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[PATCH RESEND v5 0/3] phy: qcom: edp: Add missing ref clock to x1e80100

by Abel Vesa

According to documentation, the DP PHY on x1e80100 has another clock called ref. The current X Elite devices supported upstream work fine without this clock, because the boot firmware leaves this clock enabled. But we should not rely on that. Also, when it comes to power management, this clock needs to be also disabled on suspend. So even though this change breaks the ABI, it is needed in order to make we disable this clock on runtime PM, when that is going to be enabled in the driver. So rework the driver to allow different number of clocks, fix the dt-bindings schema and add the clock to the DT node as well. Signed-off-by: Abel Vesa <abel.vesa(a)linaro.org> --- Changes in v5: - Picked-up Bjorn's R-b tags. - Replaced "parse" with "get" on clocks acquiring failure. - Link to v4: https://lore.kernel.org/r/20251029-phy-qcom-edp-add-missing-refclk-v4-0-adb… Changes in v4: - Picked Dmitry's R-b tag for the driver patch - Added x1e80100 substring to subject of dts patch - Link to v3 (resend): https://lore.kernel.org/r/20251014-phy-qcom-edp-add-missing-refclk-v3-0-078… Changes in v3 (resend) - picked-up Krzysztof's R-b tag for bindings patch - Link to v3: https://lore.kernel.org/r/20250909-phy-qcom-edp-add-missing-refclk-v3-0-4ec… Changes in v3: - Use dev_err_probe() on clocks parsing failure. - Explain why the ABI break is necessary. - Drop the extra 'clk' suffix from the clock name. So ref instead of refclk. - Link to v2: https://lore.kernel.org/r/20250903-phy-qcom-edp-add-missing-refclk-v2-0-d88… Changes in v2: - Fix schema by adding the minItems, as suggested by Krzysztof. - Use devm_clk_bulk_get_all, as suggested by Konrad. - Rephrase the commit messages to reflect the flexible number of clocks. - Link to v1: https://lore.kernel.org/r/20250730-phy-qcom-edp-add-missing-refclk-v1-0-6f7… --- Abel Vesa (3): dt-bindings: phy: qcom-edp: Add missing clock for X Elite phy: qcom: edp: Make the number of clocks flexible arm64: dts: qcom: x1e80100: Add missing TCSR ref clock to the DP PHYs .../devicetree/bindings/phy/qcom,edp-phy.yaml | 28 +++++++++++++++++++++- arch/arm64/boot/dts/qcom/hamoa.dtsi | 12 ++++++---- drivers/phy/qualcomm/phy-qcom-edp.c | 16 ++++++------- 3 files changed, 43 insertions(+), 13 deletions(-) --- base-commit: 131f3d9446a6075192cdd91f197989d98302faa6 change-id: 20250730-phy-qcom-edp-add-missing-refclk-5ab82828f8e7 Best regards, -- Abel Vesa <abel.vesa(a)oss.qualcomm.com>

2 hours, 10 minutes

[PATCH 3/4] selftests: kvm: try getting XFD and XSAVE state out of sync

by Paolo Bonzini

The host is allowed to set FPU state that includes a disabled xstate component. Check that this does not cause bad effects. Cc: stable(a)vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> --- tools/testing/selftests/kvm/x86/amx_test.c | 38 +++++++++++++++++----- 1 file changed, 30 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/kvm/x86/amx_test.c b/tools/testing/selftests/kvm/x86/amx_test.c index 4ac41c1a7255..00a42a592a37 100644 --- a/tools/testing/selftests/kvm/x86/amx_test.c +++ b/tools/testing/selftests/kvm/x86/amx_test.c @@ -125,11 +125,17 @@ static void set_tilecfg(struct tile_config *cfg) } enum { + /* Retrieve TMM0 from guest, stash it for TEST_RESTORE_TILEDATA */ + TEST_SAVE_TILEDATA = 1, + /* Check TMM0 against tiledata */ - TEST_COMPARE_TILEDATA = 1, + TEST_COMPARE_TILEDATA = 2, + + /* Restore TMM0 from earlier save */ + TEST_RESTORE_TILEDATA = 4, /* Full VM save/restore */ - TEST_SAVE_RESTORE = 2, + TEST_SAVE_RESTORE = 8, }; static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, @@ -150,7 +156,16 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, GUEST_SYNC(TEST_SAVE_RESTORE); /* Check save/restore when trap to userspace */ __tileloadd(tiledata); - GUEST_SYNC(TEST_COMPARE_TILEDATA | TEST_SAVE_RESTORE); + GUEST_SYNC(TEST_SAVE_TILEDATA | TEST_COMPARE_TILEDATA | TEST_SAVE_RESTORE); + + /* xfd=0x40000, disable amx tiledata */ + wrmsr(MSR_IA32_XFD, XFEATURE_MASK_XTILE_DATA); + + /* host tries setting tiledata while guest XFD is set */ + GUEST_SYNC(TEST_RESTORE_TILEDATA); + GUEST_SYNC(TEST_SAVE_RESTORE); + + wrmsr(MSR_IA32_XFD, 0); __tilerelease(); GUEST_SYNC(TEST_SAVE_RESTORE); /* @@ -210,10 +225,10 @@ int main(int argc, char *argv[]) struct kvm_vcpu *vcpu; struct kvm_vm *vm; struct kvm_x86_state *state; + struct kvm_x86_state *tile_state = NULL; int xsave_restore_size; vm_vaddr_t amx_cfg, tiledata, xstate; struct ucall uc; - u32 amx_offset; int ret; /* @@ -265,20 +280,27 @@ int main(int argc, char *argv[]) /* NOT REACHED */ case UCALL_SYNC: ++iter; + if (uc.args[1] & TEST_SAVE_TILEDATA) { + fprintf(stderr, "GUEST_SYNC #%d, save tiledata\n", iter); + tile_state = vcpu_save_state(vcpu); + } if (uc.args[1] & TEST_COMPARE_TILEDATA) { fprintf(stderr, "GUEST_SYNC #%d, check TMM0 contents\n", iter); /* Compacted mode, get amx offset by xsave area * size subtract 8K amx size. */ - amx_offset = xsave_restore_size - NUM_TILES*TILE_SIZE; - state = vcpu_save_state(vcpu); - void *amx_start = (void *)state->xsave + amx_offset; + u32 amx_offset = xsave_restore_size - NUM_TILES*TILE_SIZE; + void *amx_start = (void *)tile_state->xsave + amx_offset; void *tiles_data = (void *)addr_gva2hva(vm, tiledata); /* Only check TMM0 register, 1 tile */ ret = memcmp(amx_start, tiles_data, TILE_SIZE); TEST_ASSERT(ret == 0, "memcmp failed, ret=%d", ret); - kvm_x86_state_cleanup(state); + } + if (uc.args[1] & TEST_RESTORE_TILEDATA) { + fprintf(stderr, "GUEST_SYNC #%d, before KVM_SET_XSAVE\n", iter); + vcpu_xsave_set(vcpu, tile_state->xsave); + fprintf(stderr, "GUEST_SYNC #%d, after KVM_SET_XSAVE\n", iter); } if (uc.args[1] & TEST_SAVE_RESTORE) { fprintf(stderr, "GUEST_SYNC #%d, save/restore VM state\n", iter); -- 2.52.0

