4dcc29e157
Problem: An application violating the architectural rules regarding operation dependencies and having specific Register Stack Engine (RSE) state at the time of the violation, may result in an illegal operation fault and invalid RSE state. Such faults may initiate a cascade of repeated illegal operation faults within OS interruption handlers. The specific behavior is OS dependent. Implication: An application causing an illegal operation fault with specific RSE state may result in a series of illegal operation faults and an eventual OS stack overflow condition. Workaround: OS interruption handlers that switch to kernel backing store implement a check for invalid RSE state to avoid the series of illegal operation faults. The core of the workaround is the RSE_WORKAROUND code sequence inserted into each invocation of the SAVE_MIN_WITH_COVER and SAVE_MIN_WITH_COVER_R19 macros. This sequence includes hard-coded constants that depend on the number of stacked physical registers being 96. The rest of this patch consists of code to disable this workaround should this not be the case (with the presumption that if a future Itanium processor increases the number of registers, it would also remove the need for this patch). Move the start of the RBS up to a mod32 boundary to avoid some corner cases. The dispatch_illegal_op_fault code outgrew the spot it was squatting in when built with this patch and CONFIG_VIRT_CPU_ACCOUNTING=y Move it out to the end of the ivt. Signed-off-by: Tony Luck <tony.luck@intel.com>
27 lines
1.1 KiB
C
27 lines
1.1 KiB
C
#ifndef _ASM_IA64_PATCH_H
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#define _ASM_IA64_PATCH_H
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/*
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* Copyright (C) 2003 Hewlett-Packard Co
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* David Mosberger-Tang <davidm@hpl.hp.com>
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*
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* There are a number of reasons for patching instructions. Rather than duplicating code
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* all over the place, we put the common stuff here. Reasons for patching: in-kernel
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* module-loader, virtual-to-physical patch-list, McKinley Errata 9 workaround, and gate
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* shared library. Undoubtedly, some of these reasons will disappear and others will
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* be added over time.
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*/
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#include <linux/elf.h>
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#include <linux/types.h>
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extern void ia64_patch (u64 insn_addr, u64 mask, u64 val); /* patch any insn slot */
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extern void ia64_patch_imm64 (u64 insn_addr, u64 val); /* patch "movl" w/abs. value*/
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extern void ia64_patch_imm60 (u64 insn_addr, u64 val); /* patch "brl" w/ip-rel value */
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extern void ia64_patch_mckinley_e9 (unsigned long start, unsigned long end);
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extern void ia64_patch_vtop (unsigned long start, unsigned long end);
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extern void ia64_patch_phys_stack_reg(unsigned long val);
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extern void ia64_patch_rse (unsigned long start, unsigned long end);
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extern void ia64_patch_gate (void);
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#endif /* _ASM_IA64_PATCH_H */
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