June 2025 - Linux-stable-mirror

[PATCH] rust: kasan/kbuild: fix missing flags on first build

by Miguel Ojeda

If KASAN is enabled, and one runs in a clean repository e.g.: make LLVM=1 prepare make LLVM=1 prepare Then the Rust code gets rebuilt, which should not happen. The reason is some of the LLVM KASAN `rustc` flags are added in the second run: -Cllvm-args=-asan-instrumentation-with-call-threshold=10000 -Cllvm-args=-asan-stack=0 -Cllvm-args=-asan-globals=1 -Cllvm-args=-asan-kernel-mem-intrinsic-prefix=1 Further runs do not rebuild Rust because the flags do not change anymore. Rebuilding like that in the second run is bad, even if this just happens with KASAN enabled, but missing flags in the first one is even worse. The root issue is that we pass, for some architectures and for the moment, a generated `target.json` file. That file is not ready by the time `rustc` gets called for the flag test, and thus the flag test fails just because the file is not available, e.g.: $ ... --target=./scripts/target.json ... -Cllvm-args=... error: target file "./scripts/target.json" does not exist There are a few approaches we could take here to solve this. For instance, we could ensure that every time that the config is rebuilt, we regenerate the file and recompute the flags. Or we could use the LLVM version to check for these flags, instead of testing the flag (which may have other advantages, such as allowing us to detect renames on the LLVM side). However, it may be easier than that: `rustc` is aware of the `-Cllvm-args` regardless of the `--target` (e.g. I checked that the list printed is the same, plus that I can check for these flags even if I pass a completely unrelated target), and thus we can just eliminate the dependency completely. Thus filter out the target. This does mean that `rustc-option` cannot be used to test a flag that requires the right target, but we don't have other users yet, it is a minimal change and we want to get rid of custom targets in the future. We could only filter in the case `target.json` is used, to make it work in more cases, but then it would be harder to notice that it may not work in a couple architectures. Cc: Matthew Maurer <mmaurer(a)google.com> Cc: Sami Tolvanen <samitolvanen(a)google.com> Cc: stable(a)vger.kernel.org Fixes: e3117404b411 ("kbuild: rust: Enable KASAN support") Signed-off-by: Miguel Ojeda <ojeda(a)kernel.org> --- By the way, I noticed that we are not getting `asan-instrument-allocas` enabled in neither C nor Rust -- upstream LLVM renamed it in commit 8176ee9b5dda ("[asan] Rename asan-instrument-allocas -> asan-instrument-dynamic-allocas")). But it happened a very long time ago (9 years ago), and the addition in the kernel is fairly old too, in 342061ee4ef3 ("kasan: support alloca() poisoning"). I assume it should either be renamed or removed? Happy to send a patch if so. scripts/Makefile.compiler | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/Makefile.compiler b/scripts/Makefile.compiler index 8956587b8547..7ed7f92a7daa 100644 --- a/scripts/Makefile.compiler +++ b/scripts/Makefile.compiler @@ -80,7 +80,7 @@ ld-option = $(call try-run, $(LD) $(KBUILD_LDFLAGS) $(1) -v,$(1),$(2),$(3)) # TODO: remove RUSTC_BOOTSTRAP=1 when we raise the minimum GNU Make version to 4.4 __rustc-option = $(call try-run,\ echo '#![allow(missing_docs)]#![feature(no_core)]#![no_core]' | RUSTC_BOOTSTRAP=1\ - $(1) --sysroot=/dev/null $(filter-out --sysroot=/dev/null,$(2)) $(3)\ + $(1) --sysroot=/dev/null $(filter-out --sysroot=/dev/null --target=%,$(2)) $(3)\ --crate-type=rlib --out-dir=$(TMPOUT) --emit=obj=- - >/dev/null,$(3),$(4)) # rustc-option base-commit: 0af2f6be1b4281385b618cb86ad946eded089ac8 -- 2.49.0

