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* Merge tag 'mm-hotfixes-stable-2024-05-25-09-13' of ↵Linus Torvalds2024-05-261-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "16 hotfixes, 11 of which are cc:stable. A few nilfs2 fixes, the remainder are for MM: a couple of selftests fixes, various singletons fixing various issues in various parts" * tag 'mm-hotfixes-stable-2024-05-25-09-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/ksm: fix possible UAF of stable_node mm/memory-failure: fix handling of dissolved but not taken off from buddy pages mm: /proc/pid/smaps_rollup: avoid skipping vma after getting mmap_lock again nilfs2: fix potential hang in nilfs_detach_log_writer() nilfs2: fix unexpected freezing of nilfs_segctor_sync() nilfs2: fix use-after-free of timer for log writer thread selftests/mm: fix build warnings on ppc64 arm64: patching: fix handling of execmem addresses selftests/mm: compaction_test: fix bogus test success and reduce probability of OOM-killer invocation selftests/mm: compaction_test: fix incorrect write of zero to nr_hugepages selftests/mm: compaction_test: fix bogus test success on Aarch64 mailmap: update email address for Satya Priya mm/huge_memory: don't unpoison huge_zero_folio kasan, fortify: properly rename memintrinsics lib: add version into /proc/allocinfo output mm/vmalloc: fix vmalloc which may return null if called with __GFP_NOFAIL
| * arm64: patching: fix handling of execmem addressesWill Deacon2024-05-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Klara Modin reported warnings for a kernel configured with BPF_JIT but without MODULES: [ 44.131296] Trying to vfree() bad address (000000004a17c299) [ 44.138024] WARNING: CPU: 1 PID: 193 at mm/vmalloc.c:3189 remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.146675] CPU: 1 PID: 193 Comm: kworker/1:2 Tainted: G D W 6.9.0-01786-g2c9e5d4a0082 #25 [ 44.158229] Hardware name: Raspberry Pi 3 Model B (DT) [ 44.164433] Workqueue: events bpf_prog_free_deferred [ 44.170492] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 44.178601] pc : remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.183705] lr : remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.188772] sp : ffff800082a13c70 [ 44.193112] x29: ffff800082a13c70 x28: 0000000000000000 x27: 0000000000000000 [ 44.201384] x26: 0000000000000000 x25: ffff00003a44efa0 x24: 00000000d4202000 [ 44.209658] x23: ffff800081223dd0 x22: ffff00003a198a40 x21: ffff8000814dd880 [ 44.217924] x20: 00000000d4202000 x19: ffff8000814dd880 x18: 0000000000000006 [ 44.226206] x17: 0000000000000000 x16: 0000000000000020 x15: 0000000000000002 [ 44.234460] x14: ffff8000811a6370 x13: 0000000020000000 x12: 0000000000000000 [ 44.242710] x11: ffff8000811a6370 x10: 0000000000000144 x9 : ffff8000811fe370 [ 44.250959] x8 : 0000000000017fe8 x7 : 00000000fffff000 x6 : ffff8000811fe370 [ 44.259206] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 [ 44.267457] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff000002203240 [ 44.275703] Call trace: [ 44.279158] remove_vm_area (mm/vmalloc.c:3189 (discriminator 1)) [ 44.283858] vfree (mm/vmalloc.c:3322) [ 44.287835] execmem_free (mm/execmem.c:70) [ 44.292347] bpf_jit_free_exec+0x10/0x1c [ 44.297283] bpf_prog_pack_free (kernel/bpf/core.c:1006) [ 44.302457] bpf_jit_binary_pack_free (kernel/bpf/core.c:1195) [ 44.307951] bpf_jit_free (include/linux/filter.h:1083 arch/arm64/net/bpf_jit_comp.c:2474) [ 44.312342] bpf_prog_free_deferred (kernel/bpf/core.c:2785) [ 44.317785] process_one_work (kernel/workqueue.c:3273) [ 44.322684] worker_thread (kernel/workqueue.c:3342 (discriminator 2) kernel/workqueue.c:3429 (discriminator 2)) [ 44.327292] kthread (kernel/kthread.c:388) [ 44.331342] ret_from_fork (arch/arm64/kernel/entry.S:861) The problem is because bpf_arch_text_copy() silently fails to write to the read-only area as a result of patch_map() faulting and the resulting -EFAULT being chucked away. Update patch_map() to use CONFIG_EXECMEM instead of CONFIG_STRICT_MODULE_RWX to check for vmalloc addresses. Link: https://lkml.kernel.org/r/20240521213813.703309-1-rppt@kernel.org Fixes: 2c9e5d4a0082 ("bpf: remove CONFIG_BPF_JIT dependency on CONFIG_MODULES of") Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org> Reported-by: Klara Modin <klarasmodin@gmail.com> Closes: https://lore.kernel.org/all/7983fbbf-0127-457c-9394-8d6e4299c685@gmail.com Tested-by: Klara Modin <klarasmodin@gmail.com> Cc: Björn Töpel <bjorn@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'irq-urgent-2024-05-25' of ↵Linus Torvalds2024-05-251-3/+6
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Ingo Molnar: - Fix x86 IRQ vector leak caused by a CPU offlining race - Fix build failure in the riscv-imsic irqchip driver caused by an API-change semantic conflict - Fix use-after-free in irq_find_at_or_after() * tag 'irq-urgent-2024-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq/irqdesc: Prevent use-after-free in irq_find_at_or_after() genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offline irqchip/riscv-imsic: Fixup riscv_ipi_set_virq_range() conflict
| * | genirq/cpuhotplug, x86/vector: Prevent vector leak during CPU offlineDongli Zhang2024-05-231-3/+6
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The absence of IRQD_MOVE_PCNTXT prevents immediate effectiveness of interrupt affinity reconfiguration via procfs. Instead, the change is deferred until the next instance of the interrupt being triggered on the original CPU. When the interrupt next triggers on the original CPU, the new affinity is enforced within __irq_move_irq(). A vector is allocated from the new CPU, but the old vector on the original CPU remains and is not immediately reclaimed. Instead, apicd->move_in_progress is flagged, and the reclaiming process is delayed until the next trigger of the interrupt on the new CPU. Upon the subsequent triggering of the interrupt on the new CPU, irq_complete_move() adds a task to the old CPU's vector_cleanup list if it remains online. Subsequently, the timer on the old CPU iterates over its vector_cleanup list, reclaiming old vectors. However, a rare scenario arises if the old CPU is outgoing before the interrupt triggers again on the new CPU. In that case irq_force_complete_move() is not invoked on the outgoing CPU to reclaim the old apicd->prev_vector because the interrupt isn't currently affine to the outgoing CPU, and irq_needs_fixup() returns false. Even though __vector_schedule_cleanup() is later called on the new CPU, it doesn't reclaim apicd->prev_vector; instead, it simply resets both apicd->move_in_progress and apicd->prev_vector to 0. As a result, the vector remains unreclaimed in vector_matrix, leading to a CPU vector leak. To address this issue, move the invocation of irq_force_complete_move() before the irq_needs_fixup() call to reclaim apicd->prev_vector, if the interrupt is currently or used to be affine to the outgoing CPU. Additionally, reclaim the vector in __vector_schedule_cleanup() as well, following a warning message, although theoretically it should never see apicd->move_in_progress with apicd->prev_cpu pointing to an offline CPU. Fixes: f0383c24b485 ("genirq/cpuhotplug: Add support for cleaning up move in progress") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240522220218.162423-1-dongli.zhang@oracle.com
