October 2025 - Linux-stable-mirror

FAILED: patch "[PATCH] media: s5p-mfc: remove an unused/uninitialized variable" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-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-5.10.y git checkout FETCH_HEAD git cherry-pick -x 7fa37ba25a1dfc084e24ea9acc14bf1fad8af14c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101647-myspace-pavement-96d9@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 7fa37ba25a1dfc084e24ea9acc14bf1fad8af14c Mon Sep 17 00:00:00 2001 From: Arnd Bergmann <arnd(a)arndb.de> Date: Thu, 7 Aug 2025 22:54:15 +0200 Subject: [PATCH] media: s5p-mfc: remove an unused/uninitialized variable The s5p_mfc_cmd_args structure in the v6 driver is never used, not initialized to anything other than zero, but as of clang-21 this causes a warning: drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c:45:7: error: variable 'h2r_args' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer] 45 | &h2r_args); | ^~~~~~~~ Just remove this for simplicity. Since the function is also called through a callback, this does require adding a trivial wrapper with the correct prototype. Fixes: f96f3cfa0bb8 ("[media] s5p-mfc: Update MFC v4l2 driver to support MFC6.x") Cc: stable(a)vger.kernel.org Signed-off-by: Arnd Bergmann <arnd(a)arndb.de> Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org> diff --git a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c index 47bc3014b5d8..f7c682fca645 100644 --- a/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c +++ b/drivers/media/platform/samsung/s5p-mfc/s5p_mfc_cmd_v6.c @@ -14,8 +14,7 @@ #include "s5p_mfc_opr.h" #include "s5p_mfc_cmd_v6.h" -static int s5p_mfc_cmd_host2risc_v6(struct s5p_mfc_dev *dev, int cmd, - const struct s5p_mfc_cmd_args *args) +static int s5p_mfc_cmd_host2risc_v6(struct s5p_mfc_dev *dev, int cmd) { mfc_debug(2, "Issue the command: %d\n", cmd); @@ -31,7 +30,6 @@ static int s5p_mfc_cmd_host2risc_v6(struct s5p_mfc_dev *dev, int cmd, static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev) { - struct s5p_mfc_cmd_args h2r_args; const struct s5p_mfc_buf_size_v6 *buf_size = dev->variant->buf_size->priv; int ret; @@ -41,33 +39,23 @@ static int s5p_mfc_sys_init_cmd_v6(struct s5p_mfc_dev *dev) mfc_write(dev, dev->ctx_buf.dma, S5P_FIMV_CONTEXT_MEM_ADDR_V6); mfc_write(dev, buf_size->dev_ctx, S5P_FIMV_CONTEXT_MEM_SIZE_V6); - return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6, - &h2r_args); + return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SYS_INIT_V6); } static int s5p_mfc_sleep_cmd_v6(struct s5p_mfc_dev *dev) { - struct s5p_mfc_cmd_args h2r_args; - - memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args)); - return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6, - &h2r_args); + return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_SLEEP_V6); } static int s5p_mfc_wakeup_cmd_v6(struct s5p_mfc_dev *dev) { - struct s5p_mfc_cmd_args h2r_args; - - memset(&h2r_args, 0, sizeof(struct s5p_mfc_cmd_args)); - return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6, - &h2r_args); + return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_WAKEUP_V6); } /* Open a new instance and get its number */ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev; - struct s5p_mfc_cmd_args h2r_args; int codec_type; mfc_debug(2, "Requested codec mode: %d\n", ctx->codec_mode); @@ -129,23 +117,20 @@ static int s5p_mfc_open_inst_cmd_v6(struct s5p_mfc_ctx *ctx) mfc_write(dev, ctx->ctx.size, S5P_FIMV_CONTEXT_MEM_SIZE_V6); mfc_write(dev, 0, S5P_FIMV_D_CRC_CTRL_V6); /* no crc */ - return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_OPEN_INSTANCE_V6, - &h2r_args); + return s5p_mfc_cmd_host2risc_v6(dev, S5P_FIMV_H2R_CMD_OPEN_INSTANCE_V6); } /* Close instance */ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) { struct s5p_mfc_dev *dev = ctx->dev; - struct s5p_mfc_cmd_args h2r_args; int ret = 0; dev->curr_ctx = ctx->num; if (ctx->state != MFCINST_FREE) { mfc_write(dev, ctx->inst_no, S5P_FIMV_INSTANCE_ID_V6); ret = s5p_mfc_cmd_host2risc_v6(dev, - S5P_FIMV_H2R_CMD_CLOSE_INSTANCE_V6, - &h2r_args); + S5P_FIMV_H2R_CMD_CLOSE_INSTANCE_V6); } else { ret = -EINVAL; } @@ -153,9 +138,15 @@ static int s5p_mfc_close_inst_cmd_v6(struct s5p_mfc_ctx *ctx) return ret; } +static int s5p_mfc_cmd_host2risc_v6_args(struct s5p_mfc_dev *dev, int cmd, + const struct s5p_mfc_cmd_args *ignored) +{ + return s5p_mfc_cmd_host2risc_v6(dev, cmd); +} + /* Initialize cmd function pointers for MFC v6 */ static const struct s5p_mfc_hw_cmds s5p_mfc_cmds_v6 = { - .cmd_host2risc = s5p_mfc_cmd_host2risc_v6, + .cmd_host2risc = s5p_mfc_cmd_host2risc_v6_args, .sys_init_cmd = s5p_mfc_sys_init_cmd_v6, .sleep_cmd = s5p_mfc_sleep_cmd_v6, .wakeup_cmd = s5p_mfc_wakeup_cmd_v6,

