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/oprofile_stats.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/oprofile/oprofile_stats.c') diff --git a/drivers/oprofile/oprofile_stats.c b/drivers/oprofile/oprofile_stats.c index f0acb661c25..d1f6d776e9e 100644 --- a/drivers/oprofile/oprofile_stats.c +++ b/drivers/oprofile/oprofile_stats.c @@ -26,6 +26,8 @@ void oprofile_reset_stats(void) cpu_buf = &cpu_buffer[i]; cpu_buf->sample_received = 0; cpu_buf->sample_lost_overflow = 0; + cpu_buf->backtrace_aborted = 0; + cpu_buf->sample_invalid_eip = 0; } atomic_set(&oprofile_stats.sample_lost_no_mm, 0); @@ -61,6 +63,8 @@ void oprofile_create_stats_files(struct super_block * sb, struct dentry * root) &cpu_buf->sample_lost_overflow); oprofilefs_create_ro_ulong(sb, cpudir, "backtrace_aborted", &cpu_buf->backtrace_aborted); + oprofilefs_create_ro_ulong(sb, cpudir, "sample_invalid_eip", + &cpu_buf->sample_invalid_eip); } oprofilefs_create_ro_atomic(sb, dir, "sample_lost_no_mm", -- cgit v1.2.3