* | Merge tag 'x86-urgent-2024-05-25' of ↵Linus Torvalds2024-05-255-18/+65
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: - Fix regressions of the new x86 CPU VFM (vendor/family/model) enumeration/matching code - Fix crash kernel detection on buggy firmware with non-compliant ACPI MADT tables - Address Kconfig warning * tag 'x86-urgent-2024-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Fix x86_match_cpu() to match just X86_VENDOR_INTEL crypto: x86/aes-xts - switch to new Intel CPU model defines x86/topology: Handle bogus ACPI tables correctly x86/kconfig: Select ARCH_WANT_FRAME_POINTERS again when UNWINDER_FRAME_POINTER=y
| * | x86/cpu: Fix x86_match_cpu() to match just X86_VENDOR_INTELTony Luck2024-05-222-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code in v6.9 arch/x86/kernel/smpboot.c was changed by commit 4db64279bc2b ("x86/cpu: Switch to new Intel CPU model defines") from: static const struct x86_cpu_id intel_cod_cpu[] = { X86_MATCH_INTEL_FAM6_MODEL(HASWELL_X, 0), /* COD */ X86_MATCH_INTEL_FAM6_MODEL(BROADWELL_X, 0), /* COD */ X86_MATCH_INTEL_FAM6_MODEL(ANY, 1), /* SNC */ <--- 443 {} }; static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) { const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu); to: static const struct x86_cpu_id intel_cod_cpu[] = { X86_MATCH_VFM(INTEL_HASWELL_X, 0), /* COD */ X86_MATCH_VFM(INTEL_BROADWELL_X, 0), /* COD */ X86_MATCH_VFM(INTEL_ANY, 1), /* SNC */ {} }; static bool match_llc(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o) { const struct x86_cpu_id *id = x86_match_cpu(intel_cod_cpu); On an Intel CPU with SNC enabled this code previously matched the rule on line 443 to avoid printing messages about insane cache configuration. The new code did not match any rules. Expanding the macros for the intel_cod_cpu[] array shows that the old is equivalent to: static const struct x86_cpu_id intel_cod_cpu[] = { [0] = { .vendor = 0, .family = 6, .model = 0x3F, .steppings = 0, .feature = 0, .driver_data = 0 }, [1] = { .vendor = 0, .family = 6, .model = 0x4F, .steppings = 0, .feature = 0, .driver_data = 0 }, [2] = { .vendor = 0, .family = 6, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 1 }, [3] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 0 } } while the new code expands to: static const struct x86_cpu_id intel_cod_cpu[] = { [0] = { .vendor = 0, .family = 6, .model = 0x3F, .steppings = 0, .feature = 0, .driver_data = 0 }, [1] = { .vendor = 0, .family = 6, .model = 0x4F, .steppings = 0, .feature = 0, .driver_data = 0 }, [2] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 1 }, [3] = { .vendor = 0, .family = 0, .model = 0x00, .steppings = 0, .feature = 0, .driver_data = 0 } } Looking at the code for x86_match_cpu(): const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match) { const struct x86_cpu_id *m; struct cpuinfo_x86 *c = &boot_cpu_data; for (m = match; m->vendor | m->family | m->model | m->steppings | m->feature; m++) { ... } return NULL; it is clear that there was no match because the ANY entry in the table (array index 2) is now the loop termination condition (all of vendor, family, model, steppings, and feature are zero). So this code was working before because the "ANY" check was looking for any Intel CPU in family 6. But fails now because the family is a wild card. So the root cause is that x86_match_cpu() has never been able to match on a rule with just X86_VENDOR_INTEL and all other fields set to wildcards. Add a new flags field to struct x86_cpu_id that has a bit set to indicate that this entry in the array is valid. Update X86_MATCH*() macros to set that bit. Change the end-marker check in x86_match_cpu() to just check the flags field for this bit. Backporter notes: The commit in Fixes is really the one that is broken: you can't have m->vendor as part of the loop termination conditional in x86_match_cpu() because it can happen - as it has happened above - that that whole conditional is 0 albeit vendor == 0 is a valid case - X86_VENDOR_INTEL is 0. However, the only case where the above happens is the SNC check added by 4db64279bc2b1 so you only need this fix if you have backported that other commit 4db64279bc2b ("x86/cpu: Switch to new Intel CPU model defines") Fixes: 644e9cbbe3fc ("Add driver auto probing for x86 features v4") Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Borislav Petkov <bp@alien8.de> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Cc: <stable+noautosel@kernel.org> # see above Link: https://lore.kernel.org/r/20240517144312.GBZkdtAOuJZCvxhFbJ@fat_crate.local
| * | crypto: x86/aes-xts - switch to new Intel CPU model definesTony Luck2024-05-221-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | New CPU #defines encode vendor and family as well as model. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Eric Biggers <ebiggers@google.com> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Link: https://lore.kernel.org/r/20240520224620.9480-2-tony.luck@intel.com
| * | x86/topology: Handle bogus ACPI tables correctlyThomas Gleixner2024-05-211-3/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ACPI specification clearly states how the processors should be enumerated in the MADT: "To ensure that the boot processor is supported post initialization, two guidelines should be followed. The first is that OSPM should initialize processors in the order that they appear in the MADT. The second is that platform firmware should list the boot processor as the first processor entry in the MADT. ... Failure of OSPM implementations and platform firmware to abide by these guidelines can result in both unpredictable and non optimal platform operation." The kernel relies on that ordering to detect the real BSP on crash kernels which is important to avoid sending a INIT IPI to it as that would cause a full machine reset. On a Dell XPS 16 9640 the BIOS ignores this rule and enumerates the CPUs in the wrong order. As a consequence the kernel falsely detects a crash kernel and disables the corresponding CPU. Prevent this by checking the IA32_APICBASE MSR for the BSP bit on the boot CPU. If that bit is set, then the MADT based BSP detection can be safely ignored. If the kernel detects a mismatch between the BSP bit and the first enumerated MADT entry then emit a firmware bug message. This obviously also has to be taken into account when the boot APIC ID and the first enumerated APIC ID match. If the boot CPU does not have the BSP bit set in the APICBASE MSR then there is no way for the boot CPU to determine which of the CPUs is the real BSP. Sending an INIT to the real BSP would reset the machine so the only sane way to deal with that is to limit the number of CPUs to one and emit a corresponding warning message. Fixes: 5c5682b9f87a ("x86/cpu: Detect real BSP on crash kernels") Reported-by: Carsten Tolkmit <ctolkmit@ennit.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Carsten Tolkmit <ctolkmit@ennit.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/87le48jycb.ffs@tglx Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218837
