projects/linux·commit fcf01044

Merge tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux

fcf01044 · Linus Torvalds <[email protected]> · 2019-01-01 15:38:14 -08:00

Pull kgdb updates from Daniel Thompson:
 "Mostly clean ups although while Doug's was chasing down a odd lockdep
  warning he also did some work to improved debugger resilience when
  some CPUs fail to respond to the round up request.

  The main changes are:

   - Fixing a lockdep warning on architectures that cannot use an NMI
     for the round up plus related changes to make CPU round up and all
     CPU backtrace more resilient.

   - Constify the arch ops tables

   - A couple of other small clean ups

  Two of the three patchsets here include changes that spill over into
  arch/. Changes in the arch space are relatively narrow in scope (and
  directly related to kgdb). Didn't get comprehensive acks but all
  impacted maintainers were Cc:ed in good time"

* tag 'kgdb-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
  kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops
  mips/kgdb: prepare arch_kgdb_ops for constness
  kdb: use bool for binary state indicators
  kdb: Don't back trace on a cpu that didn't round up
  kgdb: Don't round up a CPU that failed rounding up before
  kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()
  kgdb: Remove irq flags from roundup
Commit
fcf010449ebe1db0cb68b2c6410972a782f2bd14
Parents
fbea8c7c · cc028297

Merge commit. Changes below are compared with the first parent: fbea8c7c.

Changes

20 files changed · +125 −141

FileStatusAddDelContent
arch/arc/kernel/kgdb.cmodified+3−9View file
arch/arm/kernel/kgdb.cmodified+1−13View file
arch/arm64/kernel/kgdb.cmodified+1−13View file
arch/h8300/kernel/kgdb.cmodified+1−1View file
arch/hexagon/kernel/kgdb.cmodified+1−33View file
arch/microblaze/kernel/kgdb.cmodified+1−1View file
arch/mips/kernel/kgdb.cmodified+8−17View file
arch/nios2/kernel/kgdb.cmodified+1−1View file
arch/powerpc/kernel/kgdb.cmodified+4−4View file
arch/sh/kernel/kgdb.cmodified+1−13View file
arch/sparc/kernel/kgdb_32.cmodified+1−1View file
arch/sparc/kernel/kgdb_64.cmodified+1−1View file
arch/sparc/kernel/smp_64.cmodified+1−1View file
arch/x86/kernel/kgdb.cmodified+3−8View file
include/linux/kgdb.hmodified+15−9View file
kernel/debug/debug_core.cmodified+64−1View file
kernel/debug/debug_core.hmodified+1−0View file
kernel/debug/kdb/kdb_bt.cmodified+10−1View file
kernel/debug/kdb/kdb_debugger.cmodified+0−7View file
kernel/debug/kdb/kdb_main.cmodified+7−7View file

Only the first 600 diff lines are shown. Download the complete patch.

arch/arc/kernel/kgdb.c

View file
diff --git a/arch/arc/kernel/kgdb.c b/arch/arc/kernel/kgdb.c
index 9a3c34a..96bca99 100644
--- a/arch/arc/kernel/kgdb.c
+++ b/arch/arc/kernel/kgdb.c
@@ -192,19 +192,13 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
instruction_pointer(regs) = ip;
}
-static void kgdb_call_nmi_hook(void *ignored)
+void kgdb_call_nmi_hook(void *ignored)
{
+ /* Default implementation passes get_irq_regs() but we don't */
kgdb_nmicallback(raw_smp_processor_id(), NULL);
}
-void kgdb_roundup_cpus(unsigned long flags)
-{
- local_irq_enable();
- smp_call_function(kgdb_call_nmi_hook, NULL, 0);
- local_irq_disable();
-}
-
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* breakpoint instruction: TRAP_S 0x3 */
#ifdef CONFIG_CPU_BIG_ENDIAN
.gdb_bpt_instr = {0x78, 0x7e},

