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Diffstat (limited to 'arch/x86/kernel/kgdb.c')
-rw-r--r--arch/x86/kernel/kgdb.c123
1 files changed, 46 insertions, 77 deletions
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 836f8322960e..8b1a9733d13e 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -1,14 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2, or (at your option) any
- * later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
*/
/*
@@ -26,7 +17,7 @@
* Updated by: Tom Rini <trini@kernel.crashing.org>
* Updated by: Jason Wessel <jason.wessel@windriver.com>
* Modified for 386 by Jim Kingdon, Cygnus Support.
- * Origianl kgdb, compatibility with 2.1.xx kernel by
+ * Original kgdb, compatibility with 2.1.xx kernel by
* David Grothe <dave@gcom.com>
* Integrated into 2.2.5 kernel by Tigran Aivazian <tigran@sco.com>
* X86_64 changes from Andi Kleen's patch merged by Jim Houston
@@ -39,17 +30,18 @@
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/kgdb.h>
-#include <linux/init.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] =
{
@@ -73,7 +65,7 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
{ "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, 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) },
@@ -126,14 +118,6 @@ char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
#ifdef CONFIG_X86_32
switch (regno) {
- case GDB_SS:
- if (!user_mode_vm(regs))
- *(unsigned long *)mem = __KERNEL_DS;
- break;
- case GDB_SP:
- if (!user_mode_vm(regs))
- *(unsigned long *)mem = kernel_stack_pointer(regs);
- break;
case GDB_GS:
case GDB_FS:
*(unsigned long *)mem = 0xFFFF;
@@ -166,21 +150,19 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
gdb_regs[GDB_DX] = 0;
gdb_regs[GDB_SI] = 0;
gdb_regs[GDB_DI] = 0;
- gdb_regs[GDB_BP] = *(unsigned long *)p->thread.sp;
+ 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_PC] = p->thread.ip;
gdb_regs[GDB_SS] = __KERNEL_DS;
gdb_regs[GDB_FS] = 0xFFFF;
gdb_regs[GDB_GS] = 0xFFFF;
#else
- gdb_regs32[GDB_PS] = *(unsigned long *)(p->thread.sp + 8);
+ gdb_regs32[GDB_PS] = 0;
gdb_regs32[GDB_CS] = __KERNEL_CS;
gdb_regs32[GDB_SS] = __KERNEL_DS;
- gdb_regs[GDB_PC] = 0;
gdb_regs[GDB_R8] = 0;
gdb_regs[GDB_R9] = 0;
gdb_regs[GDB_R10] = 0;
@@ -190,6 +172,7 @@ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
gdb_regs[GDB_R14] = 0;
gdb_regs[GDB_R15] = 0;
#endif
+ gdb_regs[GDB_PC] = 0;
gdb_regs[GDB_SP] = p->thread.sp;
}
@@ -402,7 +385,7 @@ static void kgdb_disable_hw_debug(struct pt_regs *regs)
struct perf_event *bp;
/* Disable hardware debugging while we are in kgdb: */
- set_debugreg(0UL, 7);
+ set_debugreg(DR7_FIXED_1, 7);
for (i = 0; i < HBP_NUM; i++) {
if (!breakinfo[i].enabled)
continue;
@@ -422,23 +405,18 @@ static void kgdb_disable_hw_debug(struct pt_regs *regs)
#ifdef CONFIG_SMP
/**
* kgdb_roundup_cpus - Get other CPUs into a holding pattern
- * @flags: Current IRQ state
*
* 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. In
- * this case, we have to make sure that interrupts are enabled before
- * calling smp_call_function(). The argument to this function is
- * the flags that will be used when restoring the interrupts. There is
- * local_irq_save() call before kgdb_roundup_cpus().
+ * in case of MIPS, smp_call_function() is used to roundup CPUs.
*
* On non-SMP systems, this is not called.
*/
-void kgdb_roundup_cpus(unsigned long flags)
+void kgdb_roundup_cpus(void)
{
- apic->send_IPI_allbutself(APIC_DM_NMI);
+ apic_send_IPI_allbutself(NMI_VECTOR);
}
#endif
@@ -472,6 +450,7 @@ int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
ptr = &remcomInBuffer[1];
if (kgdb_hex2long(&ptr, &addr))
linux_regs->ip = addr;
+ fallthrough;
case 'D':
case 'k':
/* clear the trace bit */
@@ -512,26 +491,31 @@ single_step_cont(struct pt_regs *regs, struct die_args *args)
return NOTIFY_STOP;
}
-static int was_in_debug_nmi[NR_CPUS];
+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 */
- kgdb_nmicallback(raw_smp_processor_id(), regs);
- was_in_debug_nmi[raw_smp_processor_id()] = 1;
+ 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:
- if (was_in_debug_nmi[raw_smp_processor_id()]) {
- was_in_debug_nmi[raw_smp_processor_id()] = 0;
+ cpu = raw_smp_processor_id();
+
+ if (__test_and_clear_bit(cpu, was_in_debug_nmi))
return NMI_HANDLED;
- }
+
break;
default:
/* do nothing */
@@ -555,7 +539,7 @@ static int __kgdb_notify(struct die_args *args, unsigned long cmd)
* a system call which should be ignored
*/
return NOTIFY_DONE;
- /* fall through */
+ fallthrough;
default:
if (user_mode(regs))
return NOTIFY_DONE;
@@ -605,9 +589,9 @@ static struct notifier_block kgdb_notifier = {
};
/**
- * kgdb_arch_init - Perform any architecture specific initalization.