3 weeks, 5 days

5
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[PATCH v3] sched/deadline: Fix race in push_dl_task

by Harshit Agarwal

When a CPU chooses to call push_dl_task and picks a task to push to another CPU's runqueue then it will call find_lock_later_rq method which would take a double lock on both CPUs' runqueues. If one of the locks aren't readily available, it may lead to dropping the current runqueue lock and reacquiring both the locks at once. During this window it is possible that the task is already migrated and is running on some other CPU. These cases are already handled. However, if the task is migrated and has already been executed and another CPU is now trying to wake it up (ttwu) such that it is queued again on the runqeue (on_rq is 1) and also if the task was run by the same CPU, then the current checks will pass even though the task was migrated out and is no longer in the pushable tasks list. Please go through the original rt change for more details on the issue. To fix this, after the lock is obtained inside the find_lock_later_rq, it ensures that the task is still at the head of pushable tasks list. Also removed some checks that are no longer needed with the addition of this new check. However, the new check of pushable tasks list only applies when find_lock_later_rq is called by push_dl_task. For the other caller i.e. dl_task_offline_migration, existing checks are used. Signed-off-by: Harshit Agarwal <harshit(a)nutanix.com> Cc: stable(a)vger.kernel.org --- Changes in v3: - Incorporated review comments from Juri around the commit message as well as around the comment regarding checks in find_lock_later_rq. - Link to v2: https://lore.kernel.org/stable/20250317022325.52791-1-harshit@nutanix.com/ Changes in v2: - As per Juri's suggestion, moved the check inside find_lock_later_rq similar to rt change. Here we distinguish among the push_dl_task caller vs dl_task_offline_migration by checking if the task is throttled or not. - Fixed the commit message to refer to the rt change by title. - Link to v1: https://lore.kernel.org/lkml/20250307204255.60640-1-harshit@nutanix.com/ --- kernel/sched/deadline.c | 73 +++++++++++++++++++++++++++-------------- 1 file changed, 49 insertions(+), 24 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 38e4537790af..e0c95f33e1ed 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -2621,6 +2621,25 @@ static int find_later_rq(struct task_struct *task) return -1; } +static struct task_struct *pick_next_pushable_dl_task(struct rq *rq) +{ + struct task_struct *p; + + if (!has_pushable_dl_tasks(rq)) + return NULL; + + p = __node_2_pdl(rb_first_cached(&rq->dl.pushable_dl_tasks_root)); + + WARN_ON_ONCE(rq->cpu != task_cpu(p)); + WARN_ON_ONCE(task_current(rq, p)); + WARN_ON_ONCE(p->nr_cpus_allowed <= 1); + + WARN_ON_ONCE(!task_on_rq_queued(p)); + WARN_ON_ONCE(!dl_task(p)); + + return p; +} + /* Locks the rq it finds */ static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq) { @@ -2648,12 +2667,37 @@ static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq) /* Retry if something changed. */ if (double_lock_balance(rq, later_rq)) { - if (unlikely(task_rq(task) != rq || + /* + * double_lock_balance had to release rq->lock, in the + * meantime, task may no longer be fit to be migrated. + * Check the following to ensure that the task is + * still suitable for migration: + * 1. It is possible the task was scheduled, + * migrate_disabled was set and then got preempted, + * so we must check the task migration disable + * flag. + * 2. The CPU picked is in the task's affinity. + * 3. For throttled task (dl_task_offline_migration), + * check the following: + * - the task is not on the rq anymore (it was + * migrated) + * - the task is not on CPU anymore + * - the task is still a dl task + * - the task is not queued on the rq anymore + * 4. For the non-throttled task (push_dl_task), the + * check to ensure that this task is still at the + * head of the pushable tasks list is enough. + */ + if (unlikely(is_migration_disabled(task) || !cpumask_test_cpu(later_rq->cpu, &task->cpus_mask) || - task_on_cpu(rq, task) || - !dl_task(task) || - is_migration_disabled(task) || - !task_on_rq_queued(task))) { + (task->dl.dl_throttled && + (task_rq(task) != rq || + task_on_cpu(rq, task) || + !dl_task(task) || + !task_on_rq_queued(task))) || + (!task->dl.dl_throttled && + task != pick_next_pushable_dl_task(rq)))) { + double_unlock_balance(rq, later_rq); later_rq = NULL; break; @@ -2676,25 +2720,6 @@ static struct rq *find_lock_later_rq(struct task_struct *task, struct rq *rq) return later_rq; } -static struct task_struct *pick_next_pushable_dl_task(struct rq *rq) -{ - struct task_struct *p; - - if (!has_pushable_dl_tasks(rq)) - return NULL; - - p = __node_2_pdl(rb_first_cached(&rq->dl.pushable_dl_tasks_root)); - - WARN_ON_ONCE(rq->cpu != task_cpu(p)); - WARN_ON_ONCE(task_current(rq, p)); - WARN_ON_ONCE(p->nr_cpus_allowed <= 1); - - WARN_ON_ONCE(!task_on_rq_queued(p)); - WARN_ON_ONCE(!dl_task(p)); - - return p; -} - /* * See if the non running -deadline tasks on this rq * can be sent to some other CPU where they can preempt -- 2.49.0.111.g5b97a56fa0