arch/arm/kernel/kgdb.c

View file
diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c
index caa0dbe..6a95b92 100644
--- a/arch/arm/kernel/kgdb.c
+++ b/arch/arm/kernel/kgdb.c
@@ -170,18 +170,6 @@ static struct undef_hook kgdb_compiled_brkpt_hook = {
.fn = kgdb_compiled_brk_fn
};
-static void kgdb_call_nmi_hook(void *ignored)
-{
- kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
-}
-
-void kgdb_roundup_cpus(unsigned long flags)
-{
- local_irq_enable();
- smp_call_function(kgdb_call_nmi_hook, NULL, 0);
- local_irq_disable();
-}
-
static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
struct pt_regs *regs = args->regs;
@@ -274,7 +262,7 @@ int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
* and we handle the normal undef case within the do_undefinstr
* handler.
*/
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
#ifndef __ARMEB__
.gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
#else /* ! __ARMEB__ */

arch/arm64/kernel/kgdb.c

View file
diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
index a20de58..ce46c4c 100644
--- a/arch/arm64/kernel/kgdb.c
+++ b/arch/arm64/kernel/kgdb.c
@@ -284,18 +284,6 @@ static struct step_hook kgdb_step_hook = {
.fn = kgdb_step_brk_fn
};
-static void kgdb_call_nmi_hook(void *ignored)
-{
- kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
-}
-
-void kgdb_roundup_cpus(unsigned long flags)
-{
- local_irq_enable();
- smp_call_function(kgdb_call_nmi_hook, NULL, 0);
- local_irq_disable();
-}
-
static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
struct pt_regs *regs = args->regs;
@@ -357,7 +345,7 @@ void kgdb_arch_exit(void)
unregister_die_notifier(&kgdb_notifier);
}
-struct kgdb_arch arch_kgdb_ops;
+const struct kgdb_arch arch_kgdb_ops;
int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
{

arch/h8300/kernel/kgdb.c

View file
diff --git a/arch/h8300/kernel/kgdb.c b/arch/h8300/kernel/kgdb.c
index 1a1d30c..602e478 100644
--- a/arch/h8300/kernel/kgdb.c
+++ b/arch/h8300/kernel/kgdb.c
@@ -129,7 +129,7 @@ void kgdb_arch_exit(void)
/* Nothing to do */
}
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: trapa #2 */
.gdb_bpt_instr = { 0x57, 0x20 },
};

arch/hexagon/kernel/kgdb.c

View file
diff --git a/arch/hexagon/kernel/kgdb.c b/arch/hexagon/kernel/kgdb.c
index 16c24b2..3fabd3f 100644
--- a/arch/hexagon/kernel/kgdb.c
+++ b/arch/hexagon/kernel/kgdb.c
@@ -83,7 +83,7 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
{ "syscall_nr", GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)},
};
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* trap0(#0xDB) 0x0cdb0054 */
.gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c},
};
@@ -115,38 +115,6 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
instruction_pointer(regs) = pc;
}
-#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().
- *
- * On non-SMP systems, this is not called.
- */
-
-static void hexagon_kgdb_nmi_hook(void *ignored)
-{
- kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
-}
-
-void kgdb_roundup_cpus(unsigned long flags)
-{
- local_irq_enable();
- smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0);
- local_irq_disable();
-}
-#endif
-
/* Not yet working */
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,

arch/microblaze/kernel/kgdb.c

View file
diff --git a/arch/microblaze/kernel/kgdb.c b/arch/microblaze/kernel/kgdb.c
index 6366f69..130cd0f 100644
--- a/arch/microblaze/kernel/kgdb.c
+++ b/arch/microblaze/kernel/kgdb.c
@@ -143,7 +143,7 @@ void kgdb_arch_exit(void)
/*
* Global data
*/
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
#ifdef __MICROBLAZEEL__
.gdb_bpt_instr = {0x18, 0x00, 0x0c, 0xba}, /* brki r16, 0x18 */
#else