2 weeks, 5 days

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FAILED: patch "[PATCH] KVM: SVM: Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 68e61f6fd65610e73b17882f86fedfd784d99229 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101537-entangled-rhyme-6714@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 68e61f6fd65610e73b17882f86fedfd784d99229 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Fri, 11 Jul 2025 10:27:46 -0700 Subject: [PATCH] KVM: SVM: Emulate PERF_CNTR_GLOBAL_STATUS_SET for PerfMonV2 Emulate PERF_CNTR_GLOBAL_STATUS_SET when PerfMonV2 is enumerated to the guest, as the MSR is supposed to exist in all AMD v2 PMUs. Fixes: 4a2771895ca6 ("KVM: x86/svm/pmu: Add AMD PerfMonV2 support") Cc: stable(a)vger.kernel.org Cc: Sandipan Das <sandipan.das(a)amd.com> Link: https://lore.kernel.org/r/20250711172746.1579423-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index b65c3ba5fa14..20fa4a79df13 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -733,6 +733,7 @@ #define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS 0xc0000300 #define MSR_AMD64_PERF_CNTR_GLOBAL_CTL 0xc0000301 #define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR 0xc0000302 +#define MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET 0xc0000303 /* AMD Hardware Feedback Support MSRs */ #define MSR_AMD_WORKLOAD_CLASS_CONFIG 0xc0000500 diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 75e9cfc689f8..a84fb3d28885 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -650,6 +650,7 @@ int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = pmu->global_ctrl; break; case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: case MSR_CORE_PERF_GLOBAL_OVF_CTRL: msr_info->data = 0; break; @@ -711,6 +712,10 @@ int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!msr_info->host_initiated) pmu->global_status &= ~data; break; + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: + if (!msr_info->host_initiated) + pmu->global_status |= data & ~pmu->global_status_rsvd; + break; default: kvm_pmu_mark_pmc_in_use(vcpu, msr_info->index); return kvm_pmu_call(set_msr)(vcpu, msr_info); diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index 288f7f2a46f2..aa4379e46e96 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -113,6 +113,7 @@ static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS: case MSR_AMD64_PERF_CNTR_GLOBAL_CTL: case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: return pmu->version > 1; default: if (msr > MSR_F15H_PERF_CTR5 && diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 79057622fa76..5dc32f2fe391 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -367,6 +367,7 @@ static const u32 msrs_to_save_pmu[] = { MSR_AMD64_PERF_CNTR_GLOBAL_CTL, MSR_AMD64_PERF_CNTR_GLOBAL_STATUS, MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR, + MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET, }; static u32 msrs_to_save[ARRAY_SIZE(msrs_to_save_base) + @@ -7353,6 +7354,7 @@ static void kvm_probe_msr_to_save(u32 msr_index) case MSR_AMD64_PERF_CNTR_GLOBAL_CTL: case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS: case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_CLR: + case MSR_AMD64_PERF_CNTR_GLOBAL_STATUS_SET: if (!kvm_cpu_cap_has(X86_FEATURE_PERFMON_V2)) return; break;

