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oprofile: fix uninitialized use of struct op_entry

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Impact: fix crash

In case of losing samples struct op_entry could have been used
uninitialized causing e.g. a wrong preemption count or NULL pointer
access. This patch fixes this.

Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Robert Richter 2009-01-17 17:13:27 +01:00 committed by Ingo Molnar
parent c903ff8379
commit fdb6a8f4db
2 changed files with 12 additions and 0 deletions
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5
drivers/oprofile/cpu_buffer.c
View File

@ -393,16 +393,21 @@ oprofile_write_reserve(struct op_entry *entry, struct pt_regs * const regs,
return;
fail:
entry->event = NULL;
cpu_buf->sample_lost_overflow++;
}
int oprofile_add_data(struct op_entry *entry, unsigned long val)
{
if (!entry->event)
return 0;
return op_cpu_buffer_add_data(entry, val);
}
int oprofile_write_commit(struct op_entry *entry)
{
if (!entry->event)
return -EINVAL;
return op_cpu_buffer_write_commit(entry);
}

7
drivers/oprofile/cpu_buffer.h
View File

@ -66,6 +66,13 @@ static inline void op_cpu_buffer_reset(int cpu)
cpu_buf->last_task = NULL;
}
/*
* op_cpu_buffer_add_data() and op_cpu_buffer_write_commit() may be
* called only if op_cpu_buffer_write_reserve() did not return NULL or
* entry->event != NULL, otherwise entry->size or entry->event will be
* used uninitialized.
*/
struct op_sample
*op_cpu_buffer_write_reserve(struct op_entry *entry, unsigned long size);
int op_cpu_buffer_write_commit(struct op_entry *entry);