From df9d177aa28d50e64bae6fbd6b263833079e3571 Mon Sep 17 00:00:00 2001 From: Philippe Elie Date: Wed, 14 Nov 2007 16:58:48 -0800 Subject: oProfile: oops when profile_pc() returns ~0LU Instruction pointer returned by profile_pc() can be a random value. This break the assumption than we can safely set struct op_sample.eip field to a magic value to signal to the per-cpu buffer reader side special event like task switch ending up in a segfault in get_task_mm() when profile_pc() return ~0UL. Fixed by sanitizing the sampled eip and reject/log invalid eip. Problem reported by Sami Farin, patch tested by him. Signed-off-by: Philippe Elie Tested-by: Sami Farin Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/oprofile/cpu_buffer.h | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/oprofile/cpu_buffer.h') diff --git a/drivers/oprofile/cpu_buffer.h b/drivers/oprofile/cpu_buffer.h index 49900d9e3235..c66c025abe75 100644 --- a/drivers/oprofile/cpu_buffer.h +++ b/drivers/oprofile/cpu_buffer.h @@ -42,6 +42,7 @@ struct oprofile_cpu_buffer { unsigned long sample_received; unsigned long sample_lost_overflow; unsigned long backtrace_aborted; + unsigned long sample_invalid_eip; int cpu; struct delayed_work work; } ____cacheline_aligned; -- cgit v1.2.3