debug_core: disable hw_breakpoints on all cores in kgdb_cpu_enter()
The slave cpus do not have the hw breakpoints disabled upon entry to
the debug_core and as a result could cause unrecoverable recursive
faults on badly placed breakpoints, or get out of sync with the arch
specific hw breakpoint operations.
This patch addresses the problem by invoking kgdb_disable_hw_debug()
earlier in kgdb_enter_cpu for each cpu that enters the debug core.
The hw breakpoint dis/enable flow should be:
master_debug_cpu slave_debug_cpu
\ /
kgdb_cpu_enter
|
kgdb_disable_hw_debug --> uninstall pre-enabled hw_breakpoint
|
do add/rm dis/enable operates to hw_breakpoints on master_debug_cpu..
|
correct_hw_break --> correct/install the enabled hw_breakpoint
|
leave_kgdb
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 5a3b04d..bb94977 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -485,6 +485,9 @@
int error;
int i, cpu;
int trace_on = 0;
+
+ kgdb_disable_hw_debug(ks->linux_regs);
+
acquirelock:
/*
* Interrupts will be restored by the 'trap return' code, except when
@@ -569,8 +572,6 @@
if (dbg_io_ops->pre_exception)
dbg_io_ops->pre_exception();
- kgdb_disable_hw_debug(ks->linux_regs);
-
/*
* Get the passive CPU lock which will hold all the non-primary
* CPU in a spin state while the debugger is active
@@ -661,6 +662,8 @@
else
kgdb_sstep_pid = 0;
}
+ if (arch_kgdb_ops.correct_hw_break)
+ arch_kgdb_ops.correct_hw_break();
if (trace_on)
tracing_on();
/* Free kgdb_active */
