7664c5a1da
This patch adds common handling for kernel BUGs, for use by architectures as they wish. The code is derived from arch/powerpc. The advantages of having common BUG handling are: - consistent BUG reporting across architectures - shared implementation of out-of-line file/line data - implement CONFIG_DEBUG_BUGVERBOSE consistently This means that in inline impact of BUG is just the illegal instruction itself, which is an improvement for i386 and x86-64. A BUG is represented in the instruction stream as an illegal instruction, which has file/line information associated with it. This extra information is stored in the __bug_table section in the ELF file. When the kernel gets an illegal instruction, it first confirms it might possibly be from a BUG (ie, in kernel mode, the right illegal instruction). It then calls report_bug(). This searches __bug_table for a matching instruction pointer, and if found, prints the corresponding file/line information. If report_bug() determines that it wasn't a BUG which caused the trap, it returns BUG_TRAP_TYPE_NONE. Some architectures (powerpc) implement WARN using the same mechanism; if the illegal instruction was the result of a WARN, then report_bug(Q) returns CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG. lib/bug.c keeps a list of loaded modules which can be searched for __bug_table entries. The architecture must call module_bug_finalize()/module_bug_cleanup() from its corresponding module_finalize/cleanup functions. Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount. At the very least, filename and line information will not be recorded for each but, but architectures may decide to store no extra information per BUG at all. Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so architectures will generally have to include an infinite loop (or similar) in the BUG code, so that gcc knows execution won't continue beyond that point. gcc does have a __builtin_trap() operator which may be useful to achieve the same effect, unfortunately it cannot be used to actually implement the BUG itself, because there's no way to get the instruction's address for use in generating the __bug_table entry. [randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors] [bunk@stusta.de: include/linux/bug.h must always #include <linux/module.h] Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Andi Kleen <ak@muc.de> Cc: Hugh Dickens <hugh@veritas.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
250 lines
8.2 KiB
C
250 lines
8.2 KiB
C
#ifndef LOAD_OFFSET
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#define LOAD_OFFSET 0
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#endif
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#ifndef VMLINUX_SYMBOL
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#define VMLINUX_SYMBOL(_sym_) _sym_
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#endif
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/* Align . to a 8 byte boundary equals to maximum function alignment. */
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#define ALIGN_FUNCTION() . = ALIGN(8)
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#define RODATA \
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. = ALIGN(4096); \
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.rodata : AT(ADDR(.rodata) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start_rodata) = .; \
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*(.rodata) *(.rodata.*) \
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*(__vermagic) /* Kernel version magic */ \
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} \
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\
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.rodata1 : AT(ADDR(.rodata1) - LOAD_OFFSET) { \
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*(.rodata1) \
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} \
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\
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/* PCI quirks */ \
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.pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start_pci_fixups_early) = .; \
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*(.pci_fixup_early) \
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VMLINUX_SYMBOL(__end_pci_fixups_early) = .; \
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VMLINUX_SYMBOL(__start_pci_fixups_header) = .; \
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*(.pci_fixup_header) \
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VMLINUX_SYMBOL(__end_pci_fixups_header) = .; \
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VMLINUX_SYMBOL(__start_pci_fixups_final) = .; \
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*(.pci_fixup_final) \
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VMLINUX_SYMBOL(__end_pci_fixups_final) = .; \
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VMLINUX_SYMBOL(__start_pci_fixups_enable) = .; \
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*(.pci_fixup_enable) \
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VMLINUX_SYMBOL(__end_pci_fixups_enable) = .; \
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} \
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\
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/* RapidIO route ops */ \
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.rio_route : AT(ADDR(.rio_route) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start_rio_route_ops) = .; \
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*(.rio_route_ops) \
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VMLINUX_SYMBOL(__end_rio_route_ops) = .; \
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} \
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\
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/* Kernel symbol table: Normal symbols */ \
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__ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___ksymtab) = .; \
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*(__ksymtab) \
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VMLINUX_SYMBOL(__stop___ksymtab) = .; \
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} \
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\
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/* Kernel symbol table: GPL-only symbols */ \
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__ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___ksymtab_gpl) = .; \
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*(__ksymtab_gpl) \
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VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .; \
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} \
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\
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/* Kernel symbol table: Normal unused symbols */ \
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__ksymtab_unused : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___ksymtab_unused) = .; \
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*(__ksymtab_unused) \
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VMLINUX_SYMBOL(__stop___ksymtab_unused) = .; \
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} \
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\
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/* Kernel symbol table: GPL-only unused symbols */ \
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__ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .; \
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*(__ksymtab_unused_gpl) \
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VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .; \
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} \
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\
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/* Kernel symbol table: GPL-future-only symbols */ \
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__ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .; \
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*(__ksymtab_gpl_future) \
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VMLINUX_SYMBOL(__stop___ksymtab_gpl_future) = .; \
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} \
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\
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/* Kernel symbol table: Normal symbols */ \
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__kcrctab : AT(ADDR(__kcrctab) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___kcrctab) = .; \
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*(__kcrctab) \
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VMLINUX_SYMBOL(__stop___kcrctab) = .; \
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} \
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\
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/* Kernel symbol table: GPL-only symbols */ \
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__kcrctab_gpl : AT(ADDR(__kcrctab_gpl) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___kcrctab_gpl) = .; \
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*(__kcrctab_gpl) \
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VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .; \
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} \
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\
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/* Kernel symbol table: Normal unused symbols */ \
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__kcrctab_unused : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___kcrctab_unused) = .; \
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*(__kcrctab_unused) \
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VMLINUX_SYMBOL(__stop___kcrctab_unused) = .; \
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} \
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\
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/* Kernel symbol table: GPL-only unused symbols */ \
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__kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .; \
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*(__kcrctab_unused_gpl) \
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VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .; \
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} \
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\
