mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
785 lines
19 KiB
785 lines
19 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
*/ |
|
|
|
/* |
|
* Copyright (C) 2004 Amit S. Kale <[email protected]> |
|
* Copyright (C) 2000-2001 VERITAS Software Corporation. |
|
* Copyright (C) 2002 Andi Kleen, SuSE Labs |
|
* Copyright (C) 2004 LinSysSoft Technologies Pvt. Ltd. |
|
* Copyright (C) 2007 MontaVista Software, Inc. |
|
* Copyright (C) 2007-2008 Jason Wessel, Wind River Systems, Inc. |
|
*/ |
|
/**************************************************************************** |
|
* Contributor: Lake Stevens Instrument Division$ |
|
* Written by: Glenn Engel $ |
|
* Updated by: Amit Kale<[email protected]> |
|
* Updated by: Tom Rini <[email protected]> |
|
* Updated by: Jason Wessel <[email protected]> |
|
* Modified for 386 by Jim Kingdon, Cygnus Support. |
|
* Origianl kgdb, compatibility with 2.1.xx kernel by |
|
* David Grothe <[email protected]> |
|
* Integrated into 2.2.5 kernel by Tigran Aivazian <[email protected]> |
|
* X86_64 changes from Andi Kleen's patch merged by Jim Houston |
|
*/ |
|
#include <linux/spinlock.h> |
|
#include <linux/kdebug.h> |
|
#include <linux/string.h> |
|
#include <linux/kernel.h> |
|
#include <linux/ptrace.h> |
|
#include <linux/sched.h> |
|
#include <linux/delay.h> |
|
#include <linux/kgdb.h> |
|
#include <linux/smp.h> |
|
#include <linux/nmi.h> |
|
#include <linux/hw_breakpoint.h> |
|
#include <linux/uaccess.h> |
|
#include <linux/memory.h> |
|
|
|
#include <asm/text-patching.h> |
|
#include <asm/debugreg.h> |
|
#include <asm/apicdef.h> |
|
#include <asm/apic.h> |
|
#include <asm/nmi.h> |
|
#include <asm/switch_to.h> |
|
|
|
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = |
|
{ |
|
#ifdef CONFIG_X86_32 |
|
{ "ax", 4, offsetof(struct pt_regs, ax) }, |
|
{ "cx", 4, offsetof(struct pt_regs, cx) }, |
|
{ "dx", 4, offsetof(struct pt_regs, dx) }, |
|
{ "bx", 4, offsetof(struct pt_regs, bx) }, |
|
{ "sp", 4, offsetof(struct pt_regs, sp) }, |
|
{ "bp", 4, offsetof(struct pt_regs, bp) }, |
|
{ "si", 4, offsetof(struct pt_regs, si) }, |
|
{ "di", 4, offsetof(struct pt_regs, di) }, |
|
{ "ip", 4, offsetof(struct pt_regs, ip) }, |
|
{ "flags", 4, offsetof(struct pt_regs, flags) }, |
|
{ "cs", 4, offsetof(struct pt_regs, cs) }, |
|
{ "ss", 4, offsetof(struct pt_regs, ss) }, |
|
{ "ds", 4, offsetof(struct pt_regs, ds) }, |
|
{ "es", 4, offsetof(struct pt_regs, es) }, |
|
#else |
|
{ "ax", 8, offsetof(struct pt_regs, ax) }, |
|
{ "bx", 8, offsetof(struct pt_regs, bx) }, |
|
{ "cx", 8, offsetof(struct pt_regs, cx) }, |
|
{ "dx", 8, offsetof(struct pt_regs, dx) }, |
|
{ "si", 8, offsetof(struct pt_regs, si) }, |
|
{ "di", 8, offsetof(struct pt_regs, di) }, |
|
{ "bp", 8, offsetof(struct pt_regs, bp) }, |
|
{ "sp", 8, offsetof(struct pt_regs, sp) }, |
|
{ "r8", 8, offsetof(struct pt_regs, r8) }, |
|
{ "r9", 8, offsetof(struct pt_regs, r9) }, |
|
{ "r10", 8, offsetof(struct pt_regs, r10) }, |
|
{ "r11", 8, offsetof(struct pt_regs, r11) }, |
|
{ "r12", 8, offsetof(struct pt_regs, r12) }, |
|
{ "r13", 8, offsetof(struct pt_regs, r13) }, |