3 weeks, 5 days

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[PATCH v2 1/3] PCI: Relaxed tail alignment should never increase min_align

by Ilpo Järvinen

When using relaxed tail alignment for the bridge window, pbus_size_mem() also tries to minimize min_align, which can under certain scenarios end up increasing min_align from that found by calculate_mem_align(). Ensure min_align is not increased by the relaxed tail alignment. Eventually, it would be better to add calculate_relaxed_head_align() similar to calculate_mem_align() which finds out what alignment can be used for the head without introducing any gaps into the bridge window to give flexibility on head address too. But that looks relatively complex algorithm so it requires much more testing than fixing the immediate problem causing a regression. Fixes: 67f9085596ee ("PCI: Allow relaxed bridge window tail sizing for optional resources") Reported-by: Rio <rio(a)r26.me> Tested-by: Rio <rio(a)r26.me> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Cc: <stable(a)vger.kernel.org> --- drivers/pci/setup-bus.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 07c3d021a47e..f90d49cd07da 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1169,6 +1169,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, resource_size_t children_add_size = 0; resource_size_t children_add_align = 0; resource_size_t add_align = 0; + resource_size_t relaxed_align; if (!b_res) return -ENOSPC; @@ -1246,8 +1247,9 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, if (bus->self && size0 && !pbus_upstream_space_available(bus, mask | IORESOURCE_PREFETCH, type, size0, min_align)) { - min_align = 1ULL << (max_order + __ffs(SZ_1M)); - min_align = max(min_align, win_align); + relaxed_align = 1ULL << (max_order + __ffs(SZ_1M)); + relaxed_align = max(relaxed_align, win_align); + min_align = min(min_align, relaxed_align); size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res), win_align); pci_info(bus->self, "bridge window %pR to %pR requires relaxed alignment rules\n", b_res, &bus->busn_res); @@ -1261,8 +1263,9 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, if (bus->self && size1 && !pbus_upstream_space_available(bus, mask | IORESOURCE_PREFETCH, type, size1, add_align)) { - min_align = 1ULL << (max_order + __ffs(SZ_1M)); - min_align = max(min_align, win_align); + relaxed_align = 1ULL << (max_order + __ffs(SZ_1M)); + relaxed_align = max(min_align, win_align); + min_align = min(min_align, relaxed_align); size1 = calculate_memsize(size, min_size, add_size, children_add_size, resource_size(b_res), win_align); pci_info(bus->self, -- 2.39.5

1 month, 1 week

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[PATCH v2 3/3] PCI: Fix failure detection during resource resize

