mirror-linux/init
Thomas Weißschuh 05988dba11 vdso/datastore: Allocate data pages dynamically
Allocating the data pages as part of the kernel image does not work on
SPARC. The MMU will raise a fault when userspace tries to access them.

Allocate the data pages through the page allocator instead.

Unused pages in the vDSO VMA are still allocated to keep the virtual
addresses aligned. Switch the mapping from PFNs to 'struct page' as that is
required for dynamically allocated pages.  This also aligns the allocation
of the datapages with the code pages and is a prerequisite for mlockall()
support.

VM_MIXEDMAP is necessary for the call to vmf_insert_page() in the timens
prefault path to work.

The data pages need to be order-0, non-compound pages so that the mapping
to userspace and the different orderings work.

These pages are also used by the timekeeping, random pool and architecture
initialization code. Some of these are running before the page allocator is
available. To keep these subsytems working without changes, introduce
early, statically data storage which will then replaced by the real one as
soon as that is available.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Link: https://patch.msgid.link/20260304-vdso-sparc64-generic-2-v6-3-d8eb3b0e1410@linutronix.de
2026-03-11 10:18:30 +01:00
..
.gitignore kbuild: build init/built-in.a just once 2022-09-29 04:40:15 +09:00
.kunitconfig initramfs_test: kunit tests for initramfs unpacking 2025-03-08 12:13:04 +01:00
Kconfig io_uring-7.0-20260305 2026-03-06 08:31:36 -08:00
Makefile initramfs_test: kunit tests for initramfs unpacking 2025-03-08 12:13:04 +01:00
calibrate.c calibrate: update header inclusion 2025-11-27 14:24:45 -08:00
do_mounts.c vfs-7.0-rc1.nullfs 2026-02-09 13:41:34 -08:00
do_mounts.h fs: use nullfs unconditionally as the real rootfs 2026-01-14 11:23:39 +01:00
do_mounts_initrd.c init: remove /proc/sys/kernel/real-root-dev 2026-01-12 17:22:27 +01:00
do_mounts_rd.c initrd: remove deprecated code path (linuxrc) 2026-01-12 17:22:22 +01:00
init_task.c Scheduler changes for v7.0: 2026-02-10 12:50:10 -08:00
initramfs.c Convert 'alloc_flex' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
initramfs_internal.h init: add initramfs_internal.h 2025-03-04 09:52:36 +01:00
initramfs_test.c Convert 'alloc_obj' family to use the new default GFP_KERNEL argument 2026-02-21 17:09:51 -08:00
main.c vdso/datastore: Allocate data pages dynamically 2026-03-11 10:18:30 +01:00
noinitramfs.c init: move usermodehelper_enable() to populate_rootfs() 2021-09-08 11:50:27 -07:00
version-timestamp.c ns: drop custom reference count initialization for initial namespaces 2025-11-11 10:01:32 +01:00
version.c init/version.c: Replace strlcpy with strscpy 2023-09-22 09:50:56 -07:00