4 hours, 13 minutes

[PATCH 2/4] selftests: kvm: replace numbered sync points with actions

by Paolo Bonzini

Rework the guest=>host syncs in the AMX test to use named actions instead of arbitrary, incrementing numbers. The "stage" of the test has no real meaning, what matters is what action the test wants the host to perform. The incrementing numbers are somewhat helpful for triaging failures, but fully debugging failures almost always requires a much deeper dive into the test (and KVM). Using named actions not only makes it easier to extend the test without having to shift all sync point numbers, it makes the code easier to read. [Commit message by Sean Christopherson] Cc: stable(a)vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> --- I wrote this before seeing your patch... It's obviously similar but different enough that I kept my version. :) Thanks anyway for including it, your commit message was better so I used it. tools/testing/selftests/kvm/x86/amx_test.c | 88 +++++++++++----------- 1 file changed, 43 insertions(+), 45 deletions(-) diff --git a/tools/testing/selftests/kvm/x86/amx_test.c b/tools/testing/selftests/kvm/x86/amx_test.c index f4ce5a185a7d..4ac41c1a7255 100644 --- a/tools/testing/selftests/kvm/x86/amx_test.c +++ b/tools/testing/selftests/kvm/x86/amx_test.c @@ -124,6 +124,14 @@ static void set_tilecfg(struct tile_config *cfg) } } +enum { + /* Check TMM0 against tiledata */ + TEST_COMPARE_TILEDATA = 1, + + /* Full VM save/restore */ + TEST_SAVE_RESTORE = 2, +}; + static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, struct tile_data *tiledata, struct xstate *xstate) @@ -131,20 +139,20 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, GUEST_ASSERT(this_cpu_has(X86_FEATURE_XSAVE) && this_cpu_has(X86_FEATURE_OSXSAVE)); check_xtile_info(); - GUEST_SYNC(1); + GUEST_SYNC(TEST_SAVE_RESTORE); /* xfd=0, enable amx */ wrmsr(MSR_IA32_XFD, 0); - GUEST_SYNC(2); + GUEST_SYNC(TEST_SAVE_RESTORE); GUEST_ASSERT(rdmsr(MSR_IA32_XFD) == 0); set_tilecfg(amx_cfg); __ldtilecfg(amx_cfg); - GUEST_SYNC(3); + GUEST_SYNC(TEST_SAVE_RESTORE); /* Check save/restore when trap to userspace */ __tileloadd(tiledata); - GUEST_SYNC(4); + GUEST_SYNC(TEST_COMPARE_TILEDATA | TEST_SAVE_RESTORE); __tilerelease(); - GUEST_SYNC(5); + GUEST_SYNC(TEST_SAVE_RESTORE); /* * After XSAVEC, XTILEDATA is cleared in the xstate_bv but is set in * the xcomp_bv. @@ -154,6 +162,8 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, GUEST_ASSERT(!(xstate->header.xstate_bv & XFEATURE_MASK_XTILE_DATA)); GUEST_ASSERT(xstate->header.xcomp_bv & XFEATURE_MASK_XTILE_DATA); + /* #NM test */ + /* xfd=0x40000, disable amx tiledata */ wrmsr(MSR_IA32_XFD, XFEATURE_MASK_XTILE_DATA); @@ -166,13 +176,13 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, GUEST_ASSERT(!(xstate->header.xstate_bv & XFEATURE_MASK_XTILE_DATA)); GUEST_ASSERT((xstate->header.xcomp_bv & XFEATURE_MASK_XTILE_DATA)); - GUEST_SYNC(6); + GUEST_SYNC(TEST_SAVE_RESTORE); GUEST_ASSERT(rdmsr(MSR_IA32_XFD) == XFEATURE_MASK_XTILE_DATA); set_tilecfg(amx_cfg); __ldtilecfg(amx_cfg); /* Trigger #NM exception */ __tileloadd(tiledata); - GUEST_SYNC(10); + GUEST_SYNC(TEST_COMPARE_TILEDATA | TEST_SAVE_RESTORE); GUEST_DONE(); } @@ -180,18 +190,18 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg, void guest_nm_handler(struct ex_regs *regs) { /* Check if #NM is triggered by XFEATURE_MASK_XTILE_DATA */ - GUEST_SYNC(7); + GUEST_SYNC(TEST_SAVE_RESTORE); GUEST_ASSERT(!(get_cr0() & X86_CR0_TS)); GUEST_ASSERT(rdmsr(MSR_IA32_XFD_ERR) == XFEATURE_MASK_XTILE_DATA); GUEST_ASSERT(rdmsr(MSR_IA32_XFD) == XFEATURE_MASK_XTILE_DATA); - GUEST_SYNC(8); + GUEST_SYNC(TEST_SAVE_RESTORE); GUEST_ASSERT(rdmsr(MSR_IA32_XFD_ERR) == XFEATURE_MASK_XTILE_DATA); GUEST_ASSERT(rdmsr(MSR_IA32_XFD) == XFEATURE_MASK_XTILE_DATA); /* Clear xfd_err */ wrmsr(MSR_IA32_XFD_ERR, 0); /* xfd=0, enable amx */ wrmsr(MSR_IA32_XFD, 0); - GUEST_SYNC(9); + GUEST_SYNC(TEST_SAVE_RESTORE); } int main(int argc, char *argv[]) @@ -244,6 +254,7 @@ int main(int argc, char *argv[]) memset(addr_gva2hva(vm, xstate), 0, PAGE_SIZE * DIV_ROUND_UP(XSAVE_SIZE, PAGE_SIZE)); vcpu_args_set(vcpu, 3, amx_cfg, tiledata, xstate); + int iter = 0; for (;;) { vcpu_run(vcpu); TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); @@ -253,20 +264,9 @@ int main(int argc, char *argv[]) REPORT_GUEST_ASSERT(uc); /* NOT REACHED */ case UCALL_SYNC: - switch (uc.args[1]) { - case 1: - case 2: - case 3: - case 5: - case 6: - case 7: - case 8: - fprintf(stderr, "GUEST_SYNC(%ld)\n", uc.args[1]); - break; - case 4: - case 10: - fprintf(stderr, - "GUEST_SYNC(%ld), check save/restore status\n", uc.args[1]); + ++iter; + if (uc.args[1] & TEST_COMPARE_TILEDATA) { + fprintf(stderr, "GUEST_SYNC #%d, check TMM0 contents\n", iter); /* Compacted mode, get amx offset by xsave area * size subtract 8K amx size. @@ -279,11 +279,25 @@ int main(int argc, char *argv[]) ret = memcmp(amx_start, tiles_data, TILE_SIZE); TEST_ASSERT(ret == 0, "memcmp failed, ret=%d", ret); kvm_x86_state_cleanup(state); - break; - case 9: - fprintf(stderr, - "GUEST_SYNC(%ld), #NM exception and enable amx\n", uc.args[1]); - break; + } + if (uc.args[1] & TEST_SAVE_RESTORE) { + fprintf(stderr, "GUEST_SYNC #%d, save/restore VM state\n", iter); + state = vcpu_save_state(vcpu); + memset(&regs1, 0, sizeof(regs1)); + vcpu_regs_get(vcpu, &regs1); + + kvm_vm_release(vm); + + /* Restore state in a new VM. */ + vcpu = vm_recreate_with_one_vcpu(vm); + vcpu_load_state(vcpu, state); + kvm_x86_state_cleanup(state); + + memset(&regs2, 0, sizeof(regs2)); + vcpu_regs_get(vcpu, &regs2); + TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)), + "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx", + (ulong) regs2.rdi, (ulong) regs2.rsi); } break; case UCALL_DONE: @@ -293,22 +307,6 @@ int main(int argc, char *argv[]) TEST_FAIL("Unknown ucall %lu", uc.cmd); } - state = vcpu_save_state(vcpu); - memset(&regs1, 0, sizeof(regs1)); - vcpu_regs_get(vcpu, &regs1); - - kvm_vm_release(vm); - - /* Restore state in a new VM. */ - vcpu = vm_recreate_with_one_vcpu(vm); - vcpu_load_state(vcpu, state); - kvm_x86_state_cleanup(state); - - memset(&regs2, 0, sizeof(regs2)); - vcpu_regs_get(vcpu, &regs2); - TEST_ASSERT(!memcmp(&regs1, &regs2, sizeof(regs2)), - "Unexpected register values after vcpu_load_state; rdi: %lx rsi: %lx", - (ulong) regs2.rdi, (ulong) regs2.rsi); } done: kvm_vm_free(vm); -- 2.52.0