by Ilpo Järvinen

Since the commit 96336ec70264 ("PCI: Perform reset_resource() and build fail list in sync") the failed list is always built and returned to let the caller decide what to do with the failures. The caller may want to retry resource fitting and assignment and before that can happen, the resources should be restored to their original state (a reset effectively clears the struct resource), which requires returning them on the failed list so that the original state remains stored in the associated struct pci_dev_resource. Resource resizing is different from the ordinary resource fitting and assignment in that it only considers part of the resources. This means failures for other resource types are not relevant at all and should be ignored. As resize doesn't unassign such unrelated resources, those resource ending up into the failed list implies assignment of that resource must have failed before resize too. The check in pci_reassign_bridge_resources() to decide if the whole assignment is successful, however, is based on list emptiness which will cause false negatives when the failed list has resources with an unrelated type. If the failed list is not empty, call pci_required_resource_failed() and extend it to be able to filter on specific resource types too (if provided). Calling pci_required_resource_failed() at this point is slightly problematic because the resource itself is reset when the failed list is constructed in __assign_resources_sorted(). As a result, pci_resource_is_optional() does not have access to the original resource flags. This could be worked around by restoring and re-reseting the resource around the call to pci_resource_is_optional(), however, it shouldn't cause issue as resource resizing is meant for 64-bit prefetchable resources according to Christian König (see the Link which unfortunately doesn't point directly to Christian's reply because lore didn't store that email at all). Fixes: 96336ec70264 ("PCI: Perform reset_resource() and build fail list in sync") Link: https://lore.kernel.org/all/c5d1b5d8-8669-5572-75a7-0b480f581ac1@linux.inte… Reported-by: D Scott Phillips <scott(a)os.amperecomputing.com> Tested-by: D Scott Phillips <scott(a)os.amperecomputing.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Reviewed-by: D Scott Phillips <scott(a)os.amperecomputing.com> Cc: Christian König <christian.koenig(a)amd.com> Cc: <stable(a)vger.kernel.org> --- drivers/pci/setup-bus.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 24863d8d0053..dbbd80d78d3d 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -28,6 +28,10 @@ #include <linux/acpi.h> #include "pci.h" +#define PCI_RES_TYPE_MASK \ + (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH |\ + IORESOURCE_MEM_64) + unsigned int pci_flags; EXPORT_SYMBOL_GPL(pci_flags); @@ -384,13 +388,19 @@ static bool pci_need_to_release(unsigned long mask, struct resource *res) } /* Return: @true if assignment of a required resource failed. */ -static bool pci_required_resource_failed(struct list_head *fail_head) +static bool pci_required_resource_failed(struct list_head *fail_head, + unsigned long type) { struct pci_dev_resource *fail_res; + type &= PCI_RES_TYPE_MASK; + list_for_each_entry(fail_res, fail_head, list) { int idx = pci_resource_num(fail_res->dev, fail_res->res); + if (type && (fail_res->flags & PCI_RES_TYPE_MASK) != type) + continue; + if (!pci_resource_is_optional(fail_res->dev, idx)) return true; } @@ -504,7 +514,7 @@ static void __assign_resources_sorted(struct list_head *head, } /* Without realloc_head and only optional fails, nothing more to do. */ - if (!pci_required_resource_failed(&local_fail_head) && + if (!pci_required_resource_failed(&local_fail_head, 0) && list_empty(realloc_head)) { list_for_each_entry(save_res, &save_head, list) { struct resource *res = save_res->res; @@ -1708,10 +1718,6 @@ static void __pci_bridge_assign_resources(const struct pci_dev *bridge, } } -#define PCI_RES_TYPE_MASK \ - (IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_PREFETCH |\ - IORESOURCE_MEM_64) - static void pci_bridge_release_resources(struct pci_bus *bus, unsigned long type) { @@ -2449,8 +2455,12 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) free_list(&added); if (!list_empty(&failed)) { - ret = -ENOSPC; - goto cleanup; + if (pci_required_resource_failed(&failed, type)) { + ret = -ENOSPC; + goto cleanup; + } + /* Only resources with unrelated types failed (again) */ + free_list(&failed); } list_for_each_entry(dev_res, &saved, list) { -- 2.39.5

1 month, 1 week

2
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[PATCH v2 2/3] PCI: Fix pdev_resources_assignable() disparity

