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![Kirill A. Shutemov](/assets/img/avatar_default.png)
Recent PAT patchset has caused issue on 32-bit PAE machines:
page:eea45000 count:0 mapcount:-128 mapping: (null) index:0x0 flags: 0x40000000()
page dumped because: VM_BUG_ON_PAGE(page_mapcount(page) < 0)
------------[ cut here ]------------
kernel BUG at /home/build/linux-boris/mm/huge_memory.c:1485!
invalid opcode: 0000 [#1] SMP
[...]
Call Trace:
unmap_single_vma
? __wake_up
unmap_vmas
unmap_region
do_munmap
vm_munmap
SyS_munmap
do_fast_syscall_32
? __do_page_fault
sysenter_past_esp
Code: ...
EIP: [<c11bde80>] zap_huge_pmd+0x240/0x260 SS:ESP 0068:f6459d98
The problem is in pmd_pfn_mask() and pmd_flags_mask(). These
helpers use PMD_PAGE_MASK to calculate resulting mask.
PMD_PAGE_MASK is 'unsigned long', not 'unsigned long long' as
phys_addr_t is on 32-bit PAE (ARCH_PHYS_ADDR_T_64BIT). As a
result, the upper bits of resulting mask get truncated.
pud_pfn_mask() and pud_flags_mask() aren't problematic since we
don't have PUD page table level on 32-bit systems, but it's
reasonable to keep them consistent with PMD counterpart.
Introduce PHYSICAL_PMD_PAGE_MASK and PHYSICAL_PUD_PAGE_MASK in
addition to existing PHYSICAL_PAGE_MASK and reworks helpers to
use them.
Reported-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
[ Fix -Woverflow warnings from the realmode code. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jürgen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Fixes: f70abb0fc3
("x86/asm: Fix pud/pmd interfaces to handle large PAT bit")
Link: http://lkml.kernel.org/r/1448878233-11390-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
173 lines
3.8 KiB
C
173 lines
3.8 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright 2007-2008 rPath, Inc. - All Rights Reserved
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*
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* This file is part of the Linux kernel, and is made available under
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* the terms of the GNU General Public License version 2.
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*
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* ----------------------------------------------------------------------- */
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/*
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* arch/i386/boot/video-mode.c
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*
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* Set the video mode. This is separated out into a different
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* file in order to be shared with the ACPI wakeup code.
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*/
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#include "boot.h"
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#include "video.h"
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#include "vesa.h"
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#include <uapi/asm/boot.h>
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/*
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* Common variables
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*/
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int adapter; /* 0=CGA/MDA/HGC, 1=EGA, 2=VGA+ */
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int force_x, force_y; /* Don't query the BIOS for cols/rows */
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int do_restore; /* Screen contents changed during mode flip */
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int graphic_mode; /* Graphic mode with linear frame buffer */
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/* Probe the video drivers and have them generate their mode lists. */
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void probe_cards(int unsafe)
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{
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struct card_info *card;
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static u8 probed[2];
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if (probed[unsafe])
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return;
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probed[unsafe] = 1;
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for (card = video_cards; card < video_cards_end; card++) {
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if (card->unsafe == unsafe) {
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if (card->probe)
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card->nmodes = card->probe();
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else
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card->nmodes = 0;
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}
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}
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}
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/* Test if a mode is defined */
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int mode_defined(u16 mode)
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{
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struct card_info *card;
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struct mode_info *mi;
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int i;
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for (card = video_cards; card < video_cards_end; card++) {
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mi = card->modes;
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for (i = 0; i < card->nmodes; i++, mi++) {
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if (mi->mode == mode)
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return 1;
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}
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}
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return 0;
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}
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/* Set mode (without recalc) */
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static int raw_set_mode(u16 mode, u16 *real_mode)
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{
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int nmode, i;
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struct card_info *card;
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struct mode_info *mi;
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/* Drop the recalc bit if set */
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mode &= ~VIDEO_RECALC;
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/* Scan for mode based on fixed ID, position, or resolution */
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nmode = 0;
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for (card = video_cards; card < video_cards_end; card++) {
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mi = card->modes;
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for (i = 0; i < card->nmodes; i++, mi++) {
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int visible = mi->x || mi->y;
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if ((mode == nmode && visible) ||
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mode == mi->mode ||
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mode == (mi->y << 8)+mi->x) {
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*real_mode = mi->mode;
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return card->set_mode(mi);
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}
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if (visible)
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nmode++;
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}
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}
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/* Nothing found? Is it an "exceptional" (unprobed) mode? */
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for (card = video_cards; card < video_cards_end; card++) {
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if (mode >= card->xmode_first &&
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mode < card->xmode_first+card->xmode_n) {
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struct mode_info mix;
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*real_mode = mix.mode = mode;
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mix.x = mix.y = 0;
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return card->set_mode(&mix);
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}
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}
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/* Otherwise, failure... */
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return -1;
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}
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/*
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* Recalculate the vertical video cutoff (hack!)
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*/
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static void vga_recalc_vertical(void)
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{
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unsigned int font_size, rows;
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u16 crtc;
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u8 pt, ov;
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set_fs(0);
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font_size = rdfs8(0x485); /* BIOS: font size (pixels) */
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rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */
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rows *= font_size; /* Visible scan lines */
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rows--; /* ... minus one */
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crtc = vga_crtc();
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pt = in_idx(crtc, 0x11);
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pt &= ~0x80; /* Unlock CR0-7 */
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out_idx(pt, crtc, 0x11);
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out_idx((u8)rows, crtc, 0x12); /* Lower height register */
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ov = in_idx(crtc, 0x07); /* Overflow register */
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ov &= 0xbd;
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ov |= (rows >> (8-1)) & 0x02;
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ov |= (rows >> (9-6)) & 0x40;
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out_idx(ov, crtc, 0x07);
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}
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/* Set mode (with recalc if specified) */
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int set_mode(u16 mode)
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{
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int rv;
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u16 real_mode;
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/* Very special mode numbers... */
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if (mode == VIDEO_CURRENT_MODE)
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return 0; /* Nothing to do... */
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else if (mode == NORMAL_VGA)
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mode = VIDEO_80x25;
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else if (mode == EXTENDED_VGA)
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mode = VIDEO_8POINT;
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rv = raw_set_mode(mode, &real_mode);
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if (rv)
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return rv;
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if (mode & VIDEO_RECALC)
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vga_recalc_vertical();
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/* Save the canonical mode number for the kernel, not
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an alias, size specification or menu position */
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#ifndef _WAKEUP
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boot_params.hdr.vid_mode = real_mode;
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#endif
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return 0;
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}
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