kmemleak: Allow the early log buffer to be configurable.

(feature suggested by Sergey Senozhatsky)

Kmemleak needs to track all the memory allocations but some of these
happen before kmemleak is initialised. These are stored in an internal
buffer which may be exceeded in some kernel configurations. This patch
adds a configuration option with a default value of 400 and also removes
the stack dump when the early log buffer is exceeded.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
This commit is contained in:
Catalin Marinas 2009-06-25 10:16:11 +01:00
parent 28d0325ce6
commit a9d9058aba
3 changed files with 19 additions and 2 deletions

View file

@ -41,6 +41,10 @@ Memory scanning parameters can be modified at run-time by writing to the
Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on
the kernel command line.
Memory may be allocated or freed before kmemleak is initialised and
these actions are stored in an early log buffer. The size of this buffer
is configured via the CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE option.
Basic Algorithm
---------------

View file

@ -359,6 +359,18 @@ config DEBUG_KMEMLEAK
In order to access the kmemleak file, debugfs needs to be
mounted (usually at /sys/kernel/debug).
config DEBUG_KMEMLEAK_EARLY_LOG_SIZE
int "Maximum kmemleak early log entries"
depends on DEBUG_KMEMLEAK
range 200 2000
default 400
help
Kmemleak must track all the memory allocations to avoid
reporting false positives. Since memory may be allocated or
freed before kmemleak is initialised, an early log buffer is
used to store these actions. If kmemleak reports "early log
buffer exceeded", please increase this value.
config DEBUG_KMEMLEAK_TEST
tristate "Simple test for the kernel memory leak detector"
depends on DEBUG_KMEMLEAK

View file

@ -235,7 +235,7 @@ struct early_log {
};
/* early logging buffer and current position */
static struct early_log early_log[200];
static struct early_log early_log[CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE];
static int crt_early_log;
static void kmemleak_disable(void);
@ -696,7 +696,8 @@ static void log_early(int op_type, const void *ptr, size_t size,
struct early_log *log;
if (crt_early_log >= ARRAY_SIZE(early_log)) {
kmemleak_stop("Early log buffer exceeded\n");
pr_warning("Early log buffer exceeded\n");
kmemleak_disable();
return;
}