Merge branch 'kgdb-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb
* 'kgdb-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kgdb: Turn off tracing while in the debugger kgdb: use atomic_inc and atomic_dec instead of atomic_set kgdb: eliminate kgdb_wait(), all cpus enter the same way kgdbts,sh: Add in breakpoint pc offset for superh kgdb: have ebin2mem call probe_kernel_write once
This commit is contained in:
Linus Torvalds
commit
5e123e5d9b
2 changed files with 109 additions and 102 deletions
|
|
@ -295,6 +295,10 @@ static int check_and_rewind_pc(char *put_str, char *arg)
|
|||
/* On x86 a breakpoint stop requires it to be decremented */
|
||||
if (addr + 1 == kgdbts_regs.ip)
|
||||
offset = -1;
|
||||
#elif defined(CONFIG_SUPERH)
|
||||
/* On SUPERH a breakpoint stop requires it to be decremented */
|
||||
if (addr + 2 == kgdbts_regs.pc)
|
||||
offset = -2;
|
||||
#endif
|
||||
if (strcmp(arg, "silent") &&
|
||||
instruction_pointer(&kgdbts_regs) + offset != addr) {
|
||||
|
|
@ -305,6 +309,8 @@ static int check_and_rewind_pc(char *put_str, char *arg)
|
|||
#ifdef CONFIG_X86
|
||||
/* On x86 adjust the instruction pointer if needed */
|
||||
kgdbts_regs.ip += offset;
|
||||
#elif defined(CONFIG_SUPERH)
|
||||
kgdbts_regs.pc += offset;
|
||||
#endif
|
||||
return 0;
|
||||
}
|
||||
|
|
|
|||
205
kernel/kgdb.c
205
kernel/kgdb.c
|
|
@ -69,9 +69,16 @@ struct kgdb_state {
|
|||
struct pt_regs *linux_regs;
|
||||
};
|
||||
|
||||
/* Exception state values */
|
||||
#define DCPU_WANT_MASTER 0x1 /* Waiting to become a master kgdb cpu */
|
||||
#define DCPU_NEXT_MASTER 0x2 /* Transition from one master cpu to another */
|
||||
#define DCPU_IS_SLAVE 0x4 /* Slave cpu enter exception */
|
||||
#define DCPU_SSTEP 0x8 /* CPU is single stepping */
|
||||
|
||||
static struct debuggerinfo_struct {
|
||||
void *debuggerinfo;
|
||||
struct task_struct *task;
|
||||
int exception_state;
|
||||
} kgdb_info[NR_CPUS];
|
||||
|
||||
/**
|
||||
|
|
@ -391,27 +398,22 @@ int kgdb_mem2hex(char *mem, char *buf, int count)
|
|||
|
||||
/*
|
||||
* Copy the binary array pointed to by buf into mem. Fix $, #, and
|
||||
* 0x7d escaped with 0x7d. Return a pointer to the character after
|
||||
* the last byte written.
|
||||
* 0x7d escaped with 0x7d. Return -EFAULT on failure or 0 on success.
|
||||
* The input buf is overwitten with the result to write to mem.
