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c21f5a9ed8
When booting through OF, setup_disp_bat() does nothing because disp_BAT are not set. By change, it used to work because BOOTX buffer is mapped 1:1 at address 0x81000000 by the bootloader, and btext_setup_display() sets virt addr same as phys addr. But since commit215b823707("powerpc/32s: set up an early static hash table for KASAN."), a temporary page table overrides the bootloader mapping. This 0x81000000 is also problematic with the newly implemented Kernel Userspace Access Protection (KUAP) because it is within user address space. This patch fixes those issues by properly setting disp_BAT through a call to btext_prepare_BAT(), allowing setup_disp_bat() to properly setup BAT3 for early bootx screen buffer access. Reported-by: Mathieu Malaterre <malat@debian.org> Fixes:215b823707("powerpc/32s: set up an early static hash table for KASAN.") Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Tested-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
94 lines
2.2 KiB
Bash
94 lines
2.2 KiB
Bash
#!/bin/sh
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#
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# Copyright © 2008 IBM Corporation
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#
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# This program is free software; you can redistribute it and/or
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# modify it under the terms of the GNU General Public License
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# as published by the Free Software Foundation; either version
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# 2 of the License, or (at your option) any later version.
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# This script checks prom_init.o to see what external symbols it
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# is using, if it finds symbols not in the whitelist it returns
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# an error. The point of this is to discourage people from
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# intentionally or accidentally adding new code to prom_init.c
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# which has side effects on other parts of the kernel.
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# If you really need to reference something from prom_init.o add
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# it to the list below:
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grep "^CONFIG_KASAN=y$" .config >/dev/null
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if [ $? -eq 0 ]
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then
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MEM_FUNCS="__memcpy __memset"
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else
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MEM_FUNCS="memcpy memset"
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fi
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WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
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_end enter_prom $MEM_FUNCS reloc_offset __secondary_hold
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__secondary_hold_acknowledge __secondary_hold_spinloop __start
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logo_linux_clut224 btext_prepare_BAT
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reloc_got2 kernstart_addr memstart_addr linux_banner _stext
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__prom_init_toc_start __prom_init_toc_end btext_setup_display TOC."
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NM="$1"
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OBJ="$2"
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ERROR=0
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function check_section()
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{
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file=$1
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section=$2
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size=$(objdump -h -j $section $file 2>/dev/null | awk "\$2 == \"$section\" {print \$3}")
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size=${size:-0}
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if [ $size -ne 0 ]; then
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ERROR=1
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echo "Error: Section $section not empty in prom_init.c" >&2
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fi
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}
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for UNDEF in $($NM -u $OBJ | awk '{print $2}')
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do
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# On 64-bit nm gives us the function descriptors, which have
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# a leading . on the name, so strip it off here.
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UNDEF="${UNDEF#.}"
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if [ $KBUILD_VERBOSE ]; then
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if [ $KBUILD_VERBOSE -ne 0 ]; then
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echo "Checking prom_init.o symbol '$UNDEF'"
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fi
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fi
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OK=0
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for WHITE in $WHITELIST
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do
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if [ "$UNDEF" = "$WHITE" ]; then
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OK=1
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break
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fi
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done
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# ignore register save/restore funcitons
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case $UNDEF in
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_restgpr_*|_restgpr0_*|_rest32gpr_*)
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OK=1
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;;
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_savegpr_*|_savegpr0_*|_save32gpr_*)
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OK=1
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;;
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esac
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if [ $OK -eq 0 ]; then
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ERROR=1
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echo "Error: External symbol '$UNDEF' referenced" \
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"from prom_init.c" >&2
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fi
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done
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check_section $OBJ .data
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check_section $OBJ .bss
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check_section $OBJ .init.data
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exit $ERROR
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