c91e02bd97
Use perf framework to manage hardware instruction and data breakpoints. Add two new ptrace calls: PTRACE_GETHBPREGS and PTRACE_SETHBPREGS to query and set instruction and data breakpoints. Address bit 0 choose instruction (0) or data (1) break register, bits 31..1 are the register number. Both calls transfer two 32-bit words: address (0) and control (1). Instruction breakpoint contorl word is 0 to clear breakpoint, 1 to set. Data breakpoint control word bit 31 is 'trigger on store', bit 30 is 'trigger on load, bits 29..0 are length. Length 0 is used to clear a breakpoint. To set a breakpoint length must be a power of 2 in the range 1..64 and the address must be length-aligned. Introduce new thread_info flag: TIF_DB_DISABLED. Set it if debug exception is raised by the kernel code accessing watched userspace address and disable corresponding data breakpoint. On exit to userspace check that flag and, if set, restore all data breakpoints. Handle debug exceptions raised with PS.EXCM set. This may happen when window overflow/underflow handler or fast exception handler hits data breakpoint, in which case save and disable all data breakpoints, single-step faulting instruction and restore data breakpoints. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
80 lines
2.4 KiB
C
80 lines
2.4 KiB
C
/*
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* include/asm-xtensa/ptrace.h
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*
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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) 2001 - 2005 Tensilica Inc.
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*/
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#ifndef _UAPI_XTENSA_PTRACE_H
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#define _UAPI_XTENSA_PTRACE_H
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/*
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* Kernel stack
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*
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* +-----------------------+ -------- STACK_SIZE
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* | register file | |
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* +-----------------------+ |
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* | struct pt_regs | |
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* +-----------------------+ | ------ PT_REGS_OFFSET
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* double : 16 bytes spill area : | ^
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* excetion :- - - - - - - - - - - -: | |
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* frame : struct pt_regs : | |
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* :- - - - - - - - - - - -: | |
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* | | | |
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* | memory stack | | |
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* | | | |
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* ~ ~ ~ ~
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* ~ ~ ~ ~
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* | | | |
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* | | | |
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* +-----------------------+ | | --- STACK_BIAS
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* | struct task_struct | | | ^
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* current --> +-----------------------+ | | |
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* | struct thread_info | | | |
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* +-----------------------+ --------
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*/
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#define KERNEL_STACK_SIZE (2 * PAGE_SIZE)
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/* Offsets for exception_handlers[] (3 x 64-entries x 4-byte tables). */
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#define EXC_TABLE_KSTK 0x004 /* Kernel Stack */
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#define EXC_TABLE_DOUBLE_SAVE 0x008 /* Double exception save area for a0 */
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#define EXC_TABLE_FIXUP 0x00c /* Fixup handler */
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#define EXC_TABLE_PARAM 0x010 /* For passing a parameter to fixup */
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#define EXC_TABLE_SYSCALL_SAVE 0x014 /* For fast syscall handler */
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#define EXC_TABLE_FAST_USER 0x100 /* Fast user exception handler */
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#define EXC_TABLE_FAST_KERNEL 0x200 /* Fast kernel exception handler */
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#define EXC_TABLE_DEFAULT 0x300 /* Default C-Handler */
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#define EXC_TABLE_SIZE 0x400
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/* Registers used by strace */
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#define REG_A_BASE 0x0000
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#define REG_AR_BASE 0x0100
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#define REG_PC 0x0020
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#define REG_PS 0x02e6
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#define REG_WB 0x0248
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#define REG_WS 0x0249
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#define REG_LBEG 0x0200
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#define REG_LEND 0x0201
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#define REG_LCOUNT 0x0202
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#define REG_SAR 0x0203
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#define SYSCALL_NR 0x00ff
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/* Other PTRACE_ values defined in <linux/ptrace.h> using values 0-9,16,17,24 */
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#define PTRACE_GETREGS 12
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#define PTRACE_SETREGS 13
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#define PTRACE_GETXTREGS 18
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#define PTRACE_SETXTREGS 19
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#define PTRACE_GETHBPREGS 20
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#define PTRACE_SETHBPREGS 21
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#endif /* _UAPI_XTENSA_PTRACE_H */
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