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authorDongdong Deng <dongdong.deng@windriver.com>2010-09-13 13:58:00 +0200
committerJason Wessel <jason.wessel@windriver.com>2010-10-22 22:34:12 +0200
commitc1bb9a9c1911036549c5cdfb23f32d7d20ffdc5a (patch)
tree8d86976df36697e54ae3582d6c30b7355a942647 /kernel/debug
parentkdb,kgdb: fix sparse fixups (diff)
downloadlinux-c1bb9a9c1911036549c5cdfb23f32d7d20ffdc5a.tar.xz
linux-c1bb9a9c1911036549c5cdfb23f32d7d20ffdc5a.zip
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>
Diffstat (limited to 'kernel/debug')
-rw-r--r--kernel/debug/debug_core.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 5a3b04d20497..bb9497724808 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -485,6 +485,9 @@ static int kgdb_cpu_enter(struct kgdb_state *ks, struct pt_regs *regs)
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 @@ return_normal:
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 @@ kgdb_restore:
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 */