|
||||
*/
|
||||
static int kgdb_ebin2mem(char *buf, char *mem, int count)
|
||||
{
|
||||
int err = 0;
|
||||
char c;
|
||||
int size = 0;
|
||||
char *c = buf;
|
||||
|
||||
while (count-- > 0) {
|
||||
c = *buf++;
|
||||
if (c == 0x7d)
|
||||
c = *buf++ ^ 0x20;
|
||||
|
||||
err = probe_kernel_write(mem, &c, 1);
|
||||
if (err)
|
||||
break;
|
||||
|
||||
mem++;
|
||||
c[size] = *buf++;
|
||||
if (c[size] == 0x7d)
|
||||
c[size] = *buf++ ^ 0x20;
|
||||
size++;
|
||||
}
|
||||
|
||||
return err;
|
||||
return probe_kernel_write(mem, c, size);
|
||||
}
|
||||
|
||||
/*
|
||||
|
|
@ -562,49 +564,6 @@ static struct task_struct *getthread(struct pt_regs *regs, int tid)
|
|||
return find_task_by_pid_ns(tid, &init_pid_ns);
|
||||
}
|
||||
|
||||
/*
|
||||
* CPU debug state control:
|
||||
*/
|
||||
|
||||
#ifdef CONFIG_SMP
|
||||
static void kgdb_wait(struct pt_regs *regs)
|
||||
{
|
||||
unsigned long flags;
|
||||
int cpu;
|
||||
|
||||
local_irq_save(flags);
|
||||
cpu = raw_smp_processor_id();
|
||||
kgdb_info[cpu].debuggerinfo = regs;
|
||||
kgdb_info[cpu].task = current;
|
||||
/*
|
||||
* Make sure the above info reaches the primary CPU before
|
||||
* our cpu_in_kgdb[] flag setting does:
|
||||
*/
|
||||
smp_wmb();
|
||||
atomic_set(&cpu_in_kgdb[cpu], 1);
|
||||
|
||||
/* Disable any cpu specific hw breakpoints */
|
||||
kgdb_disable_hw_debug(regs);
|
||||
|
||||
/* Wait till primary CPU is done with debugging */
|
||||
while (atomic_read(&passive_cpu_wait[cpu]))
|
||||
cpu_relax();
|
||||
|
||||
kgdb_info[cpu].debuggerinfo = NULL;
|
||||
kgdb_info[cpu].task = NULL;
|
||||
|
||||
/* fix up hardware debug registers on local cpu */
|
||||
if (arch_kgdb_ops.correct_hw_break)
|
||||
arch_kgdb_ops.correct_hw_break();
|
||||
|
||||
/* Signal the primary CPU that we are done: */
|
||||
atomic_set(&cpu_in_kgdb[cpu], 0);
|
||||
touch_softlockup_watchdog_sync();
|
||||
clocksource_touch_watchdog();
|
||||
local_irq_restore(flags);
|
||||
}
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Some architectures need cache flushes when we set/clear a
|
||||
* breakpoint:
|
||||
|
|
@ -1400,34 +1359,13 @@ static int kgdb_reenter_check(struct kgdb_state *ks)
|
|||
return 1;
|
||||
}
|
||||
|
||||
/*
|
||||
* kgdb_handle_exception() - main entry point from a kernel exception
|
||||
*
|
||||
* Locking hierarchy:
|
||||
* interface locks, if any (begin_session)
|
||||
* kgdb lock (kgdb_active)
|
||||
*/
|
||||
int
|
||||
kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
||||
static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
|
||||
{
|
||||
struct kgdb_state kgdb_var;
|
||||
struct kgdb_state *ks = &kgdb_var;
|
||||
unsigned long flags;
|
||||
int sstep_tries = 100;
|
||||
int error = 0;
|
||||
int i, cpu;
|
||||
|
||||
ks->cpu = raw_smp_processor_id();
|
||||
ks->ex_vector = evector;
|
||||
ks->signo = signo;
|
||||
ks->ex_vector = evector;
|
||||
ks->err_code = ecode;
|
||||
ks->kgdb_usethreadid = 0;
|
||||
ks->linux_regs = regs;
|
||||
|
||||
if (kgdb_reenter_check(ks))
|
||||
return 0; /* Ouch, double exception ! */
|
||||
|
||||
int trace_on = 0;
|
||||
acquirelock:
|
||||
/*
|
||||
* Interrupts will be restored by the 'trap return' code, except when
|
||||
|
|
@ -1435,13 +1373,43 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
|||
*/
|
||||
local_irq_save(flags);
|
||||
|
||||
cpu = raw_smp_processor_id();
|
||||
cpu = ks->cpu;
|
||||
kgdb_info[cpu].debuggerinfo = regs;
|
||||
kgdb_info[cpu].task = current;
|
||||
/*
|
||||
* Make sure the above info reaches the primary CPU before
|
||||
* our cpu_in_kgdb[] flag setting does:
|
||||
*/
|
||||
atomic_inc(&cpu_in_kgdb[cpu]);
|
||||
|
||||
/*
|
||||
* Acquire the kgdb_active lock:
|
||||
* CPU will loop if it is a slave or request to become a kgdb
|
||||
* master cpu and acquire the kgdb_active lock:
|
||||
*/
|
||||
while (atomic_cmpxchg(&kgdb_active, -1, cpu) != -1)
|
||||
while (1) {
|
||||
if (kgdb_info[cpu].exception_state & DCPU_WANT_MASTER) {
|
||||
if (atomic_cmpxchg(&kgdb_active, -1, cpu) == cpu)
|
||||
break;
|
||||
} else if (kgdb_info[cpu].exception_state & DCPU_IS_SLAVE) {
|
||||
if (!atomic_read(&passive_cpu_wait[cpu]))
|
||||
goto return_normal;
|
||||
} else {
|
||||
return_normal:
|
||||
/* Return to normal operation by executing any
|
||||
* hw breakpoint fixup.