| * | x86/kconfig: Select ARCH_WANT_FRAME_POINTERS again when UNWINDER_FRAME_POINTER=yMasahiro Yamada2024-05-201-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It took me some time to understand the purpose of the tricky code at the end of arch/x86/Kconfig.debug. Without it, the following would be shown: WARNING: unmet direct dependencies detected for FRAME_POINTER because 81d387190039 ("x86/kconfig: Consolidate unwinders into multiple choice selection") removed 'select ARCH_WANT_FRAME_POINTERS'. The correct and more straightforward approach should have been to move it where 'select FRAME_POINTER' is located. Several architectures properly handle the conditional selection of ARCH_WANT_FRAME_POINTERS. For example, 'config UNWINDER_FRAME_POINTER' in arch/arm/Kconfig.debug. Fixes: 81d387190039 ("x86/kconfig: Consolidate unwinders into multiple choice selection") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/20240204122003.53795-1-masahiroy@kernel.org
* | | Merge tag 'uml-for-linus-6.10-rc1' of ↵Linus Torvalds2024-05-2554-129/+136
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux Pull UML updates from Richard Weinberger: - Fixes for -Wmissing-prototypes warnings and further cleanup - Remove callback returning void from rtc and virtio drivers - Fix bash location * tag 'uml-for-linus-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (26 commits) um: virtio_uml: Convert to platform remove callback returning void um: rtc: Convert to platform remove callback returning void um: Remove unused do_get_thread_area function um: Fix -Wmissing-prototypes warnings for __vdso_* um: Add an internal header shared among the user code um: Fix the declaration of kasan_map_memory um: Fix the -Wmissing-prototypes warning for get_thread_reg um: Fix the -Wmissing-prototypes warning for __switch_mm um: Fix -Wmissing-prototypes warnings for (rt_)sigreturn um: Stop tracking host PID in cpu_tasks um: process: remove unused 'n' variable um: vector: remove unused len variable/calculation um: vector: fix bpfflash parameter evaluation um: slirp: remove set but unused variable 'pid' um: signal: move pid variable where needed um: Makefile: use bash from the environment um: Add winch to winch_handlers before registering winch IRQ um: Fix -Wmissing-prototypes warnings for __warp_* and foo um: Fix -Wmissing-prototypes warnings for text_poke* um: Move declarations to proper headers ...
| * | | um: virtio_uml: Convert to platform remove callback returning voidUwe Kleine-König2024-04-301-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: rtc: Convert to platform remove callback returning voidUwe Kleine-König2024-04-301-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Remove unused do_get_thread_area functionTiwei Bie2024-04-301-17/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's not used since it was introduced by commit aa6758d4867c ("[PATCH] uml: implement {get,set}_thread_area for i386"). Now, it's causing a -Wmissing-prototypes warning: arch/x86/um/tls_32.c:39:5: warning: no previous prototype for ‘do_get_thread_area’ [-Wmissing-prototypes] 39 | int do_get_thread_area(struct user_desc *info) | ^~~~~~~~~~~~~~~~~~ The original author also had doubts about whether it should be used. Considering that 18 years have passed, let's just remove it. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix -Wmissing-prototypes warnings for __vdso_*Tiwei Bie2024-04-301-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The VDSO functions are defined as globals and intended to be called from userspace. Let's just workaround the -Wmissing-prototypes warnings by declaring them locally. This will address below -Wmissing-prototypes warnings: arch/x86/um/vdso/um_vdso.c:16:5: warning: no previous prototype for ‘__vdso_clock_gettime’ [-Wmissing-prototypes] arch/x86/um/vdso/um_vdso.c:30:5: warning: no previous prototype for ‘__vdso_gettimeofday’ [-Wmissing-prototypes] arch/x86/um/vdso/um_vdso.c:44:21: warning: no previous prototype for ‘__vdso_time’ [-Wmissing-prototypes] arch/x86/um/vdso/um_vdso.c:57:1: warning: no previous prototype for ‘__vdso_getcpu’ [-Wmissing-prototypes] While at it, also fix the "WARNING: Prefer 'unsigned int *' to bare use of 'unsigned *'" checkpatch warning. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Add an internal header shared among the user codeTiwei Bie2024-04-307-6/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move relevant declarations to this header. This will address below -Wmissing-prototypes warnings: arch/um/os-Linux/elf_aux.c:26:13: warning: no previous prototype for ‘scan_elf_aux’ [-Wmissing-prototypes] arch/um/os-Linux/mem.c:213:13: warning: no previous prototype for ‘check_tmpexec’ [-Wmissing-prototypes] arch/um/os-Linux/skas/process.c:107:6: warning: no previous prototype for ‘wait_stub_done’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix the declaration of kasan_map_memoryTiwei Bie2024-04-303-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it match its definition (size_t vs unsigned long). And declare it in a shared header to fix the -Wmissing-prototypes warning, as it is defined in the user code and called in the kernel code. Fixes: 5b301409e8bc ("UML: add support for KASAN under x86_64") Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix the -Wmissing-prototypes warning for get_thread_regTiwei Bie2024-04-302-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The get_thread_reg function is defined in the user code, and is called by the kernel code. It should be declared in a shared header. Fixes: dbba7f704aa0 ("um: stop polluting the namespace with registers.h contents") Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix the -Wmissing-prototypes warning for __switch_mmTiwei Bie2024-04-302-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __switch_mm function is defined in the user code, and is called by the kernel code. It should be declared in a shared header. Fixes: 4dc706c2f292 ("um: take um_mmu.h to asm/mmu.h, clean asm/mmu_context.h a bit") Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix -Wmissing-prototypes warnings for (rt_)sigreturnTiwei Bie2024-04-301-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use SYSCALL_DEFINE0 to define (rt_)sigreturn. This will address below -Wmissing-prototypes warnings: arch/x86/um/signal.c:453:6: warning: no previous prototype for ‘sys_sigreturn’ [-Wmissing-prototypes] arch/x86/um/signal.c:560:6: warning: no previous prototype for ‘sys_rt_sigreturn’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Stop tracking host PID in cpu_tasksTiwei Bie2024-04-303-15/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The host PID tracked in 'cpu_tasks' is no longer used. Stopping tracking it will also save some cycles. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: process: remove unused 'n' variableJohannes Berg2024-04-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The return value of fn() wasn't used for a long time, so no need to assign it to a variable, addressing a W=1 warning. This seems to be - with patches from others posted to the list before - the last W=1 warning in arch/um/. Fixes: 22e2430d60db ("x86, um: convert to saner kernel_execve() semantics") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: vector: remove unused len variable/calculationJohannes Berg2024-04-221-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The len variable is unused, so not needed, remove it. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: vector: fix bpfflash parameter evaluationJohannes Berg2024-04-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With W=1 the build complains about a pointer compared to zero, clearly the result should've been compared. Fixes: 9807019a62dc ("um: Loadable BPF "Firmware" for vector drivers") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: slirp: remove set but unused variable 'pid'Johannes Berg2024-04-221-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The code doesn't use 'pid' here, just remove it. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: signal: move pid variable where neededJohannes Berg2024-04-221-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We have W=1 warnings on 64-bit because the pid is only used in branches on 32-bit; move it inside to get rid of the warnings. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Makefile: use bash from the environmentYueh-Shun Li2024-04-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Set Makefile SHELL to bash instead of /bin/bash for better portability. Some systems do not install binaries to /bin, and therefore do not provide /bin/bash. This includes Linux distros which intentionally avoid implementing the Filesystem Hierarchy Standard (FHS), such as NixOS and Guix System. The recipies inside arch/um/Makefile don't require top-level Bash to build, and setting "SHELL" to "bash" makes Make pick the Bash executable from the environment, hence this patch. Changes since last roll: - Rebase onto a more recent commit on the master branch. - Remove a dangling in-text citation from the change log. - Reword the change log. Signed-off-by: Yueh-Shun Li <shamrocklee@posteo.net> Reviewed-by: Johannes Berg <johannes@sipsolutions.net Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Add winch to winch_handlers before registering winch IRQRoberto Sassu2024-04-221-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Registering a winch IRQ is racy, an interrupt may occur before the winch is added to the winch_handlers list. If that happens, register_winch_irq() adds to that list a winch that is scheduled to be (or has already been) freed, causing a panic later in winch_cleanup(). Avoid the race by adding the winch to the winch_handlers list before registering the IRQ, and rolling back if um_request_irq() fails. Fixes: 42a359e31a0e ("uml: SIGIO support cleanup") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix -Wmissing-prototypes warnings for __warp_* and fooTiwei Bie2024-04-223-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These functions are not called explicitly. Let's just workaround the -Wmissing-prototypes warnings by declaring them locally similar to what was done in arch/x86/kernel/asm-offsets_32.c. This will address below -Wmissing-prototypes warnings: ./arch/x86/um/shared/sysdep/kernel-offsets.h:9:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes] arch/um/os-Linux/main.c:187:7: warning: no previous prototype for ‘__wrap_malloc’ [-Wmissing-prototypes] arch/um/os-Linux/main.c:208:7: warning: no previous prototype for ‘__wrap_calloc’ [-Wmissing-prototypes] arch/um/os-Linux/main.c:222:6: warning: no previous prototype for ‘__wrap_free’ [-Wmissing-prototypes] arch/x86/um/user-offsets.c:17:6: warning: no previous prototype for ‘foo’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix -Wmissing-prototypes warnings for text_poke*Tiwei Bie2024-04-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The prototypes for text_poke* are declared in asm/text-patching.h under arch/x86/include/. It's safe to include this header, as it's UML-aware (by checking CONFIG_UML_X86). This will address below -Wmissing-prototypes warnings: arch/um/kernel/um_arch.c:461:7: warning: no previous prototype for ‘text_poke’ [-Wmissing-prototypes] arch/um/kernel/um_arch.c:473:6: warning: no previous prototype for ‘text_poke_sync’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Move declarations to proper headersTiwei Bie2024-04-229-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This will address below -Wmissing-prototypes warnings: arch/um/kernel/initrd.c:18:12: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes] arch/um/kernel/um_arch.c:408:19: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes] arch/um/os-Linux/start_up.c:301:12: warning: no previous prototype for ‘parse_iomem’ [-Wmissing-prototypes] arch/x86/um/ptrace_32.c:15:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes] arch/x86/um/ptrace_32.c:101:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes] arch/x86/um/ptrace_32.c:153:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes] arch/x86/um/ptrace_64.c:111:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes] arch/x86/um/ptrace_64.c:171:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes] arch/x86/um/syscalls_64.c:48:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes] arch/x86/um/tls_32.c:184:5: warning: no previous prototype for ‘arch_switch_tls’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Add missing headersTiwei Bie2024-04-2213-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This will address below -Wmissing-prototypes warnings: arch/um/kernel/mem.c:202:8: warning: no previous prototype for ‘pgd_alloc’ [-Wmissing-prototypes] arch/um/kernel/mem.c:215:7: warning: no previous prototype for ‘uml_kmalloc’ [-Wmissing-prototypes] arch/um/kernel/process.c:207:6: warning: no previous prototype for ‘arch_cpu_idle’ [-Wmissing-prototypes] arch/um/kernel/process.c:328:15: warning: no previous prototype for ‘arch_align_stack’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:45:6: warning: no previous prototype for ‘machine_restart’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:51:6: warning: no previous prototype for ‘machine_power_off’ [-Wmissing-prototypes] arch/um/kernel/reboot.c:57:6: warning: no previous prototype for ‘machine_halt’ [-Wmissing-prototypes] arch/um/kernel/skas/mmu.c:17:5: warning: no previous prototype for ‘init_new_context’ [-Wmissing-prototypes] arch/um/kernel/skas/mmu.c:60:6: warning: no previous prototype for ‘destroy_context’ [-Wmissing-prototypes] arch/um/kernel/skas/process.c:36:12: warning: no previous prototype for ‘start_uml’ [-Wmissing-prototypes] arch/um/kernel/time.c:807:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes] arch/um/kernel/tlb.c:594:6: warning: no previous prototype for ‘force_flush_all’ [-Wmissing-prototypes] arch/x86/um/bugs_32.c:22:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes] arch/x86/um/bugs_32.c:44:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes] arch/x86/um/bugs_64.c:9:6: warning: no previous prototype for ‘arch_check_bugs’ [-Wmissing-prototypes] arch/x86/um/bugs_64.c:13:6: warning: no previous prototype for ‘arch_examine_signal’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:10:12: warning: no previous prototype for ‘elf_core_extra_phdrs’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:15:5: warning: no previous prototype for ‘elf_core_write_extra_phdrs’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:42:5: warning: no previous prototype for ‘elf_core_write_extra_data’ [-Wmissing-prototypes] arch/x86/um/elfcore.c:63:8: warning: no previous prototype for ‘elf_core_extra_data_size’ [-Wmissing-prototypes] arch/x86/um/fault.c:18:5: warning: no previous prototype for ‘arch_fixup’ [-Wmissing-prototypes] arch/x86/um/os-Linux/mcontext.c:7:6: warning: no previous prototype for ‘get_regs_from_mc’ [-Wmissing-prototypes] arch/x86/um/os-Linux/tls.c:22:6: warning: no previous prototype for ‘check_host_supports_tls’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix the return type of __switch_toTiwei Bie2024-04-221-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make it match the declaration in asm-generic/switch_to.h. And also include the header to allow the compiler to check it. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Remove unused functionsTiwei Bie2024-04-222-27/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These functions are not used anymore. Removing them will also address below -Wmissing-prototypes warnings: arch/um/kernel/process.c:51:5: warning: no previous prototype for ‘pid_to_processor_id’ [-Wmissing-prototypes] arch/um/kernel/process.c:253:5: warning: no previous prototype for ‘copy_to_user_proc’ [-Wmissing-prototypes] arch/um/kernel/process.c:263:5: warning: no previous prototype for ‘clear_user_proc’ [-Wmissing-prototypes] arch/um/kernel/tlb.c:579:6: warning: no previous prototype for ‘flush_tlb_mm_range’ [-Wmissing-prototypes] Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix the declaration of vfreeTiwei Bie2024-04-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The definition of vfree has changed since commit b3bdda02aa54 ("vmalloc: add const to void* parameters"). Update the declaration of vfree in um_malloc.h to match the latest definition. Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Make local functions and variables staticTiwei Bie2024-04-2210-17/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This will also fix the warnings like: warning: no previous prototype for ‘fork_handler’ [-Wmissing-prototypes] 140 | void fork_handler(void) | ^~~~~~~~~~~~ Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com> Signed-off-by: Richard Weinberger <richard@nod.at>
| * | | um: Fix return value in ubd_init()Duoming Zhou2024-04-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When kmalloc_array() fails to allocate memory, the ubd_init() should return -ENOMEM instead of -1. So, fix it. Fixes: f88f0bdfc32f ("um: UBD Improvements") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Richard Weinberger <richard@nod.at>
* | | | Merge tag 'mm-stable-2024-05-24-11-49' of ↵Linus Torvalds2024-05-2417-1/+18
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull more mm updates from Andrew Morton: "Jeff Xu's implementation of the mseal() syscall" * tag 'mm-stable-2024-05-24-11-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: selftest mm/mseal read-only elf memory segment mseal: add documentation selftest mm/mseal memory sealing mseal: add mseal syscall mseal: wire up mseal syscall
| * | | | mseal: wire up mseal syscallJeff Xu2024-05-2417-1/+18
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Introduce mseal", v10. This patchset proposes a new mseal() syscall for the Linux kernel. In a nutshell, mseal() protects the VMAs of a given virtual memory range against modifications, such as changes to their permission bits. Modern CPUs support memory permissions, such as the read/write (RW) and no-execute (NX) bits. Linux has supported NX since the release of kernel version 2.6.8 in August 2004 [1]. The memory permission feature improves the security stance on memory corruption bugs, as an attacker cannot simply write to arbitrary memory and point the code to it. The memory must be marked with the X bit, or else an exception will occur. Internally, the kernel maintains the memory permissions in a data structure called VMA (vm_area_struct). mseal() additionally protects the VMA itself against modifications of the selected seal type. Memory sealing is useful to mitigate memory corruption issues where a corrupted pointer is passed to a memory management system. For example, such an attacker primitive can break control-flow integrity guarantees since read-only memory that is supposed to be trusted can become writable or .text pages can get remapped. Memory sealing can automatically be applied by the runtime loader to seal .text and .rodata pages and applications can additionally seal security critical data at runtime. A similar feature already exists in the XNU kernel with the VM_FLAGS_PERMANENT [3] flag and on OpenBSD with the mimmutable syscall [4]. Also, Chrome wants to adopt this feature for their CFI work [2] and this patchset has been designed to be compatible with the Chrome use case. Two system calls are involved in sealing the map: mmap() and mseal(). The new mseal() is an syscall on 64 bit CPU, and with following signature: int mseal(void addr, size_t len, unsigned long flags) addr/len: memory range. flags: reserved. mseal() blocks following operations for the given memory range. 1> Unmapping, moving to another location, and shrinking the size, via munmap() and mremap(), can leave an empty space, therefore can be replaced with a VMA with a new set of attributes. 