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Diffstat (limited to 'arch/x86/kernel/hw_breakpoint.c')
-rw-r--r--arch/x86/kernel/hw_breakpoint.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index ff15c9dcc25..02f07634d26 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -122,7 +122,7 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
return -EBUSY;
set_debugreg(info->address, i);
- __get_cpu_var(cpu_debugreg[i]) = info->address;
+ __this_cpu_write(cpu_debugreg[i], info->address);
dr7 = &__get_cpu_var(cpu_dr7);
*dr7 |= encode_dr7(i, info->len, info->type);
@@ -397,12 +397,12 @@ void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
void hw_breakpoint_restore(void)
{
- set_debugreg(__get_cpu_var(cpu_debugreg[0]), 0);
- set_debugreg(__get_cpu_var(cpu_debugreg[1]), 1);
- set_debugreg(__get_cpu_var(cpu_debugreg[2]), 2);
- set_debugreg(__get_cpu_var(cpu_debugreg[3]), 3);
+ set_debugreg(__this_cpu_read(cpu_debugreg[0]), 0);
+ set_debugreg(__this_cpu_read(cpu_debugreg[1]), 1);
+ set_debugreg(__this_cpu_read(cpu_debugreg[2]), 2);
+ set_debugreg(__this_cpu_read(cpu_debugreg[3]), 3);
set_debugreg(current->thread.debugreg6, 6);
- set_debugreg(__get_cpu_var(cpu_dr7), 7);
+ set_debugreg(__this_cpu_read(cpu_dr7), 7);
}
EXPORT_SYMBOL_GPL(hw_breakpoint_restore);
@@ -433,6 +433,10 @@ static int __kprobes hw_breakpoint_handler(struct die_args *args)
dr6_p = (unsigned long *)ERR_PTR(args->err);
dr6 = *dr6_p;
+ /* If it's a single step, TRAP bits are random */
+ if (dr6 & DR_STEP)
+ return NOTIFY_DONE;
+
/* Do an early return if no trap bits are set in DR6 */
if ((dr6 & DR_TRAP_BITS) == 0)
return NOTIFY_DONE;