1 files changed, 238 insertions, 131 deletions

diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c
index 8074cbd3a3a8..354b11e27c07 100644
--- a/arch/arm64/kernel/vdso.c
+++ b/arch/arm64/kernel/vdso.c
@@ -1,20 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * VDSO implementations.
  *
  * 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>
  */
 
@@ -31,41 +20,212 @@
 #include <linux/slab.h>
 #include <linux/timekeeper_internal.h>
 #include <linux/vmalloc.h>
+#include <vdso/datapage.h>
+#include <vdso/helpers.h>
+#include <vdso/vsyscall.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 __ro_after_init;
+#ifdef CONFIG_COMPAT_VDSO
+extern char vdso32_start[], vdso32_end[];
+#endif /* CONFIG_COMPAT_VDSO */
+
+/* vdso_lookup arch_index */
+enum arch_vdso_type {
+	ARM64_VDSO = 0,
+#ifdef CONFIG_COMPAT_VDSO
+	ARM64_VDSO32 = 1,
+#endif /* CONFIG_COMPAT_VDSO */
+};
+#ifdef CONFIG_COMPAT_VDSO
+#define VDSO_TYPES		(ARM64_VDSO32 + 1)
+#else
+#define VDSO_TYPES		(ARM64_VDSO + 1)
+#endif /* CONFIG_COMPAT_VDSO */
+
+struct __vdso_abi {
+	const char *name;
+	const char *vdso_code_start;
+	const char *vdso_code_end;
+	unsigned long vdso_pages;
+	/* Data Mapping */
+	struct vm_special_mapping *dm;
+	/* Code Mapping */
+	struct vm_special_mapping *cm;
+};
+
+static struct __vdso_abi vdso_lookup[VDSO_TYPES] __ro_after_init = {
+	{
+		.name = "vdso",
+		.vdso_code_start = vdso_start,
+		.vdso_code_end = vdso_end,
+	},
+#ifdef CONFIG_COMPAT_VDSO
+	{
+		.name = "vdso32",
+		.vdso_code_start = vdso32_start,
+		.vdso_code_end = vdso32_end,
+	},
+#endif /* CONFIG_COMPAT_VDSO */
+};
 
 /*
  * The vDSO data page.
  */
 static union {
-	struct vdso_data	data;
+	struct vdso_data	data[CS_BASES];
 	u8			page[PAGE_SIZE];
 } vdso_data_store __page_aligned_data;
-struct vdso_data *vdso_data = &vdso_data_store.data;
+struct vdso_data *vdso_data = vdso_data_store.data;
+
+static int __vdso_remap(enum arch_vdso_type arch_index,
+			const struct vm_special_mapping *sm,
+			struct vm_area_struct *new_vma)
+{
+	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
+	unsigned long vdso_size = vdso_lookup[arch_index].vdso_code_end -
+				  vdso_lookup[arch_index].vdso_code_start;
+
+	if (vdso_size != new_size)
+		return -EINVAL;
+
+	current->mm->context.vdso = (void *)new_vma->vm_start;
+
+	return 0;
+}
+
+static int __vdso_init(enum arch_vdso_type arch_index)
+{
+	int i;
+	struct page **vdso_pagelist;
+	unsigned long pfn;
+
+	if (memcmp(vdso_lookup[arch_index].vdso_code_start, "\177ELF", 4)) {
+		pr_err("vDSO is not a valid ELF object!\n");
+		return -EINVAL;
+	}
+
+	vdso_lookup[arch_index].vdso_pages = (
+			vdso_lookup[arch_index].vdso_code_end -
+			vdso_lookup[arch_index].vdso_code_start) >>
+			PAGE_SHIFT;
+
+	/* Allocate the vDSO pagelist, plus a page for the data. */
+	vdso_pagelist = kcalloc(vdso_lookup[arch_index].vdso_pages + 1,
+				sizeof(struct page *),
+				GFP_KERNEL);
+	if (vdso_pagelist == NULL)
+		return -ENOMEM;
+
+	/* Grab the vDSO data page. */
+	vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data));
+
+
+	/* Grab the vDSO code pages. */
+	pfn = sym_to_pfn(vdso_lookup[arch_index].vdso_code_start);
+
+	for (i = 0; i < vdso_lookup[arch_index].vdso_pages; i++)
+		vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
+
+	vdso_lookup[arch_index].dm->pages = &vdso_pagelist[0];
+	vdso_lookup[arch_index].cm->pages = &vdso_pagelist[1];
+
+	return 0;
+}
+
+static int __setup_additional_pages(enum arch_vdso_type arch_index,
+				    struct mm_struct *mm,
+				    struct linux_binprm *bprm,
+				    int uses_interp)
+{
+	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
+	void *ret;
+
+	vdso_text_len = vdso_lookup[arch_index].vdso_pages << PAGE_SHIFT;
+	/* Be sure to map the data page */
+	vdso_mapping_len = vdso_text_len + PAGE_SIZE;
+
+	vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
+	if (IS_ERR_VALUE(vdso_base)) {
+		ret = ERR_PTR(vdso_base);
+		goto up_fail;
+	}
+
+	ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
+				       VM_READ|VM_MAYREAD,
+				       vdso_lookup[arch_index].dm);
+	if (IS_ERR(ret))
+		goto up_fail;
+
+	vdso_base += PAGE_SIZE;
+	mm->context.vdso = (void *)vdso_base;
+	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
+				       VM_READ|VM_EXEC|
+				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
+				       vdso_lookup[arch_index].cm);
+	if (IS_ERR(ret))
+		goto up_fail;
+
+	return 0;
+
+up_fail:
+	mm->context.vdso = NULL;
+	return PTR_ERR(ret);
+}
 
