mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-15 19:16:42 +07:00
554af0c396
The page structures associated with the vDSO pages in the kernel image
are calculated using virt_to_page(), which uses __pa() under the hood to
find the pfn associated with the virtual address. The vDSO data pointers
however point to kernel symbols, so __pa_symbol() should really be used
instead.
Since there is no equivalent to virt_to_page() which uses __pa_symbol(),
fix init_vdso_image() to work directly with pfns, calculated with
__phys_to_pfn(__pa_symbol(...)).
This issue broke the Malta Enhanced Virtual Addressing (EVA)
configuration which has a non-default implementation of __pa_symbol().
This is because it uses a physical alias so that the kernel executes
from KSeg0 (VA 0x80000000 -> PA 0x00000000), while RAM is provided to
the kernel in the KUSeg range (VA 0x00000000 -> PA 0x80000000) which
uses the same underlying RAM.
Since there are no page structures associated with the low physical
address region, some arbitrary kernel memory would be interpreted as a
page structure for the vDSO pages and badness ensues.
Fixes: ebb5e78cc6
("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/14229/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
187 lines
4.7 KiB
C
187 lines
4.7 KiB
C
/*
|
|
* Copyright (C) 2015 Imagination Technologies
|
|
* Author: Alex Smith <alex.smith@imgtec.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
* option) any later version.
|
|
*/
|
|
|
|
#include <linux/binfmts.h>
|
|
#include <linux/elf.h>
|
|
#include <linux/err.h>
|
|
#include <linux/init.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/irqchip/mips-gic.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/timekeeper_internal.h>
|
|
|
|
#include <asm/abi.h>
|
|
#include <asm/vdso.h>
|
|
|
|
/* Kernel-provided data used by the VDSO. */
|
|
static union mips_vdso_data vdso_data __page_aligned_data;
|
|
|
|
/*
|
|
* Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as
|
|
* what we map and where within the area they are mapped is determined at
|
|
* runtime.
|
|
*/
|
|
static struct page *no_pages[] = { NULL };
|
|
static struct vm_special_mapping vdso_vvar_mapping = {
|
|
.name = "[vvar]",
|
|
.pages = no_pages,
|
|
};
|
|
|
|
static void __init init_vdso_image(struct mips_vdso_image *image)
|
|
{
|
|
unsigned long num_pages, i;
|
|
unsigned long data_pfn;
|
|
|
|
BUG_ON(!PAGE_ALIGNED(image->data));
|
|
BUG_ON(!PAGE_ALIGNED(image->size));
|
|
|
|
num_pages = image->size / PAGE_SIZE;
|
|
|
|
data_pfn = __phys_to_pfn(__pa_symbol(image->data));
|
|
for (i = 0; i < num_pages; i++)
|
|
image->mapping.pages[i] = pfn_to_page(data_pfn + i);
|
|
}
|
|
|
|
static int __init init_vdso(void)
|
|
{
|
|
init_vdso_image(&vdso_image);
|
|
|
|
#ifdef CONFIG_MIPS32_O32
|
|
init_vdso_image(&vdso_image_o32);
|
|
#endif
|
|
|
|
#ifdef CONFIG_MIPS32_N32
|
|
init_vdso_image(&vdso_image_n32);
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
subsys_initcall(init_vdso);
|
|
|
|
void update_vsyscall(struct timekeeper *tk)
|
|
{
|
|
vdso_data_write_begin(&vdso_data);
|
|
|
|
vdso_data.xtime_sec = tk->xtime_sec;
|
|
vdso_data.xtime_nsec = tk->tkr_mono.xtime_nsec;