by Ilpo Järvinen

pdev_sort_resources() uses pdev_resources_assignable() helper to decide if device's resources cannot be assigned. pbus_size_mem(), on the other hand, does not do the same check. This could lead into a situation where a resource ends up on realloc_head list but is not on the head list, which is turn prevents emptying the resource from the realloc_head list in __assign_resources_sorted(). A non-empty realloc_head is unacceptable because it triggers an internal sanity check as show in this log with a device that has class 0 (PCI_CLASS_NOT_DEFINED): pci 0001:01:00.0: [144d:a5a5] type 00 class 0x000000 PCIe Endpoint pci 0001:01:00.0: BAR 0 [mem 0x00000000-0x000fffff 64bit] pci 0001:01:00.0: ROM [mem 0x00000000-0x0000ffff pref] pci 0001:01:00.0: enabling Extended Tags pci 0001:01:00.0: PME# supported from D0 D3hot D3cold pci 0001:01:00.0: 15.752 Gb/s available PCIe bandwidth, limited by 8.0 GT/s PCIe x2 link at 0001:00:00.0 (capable of 31.506 Gb/s with 16.0 GT/s PCIe x2 link) pcieport 0001:00:00.0: bridge window [mem 0x00100000-0x001fffff] to [bus 01-ff] add_size 100000 add_align 100000 pcieport 0001:00:00.0: bridge window [mem 0x40000000-0x401fffff]: assigned ------------[ cut here ]------------ kernel BUG at drivers/pci/setup-bus.c:2532! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP ... Call trace: pci_assign_unassigned_bus_resources+0x110/0x114 (P) pci_rescan_bus+0x28/0x48 Use pdev_resources_assignable() also within pbus_size_mem() to skip processing of non-assignable resources which removes the disparity in between what resources pdev_sort_resources() and pbus_size_mem() consider. As non-assignable resources are no longer processed, they are not added to the realloc_head list, thus the sanity check no longer triggers. This disparity problem is very old but only now became apparent after the commit 2499f5348431 ("PCI: Rework optional resource handling") that made the ROM resources optional when calculating bridge window sizes which required adding the resource to the realloc_head list. Previously, bridge windows were just sized larger than necessary. Fixes: 2499f5348431 ("PCI: Rework optional resource handling") Reported-by: Tudor Ambarus <tudor.ambarus(a)linaro.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen(a)linux.intel.com> Cc: <stable(a)vger.kernel.org> --- drivers/pci/setup-bus.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index f90d49cd07da..24863d8d0053 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1191,6 +1191,7 @@ static int pbus_size_mem(struct pci_bus *bus, unsigned long mask, resource_size_t r_size; if (r->parent || (r->flags & IORESOURCE_PCI_FIXED) || + !pdev_resources_assignable(dev) || ((r->flags & mask) != type && (r->flags & mask) != type2 && (r->flags & mask) != type3)) -- 2.39.5

1 month, 1 week

2
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[PATCH AUTOSEL 6.14 001/642] kconfig: merge_config: use an empty file as initfile

by Sasha Levin

From: Daniel Gomez <da.gomez(a)samsung.com> [ Upstream commit a26fe287eed112b4e21e854f173c8918a6a8596d ] The scripts/kconfig/merge_config.sh script requires an existing $INITFILE (or the $1 argument) as a base file for merging Kconfig fragments. However, an empty $INITFILE can serve as an initial starting point, later referenced by the KCONFIG_ALLCONFIG Makefile variable if -m is not used. This variable can point to any configuration file containing preset config symbols (the merged output) as stated in Documentation/kbuild/kconfig.rst. When -m is used $INITFILE will contain just the merge output requiring the user to run make (i.e. KCONFIG_ALLCONFIG=<$INITFILE> make <allnoconfig/alldefconfig> or make olddefconfig). Instead of failing when `$INITFILE` is missing, create an empty file and use it as the starting point for merges. Signed-off-by: Daniel Gomez <da.gomez(a)samsung.com> Signed-off-by: Masahiro Yamada <masahiroy(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- scripts/kconfig/merge_config.sh | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/scripts/kconfig/merge_config.sh b/scripts/kconfig/merge_config.sh index 0b7952471c18f..79c09b378be81 100755 --- a/scripts/kconfig/merge_config.sh +++ b/scripts/kconfig/merge_config.sh @@ -112,8 +112,8 @@ INITFILE=$1 shift; if [ ! -r "$INITFILE" ]; then - echo "The base file '$INITFILE' does not exist. Exit." >&2 - exit 1 + echo "The base file '$INITFILE' does not exist. Creating one..." >&2 + touch "$INITFILE" fi MERGE_LIST=$* -- 2.39.5

1 month, 1 week

19
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Instability in ALL stable and LTS distro kernels (IRQ #16 being disabled, PCIe bus errors, ath10k_pci) in Dell Inspiron 5567