 #ifdef CONFIG_COMPAT
 /*
  * Create and map the vectors page for AArch32 tasks.
  */
+#ifdef CONFIG_COMPAT_VDSO
+static int aarch32_vdso_mremap(const struct vm_special_mapping *sm,
+		struct vm_area_struct *new_vma)
+{
+	return __vdso_remap(ARM64_VDSO32, sm, new_vma);
+}
+#endif /* CONFIG_COMPAT_VDSO */
+
+/*
+ * aarch32_vdso_pages:
+ * 0 - kuser helpers
+ * 1 - sigreturn code
+ * or (CONFIG_COMPAT_VDSO):
+ * 0 - kuser helpers
+ * 1 - vdso data
+ * 2 - vdso code
+ */
 #define C_VECTORS	0
+#ifdef CONFIG_COMPAT_VDSO
+#define C_VVAR		1
+#define C_VDSO		2
+#define C_PAGES		(C_VDSO + 1)
+#else
 #define C_SIGPAGE	1
 #define C_PAGES		(C_SIGPAGE + 1)
+#endif /* CONFIG_COMPAT_VDSO */
 static struct page *aarch32_vdso_pages[C_PAGES] __ro_after_init;
-static const struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = {
+static struct vm_special_mapping aarch32_vdso_spec[C_PAGES] = {
 	{
 		.name	= "[vectors]", /* ABI */
 		.pages	= &aarch32_vdso_pages[C_VECTORS],
 	},
+#ifdef CONFIG_COMPAT_VDSO
+	{
+		.name = "[vvar]",
+	},
+	{
+		.name = "[vdso]",
+		.mremap = aarch32_vdso_mremap,
+	},
+#else
 	{
 		.name	= "[sigpage]", /* ABI */
 		.pages	= &aarch32_vdso_pages[C_SIGPAGE],
 	},
+#endif /* CONFIG_COMPAT_VDSO */
 };
 
 static int aarch32_alloc_kuser_vdso_page(void)
@@ -88,7 +248,33 @@ static int aarch32_alloc_kuser_vdso_page(void)
 	return 0;
 }
 
