From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Dan Carpenter <dan.carpenter@oracle.com>,
Paolo Bonzini <pbonzini@redhat.com>
Subject: [PATCH 5.18 18/67] x86, kvm: use correct GFP flags for preemption disabled
Date: Fri, 3 Jun 2022 19:43:19 +0200 [thread overview]
Message-ID: <20220603173821.254695331@linuxfoundation.org> (raw)
In-Reply-To: <20220603173820.731531504@linuxfoundation.org>
From: Paolo Bonzini <pbonzini@redhat.com>
commit baec4f5a018fe2d708fc1022330dba04b38b5fe3 upstream.
Commit ddd7ed842627 ("x86/kvm: Alloc dummy async #PF token outside of
raw spinlock") leads to the following Smatch static checker warning:
arch/x86/kernel/kvm.c:212 kvm_async_pf_task_wake()
warn: sleeping in atomic context
arch/x86/kernel/kvm.c
202 raw_spin_lock(&b->lock);
203 n = _find_apf_task(b, token);
204 if (!n) {
205 /*
206 * Async #PF not yet handled, add a dummy entry for the token.
207 * Allocating the token must be down outside of the raw lock
208 * as the allocator is preemptible on PREEMPT_RT kernels.
209 */
210 if (!dummy) {
211 raw_spin_unlock(&b->lock);
--> 212 dummy = kzalloc(sizeof(*dummy), GFP_KERNEL);
^^^^^^^^^^
Smatch thinks the caller has preempt disabled. The `smdb.py preempt
kvm_async_pf_task_wake` output call tree is:
sysvec_kvm_asyncpf_interrupt() <- disables preempt
-> __sysvec_kvm_asyncpf_interrupt()
-> kvm_async_pf_task_wake()
The caller is this:
arch/x86/kernel/kvm.c
290 DEFINE_IDTENTRY_SYSVEC(sysvec_kvm_asyncpf_interrupt)
291 {
292 struct pt_regs *old_regs = set_irq_regs(regs);
293 u32 token;
294
295 ack_APIC_irq();
296
297 inc_irq_stat(irq_hv_callback_count);
298
299 if (__this_cpu_read(apf_reason.enabled)) {
300 token = __this_cpu_read(apf_reason.token);
301 kvm_async_pf_task_wake(token);
302 __this_cpu_write(apf_reason.token, 0);
303 wrmsrl(MSR_KVM_ASYNC_PF_ACK, 1);
304 }
305
306 set_irq_regs(old_regs);
307 }
The DEFINE_IDTENTRY_SYSVEC() is a wrapper that calls this function
from the call_on_irqstack_cond(). It's inside the call_on_irqstack_cond()
where preempt is disabled (unless it's already disabled). The
irq_enter/exit_rcu() functions disable/enable preempt.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/kvm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -209,7 +209,7 @@ again:
*/
if (!dummy) {
raw_spin_unlock(&b->lock);
- dummy = kzalloc(sizeof(*dummy), GFP_KERNEL);
+ dummy = kzalloc(sizeof(*dummy), GFP_ATOMIC);
/*
* Continue looping on allocation failure, eventually
next prev parent reply other threads:[~2022-06-03 18:14 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-03 17:43 [PATCH 5.18 00/67] 5.18.2-rc1 review Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 01/67] netfilter: nf_tables: disallow non-stateful expression in sets earlier Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 02/67] i2c: ismt: prevent memory corruption in ismt_access() Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 03/67] assoc_array: Fix BUG_ON during garbage collect Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 04/67] pipe: make poll_usage boolean and annotate its access Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 05/67] pipe: Fix missing lock in pipe_resize_ring() Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 06/67] net: ipa: compute proper aggregation limit Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 07/67] drm/i915: Fix -Wstringop-overflow warning in call to intel_read_wm_latency() Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 08/67] exfat: check if cluster num is valid Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 09/67] exfat: fix referencing wrong parent directory information after renaming Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 10/67] netfilter: nft_limit: Clone packet limits cost value Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 11/67] netfilter: nf_tables: sanitize nft_set_desc_concat_parse() Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 12/67] netfilter: nf_tables: hold mutex on netns pre_exit path Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 13/67] netfilter: nf_tables: double hook unregistration in netns path Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 14/67] netfilter: conntrack: re-fetch conntrack after insertion Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 15/67] KVM: PPC: Book3S HV: fix incorrect NULL check on list iterator Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 16/67] x86/fpu: KVM: Set the base guest FPU uABI size to sizeof(struct kvm_xsave) Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 17/67] x86/kvm: Alloc dummy async #PF token outside of raw spinlock Greg Kroah-Hartman
2022-06-03 17:43 ` Greg Kroah-Hartman [this message]