|
{ "r14", 8, offsetof(struct pt_regs, r14) }, |
|
{ "r15", 8, offsetof(struct pt_regs, r15) }, |
|
{ "ip", 8, offsetof(struct pt_regs, ip) }, |
|
{ "flags", 4, offsetof(struct pt_regs, flags) }, |
|
{ "cs", 4, offsetof(struct pt_regs, cs) }, |
|
{ "ss", 4, offsetof(struct pt_regs, ss) }, |
|
{ "ds", 4, -1 }, |
|
{ "es", 4, -1 }, |
|
#endif |
|
{ "fs", 4, -1 }, |
|
{ "gs", 4, -1 }, |
|
}; |
|
|
|
int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) |
|
{ |
|
if ( |
|
#ifdef CONFIG_X86_32 |
|
regno == GDB_SS || regno == GDB_FS || regno == GDB_GS || |
|
#endif |
|
regno == GDB_SP || regno == GDB_ORIG_AX) |
|
return 0; |
|
|
|
if (dbg_reg_def[regno].offset != -1) |
|
memcpy((void *)regs + dbg_reg_def[regno].offset, mem, |
|
dbg_reg_def[regno].size); |
|
return 0; |
|
} |
|
|
|
char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) |
|
{ |
|
if (regno == GDB_ORIG_AX) { |
|
memcpy(mem, ®s->orig_ax, sizeof(regs->orig_ax)); |
|
return "orig_ax"; |
|
} |
|
if (regno >= DBG_MAX_REG_NUM || regno < 0) |
|
return NULL; |
|
|
|
if (dbg_reg_def[regno].offset != -1) |
|
memcpy(mem, (void *)regs + dbg_reg_def[regno].offset, |
|
dbg_reg_def[regno].size); |
|
|
|
#ifdef CONFIG_X86_32 |
|
switch (regno) { |
|
case GDB_GS: |
|
case GDB_FS: |
|
*(unsigned long *)mem = 0xFFFF; |
|
break; |
|
} |
|
#endif |
|
return dbg_reg_def[regno].name; |
|
} |
|
|
|
/** |
|
* sleeping_thread_to_gdb_regs - Convert ptrace regs to GDB regs |
|
* @gdb_regs: A pointer to hold the registers in the order GDB wants. |
|
* @p: The &struct task_struct of the desired process. |
|
* |
|
* Convert the register values of the sleeping process in @p to |
|
* the format that GDB expects. |
|
* This function is called when kgdb does not have access to the |
|
* &struct pt_regs and therefore it should fill the gdb registers |
|
* @gdb_regs with what has been saved in &struct thread_struct |
|
* thread field during switch_to. |
|
*/ |
|
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) |
|
{ |
|
#ifndef CONFIG_X86_32 |
|
u32 *gdb_regs32 = (u32 *)gdb_regs; |
|
#endif |
|
gdb_regs[GDB_AX] = 0; |
|
gdb_regs[GDB_BX] = 0; |
|
gdb_regs[GDB_CX] = 0; |
|
gdb_regs[GDB_DX] = 0; |
|
gdb_regs[GDB_SI] = 0; |
|
gdb_regs[GDB_DI] = 0; |
|
gdb_regs[GDB_BP] = ((struct inactive_task_frame *)p->thread.sp)->bp; |
|
#ifdef CONFIG_X86_32 |
|
gdb_regs[GDB_DS] = __KERNEL_DS; |
|
gdb_regs[GDB_ES] = __KERNEL_DS; |
|
gdb_regs[GDB_PS] = 0; |
|
gdb_regs[GDB_CS] = __KERNEL_CS; |
|
gdb_regs[GDB_SS] = __KERNEL_DS; |
|
gdb_regs[GDB_FS] = 0xFFFF; |
|
gdb_regs[GDB_GS] = 0xFFFF; |
|
#else |
|
gdb_regs32[GDB_PS] = 0; |
|
gdb_regs32[GDB_CS] = __KERNEL_CS; |
|
gdb_regs32[GDB_SS] = __KERNEL_DS; |
|
gdb_regs[GDB_R8] = 0; |
|
gdb_regs[GDB_R9] = 0; |
|
gdb_regs[GDB_R10] = 0; |
|
gdb_regs[GDB_R11] = 0; |
|
gdb_regs[GDB_R12] = 0; |
|
gdb_regs[GDB_R13] = 0; |
|
gdb_regs[GDB_R14] = 0; |
|
gdb_regs[GDB_R15] = 0; |
|
#endif |
|
gdb_regs[GDB_PC] = 0; |
|
gdb_regs[GDB_SP] = p->thread.sp; |
|
} |
|
|
|
static struct hw_breakpoint { |
|
unsigned enabled; |
|
unsigned long addr; |
|
int len; |
|
int type; |
|
struct perf_event * __percpu *pev; |