-static int __init aarch32_alloc_vdso_pages(void)
+#ifdef CONFIG_COMPAT_VDSO
+static int __aarch32_alloc_vdso_pages(void)
+{
+	int ret;
+
+	vdso_lookup[ARM64_VDSO32].dm = &aarch32_vdso_spec[C_VVAR];
+	vdso_lookup[ARM64_VDSO32].cm = &aarch32_vdso_spec[C_VDSO];
+
+	ret = __vdso_init(ARM64_VDSO32);
+	if (ret)
+		return ret;
+
+	ret = aarch32_alloc_kuser_vdso_page();
+	if (ret) {
+		unsigned long c_vvar =
+			(unsigned long)page_to_virt(aarch32_vdso_pages[C_VVAR]);
+		unsigned long c_vdso =
+			(unsigned long)page_to_virt(aarch32_vdso_pages[C_VDSO]);
+
+		free_page(c_vvar);
+		free_page(c_vdso);
+	}
+
+	return ret;
+}
+#else
+static int __aarch32_alloc_vdso_pages(void)
 {
 	extern char __aarch32_sigret_code_start[], __aarch32_sigret_code_end[];
 	int sigret_sz = __aarch32_sigret_code_end - __aarch32_sigret_code_start;
@@ -109,6 +295,12 @@ static int __init aarch32_alloc_vdso_pages(void)
 
 	return ret;
 }
+#endif /* CONFIG_COMPAT_VDSO */
+
+static int __init aarch32_alloc_vdso_pages(void)
+{
+	return __aarch32_alloc_vdso_pages();
+}
 arch_initcall(aarch32_alloc_vdso_pages);
 
 static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
@@ -130,6 +322,7 @@ static int aarch32_kuser_helpers_setup(struct mm_struct *mm)
 	return PTR_ERR_OR_ZERO(ret);
 }
 
+#ifndef CONFIG_COMPAT_VDSO
 static int aarch32_sigreturn_setup(struct mm_struct *mm)
 {
 	unsigned long addr;
@@ -157,6 +350,7 @@ static int aarch32_sigreturn_setup(struct mm_struct *mm)
 out:
 	return PTR_ERR_OR_ZERO(ret);
 }
+#endif /* !CONFIG_COMPAT_VDSO */
 
 int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
@@ -170,7 +364,14 @@ int aarch32_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 	if (ret)
 		goto out;
 
+#ifdef CONFIG_COMPAT_VDSO
+	ret = __setup_additional_pages(ARM64_VDSO32,
+				       mm,
+				       bprm,
+				       uses_interp);
+#else
 	ret = aarch32_sigreturn_setup(mm);
+#endif /* CONFIG_COMPAT_VDSO */
 
 out:
 	up_write(&mm->mmap_sem);
@@ -181,18 +382,18 @@ out:
 static int vdso_mremap(const struct vm_special_mapping *sm,
 		struct vm_area_struct *new_vma)
 {
-	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
-	unsigned long vdso_size = vdso_end - vdso_start;
-
-	if (vdso_size != new_size)
-		return -EINVAL;
-
-	current->mm->context.vdso = (void *)new_vma->vm_start;
-
-	return 0;
+	return __vdso_remap(ARM64_VDSO, sm, new_vma);
 }
 
-static struct vm_special_mapping vdso_spec[2] __ro_after_init = {
+/*
+ * aarch64_vdso_pages:
+ * 0 - vvar
+ * 1 - vdso
+ */
+#define A_VVAR		0
+#define A_VDSO		1
+#define A_PAGES		(A_VDSO + 1)
+static struct vm_special_mapping vdso_spec[A_PAGES] __ro_after_init = {
 	{
 		.name	= "[vvar]",
 	},
@@ -204,37 +405,10 @@ static struct vm_special_mapping vdso_spec[2] __ro_after_init = {
 
 static int __init vdso_init(void)
 {
-	int i;
-	struct page **vdso_pagelist;
-	unsigned long pfn;
-
-	if (memcmp(vdso_start, "\177ELF", 4)) {
-		pr_err("vDSO is not a valid ELF object!\n");
-		return -EINVAL;
-	}
-
-	vdso_pages = (vdso_end - vdso_start) >> PAGE_SHIFT;
-
-	/* Allocate the vDSO pagelist, plus a page for the data. */
-	vdso_pagelist = kcalloc(vdso_pages + 1, sizeof(struct page *),
-				GFP_KERNEL);
-	if (vdso_pagelist == NULL)
-		return -ENOMEM;
-
-	/* Grab the vDSO data page. */
-	vdso_pagelist[0] = phys_to_page(__pa_symbol(vdso_data));
-
+	vdso_lookup[ARM64_VDSO].dm = &vdso_spec[A_VVAR];
+	vdso_lookup[ARM64_VDSO].cm = &vdso_spec[A_VDSO];
 