2 weeks, 5 days

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FAILED: patch "[PATCH] KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-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-6.6.y git checkout FETCH_HEAD git cherry-pick -x 0910dd7c9ad45a2605c45fd2bf3d1bcac087687c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101348-gigahertz-cauterize-0303@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0910dd7c9ad45a2605c45fd2bf3d1bcac087687c Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Tue, 5 Aug 2025 12:05:09 -0700 Subject: [PATCH] KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid Skip the WRMSR and HLT fastpaths in SVM's VM-Exit handler if the next RIP isn't valid, e.g. because KVM is running with nrips=false. SVM must decode and emulate to skip the instruction if the CPU doesn't provide the next RIP, and getting the instruction bytes to decode requires reading guest memory. Reading guest memory through the emulator can fault, i.e. can sleep, which is disallowed since the fastpath handlers run with IRQs disabled. BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:106 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 32611, name: qemu preempt_count: 1, expected: 0 INFO: lockdep is turned off. irq event stamp: 30580 hardirqs last enabled at (30579): [<ffffffffc08b2527>] vcpu_run+0x1787/0x1db0 [kvm] hardirqs last disabled at (30580): [<ffffffffb4f62e32>] __schedule+0x1e2/0xed0 softirqs last enabled at (30570): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210 softirqs last disabled at (30568): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210 CPU: 298 UID: 0 PID: 32611 Comm: qemu Tainted: G U 6.16.0-smp--e6c618b51cfe-sleep #782 NONE Tainted: [U]=USER Hardware name: Google Astoria-Turin/astoria, BIOS 0.20241223.2-0 01/17/2025 Call Trace: <TASK> dump_stack_lvl+0x7d/0xb0 __might_resched+0x271/0x290 __might_fault+0x28/0x80 kvm_vcpu_read_guest_page+0x8d/0xc0 [kvm] kvm_fetch_guest_virt+0x92/0xc0 [kvm] __do_insn_fetch_bytes+0xf3/0x1e0 [kvm] x86_decode_insn+0xd1/0x1010 [kvm] x86_emulate_instruction+0x105/0x810 [kvm] __svm_skip_emulated_instruction+0xc4/0x140 [kvm_amd] handle_fastpath_invd+0xc4/0x1a0 [kvm] vcpu_run+0x11a1/0x1db0 [kvm] kvm_arch_vcpu_ioctl_run+0x5cc/0x730 [kvm] kvm_vcpu_ioctl+0x578/0x6a0 [kvm] __se_sys_ioctl+0x6d/0xb0 do_syscall_64+0x8a/0x2c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f479d57a94b </TASK> Note, this is essentially a reapply of commit 5c30e8101e8d ("KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"), but with different justification (KVM now grabs SRCU when skipping the instruction for other reasons). Fixes: b439eb8ab578 ("Revert "KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"") Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/r/20250805190526.1453366-2-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index d9931c6c4bc6..829d9d46718d 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4181,13 +4181,21 @@ static int svm_vcpu_pre_run(struct kvm_vcpu *vcpu) static fastpath_t svm_exit_handlers_fastpath(struct kvm_vcpu *vcpu) { struct vcpu_svm *svm = to_svm(vcpu); + struct vmcb_control_area *control = &svm->vmcb->control; + + /* + * Next RIP must be provided as IRQs are disabled, and accessing guest + * memory to decode the instruction might fault, i.e. might sleep. + */ + if (!nrips || !control->next_rip) + return EXIT_FASTPATH_NONE; if (is_guest_mode(vcpu)) return EXIT_FASTPATH_NONE; - switch (svm->vmcb->control.exit_code) { + switch (control->exit_code) { case SVM_EXIT_MSR: - if (!svm->vmcb->control.exit_info_1) + if (!control->exit_info_1) break; return handle_fastpath_set_msr_irqoff(vcpu); case SVM_EXIT_HLT:

