Clang supports the 'require_explicit_initialization' attribute on struct fields to enforce that the field is explicitly initialized when an aggregate object is constructed, emitting -Wuninitialized-explicit-init (enabled by default) if the field is omitted.
Following discussion at the Linux Plumbers Conference [1], this series introduces __require_explicit_initialization in include/linux/compiler_attributes.h and applies it to struct kobj_type::release. As Documentation/core-api/kobject.rst notes: "One important point cannot be overstated: every kobject must have a release() method, and the kobject must persist (in a consistent state) until that method is called. If these constraints are not met, the code is flawed." Annotating struct kobj_type::release caught 30 struct kobj_type definitions across the tree that omitted .release: - Patches 2-10 fix 10 struct kobj_type definitions where dynamically allocated kobjects, ksets, or enclosing structures were either leaked on kobject_put() or freed prematurely before kobject release (risking a use-after-free when CONFIG_DEBUG_KOBJECT_RELEASE=y). - Patch 11 annotates struct kobj_type::release with __require_explicit_initialization and explicitly sets .release = NULL (with explanatory comments) on the remaining legacy struct kobj_type definitions whose kobjects are static, per-CPU, or embedded in devm- or parent-managed structures. [1] https://lpc.events/event/20/contributions/2392/ Ian Rogers (11): Compiler Attributes: Add __require_explicit_initialization macro powerpc/secvar: Add missing kobject release callback to secvar_ktype sh: sq: Add missing kobject release callback to ktype_percpu_entry cpufreq: Initialize kobj_type release callback in ondemand and conservative governors ACPI: CPPC: Free cpc_desc in kobject release callback dlm: Free dlm_ls in kobject release callback xen/sys-hypervisor: Add release callback to hyp_sysfs_kobj_type s390/sclp_mem: Allocate struct sclp_mem dynamically and add kobject release ubifs: sysfs: Use kset_create_and_add() for ubifs_kset drm/amdkfd: Free queue in procfs_queue_type kobject release callback kobject: Require explicit initialization of struct kobj_type::release Documentation/conf.py | 1 + arch/arm64/kernel/cpuinfo.c | 2 + arch/powerpc/kernel/secvar-sysfs.c | 6 ++ arch/sh/kernel/cpu/sh4/sq.c | 6 ++ drivers/acpi/cppc_acpi.c | 39 +++++----- drivers/acpi/sysfs.c | 2 + drivers/cpufreq/cpufreq_conservative.c | 5 +- drivers/cpufreq/cpufreq_governor.c | 3 +- drivers/cpufreq/cpufreq_governor.h | 1 + drivers/cpufreq/cpufreq_ondemand.c | 5 +- drivers/dma/ioat/sysfs.c | 2 + drivers/gpu/drm/amd/amdgpu/amdgpu_xcp.c | 4 + drivers/gpu/drm/amd/amdkfd/kfd_process.c | 10 ++- drivers/gpu/drm/amd/amdkfd/kfd_queue.c | 5 +- drivers/infiniband/hw/hfi1/sysfs.c | 2 + drivers/infiniband/hw/usnic/usnic_ib_sysfs.c | 2 + drivers/parisc/pdc_stable.c | 2 + drivers/power/supply/ab8500_fg.c | 2 + drivers/s390/char/sclp_mem.c | 73 +++++++++---------- drivers/soc/hisilicon/kunpeng_hccs.c | 6 ++ .../fbdev/omap2/omapfb/dss/display-sysfs.c | 2 + .../fbdev/omap2/omapfb/dss/manager-sysfs.c | 2 + .../fbdev/omap2/omapfb/dss/overlay-sysfs.c | 2 + drivers/xen/sys-hypervisor.c | 6 ++ fs/dlm/lockspace.c | 19 +++-- fs/erofs/sysfs.c | 4 + fs/f2fs/sysfs.c | 6 ++ fs/ocfs2/cluster/masklog.c | 2 + fs/ubifs/sysfs.c | 24 ++---- include/linux/compiler_attributes.h | 11 +++ include/linux/kobject.h | 2 +- scripts/checkpatch.pl | 1 + tools/lib/python/kdoc/xforms_lists.py | 1 + 33 files changed, 170 insertions(+), 90 deletions(-) -- 2.56.0.385.gd3acb90ef8-goog
