496 lines
15 KiB
C
496 lines
15 KiB
C
/*
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* Copyright 2013 Tilera Corporation. All Rights Reserved.
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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, version 2.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
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* NON INFRINGEMENT. See the GNU General Public License for
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* more details.
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*
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* TILE-Gx KGDB support.
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*/
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#include <linux/ptrace.h>
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#include <linux/kgdb.h>
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#include <linux/kdebug.h>
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#include <linux/uaccess.h>
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#include <linux/module.h>
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#include <asm/cacheflush.h>
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static tile_bundle_bits singlestep_insn = TILEGX_BPT_BUNDLE | DIE_SSTEPBP;
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static unsigned long stepped_addr;
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static tile_bundle_bits stepped_instr;
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struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
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{ "r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0])},
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{ "r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1])},
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{ "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2])},
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{ "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3])},
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{ "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4])},
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{ "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5])},
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{ "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6])},
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{ "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7])},
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{ "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8])},
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{ "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9])},
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{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10])},
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{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11])},
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{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12])},
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{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13])},
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{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14])},
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{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15])},
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{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16])},
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{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17])},
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{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18])},
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{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19])},
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{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20])},
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{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21])},
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{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22])},
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{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23])},
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{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24])},
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{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25])},
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{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26])},
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{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27])},
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{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28])},
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{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29])},
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{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30])},
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{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31])},
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{ "r32", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[32])},
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{ "r33", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[33])},
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{ "r34", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[34])},
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{ "r35", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[35])},
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{ "r36", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[36])},
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{ "r37", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[37])},
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{ "r38", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[38])},
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{ "r39", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[39])},
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{ "r40", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[40])},
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{ "r41", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[41])},
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{ "r42", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[42])},
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{ "r43", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[43])},
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{ "r44", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[44])},
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{ "r45", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[45])},
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{ "r46", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[46])},
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{ "r47", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[47])},
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{ "r48", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[48])},
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{ "r49", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[49])},
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{ "r50", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[50])},
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{ "r51", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[51])},
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{ "r52", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[52])},
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{ "tp", GDB_SIZEOF_REG, offsetof(struct pt_regs, tp)},
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{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp)},
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{ "lr", GDB_SIZEOF_REG, offsetof(struct pt_regs, lr)},
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{ "sn", GDB_SIZEOF_REG, -1},
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{ "idn0", GDB_SIZEOF_REG, -1},
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{ "idn1", GDB_SIZEOF_REG, -1},
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{ "udn0", GDB_SIZEOF_REG, -1},
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{ "udn1", GDB_SIZEOF_REG, -1},
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{ "udn2", GDB_SIZEOF_REG, -1},
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{ "udn3", GDB_SIZEOF_REG, -1},
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{ "zero", GDB_SIZEOF_REG, -1},
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{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, pc)},
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{ "faultnum", GDB_SIZEOF_REG, offsetof(struct pt_regs, faultnum)},
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};
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char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
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{
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if (regno >= DBG_MAX_REG_NUM || regno < 0)
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return NULL;
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if (dbg_reg_def[regno].offset != -1)
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memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
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dbg_reg_def[regno].size);
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else
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memset(mem, 0, dbg_reg_def[regno].size);
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return dbg_reg_def[regno].name;
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}
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int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
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{
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if (regno >= DBG_MAX_REG_NUM || regno < 0)
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return -EINVAL;
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if (dbg_reg_def[regno].offset != -1)
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memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
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dbg_reg_def[regno].size);
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return 0;
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}
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/*
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* Similar to pt_regs_to_gdb_regs() except that process is sleeping and so
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* we may not be able to get all the info.
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*/
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void
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sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
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{
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struct pt_regs *thread_regs;
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if (task == NULL)
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return;
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/* Initialize to zero. */
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memset(gdb_regs, 0, NUMREGBYTES);
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thread_regs = task_pt_regs(task);
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memcpy(gdb_regs, thread_regs, TREG_LAST_GPR * sizeof(unsigned long));
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gdb_regs[TILEGX_PC_REGNUM] = thread_regs->pc;
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gdb_regs[TILEGX_FAULTNUM_REGNUM] = thread_regs->faultnum;
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}
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void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
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{
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regs->pc = pc;
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}
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static void kgdb_call_nmi_hook(void *ignored)
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{
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kgdb_nmicallback(raw_smp_processor_id(), NULL);
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}
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void kgdb_roundup_cpus(unsigned long flags)
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{
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local_irq_enable();
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smp_call_function(kgdb_call_nmi_hook, NULL, 0);
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local_irq_disable();
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}
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/*
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* Convert a kernel address to the writable kernel text mapping.
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*/
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static unsigned long writable_address(unsigned long addr)
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{
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unsigned long ret = 0;
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if (core_kernel_text(addr))
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ret = ktext_writable_addr(addr);
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else if (is_module_text_address(addr))
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ret = addr;
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else
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pr_err("Unknown virtual address 0x%lx\n", addr);
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return ret;
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}
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/*
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* Calculate the new address for after a step.
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*/
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static unsigned long get_step_address(struct pt_regs *regs)
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{
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int src_reg;
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int jump_off;
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int br_off;
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unsigned long addr;
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unsigned int opcode;
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tile_bundle_bits bundle;
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/* Move to the next instruction by default. */
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addr = regs->pc + TILEGX_BUNDLE_SIZE_IN_BYTES;
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bundle = *(unsigned long *)instruction_pointer(regs);
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/* 0: X mode, Otherwise: Y mode. */
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if (bundle & TILEGX_BUNDLE_MODE_MASK) {
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if (get_Opcode_Y1(bundle) == RRR_1_OPCODE_Y1 &&
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get_RRROpcodeExtension_Y1(bundle) ==
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UNARY_RRR_1_OPCODE_Y1) {
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opcode = get_UnaryOpcodeExtension_Y1(bundle);
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switch (opcode) {
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case JALR_UNARY_OPCODE_Y1:
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case JALRP_UNARY_OPCODE_Y1:
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case JR_UNARY_OPCODE_Y1:
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case JRP_UNARY_OPCODE_Y1:
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src_reg = get_SrcA_Y1(bundle);
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dbg_get_reg(src_reg, &addr, regs);
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break;
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}
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}
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} else if (get_Opcode_X1(bundle) == RRR_0_OPCODE_X1) {
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if (get_RRROpcodeExtension_X1(bundle) ==
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UNARY_RRR_0_OPCODE_X1) {
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opcode = get_UnaryOpcodeExtension_X1(bundle);
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switch (opcode) {
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case JALR_UNARY_OPCODE_X1:
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case JALRP_UNARY_OPCODE_X1:
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case JR_UNARY_OPCODE_X1:
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case JRP_UNARY_OPCODE_X1:
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src_reg = get_SrcA_X1(bundle);
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dbg_get_reg(src_reg, &addr, regs);
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break;
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}
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}
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} else if (get_Opcode_X1(bundle) == JUMP_OPCODE_X1) {
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opcode = get_JumpOpcodeExtension_X1(bundle);
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switch (opcode) {
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case JAL_JUMP_OPCODE_X1:
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case J_JUMP_OPCODE_X1:
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jump_off = sign_extend(get_JumpOff_X1(bundle), 27);
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addr = regs->pc +
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(jump_off << TILEGX_LOG2_BUNDLE_SIZE_IN_BYTES);
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break;
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}
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} else if (get_Opcode_X1(bundle) == BRANCH_OPCODE_X1) {
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br_off = 0;
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opcode = get_BrType_X1(bundle);
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switch (opcode) {
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case BEQZT_BRANCH_OPCODE_X1:
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case BEQZ_BRANCH_OPCODE_X1:
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if (get_SrcA_X1(bundle) == 0)
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br_off = get_BrOff_X1(bundle);
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break;
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case BGEZT_BRANCH_OPCODE_X1:
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case BGEZ_BRANCH_OPCODE_X1:
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if (get_SrcA_X1(bundle) >= 0)
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br_off = get_BrOff_X1(bundle);
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break;
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case BGTZT_BRANCH_OPCODE_X1:
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case BGTZ_BRANCH_OPCODE_X1:
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if (get_SrcA_X1(bundle) > 0)
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br_off = get_BrOff_X1(bundle);
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break;
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case BLBCT_BRANCH_OPCODE_X1:
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case BLBC_BRANCH_OPCODE_X1:
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if (!(get_SrcA_X1(bundle) & 1))
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br_off = get_BrOff_X1(bundle);
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break;
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case BLBST_BRANCH_OPCODE_X1:
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case BLBS_BRANCH_OPCODE_X1:
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if (get_SrcA_X1(bundle) & 1)
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br_off = get_BrOff_X1(bundle);
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break;
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case BLEZT_BRANCH_OPCODE_X1:
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case BLEZ_BRANCH_OPCODE_X1:
