Merge branch into tip/master: 'timers/vdso'

 # New commits in timers/vdso:
    ecacc9c8d3ed ("vdso: Rename HAVE_GENERIC_VDSO to VDSO_DATASTORE")
    52447180f4fb ("vdso: Drop HAVE_GENERIC_VDSO from architecture kconfig files")
    faeff8d416c4 ("vdso: Automatically select HAVE_GENERIC_VDSO if necessary")
    8c0015572c61 ("MIPS: vdso: Stop using CONFIG_HAVE_GENERIC_VDSO")
    a92426375870 ("vdso: Remove the dependency on HAVE_GENERIC_VDSO from ARCH_HAS_VDSO_ARCH_DATA")
    2558084d2b03 ("futex: Remove dependency on HAVE_GENERIC_VDSO from FUTEX_ROBUST_UNLOCK")
    369cecd238ac ("vdso/gettimeofday: Verify COMPAT_32BIT_TIME interactions")
    2700297b69fe ("sparc: vdso: Respect COMPAT_32BIT_TIME")
    377e3f2d4130 ("MIPS: VDSO: Respect COMPAT_32BIT_TIME")
    e01abc70af38 ("powerpc/vdso: Respect COMPAT_32BIT_TIME")
    95216f4647e7 ("ARM: VDSO: Respect COMPAT_32BIT_TIME")
    abb1537388ba ("arm64: vdso32: Respect COMPAT_32BIT_TIME")
    1a4660da3130 ("x86/vdso: Respect COMPAT_32BIT_TIME")
    f8b946772554 ("vdso/gettimeofday: Validate system call existence for time() and gettimeofday()")
    dce21fb3d570 ("time: Respect COMPAT_32BIT_TIME for old time type functions")
    0b50763e8439 ("vdso/datastore: Simplify the mapping logic for VDSO_TIME_PAGE_OFFSET")
    c27e727c9a60 ("vdso/datastore: Allow prefaulting by mlockall()")
    9ab500d47f5f ("vdso/datastore: Explicitly prevent remote access to timens vvar page")
    43648f9f3a67 ("vdso/datastore: Map zeroed pages for unavailable data")
    7557273419dd ("vdso/datastore: Map pages in terms of the faults pgoff")
    ff868f43eb8f ("vdso/datastore: Rename data pages variable")
    02475538bec2 ("vdso: Replace __ASSEMBLY__ with __ASSEMBLER__ in header files")

Signed-off-by: Ingo Molnar <mingo@kernel.org>

4 files changed, 54 insertions, 41 deletions

diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
index db87ba34ef19..597f5f0f9681 100644
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -1,12 +1,11 @@
 # SPDX-License-Identifier: GPL-2.0
 
-config HAVE_GENERIC_VDSO
+config VDSO_DATASTORE
 	bool
 
-if HAVE_GENERIC_VDSO
-
 config GENERIC_GETTIMEOFDAY
 	bool
+	select VDSO_DATASTORE
 	help
 	  This is a generic implementation of gettimeofday vdso.
 	  Each architecture that enables this feature has to
@@ -21,7 +20,6 @@ config GENERIC_VDSO_OVERFLOW_PROTECT
 
 config VDSO_GETRANDOM
 	bool
+	select VDSO_DATASTORE
 	help
 	  Selected by architectures that support vDSO getrandom().
-
-endif
diff --git a/lib/vdso/Makefile b/lib/vdso/Makefile
index 405f743253d7..ac304def42d6 100644
--- a/lib/vdso/Makefile
+++ b/lib/vdso/Makefile
@@ -1,3 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
-obj-$(CONFIG_HAVE_GENERIC_VDSO) += datastore.o
+obj-$(CONFIG_VDSO_DATASTORE) += datastore.o
diff --git a/lib/vdso/datastore.c b/lib/vdso/datastore.c
index 17d37b82ebc6..1426bf4e0c12 100644
--- a/lib/vdso/datastore.c
+++ b/lib/vdso/datastore.c
@@ -29,10 +29,11 @@ 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);
-	struct page *pages;
 
 	/*
 	 * Allocate the data pages dynamically. SPARC does not support mapping
@@ -42,24 +43,24 @@ void __init vdso_setup_data_pages(void)
 	 * 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().
 	 */
-	pages = alloc_pages(GFP_KERNEL, order);
-	if (!pages)
+	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(pages, order);
+	split_page(vdso_data_pages, order);
 