2022-06-03 17:43 ` [PATCH 5.18 19/67] x86/uaccess: Implement macros for CMPXCHG on user addresses Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 20/67] KVM: x86: Use __try_cmpxchg_user() to update guest PTE A/D bits Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 21/67] KVM: x86: Use __try_cmpxchg_user() to emulate atomic accesses Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 22/67] KVM: x86: fix typo in __try_cmpxchg_user causing non-atomicness Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 23/67] KVM: x86: avoid calling x86 emulator without a decoded instruction Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 24/67] KVM: x86: avoid loading a vCPU after .vm_destroy was called Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 25/67] KVM: x86: Fix the intel_pt PMI handling wrongly considered from guest Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 26/67] KVM: x86: Drop WARNs that assert a triple fault never "escapes" from L2 Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 27/67] KVM: x86/mmu: Dont rebuild page when the page is synced and no tlb flushing is required Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 28/67] KVM: SVM: Use kzalloc for sev ioctl interfaces to prevent kernel data leak Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 29/67] crypto: caam - fix i.MX6SX entropy delay value Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 30/67] crypto: ecrdsa - Fix incorrect use of vli_cmp Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 31/67] crypto: qat - rework the VF2PF interrupt handling logic Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 32/67] zsmalloc: fix races between asynchronous zspage free and page migration Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 33/67] tools/memory-model/README: Update klitmus7 compat table Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 34/67] ALSA: usb-audio: Workaround for clock setup on TEAC devices Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 35/67] ALSA: usb-audio: Add missing ep_idx in fixed EP quirks Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 36/67] ALSA: usb-audio: Configure sync endpoints before data Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 37/67] Bluetooth: hci_qca: Use del_timer_sync() before freeing Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 38/67] ARM: dts: s5pv210: Correct interrupt name for bluetooth in Aries Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 39/67] dm integrity: fix error code in dm_integrity_ctr() Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 40/67] dm crypt: make printing of the key constant-time Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 41/67] dm stats: add cond_resched when looping over entries Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 42/67] dm verity: set DM_TARGET_IMMUTABLE feature flag Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 43/67] raid5: introduce MD_BROKEN Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 44/67] fs/ntfs3: validate BOOT sectors_per_clusters Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 45/67] HID: multitouch: Add support for Google Whiskers Touchpad Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 46/67] HID: multitouch: add quirks to enable Lenovo X12 trackpoint Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 47/67] x86/sgx: Disconnect backing page references from dirty status Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 48/67] x86/sgx: Mark PCMD page as dirty when modifying contents Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 49/67] x86/sgx: Obtain backing storage page with enclave mutex held Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 50/67] x86/sgx: Fix race between reclaimer and page fault handler Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 51/67] x86/sgx: Ensure no data in PCMD page after truncate Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 52/67] media: i2c: imx412: Fix reset GPIO polarity Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 53/67] media: i2c: imx412: Fix power_off ordering Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 54/67] tpm: Fix buffer access in tpm2_get_tpm_pt() Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 55/67] tpm: ibmvtpm: Correct the return value in tpm_ibmvtpm_probe() Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 56/67] docs: submitting-patches: Fix crossref to The canonical patch format Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 57/67] NFS: Memory allocation failures are not server fatal errors Greg Kroah-Hartman
2022-06-03 17:43 ` [PATCH 5.18 58/67] NFSD: Fix possible sleep during nfsd4_release_lockowner() Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 59/67] bpf: Fill new bpf_prog_pack with illegal instructions Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 60/67] bpf: Fix potential array overflow in bpf_trampoline_get_progs() Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 61/67] bpf: Fix combination of jit blinding and pointers to bpf subprogs Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 62/67] bpf: Enlarge offset check value to INT_MAX in bpf_skb_{load,store}_bytes Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 63/67] bpf: Fix usage of trace RCU in local storage Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 64/67] bpf: Fix excessive memory allocation in stack_map_alloc() Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 65/67] bpf: Reject writes for PTR_TO_MAP_KEY in check_helper_mem_access Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 66/67] bpf: Check PTR_TO_MEM | MEM_RDONLY " Greg Kroah-Hartman
2022-06-03 17:44 ` [PATCH 5.18 67/67] bpf: Do write access check for kfunc and global func Greg Kroah-Hartman
2022-06-03 23:00 ` [PATCH 5.18 00/67] 5.18.2-rc1 review Justin Forbes
2022-06-04 6:25 ` Ron Economos
2022-06-04 16:45 ` Naresh Kamboju
2022-06-04 18:56 ` Guenter Roeck
2022-06-05 2:28 ` Rudi Heitbaum
2022-06-05 7:02 ` Bagas Sanjaya
2022-06-05 7:38 ` Greg Kroah-Hartman
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