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/* Kernel symbol table: GPL-future-only symbols */ \
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__kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .; \
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*(__kcrctab_gpl_future) \
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VMLINUX_SYMBOL(__stop___kcrctab_gpl_future) = .; \
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} \
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\
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/* Kernel symbol table: strings */ \
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__ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
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*(__ksymtab_strings) \
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} \
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\
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EH_FRAME \
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\
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/* Built-in module parameters. */ \
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__param : AT(ADDR(__param) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start___param) = .; \
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*(__param) \
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VMLINUX_SYMBOL(__stop___param) = .; \
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VMLINUX_SYMBOL(__end_rodata) = .; \
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} \
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\
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. = ALIGN(4096);
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#define SECURITY_INIT \
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.security_initcall.init : AT(ADDR(.security_initcall.init) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__security_initcall_start) = .; \
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*(.security_initcall.init) \
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VMLINUX_SYMBOL(__security_initcall_end) = .; \
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}
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/* sched.text is aling to function alignment to secure we have same
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* address even at second ld pass when generating System.map */
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#define SCHED_TEXT \
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ALIGN_FUNCTION(); \
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VMLINUX_SYMBOL(__sched_text_start) = .; \
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*(.sched.text) \
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VMLINUX_SYMBOL(__sched_text_end) = .;
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/* spinlock.text is aling to function alignment to secure we have same
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* address even at second ld pass when generating System.map */
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#define LOCK_TEXT \
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ALIGN_FUNCTION(); \
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VMLINUX_SYMBOL(__lock_text_start) = .; \
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*(.spinlock.text) \
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VMLINUX_SYMBOL(__lock_text_end) = .;
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#define KPROBES_TEXT \
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ALIGN_FUNCTION(); \
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VMLINUX_SYMBOL(__kprobes_text_start) = .; \
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*(.kprobes.text) \
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VMLINUX_SYMBOL(__kprobes_text_end) = .;
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#ifdef CONFIG_STACK_UNWIND
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#define EH_FRAME \
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/* Unwind data binary search table */ \
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. = ALIGN(8); \
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.eh_frame_hdr : AT(ADDR(.eh_frame_hdr) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start_unwind_hdr) = .; \
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*(.eh_frame_hdr) \
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VMLINUX_SYMBOL(__end_unwind_hdr) = .; \
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} \
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/* Unwind data */ \
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. = ALIGN(8); \
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.eh_frame : AT(ADDR(.eh_frame) - LOAD_OFFSET) { \
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VMLINUX_SYMBOL(__start_unwind) = .; \
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*(.eh_frame) \
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VMLINUX_SYMBOL(__end_unwind) = .; \
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}
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#else
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#define EH_FRAME
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#endif
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/* DWARF debug sections.
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Symbols in the DWARF debugging sections are relative to
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the beginning of the section so we begin them at 0. */
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#define DWARF_DEBUG \
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/* DWARF 1 */ \
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.debug 0 : { *(.debug) } \
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.line 0 : { *(.line) } \
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/* GNU DWARF 1 extensions */ \
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.debug_srcinfo 0 : { *(.debug_srcinfo) } \
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.debug_sfnames 0 : { *(.debug_sfnames) } \
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/* DWARF 1.1 and DWARF 2 */ \
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.debug_aranges 0 : { *(.debug_aranges) } \
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.debug_pubnames 0 : { *(.debug_pubnames) } \
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/* DWARF 2 */ \
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.debug_info 0 : { *(.debug_info \
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.gnu.linkonce.wi.*) } \
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.debug_abbrev 0 : { *(.debug_abbrev) } \
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.debug_line 0 : { *(.debug_line) } \
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.debug_frame 0 : { *(.debug_frame) } \
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.debug_str 0 : { *(.debug_str) } \
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.debug_loc 0 : { *(.debug_loc) } \
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.debug_macinfo 0 : { *(.debug_macinfo) } \
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/* SGI/MIPS DWARF 2 extensions */ \
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.debug_weaknames 0 : { *(.debug_weaknames) } \
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.debug_funcnames 0 : { *(.debug_funcnames) } \
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.debug_typenames 0 : { *(.debug_typenames) } \
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.debug_varnames 0 : { *(.debug_varnames) } \
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/* Stabs debugging sections. */
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#define STABS_DEBUG \
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.stab 0 : { *(.stab) } \
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.stabstr 0 : { *(.stabstr) } \
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.stab.excl 0 : { *(.stab.excl) } \
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.stab.exclstr 0 : { *(.stab.exclstr) } \
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.stab.index 0 : { *(.stab.index) } \
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.stab.indexstr 0 : { *(.stab.indexstr) } \
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.comment 0 : { *(.comment) }
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#define BUG_TABLE \
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. = ALIGN(8); \
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__bug_table : AT(ADDR(__bug_table) - LOAD_OFFSET) { \
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__start___bug_table = .; \
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*(__bug_table) \
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__stop___bug_table = .; \
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}
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#define NOTES \
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.notes : { *(.note.*) } :note
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#define INITCALLS \
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*(.initcall0.init) \
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*(.initcall0s.init) \
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*(.initcall1.init) \
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*(.initcall1s.init) \
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*(.initcall2.init) \
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*(.initcall2s.init) \
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*(.initcall3.init) \
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*(.initcall3s.init) \
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*(.initcall4.init) \
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*(.initcall4s.init) \
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*(.initcall5.init) \
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*(.initcall5s.init) \
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*(.initcall6.init) \
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*(.initcall6s.init) \
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*(.initcall7.init) \
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*(.initcall7s.init)
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