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authorPhilippe Elie <phil.el@wanadoo.fr>2007-11-14 19:58:48 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-11-14 21:45:37 -0500
commitdf9d177aa28d50e64bae6fbd6b263833079e3571 (patch)
treeb265158232a39d9d45cac0a97d5fdc17e7ca237d /drivers/oprofile/oprofile_stats.c
parent03ad369ac900116f35da7505f768ebbd481d09a4 (diff)
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 <phil.el@wanadoo.fr> Tested-by: Sami Farin <safari-kernel@safari.iki.fi> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/oprofile/oprofile_stats.c')
-rw-r--r--drivers/oprofile/oprofile_stats.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/oprofile/oprofile_stats.c b/drivers/oprofile/oprofile_stats.c
index f0acb661c253..d1f6d776e9e4 100644
--- a/drivers/oprofile/oprofile_stats.c
+++ b/drivers/oprofile/oprofile_stats.c
@@ -26,6 +26,8 @@ void oprofile_reset_stats(void)
26 cpu_buf = &cpu_buffer[i]; 26 cpu_buf = &cpu_buffer[i];
27 cpu_buf->sample_received = 0; 27 cpu_buf->sample_received = 0;
28 cpu_buf->sample_lost_overflow = 0; 28 cpu_buf->sample_lost_overflow = 0;
29 cpu_buf->backtrace_aborted = 0;
30 cpu_buf->sample_invalid_eip = 0;
29 } 31 }
30 32
31 atomic_set(&oprofile_stats.sample_lost_no_mm, 0); 33 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)
61 &cpu_buf->sample_lost_overflow); 63 &cpu_buf->sample_lost_overflow);
62 oprofilefs_create_ro_ulong(sb, cpudir, "backtrace_aborted", 64 oprofilefs_create_ro_ulong(sb, cpudir, "backtrace_aborted",
63 &cpu_buf->backtrace_aborted); 65 &cpu_buf->backtrace_aborted);
66 oprofilefs_create_ro_ulong(sb, cpudir, "sample_invalid_eip",
67 &cpu_buf->sample_invalid_eip);
64 } 68 }
65 69
66 oprofilefs_create_ro_atomic(sb, dir, "sample_lost_no_mm", 70 oprofilefs_create_ro_atomic(sb, dir, "sample_lost_no_mm",