by Bandhan Pramanik

Hello, The following is the original thread, where a bug was reported to the linux-wireless and ath10k mailing lists. The specific bug has been detailed clearly here. https://lore.kernel.org/linux-wireless/690B1DB2-C9DC-4FAD-8063-4CED659B1701… There is also a Bugzilla report by me, which was opened later: https://bugzilla.kernel.org/show_bug.cgi?id=220264 As stated, it is highly encouraged to check out all the logs, especially the line of IRQ #16 in /proc/interrupts. Here is where all the logs are: https://gist.github.com/BandhanPramanik/ddb0cb23eca03ca2ea43a1d832a16180 (these logs are taken from an Arch liveboot) On my daily driver, I found these on my IRQ #16: 16: 173210 0 0 0 IR-IO-APIC 16-fasteoi i2c_designware.0, idma64.0, i801_smbus The fixes stated on the Reddit post for this Wi-Fi card didn't quite work. (But git-cloning the firmware files did give me some more time to have stable internet) This time, I had to go for the GRUB kernel parameters. Right now, I'm using "irqpoll" to curb the errors caused. "intel_iommu=off" did not work, and the Wi-Fi was constantly crashing even then. Did not try out "pci=noaer" this time. If it's of any concern, there is a very weird error in Chromium-based browsers which has only happened after I started using irqpoll. When I Google something, the background of the individual result boxes shows as pure black, while the surrounding space is the usual greyish-blackish, like we see in Dark Mode. Here is a picture of the exact thing I'm experiencing: https://files.catbox.moe/mjew6g.png If you notice anything in my logs/bug reports, please let me know. (Because it seems like Wi-Fi errors are just a red herring, there are some ACPI or PCIe-related errors in the computers of this model - just a naive speculation, though.) Thanking you, Bandhan Pramanik

1 month, 1 week

4
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FAILED: patch "[PATCH] KVM: VMX: Flush shadow VMCS on emergency reboot" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x a0ee1d5faff135e28810f29e0f06328c66f89852 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062039-anger-volumes-9d75@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a0ee1d5faff135e28810f29e0f06328c66f89852 Mon Sep 17 00:00:00 2001 From: Chao Gao <chao.gao(a)intel.com> Date: Mon, 24 Mar 2025 22:08:48 +0800 Subject: [PATCH] KVM: VMX: Flush shadow VMCS on emergency reboot Ensure the shadow VMCS cache is evicted during an emergency reboot to prevent potential memory corruption if the cache is evicted after reboot. This issue was identified through code inspection, as __loaded_vmcs_clear() flushes both the normal VMCS and the shadow VMCS. Avoid checking the "launched" state during an emergency reboot, unlike the behavior in __loaded_vmcs_clear(). This is important because reboot NMIs can interfere with operations like copy_shadow_to_vmcs12(), where shadow VMCSes are loaded directly using VMPTRLD. In such cases, if NMIs occur right after the VMCS load, the shadow VMCSes will be active but the "launched" state may not be set. Fixes: 16f5b9034b69 ("KVM: nVMX: Copy processor-specific shadow-vmcs to VMCS12") Cc: stable(a)vger.kernel.org Signed-off-by: Chao Gao <chao.gao(a)intel.com> Reviewed-by: Kai Huang <kai.huang(a)intel.com> Link: https://lore.kernel.org/r/20250324140849.2099723-1-chao.gao@intel.com Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index ef2d7208dd20..848c4963bdb8 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -770,8 +770,11 @@ void vmx_emergency_disable_virtualization_cpu(void) return; list_for_each_entry(v, &per_cpu(loaded_vmcss_on_cpu, cpu), - loaded_vmcss_on_cpu_link) + loaded_vmcss_on_cpu_link) { vmcs_clear(v->vmcs); + if (v->shadow_vmcs) + vmcs_clear(v->shadow_vmcs); + } kvm_cpu_vmxoff(); }