|
|
vdso_data.wall_to_mono_sec = tk->wall_to_monotonic.tv_sec;
|
|
vdso_data.wall_to_mono_nsec = tk->wall_to_monotonic.tv_nsec;
|
|
vdso_data.cs_shift = tk->tkr_mono.shift;
|
|
|
|
vdso_data.clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;
|
|
if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {
|
|
vdso_data.cs_mult = tk->tkr_mono.mult;
|
|
vdso_data.cs_cycle_last = tk->tkr_mono.cycle_last;
|
|
vdso_data.cs_mask = tk->tkr_mono.mask;
|
|
}
|
|
|
|
vdso_data_write_end(&vdso_data);
|
|
}
|
|
|
|
void update_vsyscall_tz(void)
|
|
{
|
|
if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {
|
|
vdso_data.tz_minuteswest = sys_tz.tz_minuteswest;
|
|
vdso_data.tz_dsttime = sys_tz.tz_dsttime;
|
|
}
|
|
}
|
|
|
|
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
|
|
{
|
|
struct mips_vdso_image *image = current->thread.abi->vdso;
|
|
struct mm_struct *mm = current->mm;
|
|
unsigned long gic_size, vvar_size, size, base, data_addr, vdso_addr;
|
|
struct vm_area_struct *vma;
|
|
struct resource gic_res;
|
|
int ret;
|
|
|
|
if (down_write_killable(&mm->mmap_sem))
|
|
return -EINTR;
|
|
|
|
/* Map delay slot emulation page */
|
|
base = mmap_region(NULL, STACK_TOP, PAGE_SIZE,
|
|
VM_READ|VM_WRITE|VM_EXEC|
|
|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
|
|
0);
|
|
if (IS_ERR_VALUE(base)) {
|
|
ret = base;
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Determine total area size. This includes the VDSO data itself, the
|
|
* data page, and the GIC user page if present. Always create a mapping
|
|
* for the GIC user area if the GIC is present regardless of whether it
|
|
* is the current clocksource, in case it comes into use later on. We
|
|
* only map a page even though the total area is 64K, as we only need
|
|
* the counter registers at the start.
|
|
*/
|
|
gic_size = gic_present ? PAGE_SIZE : 0;
|
|
vvar_size = gic_size + PAGE_SIZE;
|
|
size = vvar_size + image->size;
|
|
|
|
base = get_unmapped_area(NULL, 0, size, 0, 0);
|
|
if (IS_ERR_VALUE(base)) {
|
|
ret = base;
|
|
goto out;
|
|
}
|
|
|
|
data_addr = base + gic_size;
|
|
vdso_addr = data_addr + PAGE_SIZE;
|
|
|
|
vma = _install_special_mapping(mm, base, vvar_size,
|
|
VM_READ | VM_MAYREAD,
|
|
&vdso_vvar_mapping);
|
|
if (IS_ERR(vma)) {
|
|
ret = PTR_ERR(vma);
|
|
goto out;
|
|
}
|
|
|
|
/* Map GIC user page. */
|
|
if (gic_size) {
|
|
ret = gic_get_usm_range(&gic_res);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = io_remap_pfn_range(vma, base,
|
|
gic_res.start >> PAGE_SHIFT,
|
|
gic_size,
|
|
pgprot_noncached(PAGE_READONLY));
|
|
if (ret)
|
|
goto out;
|
|
}
|
|
|
|
/* Map data page. */
|
|
ret = remap_pfn_range(vma, data_addr,
|
|
virt_to_phys(&vdso_data) >> PAGE_SHIFT,
|
|
PAGE_SIZE, PAGE_READONLY);
|
|
if (ret)
|
|
goto out;
|
|
|
|
/* Map VDSO image. */
|
|
vma = _install_special_mapping(mm, vdso_addr, image->size,
|
|
VM_READ | VM_EXEC |
|
|
VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
|
|
&image->mapping);
|
|
if (IS_ERR(vma)) {
|
|
ret = PTR_ERR(vma);
|
|
goto out;
|
|
}
|
|
|
|
mm->context.vdso = (void *)vdso_addr;
|
|
ret = 0;
|
|
|
|
out:
|
|
up_write(&mm->mmap_sem);
|
|
return ret;
|
|
}
|