4 hours, 13 minutes

[PATCH 1/4] x86/fpu: Clear XSTATE_BV[i] in save state whenever XFD[i]=1

by Paolo Bonzini

From: Sean Christopherson <seanjc(a)google.com> When loading guest XSAVE state via KVM_SET_XSAVE, and when updating XFD in response to a guest WRMSR, clear XFD-disabled features in the saved (or to be restored) XSTATE_BV to ensure KVM doesn't attempt to load state for features that are disabled via the guest's XFD. Because the kernel executes XRSTOR with the guest's XFD, saving XSTATE_BV[i]=1 with XFD[i]=1 will cause XRSTOR to #NM and panic the kernel. E.g. if fpu_update_guest_xfd() sets XFD without clearing XSTATE_BV: ------------[ cut here ]------------ WARNING: arch/x86/kernel/traps.c:1524 at exc_device_not_available+0x101/0x110, CPU#29: amx_test/848 Modules linked in: kvm_intel kvm irqbypass CPU: 29 UID: 1000 PID: 848 Comm: amx_test Not tainted 6.19.0-rc2-ffa07f7fd437-x86_amx_nm_xfd_non_init-vm #171 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:exc_device_not_available+0x101/0x110 Call Trace: <TASK> asm_exc_device_not_available+0x1a/0x20 RIP: 0010:restore_fpregs_from_fpstate+0x36/0x90 switch_fpu_return+0x4a/0xb0 kvm_arch_vcpu_ioctl_run+0x1245/0x1e40 [kvm] kvm_vcpu_ioctl+0x2c3/0x8f0 [kvm] __x64_sys_ioctl+0x8f/0xd0 do_syscall_64+0x62/0x940 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> ---[ end trace 0000000000000000 ]--- This can happen if the guest executes WRMSR(MSR_IA32_XFD) to set XFD[18] = 1, and a host IRQ triggers kernel_fpu_begin() prior to the vmexit handler's call to fpu_update_guest_xfd(). and if userspace stuffs XSTATE_BV[i]=1 via KVM_SET_XSAVE: ------------[ cut here ]------------ WARNING: arch/x86/kernel/traps.c:1524 at exc_device_not_available+0x101/0x110, CPU#14: amx_test/867 Modules linked in: kvm_intel kvm irqbypass CPU: 14 UID: 1000 PID: 867 Comm: amx_test Not tainted 6.19.0-rc2-2dace9faccd6-x86_amx_nm_xfd_non_init-vm #168 NONE Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:exc_device_not_available+0x101/0x110 Call Trace: <TASK> asm_exc_device_not_available+0x1a/0x20 RIP: 0010:restore_fpregs_from_fpstate+0x36/0x90 fpu_swap_kvm_fpstate+0x6b/0x120 kvm_load_guest_fpu+0x30/0x80 [kvm] kvm_arch_vcpu_ioctl_run+0x85/0x1e40 [kvm] kvm_vcpu_ioctl+0x2c3/0x8f0 [kvm] __x64_sys_ioctl+0x8f/0xd0 do_syscall_64+0x62/0x940 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> ---[ end trace 0000000000000000 ]--- The new behavior is consistent with the AMX architecture. Per Intel's SDM, XSAVE saves XSTATE_BV as '0' for components that are disabled via XFD (and non-compacted XSAVE saves the initial configuration of the state component): If XSAVE, XSAVEC, XSAVEOPT, or XSAVES is saving the state component i, the instruction does not generate #NM when XCR0[i] = IA32_XFD[i] = 1; instead, it operates as if XINUSE[i] = 0 (and the state component was in its initial state): it saves bit i of XSTATE_BV field of the XSAVE header as 0; in addition, XSAVE saves the initial configuration of the state component (the other instructions do not save state component i). Alternatively, KVM could always do XRSTOR with XFD=0, e.g. by using a constant XFD based on the set of enabled features when XSAVEing for a struct fpu_guest. However, having XSTATE_BV[i]=1 for XFD-disabled features can only happen in the above interrupt case, or in similar scenarios involving preemption on preemptible kernels, because fpu_swap_kvm_fpstate()'s call to save_fpregs_to_fpstate() saves the outgoing FPU state with the current XFD; and that is (on all but the first WRMSR to XFD) the guest XFD. Therefore, XFD can only go out of sync with XSTATE_BV in the above interrupt case, or in similar scenarios involving preemption on preemptible kernels, and it we can consider it (de facto) part of KVM ABI that KVM_GET_XSAVE returns XSTATE_BV[i]=0 for XFD-disabled features. Reported-by: Paolo Bonzini <pbonzini(a)redhat.com> Cc: stable(a)vger.kernel.org Fixes: 820a6ee944e7 ("kvm: x86: Add emulation for IA32_XFD", 2022-01-14) Signed-off-by: Sean Christopherson <seanjc(a)google.com> [Move clearing of XSTATE_BV from fpu_copy_uabi_to_guest_fpstate to kvm_vcpu_ioctl_x86_set_xsave. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> --- arch/x86/kernel/fpu/core.c | 32 +++++++++++++++++++++++++++++--- arch/x86/kvm/x86.c | 9 +++++++++ 2 files changed, 38 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index da233f20ae6f..166c380b0161 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -319,10 +319,29 @@ EXPORT_SYMBOL_FOR_KVM(fpu_enable_guest_xfd_features); #ifdef CONFIG_X86_64 void fpu_update_guest_xfd(struct fpu_guest *guest_fpu, u64 xfd) { + struct fpstate *fpstate = guest_fpu->fpstate; + fpregs_lock(); - guest_fpu->fpstate->xfd = xfd; - if (guest_fpu->fpstate->in_use) - xfd_update_state(guest_fpu->fpstate); + + /* + * KVM's guest ABI is that setting XFD[i]=1 *can* immediately revert + * the save state to initialized. Likewise, KVM_GET_XSAVE does the + * same as XSAVE and returns XSTATE_BV[i]=0 whenever XFD[i]=1. + * + * If the guest's FPU state is in hardware, just update XFD: the XSAVE + * in fpu_swap_kvm_fpstate will clear XSTATE_BV[i] whenever XFD[i]=1. + * + * If however the guest's FPU state is NOT resident in hardware, clear + * disabled components in XSTATE_BV now, or a subsequent XRSTOR will + * attempt to load disabled components and generate #NM _in the host_. + */ + if (xfd && test_thread_flag(TIF_NEED_FPU_LOAD)) + fpstate->regs.xsave.header.xfeatures &= ~xfd; + + fpstate->xfd = xfd; + if (fpstate->in_use) + xfd_update_state(fpstate); + fpregs_unlock(); } EXPORT_SYMBOL_FOR_KVM(fpu_update_guest_xfd); @@ -430,6 +449,13 @@ int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, if (ustate->xsave.header.xfeatures & ~xcr0) return -EINVAL; + /* + * Disabled features must be in their initial state, otherwise XRSTOR + * causes an exception. + */ + if (WARN_ON_ONCE(ustate->xsave.header.xfeatures & kstate->xfd)) + return -EINVAL; + /* * Nullify @vpkru to preserve its current value if PKRU's bit isn't set * in the header. KVM's odd ABI is to leave PKRU untouched in this diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ff8812f3a129..c0416f53b5f5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5807,9 +5807,18 @@ static int kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu, static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu, struct kvm_xsave *guest_xsave) { + union fpregs_state *xstate = (union fpregs_state *)guest_xsave->region; + if (fpstate_is_confidential(&vcpu->arch.guest_fpu)) return vcpu->kvm->arch.has_protected_state ? -EINVAL : 0; + /* + * Do not reject non-initialized disabled features for backwards + * compatibility, but clear XSTATE_BV[i] whenever XFD[i]=1. + * Otherwise, XRSTOR would cause a #NM. + */ + xstate->xsave.header.xfeatures &= ~vcpu->arch.guest_fpu.fpstate->xfd; + return fpu_copy_uabi_to_guest_fpstate(&vcpu->arch.guest_fpu, guest_xsave->region, kvm_caps.supported_xcr0, -- 2.52.0