2> Moving or expanding a different VMA into the current location, via mremap(). 3> Modifying a VMA via mmap(MAP_FIXED). 4> Size expansion, via mremap(), does not appear to pose any specific risks to sealed VMAs. It is included anyway because the use case is unclear. In any case, users can rely on merging to expand a sealed VMA. 5> mprotect() and pkey_mprotect(). 6> Some destructive madvice() behaviors (e.g. MADV_DONTNEED) for anonymous memory, when users don't have write permission to the memory. Those behaviors can alter region contents by discarding pages, effectively a memset(0) for anonymous memory. The idea that inspired this patch comes from Stephen Röttger’s work in V8 CFI [5]. Chrome browser in ChromeOS will be the first user of this API. Indeed, the Chrome browser has very specific requirements for sealing, which are distinct from those of most applications. For example, in the case of libc, sealing is only applied to read-only (RO) or read-execute (RX) memory segments (such as .text and .RELRO) to prevent them from becoming writable, the lifetime of those mappings are tied to the lifetime of the process. Chrome wants to seal two large address space reservations that are managed by different allocators. The memory is mapped RW- and RWX respectively but write access to it is restricted using pkeys (or in the future ARM permission overlay extensions). The lifetime of those mappings are not tied to the lifetime of the process, therefore, while the memory is sealed, the allocators still need to free or discard the unused memory. For example, with madvise(DONTNEED). However, always allowing madvise(DONTNEED) on this range poses a security risk. For example if a jump instruction crosses a page boundary and the second page gets discarded, it will overwrite the target bytes with zeros and change the control flow. Checking write-permission before the discard operation allows us to control when the operation is valid. In this case, the madvise will only succeed if the executing thread has PKEY write permissions and PKRU changes are protected in software by control-flow integrity. Although the initial version of this patch series is targeting the Chrome browser as its first user, it became evident during upstream discussions that we would also want to ensure that the patch set eventually is a complete solution for memory sealing and compatible with other use cases. The specific scenario currently in mind is glibc's use case of loading and sealing ELF executables. To this end, Stephen is working on a change to glibc to add sealing support to the dynamic linker, which will seal all non-writable segments at startup. Once this work is completed, all applications will be able to automatically benefit from these new protections. In closing, I would like to formally acknowledge the valuable contributions received during the RFC process, which were instrumental in shaping this patch: Jann Horn: raising awareness and providing valuable insights on the destructive madvise operations. Liam R. Howlett: perf optimization. Linus Torvalds: assisting in defining system call signature and scope. Theo de Raadt: sharing the experiences and insight gained from implementing mimmutable() in OpenBSD. MM perf benchmarks ================== This patch adds a loop in the mprotect/munmap/madvise(DONTNEED) to check the VMAs’ sealing flag, so that no partial update can be made, when any segment within the given memory range is sealed. To measure the performance impact of this loop, two tests are developed. [8] The first is measuring the time taken for a particular system call, by using clock_gettime(CLOCK_MONOTONIC). The second is using PERF_COUNT_HW_REF_CPU_CYCLES (exclude user space). Both tests have similar results. The tests have roughly below sequence: for (i = 0; i < 1000, i++) create 1000 mappings (1 page per VMA) start the sampling for (j = 0; j < 1000, j++) mprotect one mapping stop and save the sample delete 1000 mappings calculates all samples. Below tests are performed on Intel(R) Pentium(R) Gold 7505 @ 2.00GHz, 4G memory, Chromebook. Based on the latest upstream code: The first test (measuring time) syscall__ vmas t t_mseal delta_ns per_vma % munmap__ 1 909 944 35 35 104% munmap__ 2 1398 1502 104 52 107% munmap__ 4 2444 2594 149 37 106% munmap__ 8 4029 4323 293 37 107% munmap__ 16 6647 6935 288 18 104% munmap__ 32 11811 12398 587 18 105% mprotect 1 439 465 26 26 106% mprotect 2 1659 1745 86 43 105% mprotect 4 3747 3889 142 36 104% mprotect 8 6755 6969 215 27 103% mprotect 16 13748 14144 396 25 103% mprotect 32 27827 28969 1142 36 104% madvise_ 1 240 262 22 22 109% madvise_ 2 366 442 76 38 121% madvise_ 4 623 751 128 32 121% madvise_ 8 1110 1324 215 27 119% madvise_ 16 2127 2451 324 20 115% madvise_ 32 4109 4642 534 17 113% The second test (measuring cpu cycle) syscall__ vmas cpu cmseal delta_cpu per_vma % munmap__ 1 1790 1890 100 100 106% munmap__ 2 2819 3033 214 107 108% munmap__ 4 4959 5271 312 78 106% munmap__ 8 8262 8745 483 60 106% munmap__ 16 13099 14116 1017 64 108% munmap__ 32 23221 24785 1565 49 107% mprotect 1 906 967 62 62 107% mprotect 2 3019 3203 184 92 106% mprotect 4 6149 6569 420 105 107% mprotect 8 9978 10524 545 68 105% mprotect 16 20448 21427 979 61 105% mprotect 32 40972 42935 1963 61 105% madvise_ 1 434 497 63 63 115% madvise_ 2 752 899 147 74 120% madvise_ 4 1313 1513 200 50 115% madvise_ 8 2271 2627 356 44 116% madvise_ 16 4312 4883 571 36 113% madvise_ 32 8376 9319 943 29 111% Based on the result, for 6.8 kernel, sealing check adds 20-40 nano seconds, or around 50-100 CPU cycles, per VMA. In addition, I applied the sealing to 5.10 kernel: The first test (measuring time) syscall__ vmas t tmseal delta_ns per_vma % munmap__ 1 357 390 33 33 109% munmap__ 2 442 463 21 11 105% munmap__ 4 614 634 20 5 103% munmap__ 8 1017 1137 120 15 112% munmap__ 16 1889 2153 263 16 114% munmap__ 32 4109 4088 -21 -1 99% mprotect 1 235 227 -7 -7 97% mprotect 2 495 464 -30 -15 94% mprotect 4 741 764 24 6 103% mprotect 8 1434 1437 2 0 100% mprotect 16 2958 2991 33 2 101% mprotect 32 6431 6608 177 6 103% madvise_ 1 191 208 16 16 109% madvise_ 2 300 324 24 12 108% madvise_ 4 450 473 23 6 105% madvise_ 8 753 806 53 7 107% madvise_ 16 1467 1592 125 8 108% madvise_ 32 2795 3405 610 19 122% The second test (measuring cpu cycle) syscall__ nbr_vma cpu cmseal delta_cpu per_vma % munmap__ 1 684 715 31 31 105% munmap__ 2 861 898 38 19 104% munmap__ 4 1183 1235 51 13 104% munmap__ 8 1999 2045 46 6 102% munmap__ 16 3839 3816 -23 -1 99% munmap__ 32 7672 7887 216 7 103% mprotect 1 397 443 46 46 112% mprotect 2 738 788 50 25 107% mprotect 4 1221 1256 35 9 103% mprotect 8 2356 2429 72 9 103% mprotect 16 4961 4935 -26 -2 99% mprotect 32 9882 10172 291 9 103% madvise_ 1 351 380 29 29 108% madvise_ 2 565 615 49 25 109% madvise_ 4 872 933 61 15 