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if (get_SrcA_X1(bundle) <= 0)
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br_off = get_BrOff_X1(bundle);
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break;
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case BLTZT_BRANCH_OPCODE_X1:
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case BLTZ_BRANCH_OPCODE_X1:
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if (get_SrcA_X1(bundle) < 0)
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br_off = get_BrOff_X1(bundle);
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break;
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case BNEZT_BRANCH_OPCODE_X1:
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case BNEZ_BRANCH_OPCODE_X1:
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if (get_SrcA_X1(bundle) != 0)
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br_off = get_BrOff_X1(bundle);
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break;
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}
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if (br_off != 0) {
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br_off = sign_extend(br_off, 17);
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addr = regs->pc +
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(br_off << TILEGX_LOG2_BUNDLE_SIZE_IN_BYTES);
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}
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}
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return addr;
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}
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/*
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* Replace the next instruction after the current instruction with a
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* breakpoint instruction.
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*/
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static void do_single_step(struct pt_regs *regs)
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{
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unsigned long addr_wr;
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/* Determine where the target instruction will send us to. */
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stepped_addr = get_step_address(regs);
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probe_kernel_read((char *)&stepped_instr, (char *)stepped_addr,
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BREAK_INSTR_SIZE);
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addr_wr = writable_address(stepped_addr);
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probe_kernel_write((char *)addr_wr, (char *)&singlestep_insn,
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BREAK_INSTR_SIZE);
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smp_wmb();
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flush_icache_range(stepped_addr, stepped_addr + BREAK_INSTR_SIZE);
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}
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static void undo_single_step(struct pt_regs *regs)
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{
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unsigned long addr_wr;
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if (stepped_instr == 0)
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return;
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addr_wr = writable_address(stepped_addr);
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probe_kernel_write((char *)addr_wr, (char *)&stepped_instr,
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BREAK_INSTR_SIZE);
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stepped_instr = 0;
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smp_wmb();
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flush_icache_range(stepped_addr, stepped_addr + BREAK_INSTR_SIZE);
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}
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/*
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* Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
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* then try to fall into the debugger.
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*/
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static int
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kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
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{
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int ret;
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unsigned long flags;
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struct die_args *args = (struct die_args *)ptr;
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struct pt_regs *regs = args->regs;
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#ifdef CONFIG_KPROBES
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/*
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* Return immediately if the kprobes fault notifier has set
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* DIE_PAGE_FAULT.
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*/
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if (cmd == DIE_PAGE_FAULT)
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return NOTIFY_DONE;
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#endif /* CONFIG_KPROBES */
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switch (cmd) {
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case DIE_BREAK:
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case DIE_COMPILED_BPT:
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break;
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case DIE_SSTEPBP:
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local_irq_save(flags);
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kgdb_handle_exception(0, SIGTRAP, 0, regs);
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local_irq_restore(flags);
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return NOTIFY_STOP;
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default:
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/* Userspace events, ignore. */
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if (user_mode(regs))
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return NOTIFY_DONE;
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}
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local_irq_save(flags);
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ret = kgdb_handle_exception(args->trapnr, args->signr, args->err, regs);
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local_irq_restore(flags);
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if (ret)
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return NOTIFY_DONE;
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return NOTIFY_STOP;
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}
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static struct notifier_block kgdb_notifier = {
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.notifier_call = kgdb_notify,
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};
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/*
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* kgdb_arch_handle_exception - Handle architecture specific GDB packets.
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* @vector: The error vector of the exception that happened.
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* @signo: The signal number of the exception that happened.
