ` Dan Carpenter
2021-07-02 11:13 ` Dan Carpenter
2021-07-02 11:13 ` Dan Carpenter
2021-07-02 11:13 ` Dan Carpenter
2021-07-02 11:57 ` Matthew Auld
2021-07-02 11:57 ` Matthew Auld
2021-07-02 11:57 ` Matthew Auld
2021-07-02 11:34 ` Matthew Auld
2021-07-02 11:34 ` Matthew Auld
2021-07-02 11:34 ` Matthew Auld
2021-07-02 12:19 ` Dan Carpenter
2021-07-02 12:19 ` Dan Carpenter
2021-07-02 12:19 ` Dan Carpenter
2021-07-02 12:19 ` Dan Carpenter
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAM0jSHOb0bGWMt-tmUn62R_FpiM5TL2HFLbBqxhpqk1gH0qSUA@mail.gmail.com \
--to=matthew.william.auld@gmail.com \
--cc=chris@chris-wilson.co.uk \
--cc=dan.carpenter@oracle.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=intel-gfx@lists.freedesktop.org \
--cc=kbuild-all@lists.01.org \
--cc=kbuild@lists.01.org \
--cc=matthew.auld@intel.com \
--cc=thomas.hellstrom@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.