|
||||
*/
|
||||
if (arch_kgdb_ops.correct_hw_break)
|
||||
arch_kgdb_ops.correct_hw_break();
|
||||
if (trace_on)
|
||||
tracing_on();
|
||||
atomic_dec(&cpu_in_kgdb[cpu]);
|
||||
touch_softlockup_watchdog_sync();
|
||||
clocksource_touch_watchdog();
|
||||
local_irq_restore(flags);
|
||||
return 0;
|
||||
}
|
||||
cpu_relax();
|
||||
}
|
||||
|
||||
/*
|
||||
* For single stepping, try to only enter on the processor
|
||||
|
|
@ -1475,9 +1443,6 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
|||
if (kgdb_io_ops->pre_exception)
|
||||
kgdb_io_ops->pre_exception();
|
||||
|
||||
kgdb_info[ks->cpu].debuggerinfo = ks->linux_regs;
|
||||
kgdb_info[ks->cpu].task = current;
|
||||
|
||||
kgdb_disable_hw_debug(ks->linux_regs);
|
||||
|
||||
/*
|
||||
|
|
@ -1486,15 +1451,9 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
|||
*/
|
||||
if (!kgdb_single_step) {
|
||||
for (i = 0; i < NR_CPUS; i++)
|
||||
atomic_set(&passive_cpu_wait[i], 1);
|
||||
atomic_inc(&passive_cpu_wait[i]);
|
||||
}
|
||||
|
||||
/*
|
||||
* spin_lock code is good enough as a barrier so we don't
|
||||
* need one here:
|
||||
*/
|
||||
atomic_set(&cpu_in_kgdb[ks->cpu], 1);
|
||||
|
||||
#ifdef CONFIG_SMP
|
||||
/* Signal the other CPUs to enter kgdb_wait() */
|
||||
if ((!kgdb_single_step) && kgdb_do_roundup)
|
||||
|
|
@ -1518,6 +1477,9 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
|||
kgdb_single_step = 0;
|
||||
kgdb_contthread = current;
|
||||
exception_level = 0;
|
||||
trace_on = tracing_is_on();
|
||||
if (trace_on)
|
||||
tracing_off();
|
||||
|
||||
/* Talk to debugger with gdbserial protocol */
|
||||
error = gdb_serial_stub(ks);
|
||||
|
|
@ -1526,13 +1488,11 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
|||
if (kgdb_io_ops->post_exception)
|
||||
kgdb_io_ops->post_exception();
|
||||
|
||||
kgdb_info[ks->cpu].debuggerinfo = NULL;
|
||||
kgdb_info[ks->cpu].task = NULL;
|
||||
atomic_set(&cpu_in_kgdb[ks->cpu], 0);
|
||||
atomic_dec(&cpu_in_kgdb[ks->cpu]);
|
||||
|
||||
if (!kgdb_single_step) {
|
||||
for (i = NR_CPUS-1; i >= 0; i--)
|
||||
atomic_set(&passive_cpu_wait[i], 0);
|
||||
atomic_dec(&passive_cpu_wait[i]);
|
||||
/*
|
||||
* Wait till all the CPUs have quit
|
||||
* from the debugger.