 	/* Move the data already written by other subsystems to the new pages */
-	memcpy(page_address(pages), vdso_initdata, VDSO_NR_PAGES * PAGE_SIZE);
+	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(pages + VDSO_TIME_PAGE_OFFSET);
+		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(pages + VDSO_RNG_PAGE_OFFSET);
+		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(pages + VDSO_ARCH_PAGES_START);
+		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,
@@ -67,27 +68,28 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 {
 	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))
-			return VM_FAULT_SIGBUS;
-		page = virt_to_page(vdso_k_time_data);
-		if (timens_page) {
-			/*
-			 * 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;
-		}
+		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:
 		/*
@@ -98,18 +100,11 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 		 * See also the comment near timens_setup_vdso_data().
 		 */
 		if (!IS_ENABLED(CONFIG_TIME_NS) || !timens_page)
-			return VM_FAULT_SIGBUS;
-		page = virt_to_page(vdso_k_time_data);
+			break;
+		page = vdso_data_pages + VDSO_TIME_PAGE_OFFSET;
 		break;
 	case VDSO_RNG_PAGE_OFFSET:
-		if (!IS_ENABLED(CONFIG_VDSO_GETRANDOM))
-			return VM_FAULT_SIGBUS;
-		page = virt_to_page(vdso_k_rng_data);
-		break;
 	case VDSO_ARCH_PAGES_START ... VDSO_ARCH_PAGES_END:
-		if (!IS_ENABLED(CONFIG_ARCH_HAS_VDSO_ARCH_DATA))
-			return VM_FAULT_SIGBUS;
-		page = virt_to_page(vdso_k_arch_data) + vmf->pgoff - VDSO_ARCH_PAGES_START;
 		break;
 	default:
 		return VM_FAULT_SIGBUS;
@@ -128,7 +123,7 @@ const struct vm_special_mapping vdso_vvar_mapping = {
 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_IO | VM_DONTDUMP |
+					VM_READ | VM_MAYREAD | VM_DONTDUMP |
 					VM_MIXEDMAP | VM_SEALED_SYSMAP,
 					&vdso_vvar_mapping);
 }
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index e0f289d3d110..f7a591aba59f 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -12,6 +12,8 @@
 #include <vdso/time32.h>
 #include <vdso/time64.h>
 
+#include <uapi/linux/unistd.h>
+
 /*
  * The generic vDSO implementation requires that gettimeofday.h
  * provides:
@@ -23,6 +25,8 @@
  */
 #include <asm/vdso/gettimeofday.h>
 
+#include <linux/build_bug.h>
+
 /* Bring in default accessors */
 #include <vdso/vsyscall.h>
 
@@ -323,6 +327,8 @@ __cvdso_clock_gettime32_data(const struct vdso_time_data *vd, clockid_t clock,
 	struct __kernel_timespec ts;
 	bool ok;
 
+	BUILD_BUG_ON(!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME));
+
 	ok = __cvdso_clock_gettime_common(vd, clock, &ts);
 
 	if (unlikely(!ok))
@@ -348,6 +354,12 @@ __cvdso_gettimeofday_data(const struct vdso_time_data *vd,
 {
 	const struct vdso_clock *vc = vd->clock_data;
 
+#ifndef __NR_gettimeofday
+	BUILD_BUG();
+#endif
+
+	BUILD_BUG_ON(sizeof(tv->tv_sec) != 8 && !IS_ENABLED(CONFIG_COMPAT_32BIT_TIME));
+
 	if (likely(tv != NULL)) {
 		struct __kernel_timespec ts;
 
@@ -382,6 +394,12 @@ __cvdso_time_data(const struct vdso_time_data *vd, __kernel_old_time_t *time)
 	const struct vdso_clock *vc = vd->clock_data;
 	__kernel_old_time_t t;
 
+#ifndef __NR_time
+	BUILD_BUG();
+#endif
+
+	BUILD_BUG_ON(sizeof(*time) != 8 && !IS_ENABLED(CONFIG_COMPAT_32BIT_TIME));
+
 	if (vdso_is_timens_clock(vc)) {
 		vd = vdso_timens_data(vd);
 		vc = vd->clock_data;
@@ -471,6 +489,8 @@ __cvdso_clock_getres_time32_data(const struct vdso_time_data *vd, clockid_t cloc
 	struct __kernel_timespec ts;
 	bool ok;
 
+	BUILD_BUG_ON(!IS_ENABLED(CONFIG_COMPAT_32BIT_TIME));
+
 	ok = __cvdso_clock_getres_common(vd, clock, &ts);
 
 	if (unlikely(!ok))