4 hours, 13 minutes

[PATCH v2] arm64: errata: Workaround for SI L1 downstream coherency issue

by Lucas Wei

When software issues a Cache Maintenance Operation (CMO) targeting a dirty cache line, the CPU and DSU cluster may optimize the operation by combining the CopyBack Write and CMO into a single combined CopyBack Write plus CMO transaction presented to the interconnect (MCN). For these combined transactions, the MCN splits the operation into two separate transactions, one Write and one CMO, and then propagates the write and optionally the CMO to the downstream memory system or external Point of Serialization (PoS). However, the MCN may return an early CompCMO response to the DSU cluster before the corresponding Write and CMO transactions have completed at the external PoS or downstream memory. As a result, stale data may be observed by external observers that are directly connected to the external PoS or downstream memory. This erratum affects any system topology in which the following conditions apply: - The Point of Serialization (PoS) is located downstream of the interconnect. - A downstream observer accesses memory directly, bypassing the interconnect. Conditions: This erratum occurs only when all of the following conditions are met: 1. Software executes a data cache maintenance operation, specifically, a clean or invalidate by virtual address (DC CVAC, DC CIVAC, or DC IVAC), that hits on unique dirty data in the CPU or DSU cache. This results in a combined CopyBack and CMO being issued to the interconnect. 2. The interconnect splits the combined transaction into separate Write and CMO transactions and returns an early completion response to the CPU or DSU before the write has completed at the downstream memory or PoS. 3. A downstream observer accesses the affected memory address after the early completion response is issued but before the actual memory write has completed. This allows the observer to read stale data that has not yet been updated at the PoS or downstream memory. The implementation of workaround put a second loop of CMOs at the same virtual address whose operation meet erratum conditions to wait until cache data be cleaned to PoC.. This way of implementation mitigates performance panalty compared to purly duplicate orignial CMO. Reported-by: kernel test robot <lkp(a)intel.com> Cc: stable(a)vger.kernel.org # 6.12.x Signed-off-by: Lucas Wei <lucaswei(a)google.com> --- Changes in v2: 1. Fixed warning from kernel test robot by changing arm_si_l1_workaround_4311569 to static [Reported-by: kernel test robot <lkp(a)intel.com>] --- Documentation/arch/arm64/silicon-errata.rst | 3 ++ arch/arm64/Kconfig | 19 +++++++++++++ arch/arm64/include/asm/assembler.h | 10 +++++++ arch/arm64/kernel/cpu_errata.c | 31 +++++++++++++++++++++ arch/arm64/mm/cache.S | 13 ++++++++- arch/arm64/tools/cpucaps | 1 + 6 files changed, 76 insertions(+), 1 deletion(-) diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst index a7ec57060f64..98efdf528719 100644 --- a/Documentation/arch/arm64/silicon-errata.rst +++ b/Documentation/arch/arm64/silicon-errata.rst @@ -213,6 +213,9 @@ stable kernels. | ARM | GIC-700 | #2941627 | ARM64_ERRATUM_2941627 | +----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+ +| ARM | SI L1 | #4311569 | ARM64_ERRATUM_4311569 | ++----------------+-----------------+-----------------+-----------------------------+ ++----------------+-----------------+-----------------+-----------------------------+ | Broadcom | Brahma-B53 | N/A | ARM64_ERRATUM_845719 | +----------------+-----------------+-----------------+-----------------------------+ | Broadcom | Brahma-B53 | N/A | ARM64_ERRATUM_843419 | diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 65db12f66b8f..a834d30859cc 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1153,6 +1153,25 @@ config ARM64_ERRATUM_3194386 If unsure, say Y. +config ARM64_ERRATUM_4311569 + bool "SI L1: 4311569: workaround for premature CMO completion erratum" + default y + help + This option adds the workaround for ARM SI L1 erratum 4311569. + + The erratum of SI L1 can cause an early response to a combined write + and cache maintenance operation (WR+CMO) before the operation is fully + completed to the Point of Serialization (POS). + This can result