|
||||
|
|
@ -1551,6 +1511,8 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
|||
else
|
||||
kgdb_sstep_pid = 0;
|
||||
}
|
||||
if (trace_on)
|
||||
tracing_on();
|
||||
/* Free kgdb_active */
|
||||
atomic_set(&kgdb_active, -1);
|
||||
touch_softlockup_watchdog_sync();
|
||||
|
|
@ -1560,13 +1522,52 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
|||
return error;
|
||||
}
|
||||
|
||||
/*
|
||||
* kgdb_handle_exception() - main entry point from a kernel exception
|
||||
*
|
||||
* Locking hierarchy:
|
||||
* interface locks, if any (begin_session)
|
||||
* kgdb lock (kgdb_active)
|
||||
*/
|
||||
int
|
||||
kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
|
||||
{
|
||||
struct kgdb_state kgdb_var;
|
||||
struct kgdb_state *ks = &kgdb_var;
|
||||
int ret;
|
||||
|
||||
ks->cpu = raw_smp_processor_id();
|
||||
ks->ex_vector = evector;
|
||||
ks->signo = signo;
|
||||
ks->ex_vector = evector;
|
||||
ks->err_code = ecode;
|
||||
ks->kgdb_usethreadid = 0;
|
||||
ks->linux_regs = regs;
|
||||
|
||||
if (kgdb_reenter_check(ks))
|
||||
return 0; /* Ouch, double exception ! */
|
||||
kgdb_info[ks->cpu].exception_state |= DCPU_WANT_MASTER;
|
||||
ret = kgdb_cpu_enter(ks, regs);
|
||||
kgdb_info[ks->cpu].exception_state &= ~DCPU_WANT_MASTER;
|
||||
return ret;
|
||||
}
|
||||
|
||||
int kgdb_nmicallback(int cpu, void *regs)
|
||||
{
|
||||
#ifdef CONFIG_SMP
|
||||
struct kgdb_state kgdb_var;
|
||||
struct kgdb_state *ks = &kgdb_var;
|
||||
|
||||
memset(ks, 0, sizeof(struct kgdb_state));
|
||||
ks->cpu = cpu;
|
||||
ks->linux_regs = regs;
|
||||
|
||||
if (!atomic_read(&cpu_in_kgdb[cpu]) &&
|
||||
atomic_read(&kgdb_active) != cpu &&
|
||||
atomic_read(&cpu_in_kgdb[atomic_read(&kgdb_active)])) {
|
||||
kgdb_wait((struct pt_regs *)regs);
|
||||
atomic_read(&kgdb_active) != -1 &&
|
||||
atomic_read(&kgdb_active) != cpu) {
|
||||
kgdb_info[cpu].exception_state |= DCPU_IS_SLAVE;
|
||||
kgdb_cpu_enter(ks, regs);
|
||||
kgdb_info[cpu].exception_state &= ~DCPU_IS_SLAVE;
|
||||
return 0;
|
||||
}
|
||||
#endif
|
||||
|
|
@ -1742,11 +1743,11 @@ EXPORT_SYMBOL_GPL(kgdb_unregister_io_module);
|
|||
*/
|
||||
void kgdb_breakpoint(void)
|
||||
{
|
||||
atomic_set(&kgdb_setting_breakpoint, 1);
|
||||
atomic_inc(&kgdb_setting_breakpoint);
|
||||
wmb(); /* Sync point before breakpoint */
|
||||
arch_kgdb_breakpoint();
|
||||
wmb(); /* Sync point after breakpoint */
|
||||
atomic_set(&kgdb_setting_breakpoint, 0);
|
||||
atomic_dec(&kgdb_setting_breakpoint);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(kgdb_breakpoint);
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue