nfs: disintegrate UAPI for nfs

This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently.  After these patches, userspace
headers will be segregated into:

        include/uapi/linux/.../foo.h

for the userspace interface stuff, and:

        include/linux/.../foo.h

for the strictly kernel internal stuff.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 261 insertions, 0 deletions

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
new file mode 100644
index 000000000000..17948fc7d663
--- /dev/null
+++ b/arch/arm64/kernel/vdso.c
@@ -0,0 +1,261 @@
+/*
+ * VDSO implementation for AArch64 and vector page setup for AArch32.
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/clocksource.h>
+#include <linux/elf.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <asm/cacheflush.h>
+#include <asm/signal32.h>
+#include <asm/vdso.h>
+#include <asm/vdso_datapage.h>
+
+extern char vdso_start, vdso_end;
+static unsigned long vdso_pages;
+static struct page **vdso_pagelist;
+
+/*
+ * The vDSO data page.
+ */
+static union {
+	struct vdso_data	data;
+	u8			page[PAGE_SIZE];
+} vdso_data_store __page_aligned_data;
+struct vdso_data *vdso_data = &vdso_data_store.data;
+
+#ifdef CONFIG_COMPAT
+/*
+ * Create and map the vectors page for AArch32 tasks.
+ */
+static struct page *vectors_page[1];
+
+static int alloc_vectors_page(void)
+{
+	extern char __kuser_helper_start[], __kuser_helper_end[];
+	int kuser_sz = __kuser_helper_end - __kuser_helper_start;
+	unsigned long vpage;
+
+	vpage = get_zeroed_page(GFP_ATOMIC);
+
+	if (!vpage)
+		return -ENOMEM;
+
+	/* kuser helpers */
+	memcpy((void *)vpage + 0x1000 - kuser_sz, __kuser_helper_start,
+		kuser_sz);
+
+	/* sigreturn code */
+	memcpy((void *)vpage + AARCH32_KERN_SIGRET_CODE_OFFSET,
+		aarch32_sigret_code, sizeof(aarch32_sigret_code));
+
+	flush_icache_range(vpage, vpage + PAGE_SIZE);
+	vectors_page[0] = virt_to_page(vpage);
+
+	return 0;
+}
+arch_initcall(alloc_vectors_page);
+
+int aarch32_setup_vectors_page(struct linux_binprm *bprm, int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long addr = AARCH32_VECTORS_BASE;
+	int ret;
+
+	down_write(&mm->mmap_sem);
+	current->mm->context.vdso = (void *)addr;
+
+	/* Map vectors page at the high address. */
+	ret = install_special_mapping(mm, addr, PAGE_SIZE,
+				      VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC,
+				      vectors_page);
+
+	up_write(&mm->mmap_sem);
+
+	return ret;
+}
+#endif /* CONFIG_COMPAT */
+
+static int __init vdso_init(void)
+{
+	struct page *pg;
+	char *vbase;
+	int i, ret = 0;
+
+	vdso_pages = (&vdso_end - &vdso_start) >> PAGE_SHIFT;
+	pr_info("vdso: %ld pages (%ld code, %ld data) at base %p\n",
+		vdso_pages + 1, vdso_pages, 1L, &vdso_start);
+
+	/* Allocate the vDSO pagelist, plus a page for the data. */
+	vdso_pagelist = kzalloc(sizeof(struct page *) * (vdso_pages + 1),
+				GFP_KERNEL);
+	if (vdso_pagelist == NULL) {
+		pr_err("Failed to allocate vDSO pagelist!\n");
+		return -ENOMEM;
+	}
+
+	/* Grab the vDSO code pages. */
+	for (i = 0; i < vdso_pages; i++) {
+		pg = virt_to_page(&vdso_start + i*PAGE_SIZE);
+		ClearPageReserved(pg);
+		get_page(pg);
+		vdso_pagelist[i] = pg;
+	}
+
+	/* Sanity check the shared object header. */
+	vbase = vmap(vdso_pagelist, 1, 0, PAGE_KERNEL);
+	if (vbase == NULL) {
+		pr_err("Failed to map vDSO pagelist!\n");
+		return -ENOMEM;
+	} else if (memcmp(vbase, "\177ELF", 4)) {
+		pr_err("vDSO is not a valid ELF object!\n");
+		ret = -EINVAL;
+		goto unmap;
+	}
+
+	/* Grab the vDSO data page. */
+	pg = virt_to_page(vdso_data);
+	get_page(pg);
+	vdso_pagelist[i] = pg;
+
+unmap:
+	vunmap(vbase);
+	return ret;
+}
+arch_initcall(vdso_init);
+
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+				int uses_interp)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long vdso_base, vdso_mapping_len;
+	int ret;
+
+	/* Be sure to map the data page */
+	vdso_mapping_len = (vdso_pages + 1) << PAGE_SHIFT;
+
+	down_write(&mm->mmap_sem);
+	vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
+	if (IS_ERR_VALUE(vdso_base)) {
+		ret = vdso_base;
+		goto up_fail;
+	}
+	mm->context.vdso = (void *)vdso_base;
+
+	ret = install_special_mapping(mm, vdso_base, vdso_mapping_len,
+				      VM_READ|VM_EXEC|
+				      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+				      vdso_pagelist);
+	if (ret) {
+		mm->context.vdso = NULL;
+		goto up_fail;
+	}
+
+up_fail:
+	up_write(&mm->mmap_sem);
+
+	return ret;
+}
+
+const char *arch_vma_name(struct vm_area_struct *vma)
+{
+	/*
+	 * We can re-use the vdso pointer in mm_context_t for identifying
+	 * the vectors page for compat applications. The vDSO will always
+	 * sit above TASK_UNMAPPED_BASE and so we don't need to worry about
+	 * it conflicting with the vectors base.
+	 */
+	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) {
+#ifdef CONFIG_COMPAT
+		if (vma->vm_start == AARCH32_VECTORS_BASE)
+			return "[vectors]";
+#endif
+		return "[vdso]";
+	}
+
+	return NULL;
+}
+
+/*
+ * We define AT_SYSINFO_EHDR, so we need these function stubs to keep
+ * Linux happy.
+ */
+int in_gate_area_no_mm(unsigned long addr)
+{
+	return 0;
+}
+
+int in_gate_area(struct mm_struct *mm, unsigned long addr)
+{
+	return 0;
+}
+
+struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
+{
+	return NULL;
+}
+
+/*
+ * Update the vDSO data page to keep in sync with kernel timekeeping.
+ */
+void update_vsyscall(struct timespec *ts, struct timespec *wtm,
+		     struct clocksource *clock, u32 mult)
+{
+	struct timespec xtime_coarse;
+	u32 use_syscall = strcmp(clock->name, "arch_sys_counter");
+
+	++vdso_data->tb_seq_count;
+	smp_wmb();
+
+	xtime_coarse = __current_kernel_time();
+	vdso_data->use_syscall			= use_syscall;
+	vdso_data->xtime_coarse_sec		= xtime_coarse.tv_sec;
+	vdso_data->xtime_coarse_nsec		= xtime_coarse.tv_nsec;
+
+	if (!use_syscall) {
+		vdso_data->cs_cycle_last	= clock->cycle_last;
+		vdso_data->xtime_clock_sec	= ts->tv_sec;
+		vdso_data->xtime_clock_nsec	= ts->tv_nsec;
+		vdso_data->cs_mult		= mult;
+		vdso_data->cs_shift		= clock->shift;
+		vdso_data->wtm_clock_sec	= wtm->tv_sec;
+		vdso_data->wtm_clock_nsec	= wtm->tv_nsec;
+	}
+
+	smp_wmb();
+	++vdso_data->tb_seq_count;
+}
+
+void update_vsyscall_tz(void)
+{
+	++vdso_data->tb_seq_count;
+	smp_wmb();
+	vdso_data->tz_minuteswest	= sys_tz.tz_minuteswest;
+	vdso_data->tz_dsttime		= sys_tz.tz_dsttime;
+	smp_wmb();
+	++vdso_data->tb_seq_count;
+}