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* @err_code: The error code of the exception that happened.
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* @remcom_in_buffer: The buffer of the packet we have read.
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* @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
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* @regs: The &struct pt_regs of the current process.
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*
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* This function MUST handle the 'c' and 's' command packets,
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* as well packets to set / remove a hardware breakpoint, if used.
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* If there are additional packets which the hardware needs to handle,
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* they are handled here. The code should return -1 if it wants to
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* process more packets, and a %0 or %1 if it wants to exit from the
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* kgdb callback.
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*/
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int kgdb_arch_handle_exception(int vector, int signo, int err_code,
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char *remcom_in_buffer, char *remcom_out_buffer,
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struct pt_regs *regs)
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{
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char *ptr;
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unsigned long address;
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/* Undo any stepping we may have done. */
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undo_single_step(regs);
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switch (remcom_in_buffer[0]) {
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case 'c':
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case 's':
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case 'D':
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case 'k':
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/*
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* Try to read optional parameter, pc unchanged if no parm.
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* If this was a compiled-in breakpoint, we need to move
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* to the next instruction or we will just breakpoint
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* over and over again.
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*/
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ptr = &remcom_in_buffer[1];
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if (kgdb_hex2long(&ptr, &address))
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regs->pc = address;
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else if (*(unsigned long *)regs->pc == compiled_bpt)
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regs->pc += BREAK_INSTR_SIZE;
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if (remcom_in_buffer[0] == 's') {
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do_single_step(regs);
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kgdb_single_step = 1;
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atomic_set(&kgdb_cpu_doing_single_step,
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raw_smp_processor_id());
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} else
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atomic_set(&kgdb_cpu_doing_single_step, -1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
return -1; /* this means that we do not want to exit from the handler */
|
|
}
|
|
|
|
struct kgdb_arch arch_kgdb_ops;
|
|
|
|
/*
|
|
* kgdb_arch_init - Perform any architecture specific initalization.
|
|
*
|
|
* This function will handle the initalization of any architecture
|
|
* specific callbacks.
|
|
*/
|
|
int kgdb_arch_init(void)
|
|
{
|
|
tile_bundle_bits bundle = TILEGX_BPT_BUNDLE;
|
|
|
|
memcpy(arch_kgdb_ops.gdb_bpt_instr, &bundle, BREAK_INSTR_SIZE);
|
|
return register_die_notifier(&kgdb_notifier);
|
|
}
|
|
|
|
/*
|
|
* kgdb_arch_exit - Perform any architecture specific uninitalization.
|
|
*
|
|
* This function will handle the uninitalization of any architecture
|
|
* specific callbacks, for dynamic registration and unregistration.
|
|
*/
|
|
void kgdb_arch_exit(void)
|
|
{
|
|
unregister_die_notifier(&kgdb_notifier);
|
|
}
|
|
|
|
int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
|
|
{
|
|
int err;
|
|
unsigned long addr_wr = writable_address(bpt->bpt_addr);
|
|
|
|
if (addr_wr == 0)
|
|
return -1;
|
|
|
|
err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
|
|
BREAK_INSTR_SIZE);
|
|
if (err)
|
|
return err;
|
|
|
|
err = probe_kernel_write((char *)addr_wr, arch_kgdb_ops.gdb_bpt_instr,
|
|
BREAK_INSTR_SIZE);
|
|
smp_wmb();
|
|
flush_icache_range((unsigned long)bpt->bpt_addr,
|
|
(unsigned long)bpt->bpt_addr + BREAK_INSTR_SIZE);
|
|
return err;
|
|
}
|
|
|
|
int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
|
|
{
|
|
int err;
|
|
unsigned long addr_wr = writable_address(bpt->bpt_addr);
|
|
|
|
if (addr_wr == 0)
|
|
return -1;
|
|
|
|
err = probe_kernel_write((char *)addr_wr, (char *)bpt->saved_instr,
|
|
BREAK_INSTR_SIZE);
|
|
smp_wmb();
|
|
flush_icache_range((unsigned long)bpt->bpt_addr,
|
|
(unsigned long)bpt->bpt_addr + BREAK_INSTR_SIZE);
|
|
return err;
|
|
}
|