arch/mips/kernel/kgdb.c

View file
diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c
index eb6c0d5..149100e 100644
--- a/arch/mips/kernel/kgdb.c
+++ b/arch/mips/kernel/kgdb.c
@@ -207,7 +207,7 @@ void arch_kgdb_breakpoint(void)
".set\treorder");
}
-static void kgdb_call_nmi_hook(void *ignored)
+void kgdb_call_nmi_hook(void *ignored)
{
mm_segment_t old_fs;
@@ -219,13 +219,6 @@ static void kgdb_call_nmi_hook(void *ignored)
set_fs(old_fs);
}
-void kgdb_roundup_cpus(unsigned long flags)
-{
- local_irq_enable();
- smp_call_function(kgdb_call_nmi_hook, NULL, 0);
- local_irq_disable();
-}
-
static int compute_signal(int tt)
{
struct hard_trap_info *ht;
@@ -394,18 +387,16 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code,
return -1;
}
-struct kgdb_arch arch_kgdb_ops;
+const struct kgdb_arch arch_kgdb_ops = {
+#ifdef CONFIG_CPU_BIG_ENDIAN
+ .gdb_bpt_instr = { spec_op << 2, 0x00, 0x00, break_op },
+#else
+ .gdb_bpt_instr = { break_op, 0x00, 0x00, spec_op << 2 },
+#endif
+};
int kgdb_arch_init(void)
{
- union mips_instruction insn = {
- .r_format = {
- .opcode = spec_op,
- .func = break_op,
- }
- };
- memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE);
-
register_die_notifier(&kgdb_notifier);
return 0;

arch/nios2/kernel/kgdb.c

View file
diff --git a/arch/nios2/kernel/kgdb.c b/arch/nios2/kernel/kgdb.c
index 1178591..37b25f8 100644
--- a/arch/nios2/kernel/kgdb.c
+++ b/arch/nios2/kernel/kgdb.c
@@ -165,7 +165,7 @@ void kgdb_arch_exit(void)
/* Nothing to do */
}
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: trap 30 */
.gdb_bpt_instr = { 0xba, 0x6f, 0x3b, 0x00 },
};

arch/powerpc/kernel/kgdb.c

View file
diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c
index 59c578f..e186556 100644
--- a/arch/powerpc/kernel/kgdb.c
+++ b/arch/powerpc/kernel/kgdb.c
@@ -117,14 +117,14 @@ int kgdb_skipexception(int exception, struct pt_regs *regs)
return kgdb_isremovedbreak(regs->nip);
}
-static int kgdb_call_nmi_hook(struct pt_regs *regs)
+static int kgdb_debugger_ipi(struct pt_regs *regs)
{
kgdb_nmicallback(raw_smp_processor_id(), regs);
return 0;
}
#ifdef CONFIG_SMP
-void kgdb_roundup_cpus(unsigned long flags)
+void kgdb_roundup_cpus(void)
{
smp_send_debugger_break();
}
@@ -477,7 +477,7 @@ int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
/*
* Global data
*/
-struct kgdb_arch arch_kgdb_ops;
+const struct kgdb_arch arch_kgdb_ops;
static int kgdb_not_implemented(struct pt_regs *regs)
{
@@ -502,7 +502,7 @@ int kgdb_arch_init(void)
old__debugger_break_match = __debugger_break_match;
old__debugger_fault_handler = __debugger_fault_handler;
- __debugger_ipi = kgdb_call_nmi_hook;
+ __debugger_ipi = kgdb_debugger_ipi;
__debugger = kgdb_debugger;
__debugger_bpt = kgdb_handle_breakpoint;
__debugger_sstep = kgdb_singlestep;

arch/sh/kernel/kgdb.c

View file
diff --git a/arch/sh/kernel/kgdb.c b/arch/sh/kernel/kgdb.c
index d24bd2d..6d61f8c 100644
--- a/arch/sh/kernel/kgdb.c
+++ b/arch/sh/kernel/kgdb.c
@@ -311,18 +311,6 @@ BUILD_TRAP_HANDLER(singlestep)
local_irq_restore(flags);
}
-static void kgdb_call_nmi_hook(void *ignored)
-{
- kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
-}
-
-void kgdb_roundup_cpus(unsigned long flags)
-{
- local_irq_enable();
- smp_call_function(kgdb_call_nmi_hook, NULL, 0);
- local_irq_disable();
-}
-
static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
int ret;
@@ -379,7 +367,7 @@ void kgdb_arch_exit(void)
unregister_die_notifier(&kgdb_notifier);
}
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: trapa #0x3c */
#ifdef CONFIG_CPU_LITTLE_ENDIAN
.gdb_bpt_instr = { 0x3c, 0xc3 },

arch/sparc/kernel/kgdb_32.c

View file
diff --git a/arch/sparc/kernel/kgdb_32.c b/arch/sparc/kernel/kgdb_32.c
index 639c8e5..7580775 100644
--- a/arch/sparc/kernel/kgdb_32.c
+++ b/arch/sparc/kernel/kgdb_32.c
@@ -166,7 +166,7 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
regs->npc = regs->pc + 4;
}
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: ta 0x7d */
.gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x7d },
};

arch/sparc/kernel/kgdb_64.c

View file
diff --git a/arch/sparc/kernel/kgdb_64.c b/arch/sparc/kernel/kgdb_64.c
index a68bbdd..5d6c2d2 100644
--- a/arch/sparc/kernel/kgdb_64.c
+++ b/arch/sparc/kernel/kgdb_64.c
@@ -195,7 +195,7 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
regs->tnpc = regs->tpc + 4;
}
-struct kgdb_arch arch_kgdb_ops = {
+const struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: ta 0x72 */
.gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 },
};

arch/sparc/kernel/smp_64.c

View file
diff --git a/arch/sparc/kernel/smp_64.c b/arch/sparc/kernel/smp_64.c
index 4792e08..f45d876 100644
--- a/arch/sparc/kernel/smp_64.c
+++ b/arch/sparc/kernel/smp_64.c
@@ -1014,7 +1014,7 @@ void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
}
#ifdef CONFIG_KGDB
-void kgdb_roundup_cpus(unsigned long flags)
+void kgdb_roundup_cpus(void)
{
smp_cross_call(&xcall_kgdb_capture, 0, 0, 0);
}

arch/x86/kernel/kgdb.c

View file
diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c
index 8e36f24..5db0842 100644
--- a/arch/x86/kernel/kgdb.c
+++ b/arch/x86/kernel/kgdb.c
@@ -422,21 +422,16 @@ 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);
}
@@ -804,7 +799,7 @@ knl_write:
(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,

include/linux/kgdb.h

View file
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index e465bb1..fbf144a 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -177,22 +177,28 @@ kgdb_arch_handle_exception(int vector, int signo, int err_code,
struct pt_regs *regs);
/**
+ * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU
+ * @ignored: This parameter is only here to match the prototype.
+ *
+ * If you're using the default implementation of kgdb_roundup_cpus()
+ * this function will be called per CPU. If you don't implement
+ * kgdb_call_nmi_hook() a default will be used.
+ */
+
+extern void kgdb_call_nmi_hook(void *ignored);
+
+/**
* 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 into 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().
+ * the NMI approach is not used for rounding up all the CPUs. Normally
+ * those architectures can just not implement this and get the default.
*
* On non-SMP systems, this is not called.
*/
-extern void kgdb_roundup_cpus(unsigned long flags);
+extern void kgdb_roundup_cpus(void);
/**
* kgdb_arch_set_pc - Generic call back to the program counter
@@ -281,7 +287,7 @@ struct kgdb_io {
int is_console;
};
-extern struct kgdb_arch arch_kgdb_ops;
+extern const struct kgdb_arch arch_kgdb_ops;
extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs);

