From: Greg Kroah-Hartman Date: Mon, 19 Jun 2023 06:27:26 +0000 (+0200) Subject: 6.1-stable patches X-Git-Tag: v4.14.319~31 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=89576fe461fff617512e32fc1cdfc1cd9e9db2b1;p=thirdparty%2Fkernel%2Fstable-queue.git 6.1-stable patches added patches: drm-amdgpu-don-t-set-struct-drm_driver.output_poll_changed.patch rcu-kvfree-avoid-freeing-new-kfree_rcu-memory-after-old-grace-period.patch --- diff --git a/queue-6.1/drm-amdgpu-don-t-set-struct-drm_driver.output_poll_changed.patch b/queue-6.1/drm-amdgpu-don-t-set-struct-drm_driver.output_poll_changed.patch new file mode 100644 index 00000000000..1ecfb42aa8d --- /dev/null +++ b/queue-6.1/drm-amdgpu-don-t-set-struct-drm_driver.output_poll_changed.patch @@ -0,0 +1,56 @@ +From 0e3172bac3f43759719384403fe2d1e4c61f87e0 Mon Sep 17 00:00:00 2001 +From: Thomas Zimmermann +Date: Thu, 3 Nov 2022 16:14:27 +0100 +Subject: drm/amdgpu: Don't set struct drm_driver.output_poll_changed + +From: Thomas Zimmermann + +commit 0e3172bac3f43759719384403fe2d1e4c61f87e0 upstream. + +Don't set struct drm_driver.output_poll_changed. It's used to restore +the fbdev console. But as amdgpu uses generic fbdev emulation, the +console is being restored by the DRM client helpers already. See the +functions drm_kms_helper_hotplug_event() and +drm_kms_helper_connector_hotplug_event() in drm_probe_helper.c. + +v2: + * fix commit description (Christian) + +Signed-off-by: Thomas Zimmermann +Reviewed-by: Javier Martinez Canillas +Link: https://patchwork.freedesktop.org/patch/msgid/20221103151446.2638-5-tzimmermann@suse.de +Cc: "Gagniuc, Alexandru" +Signed-off-by: Greg Kroah-Hartman +--- + drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 1 - + drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 -- + 2 files changed, 3 deletions(-) + +--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c ++++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c +@@ -1214,7 +1214,6 @@ amdgpu_display_user_framebuffer_create(s + + const struct drm_mode_config_funcs amdgpu_mode_funcs = { + .fb_create = amdgpu_display_user_framebuffer_create, +- .output_poll_changed = drm_fb_helper_output_poll_changed, + }; + + static const struct drm_prop_enum_list amdgpu_underscan_enum_list[] = +--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c ++++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +@@ -83,7 +83,6 @@ + #include + #include + #include +-#include + #include + #include + #include +@@ -2875,7 +2874,6 @@ const struct amdgpu_ip_block_version dm_ + static const struct drm_mode_config_funcs amdgpu_dm_mode_funcs = { + .fb_create = amdgpu_display_user_framebuffer_create, + .get_format_info = amd_get_format_info, +- .output_poll_changed = drm_fb_helper_output_poll_changed, + .atomic_check = amdgpu_dm_atomic_check, + .atomic_commit = drm_atomic_helper_commit, + }; diff --git a/queue-6.1/rcu-kvfree-avoid-freeing-new-kfree_rcu-memory-after-old-grace-period.patch b/queue-6.1/rcu-kvfree-avoid-freeing-new-kfree_rcu-memory-after-old-grace-period.patch new file mode 100644 index 00000000000..84d4ee486cc --- /dev/null +++ b/queue-6.1/rcu-kvfree-avoid-freeing-new-kfree_rcu-memory-after-old-grace-period.patch @@ -0,0 +1,152 @@ +From 5da7cb193db32da783a3f3e77d8b639989321d48 Mon Sep 17 00:00:00 2001 +From: Ziwei Dai +Date: Fri, 31 Mar 2023 20:42:09 +0800 +Subject: rcu/kvfree: Avoid freeing new kfree_rcu() memory after old grace period + +From: Ziwei Dai + +commit 5da7cb193db32da783a3f3e77d8b639989321d48 upstream. + +Memory passed to kvfree_rcu() that is to be freed is tracked by a +per-CPU kfree_rcu_cpu structure, which in turn contains pointers +to kvfree_rcu_bulk_data structures that contain pointers to memory +that has not yet been handed to RCU, along with an kfree_rcu_cpu_work +structure that tracks the memory that has already been handed to RCU. +These structures track three categories of memory: (1) Memory for +kfree(), (2) Memory for kvfree(), and (3) Memory for both that arrived +during an OOM episode. The first two categories are tracked in a +cache-friendly manner involving a dynamically allocated page of pointers +(the aforementioned kvfree_rcu_bulk_data structures), while the third +uses a simple (but decidedly cache-unfriendly) linked list through the +rcu_head structures in each block of memory. + +On a given CPU, these three categories are handled as a unit, with that +CPU's kfree_rcu_cpu_work structure having one pointer for each of the +three categories. Clearly, new memory for a given category cannot be +placed in the corresponding kfree_rcu_cpu_work structure until any old +memory has had its grace period elapse and thus has been removed. And +the kfree_rcu_monitor() function does in fact check for this. + +Except that the kfree_rcu_monitor() function checks these pointers one +at a time. This means that if the previous kfree_rcu() memory passed +to RCU had only