2 weeks, 5 days

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FAILED: patch "[PATCH] KVM: x86: Don't (re)check L1 intercepts when completing" 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 e750f85391286a4c8100275516973324b621a269 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101006-moonwalk-smilingly-3725@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From e750f85391286a4c8100275516973324b621a269 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Tue, 15 Jul 2025 12:06:38 -0700 Subject: [PATCH] KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O When completing emulation of instruction that generated a userspace exit for I/O, don't recheck L1 intercepts as KVM has already finished that phase of instruction execution, i.e. has already committed to allowing L2 to perform I/O. If L1 (or host userspace) modifies the I/O permission bitmaps during the exit to userspace, KVM will treat the access as being intercepted despite already having emulated the I/O access. Pivot on EMULTYPE_NO_DECODE to detect that KVM is completing emulation. Of the three users of EMULTYPE_NO_DECODE, only complete_emulated_io() (the intended "recipient") can reach the code in question. gp_interception()'s use is mutually exclusive with is_guest_mode(), and complete_emulated_insn_gp() unconditionally pairs EMULTYPE_NO_DECODE with EMULTYPE_SKIP. The bad behavior was detected by a syzkaller program that toggles port I/O interception during the userspace I/O exit, ultimately resulting in a WARN on vcpu->arch.pio.count being non-zero due to KVM no completing emulation of the I/O instruction. WARNING: CPU: 23 PID: 1083 at arch/x86/kvm/x86.c:8039 emulator_pio_in_out+0x154/0x170 [kvm] Modules linked in: kvm_intel kvm irqbypass CPU: 23 UID: 1000 PID: 1083 Comm: repro Not tainted 6.16.0-rc5-c1610d2d66b1-next-vm #74 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:emulator_pio_in_out+0x154/0x170 [kvm] PKRU: 55555554 Call Trace: <TASK> kvm_fast_pio+0xd6/0x1d0 [kvm] vmx_handle_exit+0x149/0x610 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xda8/0x1ac0 [kvm] kvm_vcpu_ioctl+0x244/0x8c0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0x5d/0xc60 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> Reported-by: syzbot+cc2032ba16cc2018ca25(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68790db4.a00a0220.3af5df.0020.GAE@google.com Fixes: 8a76d7f25f8f ("KVM: x86: Add x86 callback for intercept check") Cc: stable(a)vger.kernel.org Cc: Jim Mattson <jmattson(a)google.com> Link: https://lore.kernel.org/r/20250715190638.1899116-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 1349e278cd2a..542d3664afa3 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -5107,12 +5107,11 @@ void init_decode_cache(struct x86_emulate_ctxt *ctxt) ctxt->mem_read.end = 0; } -int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) +int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, bool check_intercepts) { const struct x86_emulate_ops *ops = ctxt->ops; int rc = X86EMUL_CONTINUE; int saved_dst_type = ctxt->dst.type; - bool is_guest_mode = ctxt->ops->is_guest_mode(ctxt); ctxt->mem_read.pos = 0; @@ -5160,7 +5159,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) fetch_possible_mmx_operand(&ctxt->dst); } - if (unlikely(is_guest_mode) && ctxt->intercept) { + if (unlikely(check_intercepts) && ctxt->intercept) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_PRE_EXCEPT); if (rc != X86EMUL_CONTINUE) @@ -5189,7 +5188,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) goto done; } - if (unlikely(is_guest_mode) && (ctxt->d & Intercept)) { + if (unlikely(check_intercepts) && (ctxt->d & Intercept)) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_EXCEPT); if (rc != X86EMUL_CONTINUE) @@ -5243,7 +5242,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) special_insn: - if (unlikely(is_guest_mode) && (ctxt->d & Intercept)) { + if (unlikely(check_intercepts) && (ctxt->d & Intercept)) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_MEMACCESS); if (rc != X86EMUL_CONTINUE) diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h index c1df5acfacaf..7b5ddb787a25 100644 --- a/arch/x86/kvm/kvm_emulate.h +++ b/arch/x86/kvm/kvm_emulate.h @@ -235,7 +235,6 @@ struct x86_emulate_ops { void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked); bool (*is_smm)(struct x86_emulate_ctxt *ctxt); - bool (*is_guest_mode)(struct x86_emulate_ctxt *ctxt); int (*leave_smm)(struct x86_emulate_ctxt *ctxt); void (*triple_fault)(struct x86_emulate_ctxt *ctxt); int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr); @@ -521,7 +520,7 @@ bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt); #define EMULATION_RESTART 1 #define EMULATION_INTERCEPTED 2 void init_decode_cache(struct x86_emulate_ctxt *ctxt); -int x86_emulate_insn(struct x86_emulate_ctxt *ctxt); +int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, bool check_intercepts); int emulator_task_switch(struct x86_emulate_ctxt *ctxt, u16 tss_selector, int idt_index, int reason, bool has_error_code, u32 error_code); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a1c49bc681c4..79057622fa76 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8470,11 +8470,6 @@ static bool emulator_is_smm(struct x86_emulate_ctxt *ctxt) return is_smm(emul_to_vcpu(ctxt)); } -static bool emulator_is_guest_mode(struct x86_emulate_ctxt *ctxt) -{ - return is_guest_mode(emul_to_vcpu(ctxt)); -} - #ifndef CONFIG_KVM_SMM static int emulator_leave_smm(struct x86_emulate_ctxt *ctxt) { @@ -8558,7 +8553,6 @@ static const struct x86_emulate_ops emulate_ops = { .guest_cpuid_is_intel_compatible = emulator_guest_cpuid_is_intel_compatible, .set_nmi_mask = emulator_set_nmi_mask, .is_smm = emulator_is_smm, - .is_guest_mode = emulator_is_guest_mode, .leave_smm = emulator_leave_smm, .triple_fault = emulator_triple_fault, .set_xcr = emulator_set_xcr, @@ -9143,7 +9137,14 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, ctxt->exception.address = 0; } - r = x86_emulate_insn(ctxt); + /* + * Check L1's instruction intercepts when emulating instructions for + * L2, unless KVM is re-emulating a previously decoded instruction, + * e.g. to complete userspace I/O, in which case KVM has already + * checked the intercepts. + */ + r = x86_emulate_insn(ctxt, is_guest_mode(vcpu) && + !(emulation_type & EMULTYPE_NO_DECODE)); if (r == EMULATION_INTERCEPTED) return 1;

