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050e9baa9d
The changes to automatically test for working stack protector compiler support in the Kconfig files removed the special STACKPROTECTOR_AUTO option that picked the strongest stack protector that the compiler supported. That was all a nice cleanup - it makes no sense to have the AUTO case now that the Kconfig phase can just determine the compiler support directly. HOWEVER. It also meant that doing "make oldconfig" would now _disable_ the strong stackprotector if you had AUTO enabled, because in a legacy config file, the sane stack protector configuration would look like CONFIG_HAVE_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_NONE is not set # CONFIG_CC_STACKPROTECTOR_REGULAR is not set # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_STACKPROTECTOR_AUTO=y and when you ran this through "make oldconfig" with the Kbuild changes, it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version used to be disabled (because it was really enabled by AUTO), and would disable it in the new config, resulting in: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_CC_STACKPROTECTOR=y # CONFIG_CC_STACKPROTECTOR_STRONG is not set CONFIG_CC_HAS_SANE_STACKPROTECTOR=y That's dangerously subtle - people could suddenly find themselves with the weaker stack protector setup without even realizing. The solution here is to just rename not just the old RECULAR stack protector option, but also the strong one. This does that by just removing the CC_ prefix entirely for the user choices, because it really is not about the compiler support (the compiler support now instead automatially impacts _visibility_ of the options to users). This results in "make oldconfig" actually asking the user for their choice, so that we don't have any silent subtle security model changes. The end result would generally look like this: CONFIG_HAVE_CC_STACKPROTECTOR=y CONFIG_CC_HAS_STACKPROTECTOR_NONE=y CONFIG_STACKPROTECTOR=y CONFIG_STACKPROTECTOR_STRONG=y CONFIG_CC_HAS_SANE_STACKPROTECTOR=y where the "CC_" versions really are about internal compiler infrastructure, not the user selections. Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
60 lines
1.5 KiB
ArmAsm
60 lines
1.5 KiB
ArmAsm
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 1994, 1995, 1996, 1998, 1999, 2002, 2003 Ralf Baechle
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* Copyright (C) 1996 David S. Miller (davem@davemloft.net)
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* Copyright (C) 1994, 1995, 1996, by Andreas Busse
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* Copyright (C) 1999 Silicon Graphics, Inc.
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* Copyright (C) 2000 MIPS Technologies, Inc.
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* written by Carsten Langgaard, carstenl@mips.com
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*/
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#include <asm/asm.h>
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#include <asm/cachectl.h>
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#include <asm/mipsregs.h>
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#include <asm/asm-offsets.h>
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#include <asm/regdef.h>
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#include <asm/stackframe.h>
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#include <asm/thread_info.h>
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#include <asm/asmmacro.h>
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/*
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* task_struct *resume(task_struct *prev, task_struct *next,
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* struct thread_info *next_ti)
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*/
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.align 5
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LEAF(resume)
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mfc0 t1, CP0_STATUS
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LONG_S t1, THREAD_STATUS(a0)
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cpu_save_nonscratch a0
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LONG_S ra, THREAD_REG31(a0)
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#if defined(CONFIG_STACKPROTECTOR) && !defined(CONFIG_SMP)
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PTR_LA t8, __stack_chk_guard
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LONG_L t9, TASK_STACK_CANARY(a1)
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LONG_S t9, 0(t8)
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#endif
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/*
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* The order of restoring the registers takes care of the race
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* updating $28, $29 and kernelsp without disabling ints.
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*/
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move $28, a2
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cpu_restore_nonscratch a1
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PTR_ADDU t0, $28, _THREAD_SIZE - 32
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set_saved_sp t0, t1, t2
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mfc0 t1, CP0_STATUS /* Do we really need this? */
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li a3, 0xff01
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and t1, a3
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LONG_L a2, THREAD_STATUS(a1)
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nor a3, $0, a3
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and a2, a3
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or a2, t1
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mtc0 a2, CP0_STATUS
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move v0, a0
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jr ra
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END(resume)
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