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authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /lib/vdso/datastore.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'lib/vdso/datastore.c')
-rw-r--r--lib/vdso/datastore.c129
1 files changed, 129 insertions, 0 deletions
diff --git a/lib/vdso/datastore.c b/lib/vdso/datastore.c
new file mode 100644
index 000000000..1426bf4e0
--- /dev/null
+++ b/lib/vdso/datastore.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/time_namespace.h>
+#include <linux/types.h>
+#include <linux/vdso_datastore.h>
+#include <vdso/datapage.h>
+
+static u8 vdso_initdata[VDSO_NR_PAGES * PAGE_SIZE] __aligned(PAGE_SIZE) __initdata = {};
+
+#ifdef CONFIG_GENERIC_GETTIMEOFDAY
+struct vdso_time_data *vdso_k_time_data __ro_after_init =
+ (void *)&vdso_initdata[VDSO_TIME_PAGE_OFFSET * PAGE_SIZE];
+
+static_assert(sizeof(struct vdso_time_data) <= PAGE_SIZE);
+#endif /* CONFIG_GENERIC_GETTIMEOFDAY */
+
+#ifdef CONFIG_VDSO_GETRANDOM
+struct vdso_rng_data *vdso_k_rng_data __ro_after_init =
+ (void *)&vdso_initdata[VDSO_RNG_PAGE_OFFSET * PAGE_SIZE];
+
+static_assert(sizeof(struct vdso_rng_data) <= PAGE_SIZE);
+#endif /* CONFIG_VDSO_GETRANDOM */
+
+#ifdef CONFIG_ARCH_HAS_VDSO_ARCH_DATA
+struct vdso_arch_data *vdso_k_arch_data __ro_after_init =
+ (void *)&vdso_initdata[VDSO_ARCH_PAGES_START * PAGE_SIZE];
+#endif /* CONFIG_ARCH_HAS_VDSO_ARCH_DATA */
+
+static struct page *vdso_data_pages __ro_after_init;
+
+void __init vdso_setup_data_pages(void)
+{
+ unsigned int order = get_order(VDSO_NR_PAGES * PAGE_SIZE);
+
+ /*
+ * Allocate the data pages dynamically. SPARC does not support mapping
+ * static pages to be mapped into userspace.
+ * It is also a requirement for mlockall() support.
+ *
+ * Do not use folios. In time namespaces the pages are mapped in a different order
+ * to userspace, which is not handled by the folio optimizations in finish_fault().
+ */
+ vdso_data_pages = alloc_pages(GFP_KERNEL, order);
+ if (!vdso_data_pages)
+ panic("Unable to allocate VDSO storage pages");
+
+ /* The pages are mapped one-by-one into userspace and each one needs to be refcounted. */
+ split_page(vdso_data_pages, order);
+
+ /* Move the data already written by other subsystems to the new pages */
+ memcpy(page_address(vdso_data_pages), vdso_initdata, VDSO_NR_PAGES * PAGE_SIZE);
+
+ if (IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY))
+ vdso_k_time_data = page_address(vdso_data_pages + VDSO_TIME_PAGE_OFFSET);
+
+ if (IS_ENABLED(CONFIG_VDSO_GETRANDOM))
+ vdso_k_rng_data = page_address(vdso_data_pages + VDSO_RNG_PAGE_OFFSET);
+
+ if (IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA))
+ vdso_k_arch_data = page_address(vdso_data_pages + VDSO_ARCH_PAGES_START);
+}
+
+static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
+ struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct page *page, *timens_page;
+
+ if (unlikely(vmf->flags & FAULT_FLAG_REMOTE))
+ return VM_FAULT_SIGBUS;
+
+ page = vdso_data_pages + vmf->pgoff;
+ timens_page = find_timens_vvar_page(vma);
+
+ switch (vmf->pgoff) {
+ case VDSO_TIME_PAGE_OFFSET:
+ if (!IS_ENABLED(CONFIG_GENERIC_GETTIMEOFDAY) || !timens_page)
+ break;
+ /*
+ * Fault in VVAR page too, since it will be accessed
+ * to get clock data anyway.
+ */
+ unsigned long addr;
+ vm_fault_t err;
+
+ addr = vmf->address + VDSO_TIMENS_PAGE_OFFSET * PAGE_SIZE;
+ err = vmf_insert_page(vma, addr, page);
+ if (unlikely(err & VM_FAULT_ERROR))
+ return err;
+ page = timens_page;
+ break;
+ case VDSO_TIMENS_PAGE_OFFSET:
+ /*
+ * If a task belongs to a time namespace then a namespace
+ * specific VVAR is mapped with the VVAR_DATA_PAGE_OFFSET and
+ * the real VVAR page is mapped with the VVAR_TIMENS_PAGE_OFFSET
+ * offset.
+ * See also the comment near timens_setup_vdso_data().
+ */
+ if (!IS_ENABLED(CONFIG_TIME_NS) || !timens_page)
+ break;
+ page = vdso_data_pages + VDSO_TIME_PAGE_OFFSET;
+ break;
+ case VDSO_RNG_PAGE_OFFSET:
+ case VDSO_ARCH_PAGES_START ... VDSO_ARCH_PAGES_END:
+ break;
+ default:
+ return VM_FAULT_SIGBUS;
+ }
+
+ get_page(page);
+ vmf->page = page;
+ return 0;
+}
+
+const struct vm_special_mapping vdso_vvar_mapping = {
+ .name = "[vvar]",
+ .fault = vvar_fault,
+};
+
+struct vm_area_struct *vdso_install_vvar_mapping(struct mm_struct *mm, unsigned long addr)
+{
+ return _install_special_mapping(mm, addr, VDSO_NR_PAGES * PAGE_SIZE,
+ VM_READ | VM_MAYREAD | VM_DONTDUMP |
+ VM_MIXEDMAP | VM_SEALED_SYSMAP,
+ &vdso_vvar_mapping);
+}