category 1 and the current one has only category 2, the +kfree_rcu_monitor() function will send that current category-2 memory +along immediately. This can result in memory being freed too soon, +that is, out from under unsuspecting RCU readers. + +To see this, consider the following sequence of events, in which: + +o Task A on CPU 0 calls rcu_read_lock(), then uses "from_cset", + then is preempted. + +o CPU 1 calls kfree_rcu(cset, rcu_head) in order to free "from_cset" + after a later grace period. Except that "from_cset" is freed + right after the previous grace period ended, so that "from_cset" + is immediately freed. Task A resumes and references "from_cset"'s + member, after which nothing good happens. + +In full detail: + +CPU 0 CPU 1 +---------------------- ---------------------- +count_memcg_event_mm() +|rcu_read_lock() <--- +|mem_cgroup_from_task() + |// css_set_ptr is the "from_cset" mentioned on CPU 1 + |css_set_ptr = rcu_dereference((task)->cgroups) + |// Hard irq comes, current task is scheduled out. + + cgroup_attach_task() + |cgroup_migrate() + |cgroup_migrate_execute() + |css_set_move_task(task, from_cset, to_cset, true) + |cgroup_move_task(task, to_cset) + |rcu_assign_pointer(.., to_cset) + |... + |cgroup_migrate_finish() + |put_css_set_locked(from_cset) + |from_cset->refcount return 0 + |kfree_rcu(cset, rcu_head) // free from_cset after new gp + |add_ptr_to_bulk_krc_lock() + |schedule_delayed_work(&krcp->monitor_work, ..) + + kfree_rcu_monitor() + |krcp->bulk_head[0]'s work attached to krwp->bulk_head_free[] + |queue_rcu_work(system_wq, &krwp->rcu_work) + |if rwork->rcu.work is not in WORK_STRUCT_PENDING_BIT state, + |call_rcu(&rwork->rcu, rcu_work_rcufn) <--- request new gp + + // There is a perious call_rcu(.., rcu_work_rcufn) + // gp end, rcu_work_rcufn() is called. + rcu_work_rcufn() + |__queue_work(.., rwork->wq, &rwork->work); + + |kfree_rcu_work() + |krwp->bulk_head_free[0] bulk is freed before new gp end!!! + |The "from_cset" is freed before new gp end. + +// the task resumes some time later. + |css_set_ptr->subsys[(subsys_id) <--- Caused kernel crash, because css_set_ptr is freed. + +This commit therefore causes kfree_rcu_monitor() to refrain from moving +kfree_rcu() memory to the kfree_rcu_cpu_work structure until the RCU +grace period has completed for all three categories. + +v2: Use helper function instead of inserted code block at kfree_rcu_monitor(). + +Fixes: 34c881745549 ("rcu: Support kfree_bulk() interface in kfree_rcu()") +Fixes: 5f3c8d620447 ("rcu/tree: Maintain separate array for vmalloc ptrs") +Reported-by: Mukesh Ojha +Signed-off-by: Ziwei Dai +Reviewed-by: Uladzislau Rezki (Sony) +Tested-by: Uladzislau Rezki (Sony) +Signed-off-by: Paul E. McKenney +Signed-off-by: Suren Baghdasaryan +Signed-off-by: Greg Kroah-Hartman +--- + kernel/rcu/tree.c | 27 +++++++++++++++++++-------- + 1 file changed, 19 insertions(+), 8 deletions(-) + +--- a/kernel/rcu/tree.c ++++ b/kernel/rcu/tree.c +@@ -3099,6 +3099,18 @@ need_offload_krc(struct kfree_rcu_cpu *k + return !!krcp->head; + } + ++static bool ++need_wait_for_krwp_work(struct kfree_rcu_cpu_work *krwp) ++{ ++ int i; ++ ++ for (i = 0; i < FREE_N_CHANNELS; i++) ++ if (krwp->bkvhead_free[i]) ++ return true; ++ ++ return !!krwp->head_free; ++} ++ + static void + schedule_delayed_monitor_work(struct kfree_rcu_cpu *krcp) + { +@@ -3130,14 +3142,13 @@ static void kfree_rcu_monitor(struct wor + for (i = 0; i < KFREE_N_BATCHES; i++) { + struct kfree_rcu_cpu_work *krwp = &(krcp->krw_arr[i]); + +- // Try to detach bkvhead or head and attach it over any +- // available corresponding free channel. It can be that +- // a previous RCU batch is in progress, it means that +- // immediately to queue another one is not possible so +- // in that case the monitor work is rearmed. +- if ((krcp->bkvhead[0] && !krwp->bkvhead_free[0]) || +- (krcp->bkvhead[1] && !krwp->bkvhead_free[1]) || +- (krcp->head && !krwp->head_free)) { ++ // Try to detach bulk_head or head and attach it, only when ++ // all channels are free. Any channel is not free means at krwp ++ // there is on-going rcu work to handle krwp's free business. ++ if (need_wait_for_krwp_work(krwp)) ++ continue; ++ ++ if (need_offload_krc(krcp)) { + // Channel 1 corresponds to the SLAB-pointer bulk path. + // Channel 2 corresponds to vmalloc-pointer bulk path. + for (j = 0; j < FREE_N_CHANNELS; j++) { diff --git a/queue-6.1/series b/queue-6.1/series index 4b9c2731044..33521be2d2e 100644 --- a/queue-6.1/series +++ b/queue-6.1/series @@ -153,3 +153,5 @@ selftests-ptp-fix-timestamp-printf-format-for-ptp_sy.patch octeon_ep-add-missing-check-for-ioremap.patch afs-fix-vlserver-probe-rtt-handling.patch parisc-delete-redundant-register-definitions-in-asm-assembly.h.patch +rcu-kvfree-avoid-freeing-new-kfree_rcu-memory-after-old-grace-period.patch +drm-amdgpu-don-t-set-struct-drm_driver.output_poll_changed.patch