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FAILED: patch "[PATCH] KVM: x86: Don't (re)check L1 intercepts when completing" 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 e750f85391286a4c8100275516973324b621a269 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025101005-married-company-a3fc@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From e750f85391286a4c8100275516973324b621a269 Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Tue, 15 Jul 2025 12:06:38 -0700 Subject: [PATCH] KVM: x86: Don't (re)check L1 intercepts when completing userspace I/O When completing emulation of instruction that generated a userspace exit for I/O, don't recheck L1 intercepts as KVM has already finished that phase of instruction execution, i.e. has already committed to allowing L2 to perform I/O. If L1 (or host userspace) modifies the I/O permission bitmaps during the exit to userspace, KVM will treat the access as being intercepted despite already having emulated the I/O access. Pivot on EMULTYPE_NO_DECODE to detect that KVM is completing emulation. Of the three users of EMULTYPE_NO_DECODE, only complete_emulated_io() (the intended "recipient") can reach the code in question. gp_interception()'s use is mutually exclusive with is_guest_mode(), and complete_emulated_insn_gp() unconditionally pairs EMULTYPE_NO_DECODE with EMULTYPE_SKIP. The bad behavior was detected by a syzkaller program that toggles port I/O interception during the userspace I/O exit, ultimately resulting in a WARN on vcpu->arch.pio.count being non-zero due to KVM no completing emulation of the I/O instruction. WARNING: CPU: 23 PID: 1083 at arch/x86/kvm/x86.c:8039 emulator_pio_in_out+0x154/0x170 [kvm] Modules linked in: kvm_intel kvm irqbypass CPU: 23 UID: 1000 PID: 1083 Comm: repro Not tainted 6.16.0-rc5-c1610d2d66b1-next-vm #74 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:emulator_pio_in_out+0x154/0x170 [kvm] PKRU: 55555554 Call Trace: <TASK> kvm_fast_pio+0xd6/0x1d0 [kvm] vmx_handle_exit+0x149/0x610 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xda8/0x1ac0 [kvm] kvm_vcpu_ioctl+0x244/0x8c0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0x5d/0xc60 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> Reported-by: syzbot+cc2032ba16cc2018ca25(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/68790db4.a00a0220.3af5df.0020.GAE@google.com Fixes: 8a76d7f25f8f ("KVM: x86: Add x86 callback for intercept check") Cc: stable(a)vger.kernel.org Cc: Jim Mattson <jmattson(a)google.com> Link: https://lore.kernel.org/r/20250715190638.1899116-1-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc(a)google.com> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 1349e278cd2a..542d3664afa3 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -5107,12 +5107,11 @@ void init_decode_cache(struct x86_emulate_ctxt *ctxt) ctxt->mem_read.end = 0; } -int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) +int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, bool check_intercepts) { const struct x86_emulate_ops *ops = ctxt->ops; int rc = X86EMUL_CONTINUE; int saved_dst_type = ctxt->dst.type; - bool is_guest_mode = ctxt->ops->is_guest_mode(ctxt); ctxt->mem_read.pos = 0; @@ -5160,7 +5159,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) fetch_possible_mmx_operand(&ctxt->dst); } - if (unlikely(is_guest_mode) && ctxt->intercept) { + if (unlikely(check_intercepts) && ctxt->intercept) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_PRE_EXCEPT); if (rc != X86EMUL_CONTINUE) @@ -5189,7 +5188,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) goto done; } - if (unlikely(is_guest_mode) && (ctxt->d & Intercept)) { + if (unlikely(check_intercepts) && (ctxt->d & Intercept)) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_EXCEPT); if (rc != X86EMUL_CONTINUE) @@ -5243,7 +5242,7 @@ int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) special_insn: - if (unlikely(is_guest_mode) && (ctxt->d & Intercept)) { + if (unlikely(check_intercepts) && (ctxt->d & Intercept)) { rc = emulator_check_intercept(ctxt, ctxt->intercept, X86_ICPT_POST_MEMACCESS); if (rc != X86EMUL_CONTINUE) diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h index c1df5acfacaf..7b5ddb787a25 100644 --- a/arch/x86/kvm/kvm_emulate.h +++ b/arch/x86/kvm/kvm_emulate.h @@ -235,7 +235,6 @@ struct x86_emulate_ops { void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked); bool (*is_smm)(struct x86_emulate_ctxt *ctxt); - bool (*is_guest_mode)(struct x86_emulate_ctxt *ctxt); int (*leave_smm)(struct x86_emulate_ctxt *ctxt); void (*triple_fault)(struct x86_emulate_ctxt *ctxt); int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr); @@ -521,7 +520,7 @@ bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt); #define EMULATION_RESTART 1 #define EMULATION_INTERCEPTED 2 void init_decode_cache(struct x86_emulate_ctxt *ctxt); -int x86_emulate_insn(struct x86_emulate_ctxt *ctxt); +int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, bool check_intercepts); int emulator_task_switch(struct x86_emulate_ctxt *ctxt, u16 tss_selector, int idt_index, int reason, bool has_error_code, u32 error_code); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index a1c49bc681c4..79057622fa76 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8470,11 +8470,6 @@ static bool emulator_is_smm(struct x86_emulate_ctxt *ctxt) return is_smm(emul_to_vcpu(ctxt)); } -static bool emulator_is_guest_mode(struct x86_emulate_ctxt *ctxt) -{ - return is_guest_mode(emul_to_vcpu(ctxt)); -} - #ifndef CONFIG_KVM_SMM static int emulator_leave_smm(struct x86_emulate_ctxt *ctxt) { @@ -8558,7 +8553,6 @@ static const struct x86_emulate_ops emulate_ops = { .guest_cpuid_is_intel_compatible = emulator_guest_cpuid_is_intel_compatible, .set_nmi_mask = emulator_set_nmi_mask, .is_smm = emulator_is_smm, - .is_guest_mode = emulator_is_guest_mode, .leave_smm = emulator_leave_smm, .triple_fault = emulator_triple_fault, .set_xcr = emulator_set_xcr, @@ -9143,7 +9137,14 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, ctxt->exception.address = 0; } - r = x86_emulate_insn(ctxt); + /* + * Check L1's instruction intercepts when emulating instructions for + * L2, unless KVM is re-emulating a previously decoded instruction, + * e.g. to complete userspace I/O, in which case KVM has already + * checked the intercepts. + */ + r = x86_emulate_insn(ctxt, is_guest_mode(vcpu) && + !(emulation_type & EMULTYPE_NO_DECODE)); if (r == EMULATION_INTERCEPTED) return 1;