|
} breakinfo[HBP_NUM]; |
|
|
|
static unsigned long early_dr7; |
|
|
|
static void kgdb_correct_hw_break(void) |
|
{ |
|
int breakno; |
|
|
|
for (breakno = 0; breakno < HBP_NUM; breakno++) { |
|
struct perf_event *bp; |
|
struct arch_hw_breakpoint *info; |
|
int val; |
|
int cpu = raw_smp_processor_id(); |
|
if (!breakinfo[breakno].enabled) |
|
continue; |
|
if (dbg_is_early) { |
|
set_debugreg(breakinfo[breakno].addr, breakno); |
|
early_dr7 |= encode_dr7(breakno, |
|
breakinfo[breakno].len, |
|
breakinfo[breakno].type); |
|
set_debugreg(early_dr7, 7); |
|
continue; |
|
} |
|
bp = *per_cpu_ptr(breakinfo[breakno].pev, cpu); |
|
info = counter_arch_bp(bp); |
|
if (bp->attr.disabled != 1) |
|
continue; |
|
bp->attr.bp_addr = breakinfo[breakno].addr; |
|
bp->attr.bp_len = breakinfo[breakno].len; |
|
bp->attr.bp_type = breakinfo[breakno].type; |
|
info->address = breakinfo[breakno].addr; |
|
info->len = breakinfo[breakno].len; |
|
info->type = breakinfo[breakno].type; |
|
val = arch_install_hw_breakpoint(bp); |
|
if (!val) |
|
bp->attr.disabled = 0; |
|
} |
|
if (!dbg_is_early) |
|
hw_breakpoint_restore(); |
|
} |
|
|
|
static int hw_break_reserve_slot(int breakno) |
|
{ |
|
int cpu; |
|
int cnt = 0; |
|
struct perf_event **pevent; |
|
|
|
if (dbg_is_early) |
|
return 0; |
|
|
|
for_each_online_cpu(cpu) { |
|
cnt++; |
|
pevent = per_cpu_ptr(breakinfo[breakno].pev, cpu); |
|
if (dbg_reserve_bp_slot(*pevent)) |
|
goto fail; |
|
} |
|
|
|
return 0; |
|
|
|
fail: |
|
for_each_online_cpu(cpu) { |
|
cnt--; |
|
if (!cnt) |
|
break; |
|
pevent = per_cpu_ptr(breakinfo[breakno].pev, cpu); |
|
dbg_release_bp_slot(*pevent); |
|
} |
|
return -1; |
|
} |
|
|
|
static int hw_break_release_slot(int breakno) |
|
{ |
|
struct perf_event **pevent; |
|
int cpu; |
|
|
|
if (dbg_is_early) |
|
return 0; |
|
|
|
for_each_online_cpu(cpu) { |
|
pevent = per_cpu_ptr(breakinfo[breakno].pev, cpu); |
|
if (dbg_release_bp_slot(*pevent)) |
|
/* |
|
* The debugger is responsible for handing the retry on |
|
* remove failure. |
|
*/ |
|
return -1; |
|
} |
|
return 0; |
|
} |
|
|
|
static int |
|
kgdb_remove_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < HBP_NUM; i++) |
|
if (breakinfo[i].addr == addr && breakinfo[i].enabled) |
|
break; |
|
if (i == HBP_NUM) |
|
return -1; |
|
|
|
if (hw_break_release_slot(i)) { |
|
printk(KERN_ERR "Cannot remove hw breakpoint at %lx\n", addr); |
|
return -1; |
|
} |
|
breakinfo[i].enabled = 0; |
|
|
|
return 0; |
|
} |
|
|
|
static void kgdb_remove_all_hw_break(void) |
|
{ |
|
int i; |
|
int cpu = raw_smp_processor_id(); |
|
struct perf_event *bp; |
|
|
|
for (i = 0; i < HBP_NUM; i++) { |
|
if (!breakinfo[i].enabled) |
|
continue; |
|
bp = *per_cpu_ptr(breakinfo[i].pev, cpu); |
|
if (!bp->attr.disabled) { |
|
arch_uninstall_hw_breakpoint(bp); |
|
bp->attr.disabled = 1; |
|
continue; |
|
} |
|
if (dbg_is_early) |
|
early_dr7 &= ~encode_dr7(i, breakinfo[i].len, |
|
breakinfo[i].type); |
|
else if (hw_break_release_slot(i)) |
|
printk(KERN_ERR "KGDB: hw bpt remove failed %lx\n", |
|
breakinfo[i].addr); |
|
breakinfo[i].enabled = 0; |
|
} |
|
} |
|
|
|
static int |
|
kgdb_set_hw_break(unsigned long addr, int len, enum kgdb_bptype bptype) |
|
{ |
|
int i; |
|
|
|
for (i = 0; i < HBP_NUM; i++) |
|
if (!breakinfo[i].enabled) |
|
break; |
|
if (i == HBP_NUM) |
|
return -1; |
|
|
|
switch (bptype) { |
|
case BP_HARDWARE_BREAKPOINT: |
|
len = 1; |
|
breakinfo[i].type = X86_BREAKPOINT_EXECUTE; |
|
break; |
|
case BP_WRITE_WATCHPOINT: |
|
breakinfo[i].type = X86_BREAKPOINT_WRITE; |
|
break; |
|
case BP_ACCESS_WATCHPOINT: |
|
breakinfo[i].type = X86_BREAKPOINT_RW; |
|
break; |
|
default: |
|
return -1; |
|
} |
|
switch (len) { |
|
case 1: |
|
breakinfo[i].len = X86_BREAKPOINT_LEN_1; |
|
break; |
|
case 2: |
|
breakinfo[i].len = X86_BREAKPOINT_LEN_2; |
|
break; |
|
case 4: |
|
breakinfo[i].len = X86_BREAKPOINT_LEN_4; |
|
break; |
|
#ifdef CONFIG_X86_64 |
|
case 8: |
|
breakinfo[i].len = X86_BREAKPOINT_LEN_8; |
|
break; |
|
#endif |
|
default: |
|
return -1; |
|
} |
|
breakinfo[i].addr = addr; |
|
if (hw_break_reserve_slot(i)) { |
|
breakinfo[i].addr = 0; |
|
return -1; |
|
} |
|
breakinfo[i].enabled = 1; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* kgdb_disable_hw_debug - Disable hardware debugging while we in kgdb. |
|
* @regs: Current &struct pt_regs. |
|
* |
|
* This function will be called if the particular architecture must |
|
* disable hardware debugging while it is processing gdb packets or |
|
* handling exception. |
|
*/ |
|
static void kgdb_disable_hw_debug(struct pt_regs *regs) |
|
{ |
|
int i; |
|
int cpu = raw_smp_processor_id(); |
|
struct perf_event *bp; |
|
|
|
/* Disable hardware debugging while we are in kgdb: */ |
|
set_debugreg(0UL, 7); |
|
for (i = 0; i < HBP_NUM; i++) { |
|
if (!breakinfo[i].enabled) |
|
continue; |
|
if (dbg_is_early) { |
|
early_dr7 &= ~encode_dr7(i, breakinfo[i].len, |
|
breakinfo[i].type); |
|
continue; |
|
} |
|
bp = *per_cpu_ptr(breakinfo[i].pev, cpu); |
|
if (bp->attr.disabled == 1) |
|
continue; |
|
arch_uninstall_hw_breakpoint(bp); |
|
bp->attr.disabled = 1; |
|
} |
|
} |
|
|
|
#ifdef CONFIG_SMP |
|
/** |
|
* kgdb_roundup_cpus - Get other CPUs into a holding pattern |
|
* |
|
* On SMP systems, we need to get the attention of the other CPUs |
|
* and get them be in a known state. This should do what is needed |
|
* to get the other CPUs to call kgdb_wait(). Note that on some arches, |
|
* the NMI approach is not used for rounding up all the CPUs. For example, |
|
* in case of MIPS, smp_call_function() is used to roundup CPUs. |
|
* |
|
* On non-SMP systems, this is not called. |
|
*/ |
|
void kgdb_roundup_cpus(void) |
|
{ |
|
apic_send_IPI_allbutself(NMI_VECTOR); |
|
} |
|
#endif |
|
|
|
/** |
|
* kgdb_arch_handle_exception - Handle architecture specific GDB packets. |
|
* @e_vector: The error vector of the exception that happened. |
|
* @signo: The signal number of the exception that happened. |
|
* @err_code: The error code of the exception that happened. |
|
* @remcomInBuffer: The buffer of the packet we have read. |
|
* @remcomOutBuffer: The buffer of %BUFMAX bytes to write a packet into. |
|
* @linux_regs: The &struct pt_regs of the current process. |
|
* |
|
* This function MUST handle the 'c' and 's' command packets, |
|
* as well packets to set / remove a hardware breakpoint, if used. |
|
* If there are additional packets which the hardware needs to handle, |
|
* they are handled here. The code should return -1 if it wants to |
|
* process more packets, and a %0 or %1 if it wants to exit from the |
|
* kgdb callback. |
|
*/ |
|
int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, |
|
char *remcomInBuffer, char *remcomOutBuffer, |
|
struct pt_regs *linux_regs) |
|
{ |
|
unsigned long addr; |
|
char *ptr; |
|
|
|
switch (remcomInBuffer[0]) { |
|
case 'c': |
|
case 's': |
|
/* try to read optional parameter, pc unchanged if no parm */ |
|
ptr = &remcomInBuffer[1]; |
|
if (kgdb_hex2long(&ptr, &addr)) |
|
linux_regs->ip = addr; |
|
fallthrough; |
|
case 'D': |
|
case 'k': |
|
/* clear the trace bit */ |
|
linux_regs->flags &= ~X86_EFLAGS_TF; |
|
atomic_set(&kgdb_cpu_doing_single_step, -1); |
|
|
|
/* set the trace bit if we're stepping */ |
|
if (remcomInBuffer[0] == 's') { |
|
linux_regs->flags |= X86_EFLAGS_TF; |
|
atomic_set(&kgdb_cpu_doing_single_step, |
|
raw_smp_processor_id()); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* this means that we do not want to exit from the handler: */ |
|
return -1; |
|
} |
|
|
|
static inline int |
|
single_step_cont(struct pt_regs *regs, struct die_args *args) |
|
{ |
|
/* |
|
* Single step exception from kernel space to user space so |
|
* eat the exception and continue the process: |
|
*/ |
|
printk(KERN_ERR "KGDB: trap/step from kernel to user space, " |
|
"resuming...\n"); |
|
kgdb_arch_handle_exception(args->trapnr, args->signr, |
|
args->err, "c", "", regs); |
|
/* |
|
* Reset the BS bit in dr6 (pointed by args->err) to |
|
* denote completion of processing |
|
*/ |
|
(*(unsigned long *)ERR_PTR(args->err)) &= ~DR_STEP; |
|
|
|
return NOTIFY_STOP; |
|
} |
|
|
|
static DECLARE_BITMAP(was_in_debug_nmi, NR_CPUS); |
|
|
|
static int kgdb_nmi_handler(unsigned int cmd, struct pt_regs *regs) |
|
{ |
|
int cpu; |
|
|
|
switch (cmd) { |
|
case NMI_LOCAL: |
|
if (atomic_read(&kgdb_active) != -1) { |
|
/* KGDB CPU roundup */ |
|
cpu = raw_smp_processor_id(); |
|
kgdb_nmicallback(cpu, regs); |
|
set_bit(cpu, was_in_debug_nmi); |
|
touch_nmi_watchdog(); |
|
|
|
return NMI_HANDLED; |
|
} |
|
break; |
|
|
|
case NMI_UNKNOWN: |
|
cpu = raw_smp_processor_id(); |
|
|
|
if (__test_and_clear_bit(cpu, was_in_debug_nmi)) |
|
return NMI_HANDLED; |
|
|
|
break; |
|
default: |
|
/* do nothing */ |
|
break; |
|
} |
|
return NMI_DONE; |
|
} |
|
|
|
static int __kgdb_notify(struct die_args *args, unsigned long cmd) |
|
{ |
|
struct pt_regs *regs = args->regs; |
|
|
|
switch (cmd) { |
|
case DIE_DEBUG: |
|
if (atomic_read(&kgdb_cpu_doing_single_step) != -1) { |
|
if (user_mode(regs)) |
|
return single_step_cont(regs, args); |
|
break; |
|
} else if (test_thread_flag(TIF_SINGLESTEP)) |
|
/* This means a user thread is single stepping |
|
* a system call which should be ignored |
|
*/ |
|
return NOTIFY_DONE; |
|
fallthrough; |
|
default: |
|
if (user_mode(regs)) |
|