-	/* Grab the vDSO code pages. */
-	pfn = sym_to_pfn(vdso_start);
-
-	for (i = 0; i < vdso_pages; i++)
-		vdso_pagelist[i + 1] = pfn_to_page(pfn + i);
-
-	vdso_spec[0].pages = &vdso_pagelist[0];
-	vdso_spec[1].pages = &vdso_pagelist[1];
-
-	return 0;
+	return __vdso_init(ARM64_VDSO);
 }
 arch_initcall(vdso_init);
 
@@ -242,84 +416,17 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
 				int uses_interp)
 {
 	struct mm_struct *mm = current->mm;
-	unsigned long vdso_base, vdso_text_len, vdso_mapping_len;
-	void *ret;
-
-	vdso_text_len = vdso_pages << PAGE_SHIFT;
-	/* Be sure to map the data page */
-	vdso_mapping_len = vdso_text_len + PAGE_SIZE;
+	int ret;
 
 	if (down_write_killable(&mm->mmap_sem))
 		return -EINTR;
-	vdso_base = get_unmapped_area(NULL, 0, vdso_mapping_len, 0, 0);
-	if (IS_ERR_VALUE(vdso_base)) {
-		ret = ERR_PTR(vdso_base);
-		goto up_fail;
-	}
-	ret = _install_special_mapping(mm, vdso_base, PAGE_SIZE,
-				       VM_READ|VM_MAYREAD,
-				       &vdso_spec[0]);
-	if (IS_ERR(ret))
-		goto up_fail;
-
-	vdso_base += PAGE_SIZE;
-	mm->context.vdso = (void *)vdso_base;
-	ret = _install_special_mapping(mm, vdso_base, vdso_text_len,
-				       VM_READ|VM_EXEC|
-				       VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
-				       &vdso_spec[1]);
-	if (IS_ERR(ret))
-		goto up_fail;
 
+	ret = __setup_additional_pages(ARM64_VDSO,
+				       mm,
+				       bprm,
+				       uses_interp);
 
 	up_write(&mm->mmap_sem);
-	return 0;
-
-up_fail:
-	mm->context.vdso = NULL;
-	up_write(&mm->mmap_sem);
-	return PTR_ERR(ret);
-}
 
-/*
- * Update the vDSO data page to keep in sync with kernel timekeeping.
- */
-void update_vsyscall(struct timekeeper *tk)
-{
-	u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
-
-	++vdso_data->tb_seq_count;
-	smp_wmb();
-
-	vdso_data->use_syscall			= use_syscall;
-	vdso_data->xtime_coarse_sec		= tk->xtime_sec;
-	vdso_data->xtime_coarse_nsec		= tk->tkr_mono.xtime_nsec >>
-							tk->tkr_mono.shift;
-	vdso_data->wtm_clock_sec		= tk->wall_to_monotonic.tv_sec;
-	vdso_data->wtm_clock_nsec		= tk->wall_to_monotonic.tv_nsec;
-
-	/* Read without the seqlock held by clock_getres() */
-	WRITE_ONCE(vdso_data->hrtimer_res, hrtimer_resolution);
-
-	if (!use_syscall) {
-		/* tkr_mono.cycle_last == tkr_raw.cycle_last */
-		vdso_data->cs_cycle_last	= tk->tkr_mono.cycle_last;
-		vdso_data->raw_time_sec         = tk->raw_sec;
-		vdso_data->raw_time_nsec        = tk->tkr_raw.xtime_nsec;
-		vdso_data->xtime_clock_sec	= tk->xtime_sec;
-		vdso_data->xtime_clock_nsec	= tk->tkr_mono.xtime_nsec;
-		vdso_data->cs_mono_mult		= tk->tkr_mono.mult;
-		vdso_data->cs_raw_mult		= tk->tkr_raw.mult;
-		/* tkr_mono.shift == tkr_raw.shift */
-		vdso_data->cs_shift		= tk->tkr_mono.shift;
-	}
-
-	smp_wmb();
-	++vdso_data->tb_seq_count;
-}
-
-void update_vsyscall_tz(void)
-{
-	vdso_data->tz_minuteswest	= sys_tz.tz_minuteswest;
-	vdso_data->tz_dsttime		= sys_tz.tz_dsttime;
+	return ret;
 }