+ * kgdb_arch_init - Perform any architecture specific initialization.
*
- * This function will handle the initalization of any architecture
+ * This function will handle the initialization of any architecture
* specific callbacks.
*/
int kgdb_arch_init(void)
@@ -645,9 +629,10 @@ static void kgdb_hw_overflow_handler(struct perf_event *event,
struct task_struct *tsk = current;
int i;
- for (i = 0; i < 4; i++)
+ for (i = 0; i < 4; i++) {
if (breakinfo[i].enabled)
- tsk->thread.debugreg6 |= (DR_TRAP0 << i);
+ tsk->thread.virtual_dr6 |= (DR_TRAP0 << i);
+ }
}
void kgdb_arch_late(void)
@@ -657,7 +642,7 @@ void kgdb_arch_late(void)
struct perf_event **pevent;
/*
- * Pre-allocate the hw breakpoint structions in the non-atomic
+ * Pre-allocate the hw breakpoint instructions in the non-atomic
* portion of kgdb because this operation requires mutexs to
* complete.
*/
@@ -670,7 +655,7 @@ void kgdb_arch_late(void)
if (breakinfo[i].pev)
continue;
breakinfo[i].pev = register_wide_hw_breakpoint(&attr, NULL, NULL);
- if (IS_ERR((void * __force)breakinfo[i].pev)) {
+ if (IS_ERR_PCPU(breakinfo[i].pev)) {
printk(KERN_ERR "kgdb: Could not allocate hw"
"breakpoints\nDisabling the kernel debugger\n");
breakinfo[i].pev = NULL;
@@ -710,7 +695,6 @@ void kgdb_arch_exit(void)
}
/**
- *
* kgdb_skipexception - Bail out of KGDB when we've been triggered.
* @exception: Exception vector number
* @regs: Current &struct pt_regs.
@@ -746,64 +730,49 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
{
int err;
-#ifdef CONFIG_DEBUG_RODATA
- char opc[BREAK_INSTR_SIZE];
-#endif /* CONFIG_DEBUG_RODATA */
bpt->type = BP_BREAKPOINT;
- err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
+ err = copy_from_kernel_nofault(bpt->saved_instr, (char *)bpt->bpt_addr,
BREAK_INSTR_SIZE);
if (err)
return err;
- err = probe_kernel_write((char *)bpt->bpt_addr,
+ err = copy_to_kernel_nofault((char *)bpt->bpt_addr,
arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE);
-#ifdef CONFIG_DEBUG_RODATA
if (!err)
return err;
/*
- * It is safe to call text_poke() because normal kernel execution
+ * 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((void *)bpt->bpt_addr, arch_kgdb_ops.gdb_bpt_instr,
- BREAK_INSTR_SIZE);
- err = probe_kernel_read(opc, (char *)bpt->bpt_addr, BREAK_INSTR_SIZE);
- if (err)
- return err;
- if (memcmp(opc, arch_kgdb_ops.gdb_bpt_instr, BREAK_INSTR_SIZE))
- return -EINVAL;
+ text_poke_kgdb((void *)bpt->bpt_addr, arch_kgdb_ops.gdb_bpt_instr,
+ BREAK_INSTR_SIZE);
bpt->type = BP_POKE_BREAKPOINT;
-#endif /* CONFIG_DEBUG_RODATA */
- return err;
+
+ return 0;
}
int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
{
-#ifdef CONFIG_DEBUG_RODATA
- int err;
- char opc[BREAK_INSTR_SIZE];
-
if (bpt->type != BP_POKE_BREAKPOINT)
goto knl_write;
/*
- * It is safe to call text_poke() because normal kernel execution
+ * 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((void *)bpt->bpt_addr, bpt->saved_instr, BREAK_INSTR_SIZE);
- err = probe_kernel_read(opc, (char *)bpt->bpt_addr, BREAK_INSTR_SIZE);
- if (err || memcmp(opc, bpt->saved_instr, BREAK_INSTR_SIZE))
- goto knl_write;
- return err;
+ text_poke_kgdb((void *)bpt->bpt_addr, bpt->saved_instr,
+ BREAK_INSTR_SIZE);
+ return 0;
+
knl_write:
-#endif /* CONFIG_DEBUG_RODATA */
- return probe_kernel_write((char *)bpt->bpt_addr,
+ return copy_to_kernel_nofault((char *)bpt->bpt_addr,
(char *)bpt->saved_instr, BREAK_INSTR_SIZE);
}
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: */
.gdb_bpt_instr = { 0xcc },
.flags = KGDB_HW_BREAKPOINT,
generated by cgit (git 2.34.1) at 2025-12-25 08:38:18 +0000