107% madvise_ 8 1508 1640 132 16 109% madvise_ 16 3078 3323 245 15 108% madvise_ 32 5893 6704 811 25 114% For 5.10 kernel, sealing check adds 0-15 ns in time, or 10-30 CPU cycles, there is even decrease in some cases. It might be interesting to compare 5.10 and 6.8 kernel The first test (measuring time) syscall__ vmas t_5_10 t_6_8 delta_ns per_vma % munmap__ 1 357 909 552 552 254% munmap__ 2 442 1398 956 478 316% munmap__ 4 614 2444 1830 458 398% munmap__ 8 1017 4029 3012 377 396% munmap__ 16 1889 6647 4758 297 352% munmap__ 32 4109 11811 7702 241 287% mprotect 1 235 439 204 204 187% mprotect 2 495 1659 1164 582 335% mprotect 4 741 3747 3006 752 506% mprotect 8 1434 6755 5320 665 471% mprotect 16 2958 13748 10790 674 465% mprotect 32 6431 27827 21397 669 433% madvise_ 1 191 240 49 49 125% madvise_ 2 300 366 67 33 122% madvise_ 4 450 623 173 43 138% madvise_ 8 753 1110 357 45 147% madvise_ 16 1467 2127 660 41 145% madvise_ 32 2795 4109 1314 41 147% The second test (measuring cpu cycle) syscall__ vmas cpu_5_10 c_6_8 delta_cpu per_vma % munmap__ 1 684 1790 1106 1106 262% munmap__ 2 861 2819 1958 979 327% munmap__ 4 1183 4959 3776 944 419% munmap__ 8 1999 8262 6263 783 413% munmap__ 16 3839 13099 9260 579 341% munmap__ 32 7672 23221 15549 486 303% mprotect 1 397 906 509 509 228% mprotect 2 738 3019 2281 1140 409% mprotect 4 1221 6149 4929 1232 504% mprotect 8 2356 9978 7622 953 423% mprotect 16 4961 20448 15487 968 412% mprotect 32 9882 40972 31091 972 415% madvise_ 1 351 434 82 82 123% madvise_ 2 565 752 186 93 133% madvise_ 4 872 1313 442 110 151% madvise_ 8 1508 2271 763 95 151% madvise_ 16 3078 4312 1234 77 140% madvise_ 32 5893 8376 2483 78 142% From 5.10 to 6.8 munmap: added 250-550 ns in time, or 500-1100 in cpu cycle, per vma. mprotect: added 200-750 ns in time, or 500-1200 in cpu cycle, per vma. madvise: added 33-50 ns in time, or 70-110 in cpu cycle, per vma. In comparison to mseal, which adds 20-40 ns or 50-100 CPU cycles, the increase from 5.10 to 6.8 is significantly larger, approximately ten times greater for munmap and mprotect. When I discuss the mm performance with Brian Makin, an engineer who worked on performance, it was brought to my attention that such performance benchmarks, which measuring millions of mm syscall in a tight loop, may not accurately reflect real-world scenarios, such as that of a database service. Also this is tested using a single HW and ChromeOS, the data from another HW or distribution might be different. It might be best to take this data with a grain of salt. This patch (of 5): Wire up mseal syscall for all architectures. Link: https://lkml.kernel.org/r/20240415163527.626541-1-jeffxu@chromium.org Link: https://lkml.kernel.org/r/20240415163527.626541-2-jeffxu@chromium.org Signed-off-by: Jeff Xu <jeffxu@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <groeck@chromium.org> Cc: Jann Horn <jannh@google.com> [Bug #2] Cc: Jeff Xu <jeffxu@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Jorge Lucangeli Obes <jorgelo@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: Pedro Falcato <pedro.falcato@gmail.com> Cc: Stephen Röttger <sroettger@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Amer Al Shanawany <amer.shanawany@gmail.com> Cc: Javier Carrasco <javier.carrasco.cruz@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | | | Merge tag 'riscv-for-linus-6.10-mw2' of ↵Linus Torvalds2024-05-2420-181/+294
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Palmer Dabbelt: - The compression format used for boot images is now configurable at build time, and these formats are shown in `make help` - access_ok() has been optimized - A pair of performance bugs have been fixed in the uaccess handlers - Various fixes and cleanups, including one for the IMSIC build failure and one for the early-boot ftrace illegal NOPs bug * tag 'riscv-for-linus-6.10-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Fix early ftrace nop patching irqchip: riscv-imsic: Fixup riscv_ipi_set_virq_range() conflict riscv: selftests: Add signal handling vector tests riscv: mm: accelerate pagefault when badaccess riscv: uaccess: Relax the threshold for fast path riscv: uaccess: Allow the last potential unrolled copy riscv: typo in comment for get_f64_reg Use bool value in set_cpu_online() riscv: selftests: Add hwprobe binaries to .gitignore riscv: stacktrace: fixed walk_stackframe() ftrace: riscv: move from REGS to ARGS riscv: do not select MODULE_SECTIONS by default riscv: show help string for riscv-specific targets riscv: make image compression configurable riscv: cpufeature: Fix extension subset checking riscv: cpufeature: Fix thead vector hwcap removal riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context riscv: force PAGE_SIZE linear mapping if debug_pagealloc is enabled riscv: Define TASK_SIZE_MAX for __access_ok() riscv: Remove PGDIR_SIZE_L3 and TASK_SIZE_MIN
| * | | | riscv: Fix early ftrace nop patchingAlexandre Ghiti2024-05-232-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit c97bf629963e ("riscv: Fix text patching when IPI are used") converted ftrace_make_nop() to use patch_insn_write() which does not emit any icache flush relying entirely on __ftrace_modify_code() to do that. But we missed that ftrace_make_nop() was called very early directly when converting mcount calls into nops (actually on riscv it converts 2B nops emitted by the compiler into 4B nops). This caused crashes on multiple HW as reported by Conor and Björn since the booting core could have half-patched instructions in its icache which would trigger an illegal instruction trap: fix this by emitting a local flush icache when early patching nops. Fixes: c97bf629963e ("riscv: Fix text patching when IPI are used") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Link: https://lore.kernel.org/r/20240523115134.70380-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | Merge patch series "riscv: Extension parsing fixes"Palmer Dabbelt2024-05-233-7/+45