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[PATCH] rust: device: fix device context of Device::parent()

by Danilo Krummrich

Regardless of the DeviceContext of a device, we can't give any guarantees about the DeviceContext of its parent device. This is very subtle, since it's only caused by a simple typo, i.e. Self::from_raw(parent) which preserves the DeviceContext in this case, vs. Device::from_raw(parent) which discards the DeviceContext. (I should have noticed it doing the correct thing in auxiliary::Device subsequently, but somehow missed it.) Hence, fix both Device::parent() and auxiliary::Device::parent(). Cc: stable(a)vger.kernel.org Fixes: a4c9f71e3440 ("rust: device: implement Device::parent()") Signed-off-by: Danilo Krummrich <dakr(a)kernel.org> --- rust/kernel/auxiliary.rs | 8 +------- rust/kernel/device.rs | 4 ++-- 2 files changed, 3 insertions(+), 9 deletions(-) diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs index 4163129b4103..e12f78734606 100644 --- a/rust/kernel/auxiliary.rs +++ b/rust/kernel/auxiliary.rs @@ -217,13 +217,7 @@ pub fn id(&self) -> u32 { /// Returns a reference to the parent [`device::Device`], if any. pub fn parent(&self) -> Option<&device::Device> { - let ptr: *const Self = self; - // CAST: `Device<Ctx: DeviceContext>` types are transparent to each other. - let ptr: *const Device = ptr.cast(); - // SAFETY: `ptr` was derived from `&self`. - let this = unsafe { &*ptr }; - - this.as_ref().parent() + self.as_ref().parent() } } diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 23a95324cb0f..343996027c89 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -256,7 +256,7 @@ pub(crate) fn as_raw(&self) -> *mut bindings::device { /// Returns a reference to the parent device, if any. #[cfg_attr(not(CONFIG_AUXILIARY_BUS), expect(dead_code))] - pub(crate) fn parent(&self) -> Option<&Self> { + pub(crate) fn parent(&self) -> Option<&Device> { // SAFETY: // - By the type invariant `self.as_raw()` is always valid. // - The parent device is only ever set at device creation. @@ -269,7 +269,7 @@ pub(crate) fn parent(&self) -> Option<&Self> { // - Since `parent` is not NULL, it must be a valid pointer to a `struct device`. // - `parent` is valid for the lifetime of `self`, since a `struct device` holds a // reference count of its parent. - Some(unsafe { Self::from_raw(parent) }) + Some(unsafe { Device::from_raw(parent) }) } } -- 2.51.0

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[PATCH] usb: typec: ucsi: psy: Set max current to zero when disconnected

by Jameson Thies

The ucsi_psy_get_current_max function defaults to 0.1A when it is not clear how much current the partner device can support. But this does not check the port is connected, and will report 0.1A max current when nothing is connected. Update ucsi_psy_get_current_max to report 0A when there is no connection. Fixes: af833e7f7db3 ("usb: typec: ucsi: psy: Set current max to 100mA for BC 1.2 and Default") Signed-off-by: Jameson Thies <jthies(a)google.com> Reviewed-by: Benson Leung <bleung(a)chromium.org> Reviewed-by: Heikki Krogerus <heikki.krogerus(a)linux.intel.com> --- drivers/usb/typec/ucsi/psy.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/typec/ucsi/psy.c b/drivers/usb/typec/ucsi/psy.c index 62a9d68bb66d..8ae900c8c132 100644 --- a/drivers/usb/typec/ucsi/psy.c +++ b/drivers/usb/typec/ucsi/psy.c @@ -145,6 +145,11 @@ static int ucsi_psy_get_current_max(struct ucsi_connector *con, { u32 pdo; + if (!UCSI_CONSTAT(con, CONNECTED)) { + val->intval = 0; + return 0; + } + switch (UCSI_CONSTAT(con, PWR_OPMODE)) { case UCSI_CONSTAT_PWR_OPMODE_PD: if (con->num_pdos > 0) { base-commit: e40b984b6c4ce3f80814f39f86f87b2a48f2e662 -- 2.51.0.858.gf9c4a03a3a-goog

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Gratulacje, oferta prezentu

by Kristine Charity Services

2 weeks, 5 days

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[PATCH] arm64: debug: always unmask interrupts in el0_softstp()

by Ada Couprie Diaz

EL0 exception handlers should always call `exit_to_user_mode()` with interrupts unmasked. When handling a completed single-step, we skip the if block and `local_daif_restore(DAIF_PROCCTX)` never gets called, which ends up calling `exit_to_user_mode()` with interrupts masked. This is broken if pNMI is in use, as `do_notify_resume()` will try to enable interrupts, but `local_irq_enable()` will only change the PMR, leaving interrupts masked via DAIF. Move the call to `try_step_suspended_breakpoints()` outside of the check so that interrupts can be unmasked even if we don't call the step handler. Fixes: 0ac7584c08ce ("arm64: debug: split single stepping exception entry") Cc: <stable(a)vger.kernel.org> # 6.17 Signed-off-by: Ada Couprie Diaz <ada.coupriediaz(a)arm.com> ---- This was already broken in a similar fashion in kernels prior to v6.17, as `local_daif_restore()` was called _after_ the debug handlers, with some calling `send_user_sigtrap()` which would unmask interrupts via PMR while leaving them masked by DAIF. --- arch/arm64/kernel/entry-common.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 2b0c5925502e..780cbcf12695 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -832,6 +832,7 @@ static void noinstr el0_breakpt(struct pt_regs *regs, unsigned long esr) static void noinstr el0_softstp(struct pt_regs *regs, unsigned long esr) { + bool step_done; if (!is_ttbr0_addr(regs->pc)) arm64_apply_bp_hardening(); @@ -842,10 +843,11 @@ static void noinstr el0_softstp(struct pt_regs *regs, unsigned long esr) * If we are stepping a suspended breakpoint there's nothing more to do: * the single-step is complete. */ - if (!try_step_suspended_breakpoints(regs)) { - local_daif_restore(DAIF_PROCCTX); + step_done = try_step_suspended_breakpoints(regs) + local_daif_restore(DAIF_PROCCTX); + if (!step_done) do_el0_softstep(esr, regs); - } + exit_to_user_mode(regs); } base-commit: 449d48b1b99fdaa076166e200132705ac2bee711 -- 2.43.0

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[PATCH] PCI/PM: Prevent runtime suspend before devices are fully initialized

by Brian Norris

PCI devices are created via pci_scan_slot() and similar, and are promptly configured for runtime PM (pci_pm_init()). They are initially prevented from suspending by way of pm_runtime_forbid(); however, it's expected that user space may override this via sysfs [1]. Now, sometime after initial scan, a PCI device receives its BAR configuration (pci_assign_unassigned_bus_resources(), etc.). If a PCI device is allowed to suspend between pci_scan_slot() and pci_assign_unassigned_bus_resources(), then pci-driver.c will save/restore incorrect BAR configuration for the device, and the device may cease to function. This behavior races with user space, since user space may enable runtime PM [1] as soon as it sees the device, which may be before BAR configuration. Prevent suspending in this intermediate state by holding a runtime PM reference until the device is fully initialized and ready for probe(). [1] echo auto > /sys/bus/pci/devices/.../power/control Cc: <stable(a)vger.kernel.org> Signed-off-by: Brian Norris <briannorris(a)chromium.org> --- drivers/pci/bus.c | 7 +++++++ drivers/pci/pci.c | 6 ++++++ 2 files changed, 13 insertions(+) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index f26aec6ff588..227a8898acac 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -14,6 +14,7 @@ #include <linux/of.h> #include <linux/of_platform.h> #include <linux/platform_device.h> +#include <linux/pm_runtime.h> #include <linux/proc_fs.h> #include <linux/slab.h> @@ -375,6 +376,12 @@ void pci_bus_add_device(struct pci_dev *dev) put_device(&pdev->dev); } + /* + * Now that resources are assigned, drop the reference we grabbed in + * pci_pm_init(). + */ + pm_runtime_put_noidle(&dev->dev); + if (!dn || of_device_is_available(dn)) pci_dev_allow_binding(dev); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index b14dd064006c..06a901214f2c 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3226,6 +3226,12 @@ void pci_pm_init(struct pci_dev *dev) pci_pm_power_up_and_verify_state(dev); pm_runtime_forbid(&dev->dev); pm_runtime_set_active(&dev->dev); + /* + * We cannot allow a device to suspend before its resources are + * configured. Otherwise, we may allow saving/restoring unexpected BAR + * configuration. + */ + pm_runtime_get_noresume(&dev->dev); pm_runtime_enable(&dev->dev); } -- 2.51.0.858.gf9c4a03a3a-goog

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Linux-stable-mirror October 2025