return NOTIFY_DONE; |
|
} |
|
|
|
if (kgdb_handle_exception(args->trapnr, args->signr, cmd, regs)) |
|
return NOTIFY_DONE; |
|
|
|
/* Must touch watchdog before return to normal operation */ |
|
touch_nmi_watchdog(); |
|
return NOTIFY_STOP; |
|
} |
|
|
|
int kgdb_ll_trap(int cmd, const char *str, |
|
struct pt_regs *regs, long err, int trap, int sig) |
|
{ |
|
struct die_args args = { |
|
.regs = regs, |
|
.str = str, |
|
.err = err, |
|
.trapnr = trap, |
|
.signr = sig, |
|
|
|
}; |
|
|
|
if (!kgdb_io_module_registered) |
|
return NOTIFY_DONE; |
|
|
|
return __kgdb_notify(&args, cmd); |
|
} |
|
|
|
static int |
|
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) |
|
{ |
|
unsigned long flags; |
|
int ret; |
|
|
|
local_irq_save(flags); |
|
ret = __kgdb_notify(ptr, cmd); |
|
local_irq_restore(flags); |
|
|
|
return ret; |
|
} |
|
|
|
static struct notifier_block kgdb_notifier = { |
|
.notifier_call = kgdb_notify, |
|
}; |
|
|
|
/** |
|
* kgdb_arch_init - Perform any architecture specific initialization. |
|
* |
|
* This function will handle the initialization of any architecture |
|
* specific callbacks. |
|
*/ |
|
int kgdb_arch_init(void) |
|
{ |
|
int retval; |
|
|
|
retval = register_die_notifier(&kgdb_notifier); |
|
if (retval) |
|
goto out; |
|
|
|
retval = register_nmi_handler(NMI_LOCAL, kgdb_nmi_handler, |
|
0, "kgdb"); |
|
if (retval) |
|
goto out1; |
|
|
|
retval = register_nmi_handler(NMI_UNKNOWN, kgdb_nmi_handler, |
|
0, "kgdb"); |
|
|
|
if (retval) |
|
goto out2; |
|
|
|
return retval; |
|
|
|
out2: |
|
unregister_nmi_handler(NMI_LOCAL, "kgdb"); |
|
out1: |
|
unregister_die_notifier(&kgdb_notifier); |
|
out: |
|
return retval; |
|
} |
|
|
|
static void kgdb_hw_overflow_handler(struct perf_event *event, |
|
struct perf_sample_data *data, struct pt_regs *regs) |
|
{ |
|
struct task_struct *tsk = current; |
|
int i; |
|
|
|
for (i = 0; i < 4; i++) { |
|
if (breakinfo[i].enabled) |
|
tsk->thread.virtual_dr6 |= (DR_TRAP0 << i); |
|
} |
|
} |
|
|
|
void kgdb_arch_late(void) |
|
{ |
|
int i, cpu; |
|
struct perf_event_attr attr; |
|
struct perf_event **pevent; |
|
|
|
/* |
|
* Pre-allocate the hw breakpoint structions in the non-atomic |
|
* portion of kgdb because this operation requires mutexs to |
|
* complete. |
|
*/ |
|
hw_breakpoint_init(&attr); |
|
attr.bp_addr = (unsigned long)kgdb_arch_init; |
|
attr.bp_len = HW_BREAKPOINT_LEN_1; |
|
attr.bp_type = HW_BREAKPOINT_W; |
|
attr.disabled = 1; |
|
for (i = 0; i < HBP_NUM; i++) { |
|
if (breakinfo[i].pev) |
|
continue; |
|
breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL, NULL); |
|
if (IS_ERR((void * __force)breakinfo[i].pev)) { |
|
printk(KERN_ERR "kgdb: Could not allocate hw" |
|
"breakpoints\nDisabling the kernel debugger\n"); |
|
breakinfo[i].pev = NULL; |
|
kgdb_arch_exit(); |
|
return; |
|
} |
|
for_each_online_cpu(cpu) { |
|
pevent = per_cpu_ptr(breakinfo[i].pev, cpu); |
|
pevent[0]->hw.sample_period = 1; |
|
pevent[0]->overflow_handler = kgdb_hw_overflow_handler; |
|
if (pevent[0]->destroy != NULL) { |
|
pevent[0]->destroy = NULL; |
|
release_bp_slot(*pevent); |
|