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Charlie Jenkins <charlie@rivosinc.com> says: This series contains two minor fixes for the extension parsing in cpufeature.c. Some T-Head boards without vector 1.0 support report "v" in the isa string in their DT which will cause the kernel to run vector code. The code to blacklist "v" from these boards was doing so by using riscv_cached_mvendorid() which has not been populated at the time of extension parsing. This fix instead greedily reads the mvendorid CSR of the boot hart to determine if the cpu is from T-Head. The other fix is for an incorrect indexing bug. riscv extensions sometimes imply other extensions. When adding these "subset" extensions to the hardware capabilities array, they need to be checked if they are valid. The current code only checks if the extension that is including other extensions is valid and not the subset extensions. These patches were previously included in: https://lore.kernel.org/lkml/20240420-dev-charlie-support_thead_vector_6_9-v3-0-67cff4271d1d@rivosinc.com/ * b4-shazam-merge: riscv: cpufeature: Fix extension subset checking riscv: cpufeature: Fix thead vector hwcap removal Link: https://lore.kernel.org/r/20240502-cpufeature_fixes-v4-0-b3d1a088722d@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | riscv: cpufeature: Fix extension subset checkingCharlie Jenkins2024-05-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This loop is supposed to check if ext->subset_ext_ids[j] is valid, rather than if ext->subset_ext_ids[i] is valid, before setting the extension id ext->subset_ext_ids[j] in isainfo->isa. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Fixes: 0d8295ed975b ("riscv: add ISA extension parsing for scalar crypto") Link: https://lore.kernel.org/r/20240502-cpufeature_fixes-v4-2-b3d1a088722d@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | riscv: cpufeature: Fix thead vector hwcap removalCharlie Jenkins2024-05-223-6/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The riscv_cpuinfo struct that contains mvendorid and marchid is not populated until all harts are booted which happens after the DT parsing. Use the mvendorid/marchid from the boot hart to determine if the DT contains an invalid V. Fixes: d82f32202e0d ("RISC-V: Ignore V from the riscv,isa DT property on older T-Head CPUs") Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20240502-cpufeature_fixes-v4-1-b3d1a088722d@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | riscv: mm: accelerate pagefault when badaccessKefeng Wang2024-05-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The access_error() of vma already checked under per-VMA lock, if it is a bad access, directly handle error, no need to retry with mmap_lock again. Since the page faut is handled under per-VMA lock, count it as a vma lock event with VMA_LOCK_SUCCESS. Reviewed-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240403083805.1818160-6-wangkefeng.wang@huawei.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | riscv: uaccess: Relax the threshold for fast pathXiao Wang2024-05-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bytes copy for unaligned head would cover at most SZREG-1 bytes, so it's better to set the threshold as >= (SZREG-1 + word_copy stride size) which equals to 9*SZREG-1. Signed-off-by: Xiao Wang <xiao.w.wang@intel.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240313091929.4029960-1-xiao.w.wang@intel.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | riscv: uaccess: Allow the last potential unrolled copyXiao Wang2024-05-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the dst buffer pointer points to the last accessible aligned addr, we could still run another iteration of unrolled copy. Signed-off-by: Xiao Wang <xiao.w.wang@intel.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240313103334.4036554-1-xiao.w.wang@intel.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | riscv: typo in comment for get_f64_regXingyou Chen2024-05-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Xingyou Chen <rockrush@rockwork.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20240317055556.9449-1-rockrush@rockwork.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | Use bool value in set_cpu_online()Zhao Ke2024-05-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The declaration of set_cpu_online() takes a bool value. So replace int here to make it consistent with the declaration. Signed-off-by: Zhao Ke <ke.zhao@shingroup.cn> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240318065404.123668-1-ke.zhao@shingroup.cn Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| * | | | | Merge patch series "riscv: fix debug_pagealloc"Palmer Dabbelt2024-05-232-6/+25
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Nam Cao <namcao@linutronix.de> says: The debug_pagealloc feature is not functional on RISCV. With this feature enabled (CONFIG_DEBUG_PAGEALLOC=y and debug_pagealloc=on), kernel crashes early during boot. QEMU command that can reproduce this problem: qemu-system-riscv64 -machine virt \ -kernel Image \ -append "console=ttyS0 root=/dev/vda debug_pagealloc=on" \ -nographic \ -drive "file=root.img,format=raw,id=hd0" \ -device virtio-blk-device,drive=hd0 \ -m 4G \ This series makes debug_pagealloc functional. * b4-shazam-merge: riscv: rewrite __kernel_map_pages() to fix sleeping in invalid context riscv: force PAGE_SIZE linear mapping if debug_pagealloc is enabled Link: https://lore.kernel.org/r/cover.1715750938.git.namcao@linutronix.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
| | * | | | | riscv: rewrite __kernel_map_pages() to fix sleeping in invalid contextNam Cao2024-05-221-6/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __kernel_map_pages() is a debug function which clears the valid bit in page table entry for deallocated pages to detect illegal memory accesses to freed pages. This function set/clear the valid bit using __set_memory(). __set_memory() acquires init_mm's semaphore, and this operation may sleep. This is problematic, because __kernel_map_pages() can be called in atomic context, and thus is illegal to sleep. An example warning that this causes: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1578 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd preempt_count: 2, expected: 0 CPU: 0 PID: 2 Comm: kthreadd Not tainted 6.9.0-g1d4c6d784ef6 #37 Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff800060dc>] dump_backtrace+0x1c/0x24 [<ffffffff8091ef6e>] show_stack+0x2c/0x38 [<ffffffff8092baf8>] dump_stack_lvl+0x5a/0x72 [<ffffffff8092bb24>] dump_stack+0x14/0x1c [<ffffffff8003b7ac>] __might_resched+0x104/0x10e [<ffffffff8003b7f4>] __might_sleep+0x3e/0x62 [<ffffffff8093276a>] down_write+0x20/0x72 [<ffffffff8000cf00>] __set_memory+0x82/0x2fa [<ffffffff8000d324>] __kernel_map_pages+0x5a/0xd4 [<ffffffff80196cca>] __alloc_pages_bulk+0x3b2/0x43a [<ffffffff8018ee82>] __vmalloc_node_range+0x196/0x6ba [<ffffffff80011904>] copy_process+0x72c/0x17ec [<ffffffff80012ab4>] kernel_clone+0x60/0x2fe [<ffffffff80012f62>] kernel_thread+0x82/0xa0 [<ffffffff8003552c>] kthreadd+0x14a/0x1be [<ffffffff809357de>] ret_from_fork+0xe/0x1c Rewrite this function with apply_to_existing_page_range(). It is fine to not have any locking, because __kernel_map_pages() works with pages being allocated/deallocated and those pages are not changed by anyone else in the meantime. Fixes: 5fde3db5eb02 ("riscv: add ARCH_SUPPORTS_DEBUG_PAGEALLOC support") Signed-off-by: Nam Cao <namcao@linutronix.de> Cc: stable@vger.kernel.org Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/1289ecba9606a19917bc12b6c27da8aa23e1e5ae.1715750938.git.namcao@linutronix.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-13 21:40:24 +0100