1 month, 2 weeks

3
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FAILED: patch "[PATCH] KVM: VMX: Flush shadow VMCS on emergency reboot" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x a0ee1d5faff135e28810f29e0f06328c66f89852 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025062034-chastise-wrecking-9a12@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a0ee1d5faff135e28810f29e0f06328c66f89852 Mon Sep 17 00:00:00 2001 From: Chao Gao <chao.gao(a)intel.com> Date: Mon, 24 Mar 2025 22:08:48 +0800 Subject: [PATCH] KVM: VMX: Flush shadow VMCS on emergency reboot Ensure the shadow VMCS cache is evicted during an emergency reboot to prevent potential memory corruption if the cache is evicted after reboot. This issue was identified through code inspection, as __loaded_vmcs_clear() flushes both the normal VMCS and the shadow VMCS. Avoid checking the "launched" state during an emergency reboot, unlike the behavior in __loaded_vmcs_clear(). This is important because reboot NMIs can interfere with operations like copy_shadow_to_vmcs12(), where shadow VMCSes are loaded directly using VMPTRLD. In such cases, if NMIs occur right after the VMCS load, the shadow VMCSes will be active but the "launched" state may not be set. Fixes: 16f5b9034b69 ("KVM: nVMX: Copy processor-specific shadow-vmcs to VMCS12") Cc: stable(a)vger.kernel.org Signed-off-by: Chao Gao <chao.gao(a)intel.com> Reviewed-by: Kai Huang <kai.huang(a)intel.com> Link: https://lore.kernel.org/r/20250324140849.2099723-1-chao.gao@intel.com Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index ef2d7208dd20..848c4963bdb8 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -770,8 +770,11 @@ void vmx_emergency_disable_virtualization_cpu(void) return; list_for_each_entry(v, &per_cpu(loaded_vmcss_on_cpu, cpu), - loaded_vmcss_on_cpu_link) + loaded_vmcss_on_cpu_link) { vmcs_clear(v->vmcs); + if (v->shadow_vmcs) + vmcs_clear(v->shadow_vmcs); + } kvm_cpu_vmxoff(); }

1 month, 2 weeks

3
6
0 0

[PATCH] usb: hub: Don't try to recover devices lost during warm reset.

by Mathias Nyman

Hub driver warm-resets ports in SS.Inactive or Compliance mode to recover a possible connected device. The port reset code correctly detects if a connection is lost during reset, but hub driver port_event() fails to take this into account in some cases. port_event() ends up using stale values and assumes there is a connected device, and will try all means to recover it, including power-cycling the port. Details: This case was triggered when xHC host was suspended with DbC (Debug Capability) enabled and connected. DbC turns one xHC port into a simple usb debug device, allowing debugging a system with an A-to-A USB debug cable. xhci DbC code disables DbC when xHC is system suspended to D3, and enables it back during resume. We essentially end up with two hosts connected to each other during suspend, and, for a short while during resume, until DbC is enabled back. The suspended xHC host notices some activity on the roothub port, but can't train the link due to being suspended, so xHC hardware sets a CAS (Cold Attach Status) flag for this port to inform xhci host driver that the port needs to be warm reset once xHC resumes. CAS is xHCI specific, and not part of USB specification, so xhci driver tells usb core that the port has a connection and link is in compliance mode. Recovery from complinace mode is similar to CAS recovery. xhci CAS driver support that fakes a compliance mode connection was added in commit 8bea2bd37df0 ("usb: Add support for root hub port status CAS") Once xHCI resumes and DbC is enabled back, all activity on the xHC roothub host side port disappears. The hub driver will anyway think port has a connection and link is in compliance mode, and hub driver will try to recover it. The port power-cycle during recovery seems to cause issues to the active DbC connection. Fix this by clearing connect_change flag if hub_port_reset() returns -ENOTCONN, thus avoiding the whole unnecessary port recovery and initialization attempt. Cc: stable(a)vger.kernel.org Fixes: 8bea2bd37df0 ("usb: Add support for root hub port status CAS") Tested-by: Łukasz Bartosik <ukaszb(a)chromium.org> Signed-off-by: Mathias Nyman <mathias.nyman(a)linux.intel.com> --- drivers/usb/core/hub.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 6bb6e92cb0a4..f981e365be36 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -5754,6 +5754,7 @@ static void port_event(struct usb_hub *hub, int port1) struct usb_device *hdev = hub->hdev; u16 portstatus, portchange; int i = 0; + int err; connect_change = test_bit(port1, hub->change_bits); clear_bit(port1, hub->event_bits); @@ -5850,8 +5851,11 @@ static void port_event(struct usb_hub *hub, int port1) } else if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION) || udev->state == USB_STATE_NOTATTACHED) { dev_dbg(&port_dev->dev, "do warm reset, port only\n"); - if (hub_port_reset(hub, port1, NULL, - HUB_BH_RESET_TIME, true) < 0) + err = hub_port_reset(hub, port1, NULL, + HUB_BH_RESET_TIME, true); + if (!udev && err == -ENOTCONN) + connect_change = 0; + else if (err < 0) hub_port_disable(hub, port1, 1); } else { dev_dbg(&port_dev->dev, "do warm reset, full device\n"); -- 2.43.0

1 month, 2 weeks

6
17
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