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Diffstat (limited to 'arch/mips/kernel/traps.c')
-rw-r--r--arch/mips/kernel/traps.c24
1 files changed, 19 insertions, 5 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index b602ac6eb47..80b9e070c20 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -42,6 +42,7 @@
#include <asm/tlbdebug.h>
#include <asm/traps.h>
#include <asm/uaccess.h>
+#include <asm/watch.h>
#include <asm/mmu_context.h>
#include <asm/types.h>
#include <asm/stacktrace.h>
@@ -912,13 +913,26 @@ asmlinkage void do_mdmx(struct pt_regs *regs)
asmlinkage void do_watch(struct pt_regs *regs)
{
+ u32 cause;
+
/*
- * We use the watch exception where available to detect stack
- * overflows.
+ * Clear WP (bit 22) bit of cause register so we don't loop
+ * forever.
*/
- dump_tlb_all();
- show_regs(regs);
- panic("Caught WATCH exception - probably caused by stack overflow.");
+ cause = read_c0_cause();
+ cause &= ~(1 << 22);
+ write_c0_cause(cause);
+
+ /*
+ * If the current thread has the watch registers loaded, save
+ * their values and send SIGTRAP. Otherwise another thread
+ * left the registers set, clear them and continue.
+ */
+ if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
+ mips_read_watch_registers();
+ force_sig(SIGTRAP, current);
+ } else
+ mips_clear_watch_registers();
}
asmlinkage void do_mcheck(struct pt_regs *regs)