in a non-I/O coherent agent observing stale data, + potentially leading to system instability or incorrect behavior. + + Enabling this option implements a software workaround by inserting a + second loop of Cache Maintenance Operation (CMO) immediately following the + end of function to do CMOs. This ensures that the data is correctly serialized + before the buffer is handed off to a non-coherent agent. + + If unsure, say Y. + config CAVIUM_ERRATUM_22375 bool "Cavium erratum 22375, 24313" default y diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index f0ca7196f6fa..d3d46e5f7188 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -381,6 +381,9 @@ alternative_endif .macro dcache_by_myline_op op, domain, start, end, linesz, tmp, fixup sub \tmp, \linesz, #1 bic \start, \start, \tmp +alternative_if ARM64_WORKAROUND_4311569 + mov \tmp, \start +alternative_else_nop_endif .Ldcache_op\@: .ifc \op, cvau __dcache_op_workaround_clean_cache \op, \start @@ -402,6 +405,13 @@ alternative_endif add \start, \start, \linesz cmp \start, \end b.lo .Ldcache_op\@ +alternative_if ARM64_WORKAROUND_4311569 + .ifnc \op, cvau + mov \start, \tmp + mov \tmp, xzr + cbnz \start, .Ldcache_op\@ + .endif +alternative_else_nop_endif dsb \domain _cond_uaccess_extable .Ldcache_op\@, \fixup diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 8cb3b575a031..5c0ab6bfd44a 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -141,6 +141,30 @@ has_mismatched_cache_type(const struct arm64_cpu_capabilities *entry, return (ctr_real != sys) && (ctr_raw != sys); } +#ifdef CONFIG_ARM64_ERRATUM_4311569 +static DEFINE_STATIC_KEY_FALSE(arm_si_l1_workaround_4311569); +static int __init early_arm_si_l1_workaround_4311569_cfg(char *arg) +{ + static_branch_enable(&arm_si_l1_workaround_4311569); + pr_info("Enabling cache maintenance workaround for ARM SI-L1 erratum 4311569\n"); + + return 0; +} +early_param("arm_si_l1_workaround_4311569", early_arm_si_l1_workaround_4311569_cfg); + +/* + * We have some earlier use cases to call cache maintenance operation functions, for example, + * dcache_inval_poc() and dcache_clean_poc() in head.S, before making decision to turn on this + * workaround. Since the scope of this workaround is limited to non-coherent DMA agents, its + * safe to have the workaround off by default. + */ +static bool +need_arm_si_l1_workaround_4311569(const struct arm64_cpu_capabilities *entry, int scope) +{ + return static_branch_unlikely(&arm_si_l1_workaround_4311569); +} +#endif + static void cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *cap) { @@ -870,6 +894,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = { ERRATA_MIDR_RANGE_LIST(erratum_spec_ssbs_list), }, #endif +#ifdef CONFIG_ARM64_ERRATUM_4311569 + { + .capability = ARM64_WORKAROUND_4311569, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = need_arm_si_l1_workaround_4311569, + }, +#endif #ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD { .desc = "ARM errata 2966298, 3117295", diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S index 503567c864fd..ddf0097624ed 100644 --- a/arch/arm64/mm/cache.S +++ b/arch/arm64/mm/cache.S @@ -143,9 +143,14 @@ SYM_FUNC_END(dcache_clean_pou) * - end - kernel end address of region */ SYM_FUNC_START(__pi_dcache_inval_poc) +alternative_if ARM64_WORKAROUND_4311569 + mov x4, x0 + mov x5, x1 + mov x6, #1 +alternative_else_nop_endif dcache_line_size x2, x3 sub x3, x2, #1 - tst x1, x3 // end cache line aligned? +again: tst x1, x3 // end cache line aligned? bic x1, x1, x3 b.eq 1f dc civac, x1 // clean & invalidate D / U line @@ -158,6 +163,12 @@ SYM_FUNC_START(__pi_dcache_inval_poc) 3: add x0, x0, x2 cmp x0, x1 b.lo 2b +alternative_if ARM64_WORKAROUND_4311569 + mov x0, x4 + mov x1, x5 + sub x6, x6, #1 + cbz x6, again +alternative_else_nop_endif dsb sy ret SYM_FUNC_END(__pi_dcache_inval_poc) diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 1b32c1232d28..3b18734f9744 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -101,6 +101,7 @@ WORKAROUND_2077057 WORKAROUND_2457168 WORKAROUND_2645198 WORKAROUND_2658417 +WORKAROUND_4311569 WORKAROUND_AMPERE_AC03_CPU_38 WORKAROUND_AMPERE_AC04_CPU_23 WORKAROUND_TRBE_OVERWRITE_FILL_MODE base-commit: edde060637b92607f3522252c03d64ad06369933 -- 2.52.0.358.g0dd7633a29-goog

4 hours, 51 minutes

[PATCH] mm/damon/core: remove call_control in inactive contexts

by SeongJae Park

If damon_call() is executed against a DAMON context that is not running, the function returns error while keeping the damon_call_control object linked to the context's call_controls list. Let's suppose the object is deallocated after the damon_call(), and yet another damon_call() is executed against the same context. The function tries to add the new damon_call_control object to the call_controls list, which still has the pointer to the previous damon_call_control object, which is deallocated. As a result, use-after-free happens. This can actually be triggered using the DAMON sysfs interface. It is not easily exploitable since it requires the sysfs write permission and making a definitely weird file writes, though. Please refer to the report for more details about the issue reproduction steps. Fix the issue by making damon_call() to cleanup the damon_call_control object before returning the error. Reported-by: JaeJoon Jung <rgbi3307(a)gmail.com> Closes: https://lore.kernel.org/20251224094401.20384-1-rgbi3307@gmail.com Fixes: 42b7491af14c ("mm/damon/core: introduce damon_call()") Cc: <stable(a)vger.kernel.org> # 6.14.x Signed-off-by: SeongJae Park <sj(a)kernel.org> --- mm/damon/core.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index 2d3e8006db50..65482a0ce20b 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -1442,6 +1442,35 @@ bool damon_is_running(struct damon_ctx *ctx) return running; } +/* + * damon_call_handle_inactive_ctx() - handle DAMON call request that added to + * an inactive context. + * @ctx: The inactive DAMON context. + * @control: Control variable of the call request. + * + * This function is called in a case that @control is added to @ctx but @ctx is + * not running (inactive). See if @ctx handled @control or not, and cleanup + * @control if it was not handled. + * + * Returns 0 if @control was handled by @ctx, negative error code otherwise. + */ +static int damon_call_handle_inactive_ctx( + struct damon_ctx *ctx, struct damon_call_control *control) +{ + struct damon_call_control *c; + + mutex_lock(&ctx->call_controls_lock); + list_for_each_entry(c, &ctx->call_controls, list) { + if (c == control) { + list_del(&control->list); + mutex_unlock(&ctx->call_controls_lock); + return -EINVAL; + } + } + mutex_unlock(&ctx->call_controls_lock); + return 0; +} + /** * damon_call() - Invoke a given function on DAMON worker thread (kdamond). * @ctx: DAMON context to call the function for. @@ -1472,7 +1501,7 @@ int damon_call(struct damon_ctx *ctx, struct damon_call_control *control) list_add_tail(&control->list, &ctx->call_controls); mutex_unlock(&ctx->call_controls_lock); if (!damon_is_running(ctx)) - return -EINVAL; + return damon_call_handle_inactive_ctx(ctx, control); if (control->repeat) return 0; wait_for_completion(&control->completion); base-commit: a100272b3541cb00a5e29fdc16e428234ebfddd1 -- 2.47.3

10 hours, 20 minutes

+ mm-damon-core-remove-call_control-in-inactive-contexts.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: mm/damon/core: remove call_control in inactive contexts has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-core-remove-call_control-in-inactive-contexts.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: SeongJae Park <sj(a)kernel.org> Subject: mm/damon/core: remove call_control in inactive contexts Date: Tue, 30 Dec 2025 17:23:13 -0800 If damon_call() is executed against a DAMON context that is not running, the function returns error while keeping the damon_call_control object linked to the context's call_controls list. Let's suppose the object is deallocated after the damon_call(), and yet another damon_call() is executed against the same context. The function tries to add the new damon_call_control object to the call_controls list, which still has the pointer to the previous damon_call_control object, which is deallocated. As a result, use-after-free happens. This can actually be triggered using the DAMON sysfs interface. It is not easily exploitable since it requires the sysfs write permission and making a definitely weird file writes, though. Please refer to the report for more details about the issue reproduction steps. Fix the issue by making two changes. Firstly, move the final kdamond_call() for cancelling all existing damon_call() requests from terminating DAMON context to be done before the ctx->kdamond reset. This makes any code that sees NULL ctx->kdamond can safely assume the context may not access damon_call() requests anymore. Secondly, let damon_call() to cleanup the damon_call_control objects that were added to the already-terminated DAMON context, before returning the error. Link: https://lkml.kernel.org/r/20251231012315.75835-1-sj@kernel.org Fixes: 004ded6bee11 ("mm/damon: accept parallel damon_call() requests") Signed-off-by: SeongJae Park <sj(a)kernel.org> Reported-by: JaeJoon Jung <rgbi3307(a)gmail.com> Closes: https://lore.kernel.org/20251224094401.20384-1-rgbi3307@gmail.com Cc: <stable(a)vger.kernel.org> # 6.17.x Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/damon/core.c | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) --- a/mm/damon/core.c~mm-damon-core-remove-call_control-in-inactive-contexts +++ a/mm/damon/core.c @@ -1431,6 +1431,35 @@ bool damon_is_running(struct damon_ctx * return running; } +/* + * damon_call_handle_inactive_ctx() - handle DAMON call request that added to + * an inactive context. + * @ctx: The inactive DAMON context. + * @control: Control variable of the call request. + * + * This function is called in a case that @control is added to @ctx but @ctx is + * not running (inactive). See if @ctx handled @control or not, and cleanup + * @control if it was not handled. + * + * Returns 0 if @control was handled by @ctx, negative error code otherwise. + */ +static int damon_call_handle_inactive_ctx( + struct damon_ctx *ctx, struct damon_call_control *control) +{ + struct damon_call_control *c; + + mutex_lock(&ctx->call_controls_lock); + list_for_each_entry(c, &ctx->call_controls, list) { + if (c == control) { + list_del(&control->list); + mutex_unlock(&ctx->call_controls_lock); + return -EINVAL; + } + } + mutex_unlock(&ctx->call_controls_lock); + return 0; +} + /** * damon_call() - Invoke a given function on DAMON worker thread (kdamond). * @ctx: DAMON context to call the function for. @@ -1461,7 +1490,7 @@ int damon_call(struct damon_ctx *ctx, st list_add_tail(&control->list, &ctx->call_controls); mutex_unlock(&ctx->call_controls_lock); if (!damon_is_running(ctx)) - return -EINVAL; + return damon_call_handle_inactive_ctx(ctx, control); if (control->repeat) return 0; wait_for_completion(&control->completion); @@ -2755,13 +2784,13 @@ done: if (ctx->ops.cleanup) ctx->ops.cleanup(ctx); kfree(ctx->regions_score_histogram); + kdamond_call(ctx, true); pr_debug("kdamond (%d) finishes\n", current->pid); mutex_lock(&ctx->kdamond_lock); ctx->kdamond = NULL; mutex_unlock(&ctx->kdamond_lock); - kdamond_call(ctx, true); damos_walk_cancel(ctx); mutex_lock(&damon_lock); _ Patches currently in -mm which might be from sj(a)kernel.org are mm-damon-core-remove-call_control-in-inactive-contexts.patch mm-damon-core-introduce-nr_snapshots-damos-stat.patch mm-damon-sysfs-schemes-introduce-nr_snapshots-damos-stat-file.patch docs-mm-damon-design-update-for-nr_snapshots-damos-stat.patch docs-admin-guide-mm-damon-usage-update-for-nr_snapshots-damos-stat.patch docs-abi-damon-update-for-nr_snapshots-damos-stat.patch mm-damon-update-damos-kerneldoc-for-stat-field.patch mm-damon-core-implement-max_nr_snapshots.patch mm-damon-sysfs-schemes-implement-max_nr_snapshots-file.patch docs-mm-damon-design-update-for-max_nr_snapshots.patch docs-admin-guide-mm-damon-usage-update-for-max_nr_snapshots.patch docs-abi-damon-update-for-max_nr_snapshots.patch mm-damon-core-add-trace-point-for-damos-stat-per-apply-interval.patch mm-damon-sysfs-cleanup-intervals-subdirs-on-attrs-dir-setup-failure.patch mm-damon-sysfs-cleanup-attrs-subdirs-on-context-dir-setup-failure.patch mm-damon-sysfs-scheme-cleanup-quotas-subdirs-on-scheme-dir-setup-failure.patch mm-damon-sysfs-scheme-cleanup-access_pattern-subdirs-on-scheme-dir-setup-failure.patch mm-damon-tests-core-kunit-add-test-cases-for-multiple-regions-in-damon_test_split_regions_of-fix.patch

10 hours, 36 minutes

+ x86-kexec-add-a-sanity-check-on-previous-kernels-ima-kexec-buffer.patch added to mm-nonmm-unstable branch

by Andrew Morton

The patch titled Subject: x86/kexec: add a sanity check on previous kernel's ima kexec buffer has been added to the -mm mm-nonmm-unstable branch. Its filename is x86-kexec-add-a-sanity-check-on-previous-kernels-ima-kexec-buffer.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Harshit Mogalapalli <harshit.m.mogalapalli(a)oracle.com> Subject: x86/kexec: add a sanity check on previous kernel's ima kexec buffer Date: Tue, 30 Dec 2025 22:16:09 -0800 When the second-stage kernel is booted via kexec with a limiting command line such as "mem=<size>", the physical range that contains the carried over IMA measurement list may fall outside the truncated RAM leading to a kernel panic. BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) �� not-present page Other architectures already validate the range with page_is_ram(), as done in commit cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds") do a similar check on x86. Without carrying the measurement list across kexec, the attestation would fail. Link: https://lkml.kernel.org/r/20251231061609.907170-4-harshit.m.mogalapalli@ora… Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli(a)oracle.com> Fixes: b69a2afd5afc ("x86/kexec: Carry forward IMA measurement log on kexec") Reported-by: Paul Webb <paul.x.webb(a)oracle.com> Reviewed-by: Mimi Zohar <zohar(a)linux.ibm.com> Cc: Alexander Graf <graf(a)amazon.com> Cc: Ard Biesheuvel <ardb(a)kernel.org> Cc: Baoquan He <bhe(a)redhat.com> Cc: Borislav Betkov <bp(a)alien8.de> Cc: guoweikang <guoweikang.kernel(a)gmail.com> Cc: Henry Willard <henry.willard(a)oracle.com> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jiri Bohac <jbohac(a)suse.cz> Cc: Joel Granados <joel.granados(a)kernel.org> Cc: Jonathan McDowell <noodles(a)fb.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Sohil Mehta <sohil.mehta(a)intel.com> Cc: Sourabh Jain <sourabhjain(a)linux.ibm.com> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: Yifei Liu <yifei.l.liu(a)oracle.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- arch/x86/kernel/setup.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/arch/x86/kernel/setup.c~x86-kexec-add-a-sanity-check-on-previous-kernels-ima-kexec-buffer +++ a/arch/x86/kernel/setup.c @@ -439,9 +439,15 @@ int __init ima_free_kexec_buffer(void) int __init ima_get_kexec_buffer(void **addr, size_t *size) { + int ret; + if (!ima_kexec_buffer_size) return -ENOENT; + ret = ima_validate_range(ima_kexec_buffer_phys, ima_kexec_buffer_size); + if (ret) + return ret; + *addr = __va(ima_kexec_buffer_phys); *size = ima_kexec_buffer_size; _ Patches currently in -mm which might be from harshit.m.mogalapalli(a)oracle.com are ima-verify-the-previous-kernels-ima-buffer-lies-in-addressable-ram.patch of-kexec-refactor-ima_get_kexec_buffer-to-use-ima_validate_range.patch x86-kexec-add-a-sanity-check-on-previous-kernels-ima-kexec-buffer.patch

10 hours, 48 minutes

+ of-kexec-refactor-ima_get_kexec_buffer-to-use-ima_validate_range.patch added to mm-nonmm-unstable branch

by Andrew Morton

The patch titled Subject: of/kexec: refactor ima_get_kexec_buffer() to use ima_validate_range() has been added to the -mm mm-nonmm-unstable branch. Its filename is of-kexec-refactor-ima_get_kexec_buffer-to-use-ima_validate_range.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Harshit Mogalapalli <harshit.m.mogalapalli(a)oracle.com> Subject: of/kexec: refactor ima_get_kexec_buffer() to use ima_validate_range() Date: Tue, 30 Dec 2025 22:16:08 -0800 Refactor the OF/DT ima_get_kexec_buffer() to use a generic helper to validate the address range. No functional change intended. Link: https://lkml.kernel.org/r/20251231061609.907170-3-harshit.m.mogalapalli@ora… Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli(a)oracle.com> Reviewed-by: Mimi Zohar <zohar(a)linux.ibm.com> Cc: Alexander Graf <graf(a)amazon.com> Cc: Ard Biesheuvel <ardb(a)kernel.org> Cc: Baoquan He <bhe(a)redhat.com> Cc: Borislav Betkov <bp(a)alien8.de> Cc: guoweikang <guoweikang.kernel(a)gmail.com> Cc: Henry Willard <henry.willard(a)oracle.com> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jiri Bohac <jbohac(a)suse.cz> Cc: Joel Granados <joel.granados(a)kernel.org> Cc: Jonathan McDowell <noodles(a)fb.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Paul Webb <paul.x.webb(a)oracle.com> Cc: Sohil Mehta <sohil.mehta(a)intel.com> Cc: Sourabh Jain <sourabhjain(a)linux.ibm.com> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: Yifei Liu <yifei.l.liu(a)oracle.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- drivers/of/kexec.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) --- a/drivers/of/kexec.c~of-kexec-refactor-ima_get_kexec_buffer-to-use-ima_validate_range +++ a/drivers/of/kexec.c @@ -128,7 +128,6 @@ int __init ima_get_kexec_buffer(void **a { int ret, len; unsigned long tmp_addr; - unsigned long start_pfn, end_pfn; size_t tmp_size; const void *prop; @@ -144,17 +143,9 @@ int __init ima_get_kexec_buffer(void **a if (!tmp_size) return -ENOENT; - /* - * Calculate the PFNs for the buffer and ensure - * they are with in addressable memory. - */ - start_pfn = PHYS_PFN(tmp_addr); - end_pfn = PHYS_PFN(tmp_addr + tmp_size - 1); - if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) { - pr_warn("IMA buffer at 0x%lx, size = 0x%zx beyond memory\n", - tmp_addr, tmp_size); - return -EINVAL; - } + ret = ima_validate_range(tmp_addr, tmp_size); + if (ret) + return ret; *addr = __va(tmp_addr); *size = tmp_size; _ Patches currently in -mm which might be from harshit.m.mogalapalli(a)oracle.com are ima-verify-the-previous-kernels-ima-buffer-lies-in-addressable-ram.patch of-kexec-refactor-ima_get_kexec_buffer-to-use-ima_validate_range.patch x86-kexec-add-a-sanity-check-on-previous-kernels-ima-kexec-buffer.patch

10 hours, 48 minutes

+ ima-verify-the-previous-kernels-ima-buffer-lies-in-addressable-ram.patch added to mm-nonmm-unstable branch

by Andrew Morton

The patch titled Subject: ima: verify the previous kernel's IMA buffer lies in addressable RAM has been added to the -mm mm-nonmm-unstable branch. Its filename is ima-verify-the-previous-kernels-ima-buffer-lies-in-addressable-ram.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Harshit Mogalapalli <harshit.m.mogalapalli(a)oracle.com> Subject: ima: verify the previous kernel's IMA buffer lies in addressable RAM Date: Tue, 30 Dec 2025 22:16:07 -0800 Patch series "Address page fault in ima_restore_measurement_list()", v3. When the second-stage kernel is booted via kexec with a limiting command line such as "mem=<size>" we observe a pafe fault that happens. BUG: unable to handle page fault for address: ffff97793ff47000 RIP: ima_restore_measurement_list+0xdc/0x45a #PF: error_code(0x0000) not-present page This happens on x86_64 only, as this is already fixed in aarch64 in commit: cbf9c4b9617b ("of: check previous kernel's ima-kexec-buffer against memory bounds") This patch (of 3): When the second-stage kernel is booted with a limiting command line (e.g. "mem=<size>"), the IMA measurement buffer handed over from the previous kernel may fall outside the addressable RAM of the new kernel. Accessing such a buffer can fault during early restore. Introduce a small generic helper, ima_validate_range(), which verifies that a physical [start, end] range for the previous-kernel IMA buffer lies within addressable memory: - On x86, use pfn_range_is_mapped(). - On OF based architectures, use page_is_ram(). Link: https://lkml.kernel.org/r/20251231061609.907170-1-harshit.m.mogalapalli@ora… Link: https://lkml.kernel.org/r/20251231061609.907170-2-harshit.m.mogalapalli@ora… Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli(a)oracle.com> Cc: Alexander Graf <graf(a)amazon.com> Cc: Ard Biesheuvel <ardb(a)kernel.org> Cc: Borislav Betkov <bp(a)alien8.de> Cc: guoweikang <guoweikang.kernel(a)gmail.com> Cc: Henry Willard <henry.willard(a)oracle.com> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jiri Bohac <jbohac(a)suse.cz> Cc: Joel Granados <joel.granados(a)kernel.org> Cc: Jonathan McDowell <noodles(a)fb.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Mimi Zohar <zohar(a)linux.ibm.com> Cc: Paul Webb <paul.x.webb(a)oracle.com> Cc: Sohil Mehta <sohil.mehta(a)intel.com> Cc: Sourabh Jain <sourabhjain(a)linux.ibm.com> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: Yifei Liu <yifei.l.liu(a)oracle.com> Cc: Baoquan He <bhe(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/ima.h | 1 security/integrity/ima/ima_kexec.c | 35 +++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) --- a/include/linux/ima.h~ima-verify-the-previous-kernels-ima-buffer-lies-in-addressable-ram +++ a/include/linux/ima.h @@ -69,6 +69,7 @@ static inline int ima_measure_critical_d #ifdef CONFIG_HAVE_IMA_KEXEC int __init ima_free_kexec_buffer(void); int __init ima_get_kexec_buffer(void **addr, size_t *size); +int ima_validate_range(phys_addr_t phys, size_t size); #endif #ifdef CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT --- a/security/integrity/ima/ima_kexec.c~ima-verify-the-previous-kernels-ima-buffer-lies-in-addressable-ram +++ a/security/integrity/ima/ima_kexec.c @@ -12,6 +12,8 @@ #include <linux/kexec.h> #include <linux/of.h> #include <linux/ima.h> +#include <linux/mm.h> +#include <linux/overflow.h> #include <linux/reboot.h> #include <asm/page.h> #include "ima.h" @@ -294,3 +296,36 @@ void __init ima_load_kexec_buffer(void) pr_debug("Error restoring the measurement list: %d\n", rc); } } + +/* + * ima_validate_range - verify a physical buffer lies in addressable RAM + * @phys: physical start address of the buffer from previous kernel + * @size: size of the buffer + * + * On success return 0. On failure returns -EINVAL so callers can skip + * restoring. + */ +int ima_validate_range(phys_addr_t phys, size_t size) +{ + unsigned long start_pfn, end_pfn; + phys_addr_t end_phys; + + if (check_add_overflow(phys, (phys_addr_t)size - 1, &end_phys)) + return -EINVAL; + + start_pfn = PHYS_PFN(phys); + end_pfn = PHYS_PFN(end_phys); + +#ifdef CONFIG_X86 + if (!pfn_range_is_mapped(start_pfn, end_pfn)) +#else + if (!page_is_ram(start_pfn) || !page_is_ram(end_pfn)) +#endif + { + pr_warn("IMA: previous kernel measurement buffer %pa (size 0x%zx) lies outside available memory\n", + &phys, size); + return -EINVAL; + } + + return 0; +} _ Patches currently in -mm which might be from harshit.m.mogalapalli(a)oracle.com are ima-verify-the-previous-kernels-ima-buffer-lies-in-addressable-ram.patch of-kexec-refactor-ima_get_kexec_buffer-to-use-ima_validate_range.patch x86-kexec-add-a-sanity-check-on-previous-kernels-ima-kexec-buffer.patch

10 hours, 48 minutes

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