Revision 4ceb5db9757aaeadcf8fbbf97d76bd42aa4df0d6 authored by Linus Torvalds on 01 August 2005, 18:14:49 UTC, committed by Linus Torvalds on 01 August 2005, 18:14:49 UTC
There's no real guarantee that handle_mm_fault() will always be able to break a COW situation - if an update from another thread ends up modifying the page table some way, handle_mm_fault() may end up requiring us to re-try the operation. That's normally fine, but get_user_pages() ended up re-trying it as a read, and thus a write access could in theory end up losing the dirty bit or be done on a page that had not been properly COW'ed. This makes get_user_pages() always retry write accesses as write accesses by making "follow_page()" require that a writable follow has the dirty bit set. That simplifies the code and solves the race: if the COW break fails for some reason, we'll just loop around and try again. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1 parent 8d894c4
makelst
#!/bin/bash
# A script to dump mixed source code & assembly
# with correct relocations from System.map
# Requires the following lines in Rules.make.
# Author(s): DJ Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
# William Stearns <wstearns@pobox.com>
#%.lst: %.c
# $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$@) -g -c -o $*.o $<
# $(TOPDIR)/scripts/makelst $*.o $(TOPDIR)/System.map $(OBJDUMP)
#
# Copyright (C) 2000 IBM Corporation
# Author(s): DJ Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
#
t1=`$3 --syms $1 | grep .text | grep " F " | head -n 1`
if [ -n "$t1" ]; then
t2=`echo $t1 | gawk '{ print $6 }'`
if [ ! -r $2 ]; then
echo "No System.map" >&2
t7=0
else
t3=`grep $t2 $2`
t4=`echo $t3 | gawk '{ print $1 }'`
t5=`echo $t1 | gawk '{ print $1 }'`
t6=`echo $t4 - $t5 | tr a-f A-F`
t7=`( echo ibase=16 ; echo $t6 ) | bc`
fi
else
t7=0
fi
$3 -r --source --adjust-vma=$t7 $1
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