kernel/debug/debug_core.c

View file
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 65c0f13..5cc608d 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -55,6 +55,7 @@
#include <linux/mm.h>
#include <linux/vmacache.h>
#include <linux/rcupdate.h>
+#include <linux/irq.h>
#include <asm/cacheflush.h>
#include <asm/byteorder.h>
@@ -220,6 +221,62 @@ int __weak kgdb_skipexception(int exception, struct pt_regs *regs)
return 0;
}
+#ifdef CONFIG_SMP
+
+/*
+ * Default (weak) implementation for kgdb_roundup_cpus
+ */
+
+static DEFINE_PER_CPU(call_single_data_t, kgdb_roundup_csd);
+
+void __weak kgdb_call_nmi_hook(void *ignored)
+{
+ /*
+ * NOTE: get_irq_regs() is supposed to get the registers from
+ * before the IPI interrupt happened and so is supposed to
+ * show where the processor was. In some situations it's
+ * possible we might be called without an IPI, so it might be
+ * safer to figure out how to make kgdb_breakpoint() work
+ * properly here.
+ */
+ kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
+}
+
+void __weak kgdb_roundup_cpus(void)
+{
+ call_single_data_t *csd;
+ int this_cpu = raw_smp_processor_id();
+ int cpu;
+ int ret;
+
+ for_each_online_cpu(cpu) {
+ /* No need to roundup ourselves */
+ if (cpu == this_cpu)
+ continue;
+
+ csd = &per_cpu(kgdb_roundup_csd, cpu);
+
+ /*
+ * If it didn't round up last time, don't try again
+ * since smp_call_function_single_async() will block.
+ *
+ * If rounding_up is false then we know that the
+ * previous call must have at least started and that
+ * means smp_call_function_single_async() won't block.
+ */
+ if (kgdb_info[cpu].rounding_up)
+ continue;
+ kgdb_info[cpu].rounding_up = true;
+
+ csd->func = kgdb_call_nmi_hook;
+ ret = smp_call_function_single_async(cpu, csd);
+ if (ret)
+ kgdb_info[cpu].rounding_up = false;
+ }
+}
+
+#endif
+
/*
* Some architectures need cache flushes when we set/clear a
* breakpoint:
@@ -535,6 +592,8 @@ return_normal:
arch_kgdb_ops.correct_hw_break();
if (trace_on)
tracing_on();
+ kgdb_info[cpu].debuggerinfo = NULL;
+ kgdb_info[cpu].task = NULL;
kgdb_info[cpu].exception_state &=
~(DCPU_WANT_MASTER | DCPU_IS_SLAVE);
kgdb_info[cpu].enter_kgdb--;
@@ -593,7 +652,7 @@ return_normal:
/* Signal the other CPUs to enter kgdb_wait() */
else if ((!kgdb_single_step) && kgdb_do_roundup)
- kgdb_roundup_cpus(flags);
+ kgdb_roundup_cpus();
#endif
/*
@@ -667,6 +726,8 @@ kgdb_restore:
if (trace_on)
tracing_on();
+ kgdb_info[cpu].debuggerinfo = NULL;
+ kgdb_info[cpu].task = NULL;
kgdb_info[cpu].exception_state &=
~(DCPU_WANT_MASTER | DCPU_IS_SLAVE);
kgdb_info[cpu].enter_kgdb--;
@@ -747,6 +808,8 @@ int kgdb_nmicallback(int cpu, void *regs)
struct kgdb_state kgdb_var;
struct kgdb_state *ks = &kgdb_var;
+ kgdb_info[cpu].rounding_up = false;
+
memset(ks, 0, sizeof(struct kgdb_state));
ks->cpu = cpu;
ks->linux_regs = regs;

kernel/debug/debug_core.h

View file
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index 127d9bc..b4a7c32 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -42,6 +42,7 @@ struct debuggerinfo_struct {
int ret_state;
int irq_depth;
int enter_kgdb;
+ bool rounding_up;
};
extern struct debuggerinfo_struct kgdb_info[];

kernel/debug/kdb/kdb_bt.c

View file
diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c
index 7921ae4..7e2379a 100644
--- a/kernel/debug/kdb/kdb_bt.c
+++ b/kernel/debug/kdb/kdb_bt.c
@@ -186,7 +186,16 @@ kdb_bt(int argc, const char **argv)
kdb_printf("btc: cpu status: ");
kdb_parse("cpu\n");
for_each_online_cpu(cpu) {
- sprintf(buf, "btt 0x%px\n", KDB_TSK(cpu));
+ void *kdb_tsk = KDB_TSK(cpu);
+
+ /* If a CPU failed to round up we could be here */
+ if (!kdb_tsk) {
+ kdb_printf("WARNING: no task for cpu %ld\n",
+ cpu);
+ continue;
+ }
+
+ sprintf(buf, "btt 0x%px\n", kdb_tsk);
kdb_parse(buf);
touch_nmi_watchdog();
}

kernel/debug/kdb/kdb_debugger.c

View file
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index 15e1a7a..53a0df6 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -118,13 +118,6 @@ int kdb_stub(struct kgdb_state *ks)
kdb_bp_remove();
KDB_STATE_CLEAR(DOING_SS);
KDB_STATE_SET(PAGER);
- /* zero out any offline cpu data */
- for_each_present_cpu(i) {
- if (!cpu_online(i)) {
- kgdb_info[i].debuggerinfo = NULL;
- kgdb_info[i].task = NULL;
- }
- }
if (ks->err_code == DIE_OOPS || reason == KDB_REASON_OOPS) {
ks->pass_exception = 1;
KDB_FLAG_SET(CATASTROPHIC);

kernel/debug/kdb/kdb_main.c

View file
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index d72b32c..82a3b32 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -658,7 +658,7 @@ static void kdb_cmderror(int diag)

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