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-rw-r--r--arch/arm64/kernel/vdso.c369
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;
}