} |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* 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) |
|
{ |
|
int i; |
|
for (i = 0; i < 4; i++) { |
|
if (breakinfo[i].pev) { |
|
unregister_wide_hw_breakpoint(breakinfo[i].pev); |
|
breakinfo[i].pev = NULL; |
|
} |
|
} |
|
unregister_nmi_handler(NMI_UNKNOWN, "kgdb"); |
|
unregister_nmi_handler(NMI_LOCAL, "kgdb"); |
|
unregister_die_notifier(&kgdb_notifier); |
|
} |
|
|
|
/** |
|
* |
|
* kgdb_skipexception - Bail out of KGDB when we've been triggered. |
|
* @exception: Exception vector number |
|
* @regs: Current &struct pt_regs. |
|
* |
|
* On some architectures we need to skip a breakpoint exception when |
|
* it occurs after a breakpoint has been removed. |
|
* |
|
* Skip an int3 exception when it occurs after a breakpoint has been |
|
* removed. Backtrack eip by 1 since the int3 would have caused it to |
|
* increment by 1. |
|
*/ |
|
int kgdb_skipexception(int exception, struct pt_regs *regs) |
|
{ |
|
if (exception == 3 && kgdb_isremovedbreak(regs->ip - 1)) { |
|
regs->ip -= 1; |
|
return 1; |
|
} |
|
return 0; |
|
} |
|
|
|
unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs) |
|
{ |
|
if (exception == 3) |
|
return instruction_pointer(regs) - 1; |
|
return instruction_pointer(regs); |
|
} |
|
|
|
void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) |
|
{ |
|
regs->ip = ip; |
|
} |
|
|
|
int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) |
|
{ |
|
int err; |
|
|
|
bpt->type = BP_BREAKPOINT; |
|
err = copy_from_kernel_nofault(bpt->saved_instr, (char *)bpt->bpt_addr, |
|
BREAK_INSTR_SIZE); |
|
if (err) |
|
return err; |
|
err = copy_to_kernel_nofault((char *)bpt->bpt_addr, |
|
arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE); |
|
if (!err) |
|
return err; |
|
/* |
|
* It is safe to call text_poke_kgdb() because normal kernel execution |
|
* is stopped on all cores, so long as the text_mutex is not locked. |
|
*/ |
|
if (mutex_is_locked(&text_mutex)) |
|
return -EBUSY; |
|
text_poke_kgdb((void *)bpt->bpt_addr, arch_kgdb_ops.gdb_bpt_instr, |
|
BREAK_INSTR_SIZE); |
|
bpt->type = BP_POKE_BREAKPOINT; |
|
|
|
return 0; |
|
} |
|
|
|
int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) |
|
{ |
|
if (bpt->type != BP_POKE_BREAKPOINT) |
|
goto knl_write; |
|
/* |
|
* It is safe to call text_poke_kgdb() because normal kernel execution |
|
* is stopped on all cores, so long as the text_mutex is not locked. |
|
*/ |
|
if (mutex_is_locked(&text_mutex)) |
|
goto knl_write; |
|
text_poke_kgdb((void *)bpt->bpt_addr, bpt->saved_instr, |
|
BREAK_INSTR_SIZE); |
|
return 0; |
|
|
|
knl_write: |
|
return copy_to_kernel_nofault((char *)bpt->bpt_addr, |
|
(char *)bpt->saved_instr, BREAK_INSTR_SIZE); |
|
} |
|
|
|
const struct kgdb_arch arch_kgdb_ops = { |
|
/* Breakpoint instruction: */ |
|
.gdb_bpt_instr = { 0xcc }, |
|
.flags = KGDB_HW_BREAKPOINT, |
|
.set_hw_breakpoint = kgdb_set_hw_break, |
|
.remove_hw_breakpoint = kgdb_remove_hw_break, |
|
.disable_hw_break = kgdb_disable_hw_debug, |
|
.remove_all_hw_break = kgdb_remove_all_hw_break, |
|
.correct_hw_break = kgdb_correct_hw_break, |
|
};
|
|
|